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Sample records for breeding cichlid neolamprologus

  1. Large group size yields group stability in the cooperatively breeding cichlid Neolamprologus pulcher

    NARCIS (Netherlands)

    Heg, D; Bachar, Z; Taborsky, M

    2005-01-01

    Group size has been shown to positively influence survival of group members in many cooperatively breeding vertebrates, including the Lake Tanganyika cichlid Neolamprologus pulcher, suggesting Allee effects. However, long-term data are scarce to test how these survival differences translate into cha

  2. Behavioural types and ecological effects in a natural population of the cooperative cichlid Neolamprologus pulcher

    NARCIS (Netherlands)

    Witsenburg, Fardo; Schuerch, Roger; Otti, Oliver; Heg, Dik

    2010-01-01

    The ecological relevance of behavioural syndromes is little studied in cooperative breeding systems where it is assumed that the behavioural type might influence individual decisions on helping and dispersal (e.g. shy, nonaggressive and nonexplorative individuals remain philopatric and helpful, wher

  3. Mixed parentage in Neolamprologus pulcher groups.

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    Stiver, K A; Fitzpatrick, J L; Desjardins, J K; Balshine, S

    2009-04-01

    Genetic data collected on co-operatively breeding Neolamprologus pulcher groups from Lake Tanganyika revealed mixed parentage in 80% of the groups examined. A case (1/11) of shared maternity was detected where a subordinate female bred alongside the dominant female in a social group. Extra-pair paternity was assigned to other dominant males who held their own social groups, but subordinate males were not found to father young in any group (0/9).

  4. Sexual conflict over breeding substrate causes female expulsion and offspring loss in a cichlid fish

    NARCIS (Netherlands)

    Maan, Martine E.; Taborsky, Michael

    2008-01-01

    Females of the Lake Tanganyika cichlid Lamprologus callipterus exclusively breed in empty snail shells that males collect in their territories. Male-male competition for shells is severe, leading to frequent shell stealing and territory takeover. As a consequence, males have breeding females in thei

  5. Social status, breeding state, and GnRH soma size in convict cichlids (Cryptoheros nigrofasciatus).

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    Chee, San-San Amy; Espinoza, Walter A S; Iwaniuk, Andrew N; Pakan, Janelle M P; Gutiérrez-Ibáñez, Cristian; Wylie, Douglas R; Hurd, Peter L

    2013-01-15

    Gonadotropin-releasing hormone (GnRH) expressing neurons in the preoptic area (POA) of the hypothalamus plays a key role in regulating reproductive function through the control of gonadotropin release. Several studies have illustrated the importance of the social environment in modulating the size of GnRH expressing neurons. In the African cichlid fish Astatotilapia burtoni, the size of the soma of GnRH expressing neurons in the POA varies with social status in males, and with breeding state in females. Territorial males have larger GnRH+ cells than non-territorial males, while brooder females have smaller GnRH+ cells than control females. The lek-like breeding system of A. burtoni is, however, only one type of social system within the diverse assemblage of cichlids. To gain a better understanding of GnRH neuronal plasticity in response to the changes in the social environment, we tested whether similar effects occur in the monogamous New World cichlid, the convict cichlid (Cryptoheros nigrofasciatus), a model species for the study of social behaviour. Our results indicate that, indeed GnRH expressing neuron soma size, and not cell number, varies with both male territorial status, and manipulations of female breeding state in this monogamous, biparental, New World cichlid.

  6. Reticulate phylogeny of gastropod-shell-breeding cichlids from Lake Tanganyika – the result of repeated introgressive hybridization

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    Blanc Michel

    2007-01-01

    Full Text Available Abstract Background The tribe Lamprologini is the major substrate breeding lineage of Lake Tanganyika's cichlid species flock. Among several different life history strategies found in lamprologines, the adaptation to live and breed in empty gastropod shells is probably the most peculiar. Although shell-breeding arose several times in the evolutionary history of the lamprologines, all obligatory and most facultative shell-breeders belong to the so called "ossified group", a monophyletic lineage within the lamprologine cichlids. Since their distinctive life style enables these species to live and breed in closest vicinity, we hypothesized that these cichlids might be particularly prone to accidental hybridization, and that introgression might have affected the evolutionary history of this cichlid lineage. Results Our analyses revealed discrepancies between phylogenetic hypotheses based on mitochondrial and nuclear (AFLP data. While the nuclear phylogeny was congruent with morphological, behavioral and ecological characteristics, several species – usually highly specialized shell-breeders – were placed at contradicting positions in the mitochondrial phylogeny. The discordant phylogenies strongly suggest repeated incidents of introgressive hybridization between several distantly related shell-breeding species, which reticulated the phylogeny of this group of cichlids. Long interior branches and high bootstrap support for many interior nodes in the mitochondrial phylogeny argue against a major effect of ancient incomplete lineage sorting on the phylogenetic reconstruction. Moreover, we provide morphological and genetic (mtDNA and microsatellites evidence for ongoing hybridization among distantly related shell-breeders. In these cases, the territorial males of the inferred paternal species are too large to enter the shells of their mate, such that they have to release their sperm over the entrance of the shell to fertilize the eggs. With sperm

  7. Rearing-group size determines social competence and brain structure in a cooperatively breeding cichlid.

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    Fischer, Stefan; Bessert-Nettelbeck, Mathilde; Kotrschal, Alexander; Taborsky, Barbara

    2015-07-01

    Social animals can greatly benefit from well-developed social skills. Because the frequency and diversity of social interactions often increase with the size of social groups, the benefits of advanced social skills can be expected to increase with group size. Variation in social skills often arises during ontogeny, depending on early social experience. Whether variation of social-group sizes affects development of social skills and related changes in brain structures remains unexplored. We investigated whether, in a cooperatively breeding cichlid, early group size (1) shapes social behavior and social skills and (2) induces lasting plastic changes in gross brain structures and (3) whether the development of social skills is confined to a sensitive ontogenetic period. Rearing-group size and the time juveniles spent in these groups interactively influenced the development of social skills and the relative sizes of four main brain regions. We did not detect a sensitive developmental period for the shaping of social behavior within the 2-month experience phase. Instead, our results suggest continuous plastic behavioral changes over time. We discuss how developmental effects on social behavior and brain architecture may adaptively tune phenotypes to their current or future environments.

  8. Paternity of subordinates raises cooperative effort in cichlids.

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    Rick Bruintjes

    Full Text Available BACKGROUND: In cooperative breeders, subordinates generally help a dominant breeding pair to raise offspring. Parentage studies have shown that in several species subordinates can participate in reproduction. This suggests an important role of direct fitness benefits for cooperation, particularly where groups contain unrelated subordinates. In this situation parentage should influence levels of cooperation. Here we combine parentage analyses and detailed behavioural observations in the field to study whether in the highly social cichlid Neolamprologus pulcher subordinates participate in reproduction and if so, whether and how this affects their cooperative care, controlling for the effect of kinship. METHODOLOGY/PRINCIPAL FINDINGS: We show that: (i male subordinates gained paternity in 27.8% of all clutches and (ii if they participated in reproduction, they sired on average 11.8% of young. Subordinate males sharing in reproduction showed more defence against experimentally presented egg predators compared to subordinates not participating in reproduction, and they tended to stay closer to the breeding shelter. No effects of relatedness between subordinates and dominants (to mid-parent, dominant female or dominant male were detected on parentage and on helping behaviour. CONCLUSIONS/SIGNIFICANCE: This is the first evidence in a cooperatively breeding fish species that the helping effort of male subordinates may depend on obtained paternity, which stresses the need to consider direct fitness benefits in evolutionary studies of helping behaviour.

  9. Sexual selection promotes colonial breeding in shell-brooding cichlid fish

    NARCIS (Netherlands)

    Schuetz, Dolores; Ocana, Sabine Wirtz; Maan, martine E.; Taborsky, Michael

    2016-01-01

    Colonial species breed in densely aggregated territories containing no resources other than nest sites. This behaviour is usually explained by natural selection, for instance through benefits resulting from reduced predation risk. An alternative hypothesis suggests that, as in lek breeding systems,

  10. Same school, different conduct: rates of multiple paternity vary within a mixed-species breeding school of semi-pelagic cichlid fish (Cyprichromis spp.).

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    Anderson, Caleb; Werdenig, Alexandra; Koblmüller, Stephan; Sefc, Kristina M

    2016-01-01

    Mating system variability is known to exist between and within species, often due to environmental influences. An open question is whether, vice versa, similar environmental conditions entail congruent mating behavior, for example in terms of multiple paternity, in species or populations sharing largely comparable breeding modes. This study employed microsatellite markers to investigate the incidence of multiple paternity in Cyprichromis coloratus and Cyprichromis leptosoma, two sympatric, closely related, mouthbrooding Lake Tanganyika cichlids with similar ecological and behavioral characteristics including the formation of open-water schools. Mouthbrooding females of both species were collected from the same mixed-species breeding school at the same time, minimizing environmental variation during courtship and mating. In C. coloratus, four of 12 broods had more than one sire, with a mean of 1.33 reconstructed sires per brood. C. leptosoma exhibited multiple paternity in 18 of 22 broods, with a mean of 2.59 or 2.86 reconstructed sires per brood according to the programs gerud and colony, respectively. In addition, two broods were found to contain offspring transplanted from another brood. There was no significant difference in brood size between species, but mean sire number did differ significantly. Hence, substantial similarity in reproductive behavior along with shared environmental conditions during courtship and spawning did not lead to equal rates of polyandry or sneaking in the two species.

  11. Repeatability and Heritability of Behavioural Types in a Social Cichlid

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    Noémie Chervet

    2011-01-01

    Full Text Available Aim. The quantitative genetics underlying correlated behavioural traits (‘‘animal personality’’ have hitherto been studied mainly in domesticated animals. Here we report the repeatability ( and heritability (ℎ2 of behavioural types in the highly social cichlid fish Neolamprologus pulcher. Methods. We tested 1779 individuals repeatedly and calculated the ℎ2 of behavioural types by variance components estimation (GLMM REML, using 1327 offspring from 162 broods from 74 pairs. Results. Repeatability of behavioural types was significant and considerable (0.546, but declined from 0.83 between tests conducted on the same day, to 0.19 on tests conducted up to 1201 days apart. All ℎ2 estimates were significant but low (e.g., pair identity ℎ2=0.15±0.03 SE. Additionally, we found significant variation between broods nested within the parent(s, but these were not related to several environmental factors tested. Conclusions. We conclude that despite a considerable , ℎ2 in this cichlid species is low, and variability in behavioural type appears to be strongly affected by other (nongenetic effects.

  12. Mating and Parental Care in Lake Tanganyika's Cichlids

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    Kristina M. Sefc

    2011-01-01

    Full Text Available Cichlid fishes of Lake Tanganyika display a variety of mating and parental care behaviors, including polygamous and monogamous mouthbrooding and substrate breeding, cooperative breeding, as well as various alternative reproductive tactics such as sneaking and piracy. Moreover, reproductive behaviors sometimes vary within species both in space and in time. Here, I survey reports on mating and parenting behaviors of Lake Tanganyika cichlid species and address the evolution of mating and parental care patterns and sexual dimorphism. Notes on measures of sexual selection intensity and the difficulties of defining mating systems and estimating selection intensities at species level conclude the essay.

  13. Same school, different conduct: rates of multiple paternity vary within a mixed‐species breeding school of semi‐pelagic cichlid fish ( Cyprichromis spp.)

    OpenAIRE

    Anderson, Caleb; Werdenig, Alexandra; Koblmüller, Stephan; Sefc, Kristina M.

    2015-01-01

    Abstract Mating system variability is known to exist between and within species, often due to environmental influences. An open question is whether, vice versa, similar environmental conditions entail congruent mating behavior, for example in terms of multiple paternity, in species or populations sharing largely comparable breeding modes. This study employed microsatellite markers to investigate the incidence of multiple paternity in Cyprichromis coloratus and Cyprichromis leptosoma, two symp...

  14. Sensory drive in cichlid speciation

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    Maan, Martine E.; Hofker, Kees D.; van Alphen, Jacques J. M.; Seehausen, Ole

    2006-01-01

    The role of selection in speciation is a central yet poorly understood problem in evolutionary biology. The rapid radiations of extremely colorful cichlid fish in African lakes have fueled the hypothesis that sexual selection can drive species divergence without geographical isolation. Here we prese

  15. Using Cichlids for Illustrating Mendel's Laws

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    Gennaro, Eugene D.; Winters, Charlotte M.

    1978-01-01

    A classroom experiment is proposed in which students can mate a banded or spotted convict cichlid with a pink convict cichlid and observe the markings of their "children" and "grandchildren" as a way of illustrating Mendel's Laws of Dominance and Segregation. (MN)

  16. Species-specific differences in adaptive phenotypic plasticity in an ecologically relevant trophic trait: hypertrophic lips in Midas cichlid fishes.

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    Machado-Schiaffino, Gonzalo; Henning, Frederico; Meyer, Axel

    2014-07-01

    The spectacular species richness of cichlids and their diversity in morphology, coloration, and behavior have made them an ideal model for the study of speciation and adaptive evolution. Hypertrophic lips evolved repeatedly and independently in African and Neotropical cichlid radiations. Cichlids with hypertrophic lips forage predominantly in rocky crevices and it has been hypothesized that mechanical stress caused by friction could result in larger lips through phenotypic plasticity. To test the influence of the environment on the size and development of lips, we conducted a series of breeding and feeding experiments on Midas cichlids. Full-sibs of Amphilophus labiatus (thick-lipped) and Amphilophus citrinellus (thin-lipped) each were split into a control group which was fed food from the water column and a treatment group whose food was fixed to substrates. We found strong evidence for phenotypic plasticity on lip area in the thick-lipped species, but not in the thin-lipped species. Intermediate phenotypic values were observed in hybrids from thick- and thin-lipped species reared under "control" conditions. Thus, both a genetic, but also a phenotypic plastic component is involved in the development of hypertrophic lips in Neotropical cichlids. Moreover, species-specific adaptive phenotypic plasticity was found, suggesting that plasticity is selected for in recent thick-lipped species.

  17. B chromosomes have a functional effect on female sex determination in Lake Victoria cichlid fishes.

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    Yoshida, Kohta; Terai, Yohey; Mizoiri, Shinji; Aibara, Mitsuto; Nishihara, Hidenori; Watanabe, Masakatsu; Kuroiwa, Asato; Hirai, Hirohisa; Hirai, Yuriko; Matsuda, Yoichi; Okada, Norihiro

    2011-08-01

    The endemic cichlid fishes in Lake Victoria are a model system for speciation through adaptive radiation. Although the evolution of the sex-determination system may also play a role in speciation, little is known about the sex-determination system of Lake Victoria cichlids. To understand the evolution of the sex-determination system in these fish, we performed cytogenetic analysis in 11 cichlid species from Lake Victoria. B chromosomes, which are present in addition to standard chromosomes, were found at a high prevalence rate (85%) in these cichlids. In one species, B chromosomes were female-specific. Cross-breeding using females with and without the B chromosomes demonstrated that the presence of the B chromosomes leads to a female-biased sex ratio in this species. Although B chromosomes were believed to be selfish genetic elements with little effect on phenotype and to lack protein-coding genes, the present study provides evidence that B chromosomes have a functional effect on female sex determination. FISH analysis using a BAC clone containing B chromosome DNA suggested that the B chromosomes are derived from sex chromosomes. Determination of the nucleotide sequences of this clone (104.5 kb) revealed the presence of several protein-coding genes in the B chromosome, suggesting that B chromosomes have the potential to contain functional genes. Because some sex chromosomes in amphibians and arthropods are thought to be derived from B chromosomes, the B chromosomes in Lake Victoria cichlids may represent an evolutionary transition toward the generation of sex chromosomes.

  18. B chromosomes have a functional effect on female sex determination in Lake Victoria cichlid fishes.

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    Kohta Yoshida

    2011-08-01

    Full Text Available The endemic cichlid fishes in Lake Victoria are a model system for speciation through adaptive radiation. Although the evolution of the sex-determination system may also play a role in speciation, little is known about the sex-determination system of Lake Victoria cichlids. To understand the evolution of the sex-determination system in these fish, we performed cytogenetic analysis in 11 cichlid species from Lake Victoria. B chromosomes, which are present in addition to standard chromosomes, were found at a high prevalence rate (85% in these cichlids. In one species, B chromosomes were female-specific. Cross-breeding using females with and without the B chromosomes demonstrated that the presence of the B chromosomes leads to a female-biased sex ratio in this species. Although B chromosomes were believed to be selfish genetic elements with little effect on phenotype and to lack protein-coding genes, the present study provides evidence that B chromosomes have a functional effect on female sex determination. FISH analysis using a BAC clone containing B chromosome DNA suggested that the B chromosomes are derived from sex chromosomes. Determination of the nucleotide sequences of this clone (104.5 kb revealed the presence of several protein-coding genes in the B chromosome, suggesting that B chromosomes have the potential to contain functional genes. Because some sex chromosomes in amphibians and arthropods are thought to be derived from B chromosomes, the B chromosomes in Lake Victoria cichlids may represent an evolutionary transition toward the generation of sex chromosomes.

  19. Temporal diversification of Central American cichlids

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    Hulsey C Darrin

    2010-09-01

    Full Text Available Abstract Background Cichlid fishes are classic examples of adaptive radiation because of their putative tendency to explosively diversify after invading novel environments. To examine whether ecological opportunity increased diversification (speciation minus extinction early in a species-rich cichlid radiation, we determined if Heroine cichlids experienced a burst of diversification following their invasion of Central America. Results We first reconstructed the Heroine phylogeny and determined the basal node to use as the root of Central American Heroine diversification. We then examined the influence of incomplete taxon sampling on this group's diversification patterns. First, we added missing species randomly to the phylogeny and assessed deviations from a constant rate of lineage accumulation. Using a range of species numbers, we failed to recover significant deviations from a pure-birth process and found little support for an early burst of diversification. Then, we examined patterns of lineage accumulation as nodes were increasingly truncated. We assumed that as we removed more recently diverged lineages that sampling would become more complete thereby increasing the power to detect deviations from a pure-birth model. However, truncation of nodes provided even less support for an early burst of diversification. Conclusions Contrary to expectations, our analyses suggest Heroine cichlids did not undergo a burst of diversification when they invaded from South America. Throughout their history in Central America, Heroine cichlids appear to have diversified at a constant rate.

  20. Eggspot number and sexual selection in the cichlid fish Astatotilapia burtoni.

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    Henning, Frederico; Meyer, Axel

    2012-01-01

    Sexual selection on male coloration is one of the main mechanisms proposed to explain the explosive speciation rates in East African cichlid fish. True eggspots are color patterns characteristic of the most species-rich lineage of cichlids, the Haplochromini, and have been suggested to be causally related to the speciation processes. Eggspots are thought to have originated by sensory exploitation and subsequently gained several roles in sexual advertisement. However, for most of these functions the evidence is equivocal. In addition, the genetic architecture of this trait still is largely unknown. We conducted bidirectional selective breeding experiments for eggspot numbers in the model cichlid, Astatotilapia burtoni. After two generations, low lines responded significantly, whereas the high lines did not. Body size was both phenotypically and genotypically correlated with eggspot number and showed correlated response to selection. Males with higher numbers of eggspots were found to sire larger offspring. Despite the potential to act as honest indicators of fitness, the behavioral experiments showed no evidence of a role in either intra- or inter-sexual selection. Visual-based female preference was instead explained by courtship intensity. The evolution of this trait has been interpreted in light of adaptive theories of sexual selection, however the present and published results suggest the influence of non-adaptive factors such as sensory exploitation, environmental constraints and sexual antagonism.

  1. Eggspot number and sexual selection in the cichlid fish Astatotilapia burtoni.

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    Frederico Henning

    Full Text Available Sexual selection on male coloration is one of the main mechanisms proposed to explain the explosive speciation rates in East African cichlid fish. True eggspots are color patterns characteristic of the most species-rich lineage of cichlids, the Haplochromini, and have been suggested to be causally related to the speciation processes. Eggspots are thought to have originated by sensory exploitation and subsequently gained several roles in sexual advertisement. However, for most of these functions the evidence is equivocal. In addition, the genetic architecture of this trait still is largely unknown. We conducted bidirectional selective breeding experiments for eggspot numbers in the model cichlid, Astatotilapia burtoni. After two generations, low lines responded significantly, whereas the high lines did not. Body size was both phenotypically and genotypically correlated with eggspot number and showed correlated response to selection. Males with higher numbers of eggspots were found to sire larger offspring. Despite the potential to act as honest indicators of fitness, the behavioral experiments showed no evidence of a role in either intra- or inter-sexual selection. Visual-based female preference was instead explained by courtship intensity. The evolution of this trait has been interpreted in light of adaptive theories of sexual selection, however the present and published results suggest the influence of non-adaptive factors such as sensory exploitation, environmental constraints and sexual antagonism.

  2. Eggspot Number and Sexual Selection in the Cichlid Fish Astatotilapia burtoni

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    Henning, Frederico; Meyer, Axel

    2012-01-01

    Sexual selection on male coloration is one of the main mechanisms proposed to explain the explosive speciation rates in East African cichlid fish. True eggspots are color patterns characteristic of the most species-rich lineage of cichlids, the Haplochromini, and have been suggested to be causally related to the speciation processes. Eggspots are thought to have originated by sensory exploitation and subsequently gained several roles in sexual advertisement. However, for most of these functions the evidence is equivocal. In addition, the genetic architecture of this trait still is largely unknown. We conducted bidirectional selective breeding experiments for eggspot numbers in the model cichlid, Astatotilapia burtoni. After two generations, low lines responded significantly, whereas the high lines did not. Body size was both phenotypically and genotypically correlated with eggspot number and showed correlated response to selection. Males with higher numbers of eggspots were found to sire larger offspring. Despite the potential to act as honest indicators of fitness, the behavioral experiments showed no evidence of a role in either intra- or inter-sexual selection. Visual-based female preference was instead explained by courtship intensity. The evolution of this trait has been interpreted in light of adaptive theories of sexual selection, however the present and published results suggest the influence of non-adaptive factors such as sensory exploitation, environmental constraints and sexual antagonism. PMID:22937082

  3. Male convict cichlid 11-ketotestosterone levels throughout the reproductive cycle: an exploratory profile study in laboratory and field populations

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    Natalie April van Breukelen

    2015-05-01

    Full Text Available The convict cichlid (Amatitlania nigrofasciata has been extensively examined in relation to many behavioral topics, such as courtship, pair-bonding, bi-parental care, and territoriality. Recently, this model species has been utilized in studies on genetics, endocrinology, and neuroanatomy, with an ultimate goal of connecting behavior with its underlying mechanisms. The goal of this study was two-fold: (1 profile the circulating levels of plasma 11KT in the male convict cichlid at multiple points during the reproductive cycle and (2 generally compare the hormonal profiles of the widely used laboratory populations and those of a free-living population in the streams of Costa Rica. The results of the field experiment showed that male convict cichlids had higher levels of circulating 11KT during courtship and lower during the parental care and non-breeding phases. The profile of the laboratory population was similar to the profile of the free-living individuals, with significantly higher levels of 11KT occurring during courtship than during parental care, though the level of 11KT during non-breeding phase was elevated in the laboratory. The high levels of 11KT during courtship and low levels of 11KT during parental care found in both the field and the laboratory is similar to what has been reported in other species of teleosts, and may suggest an important function of 11KT in the expression of courtship behavior and the subsequent onset of parental behaviors in this model species.

  4. Annotation of expressed sequence tags for the East African cichlid fish Astatotilapia burtoni and evolutionary analyses of cichlid ORFs

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    Braasch Ingo

    2008-02-01

    Full Text Available Abstract Background The cichlid fishes in general, and the exceptionally diverse East African haplochromine cichlids in particular, are famous examples of adaptive radiation and explosive speciation. Here we report the collection and annotation of more than 12,000 expressed sequence tags (ESTs generated from three different cDNA libraries obtained from the East African haplochromine cichlid species Astatotilapia burtoni and Metriaclima zebra. Results We first annotated more than 12,000 newly generated cichlid ESTs using the Gene Ontology classification system. For evolutionary analyses, we combined these ESTs with all available sequence data for haplochromine cichlids, which resulted in a total of more than 45,000 ESTs. The ESTs represent a broad range of molecular functions and biological processes. We compared the haplochromine ESTs to sequence data from those available for other fish model systems such as pufferfish (Takifugu rubripes and Tetraodon nigroviridis, trout, and zebrafish. We characterized genes that show a faster or slower rate of base substitutions in haplochromine cichlids compared to other fish species, as this is indicative of a relaxed or reinforced selection regime. Four of these genes showed the signature of positive selection as revealed by calculating Ka/Ks ratios. Conclusion About 22% of the surveyed ESTs were found to have cichlid specific rate differences suggesting that these genes might play a role in lineage specific characteristics of cichlids. We also conclude that the four genes with a Ka/Ks ratio greater than one appear as good candidate genes for further work on the genetic basis of evolutionary success of haplochromine cichlid fishes.

  5. Replicated divergence in cichlid radiations mirrors a major vertebrate innovation.

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    McGee, Matthew D; Faircloth, Brant C; Borstein, Samuel R; Zheng, Jimmy; Darrin Hulsey, C; Wainwright, Peter C; Alfaro, Michael E

    2016-01-13

    Decoupling of the upper jaw bones--jaw kinesis--is a distinctive feature of the ray-finned fishes, but it is not clear how the innovation is related to the extraordinary diversity of feeding behaviours and feeding ecology in this group. We address this issue in a lineage of ray-finned fishes that is well known for its ecological and functional diversity--African rift lake cichlids. We sequenced ultraconserved elements to generate a phylogenomic tree of the Lake Tanganyika and Lake Malawi cichlid radiations. We filmed a diverse array of over 50 cichlid species capturing live prey and quantified the extent of jaw kinesis in the premaxillary and maxillary bones. Our combination of phylogenomic and kinematic data reveals a strong association between biting modes of feeding and reduced jaw kinesis, suggesting that the contrasting demands of biting and suction feeding have strongly influenced cranial evolution in both cichlid radiations.

  6. Introgressive hybridization in a trophically polymorphic cichlid.

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    Hulsey, C Darrin; García-de-León, Francisco J

    2013-11-01

    Trophically polymorphic species could represent lineages that are rapidly diverging along an ecological axis or could phenotypically mark the collapse of species through introgressive hybridization. We investigated patterns of introgression between the trophically polymorphic cichlid fish Herichthys minckleyi and its relative H. cyanoguttatus using a combination of population genetics and species tree analyses. We first examined the distribution of mitochondrial haplotypes within the alternative H. minckleyi pharyngeal jaw morphotypes that are endemic to the small desert valley of Cuatro Ciénegas. We recovered two clusters of mitochondrial haplotypes. The first contained a number of slightly differentiated cytochrome b (cytb) haplotypes that showed some phylogeographic signal and were present in both jaw morphotypes. The other haplotype was monomorphic, highly differentiated from the other cluster, present in equal frequencies in the morphotypes, and identical to H. cyanoguttatus haplotypes found outside Cuatro Ciénegas. Then, we investigated whether H. minckleyi individuals with the H. cyanoguttatus cytb were more evolutionarily similar to H. cyanoguttatus or other H. minckleyi using a species tree analysis of 84 nuclear loci. Both H. minckleyi pharyngeal morphotypes, regardless of their cytb haplotype, were quite distinct from H. cyanoguttatus. However, hybridization could be blurring subdivision within H. minckleyi as the alternative jaw morphotypes were not genetically distinct from one another. Accounting for introgression from H. cyanoguttatus will be essential to understand the evolution of the trophically polymorphic cichlid H. minckleyi.

  7. Genomic islands of speciation separate cichlid ecomorphs in an East African crater lake.

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    Malinsky, Milan; Challis, Richard J; Tyers, Alexandra M; Schiffels, Stephan; Terai, Yohey; Ngatunga, Benjamin P; Miska, Eric A; Durbin, Richard; Genner, Martin J; Turner, George F

    2015-12-18

    The genomic causes and effects of divergent ecological selection during speciation are still poorly understood. Here we report the discovery and detailed characterization of early-stage adaptive divergence of two cichlid fish ecomorphs in a small (700 meters in diameter) isolated crater lake in Tanzania. The ecomorphs differ in depth preference, male breeding color, body shape, diet, and trophic morphology. With whole-genome sequences of 146 fish, we identified 98 clearly demarcated genomic "islands" of high differentiation and demonstrated the association of genotypes across these islands with divergent mate preferences. The islands contain candidate adaptive genes enriched for functions in sensory perception (including rhodopsin and other twilight-vision-associated genes), hormone signaling, and morphogenesis. Our study suggests mechanisms and genomic regions that may play a role in the closely related mega-radiation of Lake Malawi.

  8. Identification of cichlid fishes from Lake Malawi using computer vision.

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    Deokjin Joo

    Full Text Available BACKGROUND: The explosively radiating evolution of cichlid fishes of Lake Malawi has yielded an amazing number of haplochromine species estimated as many as 500 to 800 with a surprising degree of diversity not only in color and stripe pattern but also in the shape of jaw and body among them. As these morphological diversities have been a central subject of adaptive speciation and taxonomic classification, such high diversity could serve as a foundation for automation of species identification of cichlids. METHODOLOGY/PRINCIPAL FINDING: Here we demonstrate a method for automatic classification of the Lake Malawi cichlids based on computer vision and geometric morphometrics. For this end we developed a pipeline that integrates multiple image processing tools to automatically extract informative features of color and stripe patterns from a large set of photographic images of wild cichlids. The extracted information was evaluated by statistical classifiers Support Vector Machine and Random Forests. Both classifiers performed better when body shape information was added to the feature of color and stripe. Besides the coloration and stripe pattern, body shape variables boosted the accuracy of classification by about 10%. The programs were able to classify 594 live cichlid individuals belonging to 12 different classes (species and sexes with an average accuracy of 78%, contrasting to a mere 42% success rate by human eyes. The variables that contributed most to the accuracy were body height and the hue of the most frequent color. CONCLUSIONS: Computer vision showed a notable performance in extracting information from the color and stripe patterns of Lake Malawi cichlids although the information was not enough for errorless species identification. Our results indicate that there appears an unavoidable difficulty in automatic species identification of cichlid fishes, which may arise from short divergence times and gene flow between closely related species.

  9. Species tree estimation and the historical biogeography of heroine cichlids.

    Science.gov (United States)

    Hulsey, C Darrin; Keck, Benjamin P; Hollingsworth, Phillip R

    2011-01-01

    Heroine cichlids are major components of the fish faunas in both Central America and the Caribbean. To examine the evolutionary patterns of how cichlids colonized both of these regions, we reconstructed the phylogenetic relationships among 23 cichlid lineages. We used three phylogenetically novel nuclear markers (Dystropin b, Myomesin1, and Wnt7b) in combination with sequence data from seven other gene regions (Nd2, Rag1, Enc1, Sreb2, Ptr, Plagl2, and Zic1) to elucidate the species tree of these cichlids. The species examined represent major heroine lineages in South America, Central America, and the Greater Antilles. The individual gene trees of these groups were topologically quite discordant. Therefore, we combined the genetic partitions and inferred the species tree using both concatenation and a coalescent-based Bayesian method. The two resulting phylogenetic topologies were largely concordant but differed in two fundamental ways. First, more nodes in the concatenated tree were supported with substantial or 100% Bayesian posterior support than in the coalescent-based tree. Second, there was a minor, but biogeographically critical, topological difference between the concatenated and coalescent-based trees. Nevertheless, both analyses recovered topologies consistent with the Greater Antillean heroines being phylogenetically nested within the largely Central American heroine radiation. This study suggests that reconstructions of cichlid phylogeny and historical biogeography should account for the vagaries of individual gene histories.

  10. Colour forms of Amazonian cichlid fish represent reproductively isolated species.

    Science.gov (United States)

    Ready, J S; Sampaio, I; Schneider, H; Vinson, C; Dos Santos, T; Turner, G F

    2006-07-01

    Laboratory mate choice experiments have confirmed species status for cichlid fish in the African Great Lakes that differ in colour and little else. Colour differences between allopatric populations of the South American cichlid genus Apistogramma are known for many species, yet the status of such populations has not been previously tested. Analysis of the genetic relationships and mate choice characteristics of populations previously described as Apistogramma caetei from eastern Amazonia indicates genetic differentiation into at least three allopatric lineages, which also show strong prezygotic isolation through female mate choice, confirming them as Biological species. If future studies confirm that this result is indicative of a general trend, the species richness of the South American cichlid fishes may presently be seriously underestimated.

  11. Predator-induced neophobia in juvenile cichlids.

    Science.gov (United States)

    Meuthen, Denis; Baldauf, Sebastian A; Bakker, Theo C M; Thünken, Timo

    2016-08-01

    Predation is an important but often fluctuating selection factor for prey animals. Accordingly, individuals plastically adopt antipredator strategies in response to current predation risk. Recently, it was proposed that predation risk also plastically induces neophobia (an antipredator response towards novel cues). Previous studies, however, do not allow a differentiation between general neophobia and sensory channel-specific neophobic responses. Therefore, we tested the neophobia hypothesis focusing on adjustment in shoaling behavior in response to a novel cue addressing a different sensory channel than the one from which predation risk was initially perceived. From hatching onwards, juveniles of the cichlid Pelvicachromis taeniatus were exposed to different chemical cues in a split-clutch design: conspecific alarm cues which signal predation risk and heterospecific alarm cues or distilled water as controls. At 2 months of age, their shoaling behavior was examined prior and subsequent to a tactical disturbance cue. We found that fish previously exposed to predation risk formed more compact shoals relative to the control groups in response to the novel disturbance cue. Moreover, the relationship between shoal density and shoal homogeneity was also affected by experienced predation risk. Our findings indicate predator-induced, increased cross-sensory sensitivity towards novel cues making neophobia an effective antipredator mechanism.

  12. Complete mitochondrial DNA sequences of the threadfin cichlid (Petrochromis trewavasae and the blunthead cichlid (Tropheus moorii and patterns of mitochondrial genome evolution in cichlid fishes.

    Directory of Open Access Journals (Sweden)

    Christoph Fischer

    Full Text Available The cichlid fishes of the East African Great Lakes represent a model especially suited to study adaptive radiation and speciation. With several African cichlid genome projects being in progress, a promising set of closely related genomes is emerging, which is expected to serve as a valuable data base to solve questions on genotype-phenotype relations. The mitochondrial (mt genomes presented here are the first results of the assembly and annotation process for two closely related but eco-morphologically highly distinct Lake Tanganyika cichlids, Petrochromis trewavasae and Tropheus moorii. The genomic sequences comprise 16,588 bp (P. trewavasae and 16,590 bp (T. moorii, and exhibit the typical mitochondrial structure, with 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, and a non-coding control region. Analyses confirmed that the two species are very closely related with an overall sequence similarity of 96%. We analyzed the newly generated sequences in the phylogenetic context of 21 published labroid fish mitochondrial genomes. Consistent with other vertebrates, the D-loop region was found to evolve faster than protein-coding genes, which in turn are followed by the rRNAs; the tRNAs vary greatly in the rate of sequence evolution, but on average evolve the slowest. Within the group of coding genes, ND6 evolves most rapidly. Codon usage is similar among examined cichlid tribes and labroid families; although a slight shift in usage patterns down the gene tree could be observed. Despite having a clearly different nucleotide composition, ND6 showed a similar codon usage. C-terminal ends of Cox1 exhibit variations, where the varying number of amino acids is related to the structure of the obtained phylogenetic tree. This variation may be of functional relevance for Cox1 synthesis.

  13. Male-male competition and nuptial-colour displacement as a diversifying force in Lake Victoria cichlid fishes.

    Science.gov (United States)

    Seehausen, Ole; Schluter, Dolph

    2004-07-01

    We propose a new mechanism for diversification of male nuptial-colour patterns in the rapidly speciating cichlid fishes of Lake Victoria. Sympatric closely related species often display nuptial colours at opposite ends of the spectrum with males either blue or yellow to red. Colour polymorphisms within single populations are common too. We propose that competition between males for breeding sites promotes such colour diversification, and thereby speciation. We hypothesize that male aggression is primarily directed towards males of the common colour, and that rare colour morphs enjoy a negatively frequency-dependent fitness advantage. We test our hypothesis with a large dataset on the distributions and nuptial colorations of 52 species on 47 habitat islands in Lake Victoria, and with a smaller dataset on the within-spawning-site distributions of males with different coloration. We report that territories of males of the same colour are negatively associated on the spawning site, and that the distribution of closely related species over habitat islands is determined by nuptial coloration in the fashion predicted by our hypothesis. Whereas among unrelated species those with similar nuptial colour are positively associated, among closely related species those with similar colour are negatively associated and those with different colour are positively associated. This implies that negatively frequency-dependent selection on nuptial coloration among closely related species is a sufficiently strong force to override other effects on species distributions. We suggest that male-male competition is an important and previously neglected agent of diversification among haplochromine cichlid fishes.

  14. Tempo and mode of diversification of lake Tanganyika cichlid fishes.

    Directory of Open Access Journals (Sweden)

    Julia J Day

    Full Text Available BACKGROUND: Understanding the causes of disparities in species diversity across taxonomic groups and regions is a fundamental aim in evolutionary biology. Addressing these questions is difficult because of the need for densely sampled phylogenies and suitable empirical systems. METHODOLOGY/PRINCIPAL FINDINGS: Here we investigate the cichlid fish radiation of Lake Tanganyika and show that per lineage diversification rates have been more than six times slower than in the species flocks of Lakes Victoria and Malawi. The result holds even at peak periods of diversification in Lake Tanganyika, ruling out the age of the lake as an explanation for slow average rates, and is robust to uncertainties over the calibration of cichlid radiations in geological time. Moreover, Lake Tanganyika lineages, irrespective of different biological characteristics (e.g. sexually dichromatic versus sexually monochromatic clades, have diversified at similar rates, falling within typical estimates across a range of plant and animal clades. For example, the mostly sexually dichromatic haplochromines, which have speciated explosively in Lakes Victoria and Malawi, have displayed modest rates in Lake Tanganyika (where they are called Tropheini. CONCLUSION/SIGNIFICANCE: Our results show that either the Lake Tanganyika environment is less conducive for cichlid speciation or the remarkable diversifying abilities of the haplochromines were inhibited by the prior occupancy of older radiations. Although the results indicate a dominant role for the environment in shaping cichlid diversification, differences in the timing of diversification among the Tanganyikan tribes indicate that biological differences were still important for the dynamics of species build-up in the lake. While we cannot resolve the timing of the radiation relative to the origin of the lake, because of the lack of robust geological date calibrations for cichlids, our results are consistent with a scenario that the

  15. Social regulation of reproduction in male cichlid fishes.

    Science.gov (United States)

    Maruska, Karen P

    2014-10-01

    Social interactions and relative positions within a dominance hierarchy have helped shape the evolution of reproduction in many animals. Since reproduction is crucial in all animals, and rank typically regulates access to reproductive opportunities, understanding the mechanisms that regulate socially-induced reproductive processes is extremely important. How does position in a dominance hierarchy impact an individual's reproductive behavior, morphology, and physiology? Teleost fishes, and cichlids in particular, are ideally-suited models for studying how social status influences reproduction on multiple levels of biological organization. Here I review the current knowledge on the reproductive behavioral and physiological consequences of relative position in a dominance hierarchy, with a particular focus on male cichlids. Dominant and subordinate social status is typically associated with distinct differences in activity along the entire hypothalamic-pituitary-gonadal axis. Further, when transitions in social status occur between subordinate and dominant individuals, there are plastic changes from whole-organism behavior to molecular-level gene expression modifications that occur quickly. These rapid changes in behavior and physiology have allowed cichlids the flexibility to adapt to and thrive in their often dynamic physical and social environments. Studies in cichlid fishes have, and will continue, to advance our understanding of how the social environment can modulate molecular, cellular, and behavioral outcomes relevant to reproductive success. Future studies that take advantage of the extreme diversity in mating systems, reproductive tactics, and parental care strategies within the cichlid group will help generate hypotheses and careful experimental tests on the mechanisms governing the social control of reproduction in many vertebrates.

  16. Evolution of cichlid vision via trans-regulatory divergence

    Directory of Open Access Journals (Sweden)

    O’Quin Kelly E

    2012-12-01

    Full Text Available Abstract Background Phenotypic evolution may occur through mutations that affect either the structure or expression of protein-coding genes. Although the evolution of color vision has historically been attributed to structural mutations within the opsin genes, recent research has shown that opsin regulatory mutations can also tune photoreceptor sensitivity and color vision. Visual sensitivity in African cichlid fishes varies as a result of the differential expression of seven opsin genes. We crossed cichlid species that express different opsin gene sets and scanned their genome for expression Quantitative Trait Loci (eQTL responsible for these differences. Our results shed light on the role that different structural, cis-, and trans-regulatory mutations play in the evolution of color vision. Results We identified 11 eQTL that contribute to the divergent expression of five opsin genes. On three linkage groups, several eQTL formed regulatory “hotspots” associated with the expression of multiple opsins. Importantly, however, the majority of the eQTL we identified (8/11 or 73% occur on linkage groups located trans to the opsin genes, suggesting that cichlid color vision has evolved primarily via trans-regulatory divergence. By modeling the impact of just two of these trans-regulatory eQTL, we show that opsin regulatory mutations can alter cichlid photoreceptor sensitivity and color vision at least as much as opsin structural mutations can. Conclusions Combined with previous work, we demonstrate that the evolution of cichlid color vision results from the interplay of structural, cis-, and especially trans-regulatory loci. Although there are numerous examples of structural and cis-regulatory mutations that contribute to phenotypic evolution, our results suggest that trans-regulatory mutations could contribute to phenotypic divergence more commonly than previously expected, especially in systems like color vision, where compensatory changes in the

  17. Geographical ancestry of Lake Malawi's cichlid fish diversity

    OpenAIRE

    Genner, Martin J; Ngatunga, Benjamin P.; Mzighani, Semvua; Smith, Alan; Turner, George F

    2015-01-01

    The Lake Malawi haplochromine cichlid flock is one of the largest vertebrate adaptive radiations. The geographical source of the radiation has been assumed to be rivers to the south and east of Lake Malawi, where extant representatives of the flock are now present. Here, we provide mitochondrial DNA evidence suggesting the sister taxon to the Lake Malawi radiation is within the Great Ruaha river in Tanzania, north of Lake Malawi. Estimates of the time of divergence between the Lake Malawi flo...

  18. New record of a fossil haplotilapiine cichlid from Central Kenya

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    Stefanie B. R. Penk

    2015-11-01

    Full Text Available African freshwater cichlids (Cichlidae: Pseudocrenilabrinae are well known for their exceptionally great diversity and their capability of rapid speciation as well as diverse adaptations. The extant Pseudocrenilabrinae can be grouped into 27 tribes, with more than 2000 species harbored in the Great Lakes and surrounding water bodies of the East African Rift System. However, this unique diversity is not reflected in the fossil record because fossil cichlids were predominantly reported based on isolated teeth and bones. Moreover, the few articulated specimens that are known have not been analyzed sufficiently with regard to their systematic position due to lack of comparative material. Here we present a new extraordinarily well-preserved cichlid fish fossil from the Middle Miocene (c. 12.5 Ma Lagerstaette Kabchore, which was recovered during recent fieldwork in the Tugen Hills (Baringo County, Central Kenya Rift. Based on the evidence of tricuspid teeth, the Kabchore fossil can be assigned to the subclade of the Haplotilapiines within the Pseudocrenilabrinae. The multivariate analysis of a large meristic data set, derived from 1014 extant specimens (encompassing all main lineages of Haplotilapiines and usage of available osteological data suggest that this fossil is most likely related to one of the three haplotilapiine tribes Tilapiini, Haplochromini or Oreochromini. Moreover, the fossil specimen closely resembles the extinct cichlid Oreochromis martyni (Van Couvering, 1982, previously described as species of Sarotherodon from the Middle Miocene alkaline Kapkiamu Lake in the Tugen Hills. The analysis of the greatly preserved fossil fish specimen from Kabchore definitely supplements the fragmentary fossil record of Africa’s Cichlidae and will afford new insights into its evolutionary history. We also expect that this fossil will be useful as calibration point for new divergence-time estimates.

  19. Interactions between aggression, boldness and shoaling within a brood of convict cichlids (Amatitlania nigrofasciatus).

    Science.gov (United States)

    Moss, Sarah; Tittaferrante, Stephanie; Way, Gregory P; Fuller, Ashlei; Sullivan, Nicole; Ruhl, Nathan; McRobert, Scott P

    2015-12-01

    A behavioral syndrome is considered present when individuals consistently express correlated behaviors across two or more axes of behavior. These axes of behavior are shy-bold, exploration-avoidance, activity, aggression, and sociability. In this study we examined aggression, boldness and sociability (shoaling) within a juvenile convict cichlid brood (Amatitlania nigrofasciatus). Because young convict cichlids are social, we used methodologies commonly used by ethologists studying social fishes. We did not detect an aggression-boldness behavioral syndrome, but we did find that the aggression, boldness, and possibly the exploration behavioral axes play significant roles in shaping the observed variation in individual convict cichlid behavior. While juvenile convict cichlids did express a shoaling preference, this social preference was likely convoluted by aggressive interactions, despite the small size and young age of the fish. There is a need for the development of behavioral assays that allow for more reliable measurement of behavioral axes in juvenile neo-tropical cichlids.

  20. Fight for your breeding right: hierarchy re-establishment predicts aggression in a social queue.

    Science.gov (United States)

    Wong, Marian; Balshine, Sigal

    2011-04-23

    Social aggression is one of the most conspicuous features of animal societies, yet little is known about the causes of individual variation in aggression within social hierarchies. Recent theory suggests that when individuals form queues for breeding, variation in social aggression by non-breeding group members is related to their probability of inheriting breeding status. However, levels of aggression could also vary as a temporary response to changes in the hierarchy, with individuals becoming more aggressive as they ascend in rank, in order to re-establish dominance relationships. Using the group-living fish, Neolamprologus pulcher, we show that subordinates became more aggressive after they ascended in rank. Female ascenders exhibited more rapid increases in aggression than males, and the increased aggression was primarily directed towards group members of adjacent rather than non-adjacent rank, suggesting that social aggression was related to conflict over rank. Elevated aggression by ascenders was not sustained over time, there was no relationship between rank and aggression in stable groups, and aggression given by ascenders was not sex-biased. Together, these results suggest that the need to re-establish dominance relationships following rank ascension is an important determinant of variation in aggression in animal societies.

  1. Living on the wedge: female control of paternity in a cooperatively polyandrous cichlid.

    Science.gov (United States)

    Kohda, Masanori; Heg, Dik; Makino, Yoshimi; Takeyama, Tomohiro; Shibata, Jun-ya; Watanabe, Katsutoshi; Munehara, Hiroyuki; Hori, Michio; Awata, Satoshi

    2009-12-07

    Theories suggest that, in cooperatively breeding species, female control over paternity and reproductive output may affect male reproductive skew and group stability. Female paternity control may come about through cryptic female choice or female reproductive behaviour, but experimental studies are scarce. Here, we show a new form of female paternity control in a cooperatively polyandrous cichlid fish (Julidochromis transcriptus), in which females prefer wedge-shaped nesting sites. Wedge-shaped sites allowed females to manipulate the siring success of the group member males by spawning the clutch at the spot where the large males were just able to enter and fertilize the outer part of the clutch. Small males fertilized the inner part of the clutch, protected from the large aggressive males, leading to low male reproductive skew. Small males provided more brood care than large males. Multiple paternity induced both males to provide brood care and reduced female brood care accordingly. This is, to our knowledge, the first documented case in a species with external fertilization showing female mating behaviour leading to multiple male paternity and increased male brood care as a result.

  2. Unusual allometry for sexual size dimorphism in a cichlid where males are extremely larger than females

    Indian Academy of Sciences (India)

    Kazutaka Ota; Masanori Kohda; Tetsu Sato

    2010-06-01

    When males are the larger sex, a positive allometric relationship between male and female sizes is often found across populations of a single species (i.e. Rensch’s rule). This pattern is typically explained by a sexual selection pressure on males. Here, we report that the allometric relationship was negative across populations of a shell-brooding cichlid fish Lamprologus callipterus, although males are extremely larger than females. Male L. callipterus collect and defend empty snail shells in each of which a female breeds. We found that, across six populations, male and female sizes are positively correlated with not only sexual and fecundity selection indices, but also with shell sizes. Given their different reproductive behaviours, these correlations mean that males are required to be more powerful, and thus larger, to transport larger shells, while female bodies are reduced to the shell size to enable them to enter the shells. Among the three size selections (sexual selection, fecundity selection and shell size), shell size explained the allometry, suggesting that females are more strongly subject to size selection associated with shell size availability than males. However, the allometry was violated when considering an additional population where size-selection regimes of males differed from that of other populations. Therefore, sexual size allometry will be violated by body size divergence induced by multiple selection regimes.

  3. Ecology and life history of an Amazon floodplain cichlid: the discus fish Symphysodon (Perciformes: Cichlidae

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    William G. R. Crampton

    Full Text Available The discus fishes of the genus Symphysodon are popular ornamental cichlids that occur in floodplain lakes and flooded forests of the lowland Amazon Basin. These habitats are characterized by extreme seasonal fluctuations in the availability of food, shelter and dissolved oxygen, and also the densities of predators and parasites. Most aspects of discus biology are influenced by these fluctuating conditions. This paper reports an autoecological study of the western Amazonian discus S. haraldi (until recently classified as S. aequifasciatus. This species feeds predominantly on algal periphyton, fine organic detritus, plant matter, and small aquatic invertebrates. At high water it forages alone or in small groups in flooded forests. At low water it forms large aggregations in fallen tree crowns along lake margins. Breeding occurs at the beginning of the flood season, ensuring that the progeny are well grown before the next low water period. Symphysodon haraldi is an iteroparous partial spawner, reaches reproductive maturity within a year, and undertakes parental care of its eggs and larvae. The timing of spawning events, and/or the rate of brood survival, may be influenced by fluctuations in the flood level, resulting in a non-unimodal distribution of size classes for the subsequent 1+ cohort.

  4. Monogeneans in introduced and native cichlids in México: evidence for transfer.

    Science.gov (United States)

    Jiménez-García, M I; Vidal-Martínez, V M; López-Jiménez, S

    2001-08-01

    We examined 2 cichlid fish species native to México, Cichlasoma callolepis and C. fenestratum, and 2 introduced African cichlids, Oreochromis aureus and O. niloticus, from 3 localities in southeastern México for monogeneans. Six monogenean species infected the African cichlids: Cichlidogyrus haplochromii, C. dossoui, C. longicornis longicornis, C. sclerosus, C. tilapiae, and Enterogyrus malmbergi. We found all these parasite species, except C. haplochromii and C. dossoui, on the native C. fenestratum and C. callolepis. Prevalences of Cichlidogyrus spp. were 3-10% and abundances ranged from 0.03 +/- 0.2 to 0.1 +/- 0.3 for native cichlids. We only recovered a single E. malmbergi from 1 C. callolepis. We found Sciadicleithrum bravohollisae, a monogenean of native Cichlasoma spp., on the gills of the introduced O. aureus from Lake Catemaco (prevalence 3%, abundance 0.03 +/- 0.2). Although prevalence and abundance in atypical hosts were fairly low, the present findings provide evidence of monogenean transfer from African to American cichlids and vice versa. This is the first record of exotic monogeneans in the genus Cichlidogyrus and Enterogyrus infecting native American cichlid fish. It is also the first record from southeastern México of a native American monogenean infecting introduced African cichlids.

  5. Monogeneans of West African cichlid fish: evolution and cophylogenetic interactions.

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    Monika Mendlová

    Full Text Available The goals of this paper were to investigate phylogenetic and evolutionary patterns of cichlid fish from West Africa and their Cichlidogyrus and Scutogyrus monogenean parasites, to uncover the presence of host-parasite cospeciation and to assess the level of morphological adaptation in parasites. This required the following steps, each one representing specific objectives of this paper: (1 to build phylogenetic trees for Cichlidogyrus and Scutogyrus species based on ribosomal DNA sequences, (2 to investigate phylogenetic relationships within West African cichlid fish based on the analysis of mitochondrial cytochrome b DNA sequences, (3 to investigate host-parasite cophylogenetic history to gain clues on parasite speciation process, and (4 to investigate the link between the morphology of the attachment apparatus and parasite phylogeny. Phylogenetic analyses supported the monophyletic origin of the Cichlidogyrus/Scutogyrus group, and suggested that Cichlidogyrus is polyphyletic and that Scutogyrus is monophyletic. The phylogeny of Cichlidae supported the separation of mouthbrooders and substrate-brooders and is consistent with the hypothesis that the mouthbrooding behavior of Oreochromis and Sarotherodon evolved from substrate-brooding behavior. The mapping of morphological characters of the haptor onto the parasite phylogenetic tree suggests that the attachment organ has evolved from a very simple form to a more complex one. The cophylogenetic analyses indicated a significant fit between trees using distance-based tests, but no significant cospeciation signal using tree-based tests, suggesting the presence of parasite duplications and host switches on related host species. This shed some light on the diversification process of Cichlidogyrus species parasitizing West African cichlids.

  6. Intraspecific sexual selection on a speciation trait, male coloration, in the Lake Victoria cichlid Pundamilia nyererei

    NARCIS (Netherlands)

    Maan, ME; Seehausen, O; Soderberg, L; Johnson, L; Ripmeester, EAP; Mrosso, HDJ; Taylor, MI; van Dooren, TJM; van Alphen, JJM

    2004-01-01

    The haplochromine cichlids of Lake Victoria constitute a classical example of explosive speciation. Extensive intra- and interspecific variation in male nuptial coloration and female mating preferences, in the absence of postzygotic isolation between species, has inspired the hypothesis that sexual

  7. MHC adaptive divergence between closely related and sympatric African cichlids.

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    Jonatan Blais

    Full Text Available BACKGROUND: The haplochromine cichlid species assemblages of Lake Malawi and Victoria represent some of the most important study systems in evolutionary biology. Identifying adaptive divergence between closely-related species can provide important insights into the processes that may have contributed to these spectacular radiations. Here, we studied a pair of sympatric Lake Malawi species, Pseudotropheus fainzilberi and P. emmiltos, whose reproductive isolation depends on olfactory communication. We tested the hypothesis that these species have undergone divergent selection at MHC class II genes, which are known to contribute to olfactory-based mate choice in other taxa. METHODOLOGY/PRINCIPAL FINDINGS: Divergent selection on functional alleles was inferred from the higher genetic divergence at putative antigen binding sites (ABS amino acid sequences than at putatively neutrally evolving sites at intron 1, exon 2 synonymous sequences and exon 2 amino acid residues outside the putative ABS. In addition, sympatric populations of these fish species differed significantly in communities of eukaryotic parasites. CONCLUSIONS/SIGNIFICANCE: We propose that local host-parasite coevolutionary dynamics may have driven adaptive divergence in MHC alleles, influencing odor-mediated mate choice and leading to reproductive isolation. These results provide the first evidence for a novel mechanism of adaptive speciation and the first evidence of adaptive divergence at the MHC in closely related African cichlid fishes.

  8. The interaction of sexually and naturally selected traits in the adaptive radiations of cichlid fishes.

    Science.gov (United States)

    Salzburger, Walter

    2009-01-01

    The question of how genetic variation translates into organismal diversity has puzzled biologists for decades. Despite recent advances in evolutionary and developmental genetics, the mechanisms that underlie adaptation, diversification and evolutionary innovation remain largely unknown. The exceptionally diverse species flocks of cichlid fishes are textbook examples of adaptive radiation and explosive speciation and emerge as powerful model systems to study the genetic basis of animal diversification. East Africa's hundreds of endemic cichlid species are akin to a natural mutagenesis screen and differ greatly not only in ecologically relevant (hence naturally selected) characters such as mouth morphology and body shape, but also in sexually selected traits such as coloration. One of the most fascinating aspects of cichlid evolution is the frequent occurrence of evolutionary parallelisms, which has led to the question whether selection alone is sufficient to produce these parallel morphologies, or whether a developmental or genetic bias has influenced the direction of diversification. Here, I review fitness-relevant traits that could be responsible for the cichlids' evolutionary success and assess whether these were shaped by sexual or natural selection. I then focus on the interaction and the relative importance of sexual vs. natural selection in cichlid evolution. Finally, I discuss what is currently known about the genes underlying the morphogenesis of adaptively relevant traits and highlight the importance of the forthcoming cichlid genomes in the quest of the genetic basis of diversification in this group.

  9. Ancient hybridization fuels rapid cichlid fish adaptive radiations

    Science.gov (United States)

    Meier, Joana I.; Marques, David A.; Mwaiko, Salome; Wagner, Catherine E.; Excoffier, Laurent; Seehausen, Ole

    2017-01-01

    Understanding why some evolutionary lineages generate exceptionally high species diversity is an important goal in evolutionary biology. Haplochromine cichlid fishes of Africa's Lake Victoria region encompass >700 diverse species that all evolved in the last 150,000 years. How this ‘Lake Victoria Region Superflock' could evolve on such rapid timescales is an enduring question. Here, we demonstrate that hybridization between two divergent lineages facilitated this process by providing genetic variation that subsequently became recombined and sorted into many new species. Notably, the hybridization event generated exceptional allelic variation at an opsin gene known to be involved in adaptation and speciation. More generally, differentiation between new species is accentuated around variants that were fixed differences between the parental lineages, and that now appear in many new combinations in the radiation species. We conclude that hybridization between divergent lineages, when coincident with ecological opportunity, may facilitate rapid and extensive adaptive radiation. PMID:28186104

  10. Adaptive phenotypic plasticity in the Midas cichlid fish pharyngeal jaw and its relevance in adaptive radiation

    Directory of Open Access Journals (Sweden)

    Salzburger Walter

    2011-04-01

    Full Text Available Abstract Background Phenotypic evolution and its role in the diversification of organisms is a central topic in evolutionary biology. A neglected factor during the modern evolutionary synthesis, adaptive phenotypic plasticity, more recently attracted the attention of many evolutionary biologists and is now recognized as an important ingredient in both population persistence and diversification. The traits and directions in which an ancestral source population displays phenotypic plasticity might partly determine the trajectories in morphospace, which are accessible for an adaptive radiation, starting from the colonization of a novel environment. In the case of repeated colonizations of similar environments from the same source population this "flexible stem" hypothesis predicts similar phenotypes to arise in repeated subsequent radiations. The Midas Cichlid (Amphilophus spp. in Nicaragua has radiated in parallel in several crater-lakes seeded by populations originating from the Nicaraguan Great Lakes. Here, we tested phenotypic plasticity in the pharyngeal jaw of Midas Cichlids. The pharyngeal jaw apparatus of cichlids, a second set of jaws functionally decoupled from the oral ones, is known to mediate ecological specialization and often differs strongly between sister-species. Results We performed a common garden experiment raising three groups of Midas cichlids on food differing in hardness and calcium content. Analyzing the lower pharyngeal jaw-bones we find significant differences between diet groups qualitatively resembling the differences found between specialized species. Observed differences in pharyngeal jaw expression between groups were attributable to the diet's mechanical resistance, whereas surplus calcium in the diet was not found to be of importance. Conclusions The pharyngeal jaw apparatus of Midas Cichlids can be expressed plastically if stimulated mechanically during feeding. Since this trait is commonly differentiated - among

  11. The impact of the geologic history and paleoclimate on the diversification of East african cichlids.

    Science.gov (United States)

    Danley, Patrick D; Husemann, Martin; Ding, Baoqing; Dipietro, Lyndsay M; Beverly, Emily J; Peppe, Daniel J

    2012-01-01

    The cichlid fishes of the East African Great Lakes are the largest extant vertebrate radiation identified to date. These lakes and their surrounding waters support over 2,000 species of cichlid fish, many of which are descended from a single common ancestor within the past 10 Ma. The extraordinary East African cichlid diversity is intricately linked to the highly variable geologic and paleoclimatic history of this region. Greater than 10 Ma, the western arm of the East African rift system began to separate, thereby creating a series of rift basins that would come to contain several water bodies, including the extremely deep Lakes Tanganyika and Malawi. Uplifting associated with this rifting backponded many rivers and created the extremely large, but shallow Lake Victoria. Since their creation, the size, shape, and existence of these lakes have changed dramatically which has, in turn, significantly influenced the evolutionary history of the lakes' cichlids. This paper reviews the geologic history and paleoclimate of the East African Great Lakes and the impact of these forces on the region's endemic cichlid flocks.

  12. Extraordinarily long sperm in the socially monogamous cichlid fish Pelvicachromis taeniatus

    Science.gov (United States)

    Thünken, Timo; Bakker, Theo C. M.; Kullmann, Harald

    2007-06-01

    The main function of the spermatozoon is the transfer of the male haploid genome during fertilisation. In animals in general and in fishes in particular, there is huge variation in sperm size. In fishes, sperm size ranges from 13 μm in Mugil cephlus to nearly 100 μm in the channel catfish Ictalurus punctatus. We examined intra-specific variation in sperm morphometry in the socially monogamous cichlid Pelvicachromis taeniatus using scanning electron microscopy. The mean total sperm length of nearly 70 μm was extraordinarily large for cichlids. Furthermore, within-male variation was remarkably high. To our knowledge, P. taeniatus produces the longest cichlid sperm ever documented. Several hypotheses concerning the adaptive significance of these results are presented.

  13. Divergence in cis-regulatory sequences surrounding the opsin gene arrays of African cichlid fishes

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    Streelman J Todd

    2011-05-01

    Full Text Available Abstract Background Divergence within cis-regulatory sequences may contribute to the adaptive evolution of gene expression, but functional alleles in these regions are difficult to identify without abundant genomic resources. Among African cichlid fishes, the differential expression of seven opsin genes has produced adaptive differences in visual sensitivity. Quantitative genetic analysis suggests that cis-regulatory alleles near the SWS2-LWS opsins may contribute to this variation. Here, we sequence BACs containing the opsin genes of two cichlids, Oreochromis niloticus and Metriaclima zebra. We use phylogenetic footprinting and shadowing to examine divergence in conserved non-coding elements, promoter sequences, and 3'-UTRs surrounding each opsin in search of candidate cis-regulatory sequences that influence cichlid opsin expression. Results We identified 20 conserved non-coding elements surrounding the opsins of cichlids and other teleosts, including one known enhancer and a retinal microRNA. Most conserved elements contained computationally-predicted binding sites that correspond to transcription factors that function in vertebrate opsin expression; O. niloticus and M. zebra were significantly divergent in two of these. Similarly, we found a large number of relevant transcription factor binding sites within each opsin's proximal promoter, and identified five opsins that were considerably divergent in both expression and the number of transcription factor binding sites shared between O. niloticus and M. zebra. We also found several microRNA target sites within the 3'-UTR of each opsin, including two 3'-UTRs that differ significantly between O. niloticus and M. zebra. Finally, we examined interspecific divergence among 18 phenotypically diverse cichlids from Lake Malawi for one conserved non-coding element, two 3'-UTRs, and five opsin proximal promoters. We found that all regions were highly conserved with some evidence of CRX transcription

  14. Social familiarity modulates personality trait in a cichlid fish

    Science.gov (United States)

    Galhardo, L.; Vitorino, A.; Oliveira, R. F.

    2012-01-01

    Personality traits, such as exploration–avoidance, are expected to be adaptive in a given context (e.g. low-risk environment) but to be maladaptive in others (e.g. high-risk environment). Therefore, it is expected that personality traits are flexible and respond to environmental fluctuations, given that consistency across different contexts is maintained, so that the relative individual responses in relation to others remains the same (i.e. although the magnitude of the response varies the differences between high and low responders are kept). Here, we tested the response of male cichlid fish (Oreochromis mossambicus) to a novel object (NO) in three different social contexts: (i) social isolation, (ii) in the presence of an unfamiliar conspecific, and (iii) in the presence of a familiar conspecific. Males in the familiar treatment exhibited more exploratory behaviour and less neophobia than males in either the unfamiliar or the social isolation treatments. However, there were no overall correlations in individual behaviour across the three treatments, suggesting a lack of consistency in exploration–avoidance as measured by the NO test in this species. Moreover, there were no differences in cortisol responsiveness to an acute stressor between the three treatments. Together, these results illustrate how behavioural traits usually taken as measures of personality may exhibit significant flexibility and lack the expected consistency across different social contexts. PMID:22859562

  15. Ontogenesis of agonistic vocalizations in the cichlid fish Metriaclima zebra.

    Science.gov (United States)

    Bertucci, Frédéric; Scaion, Delphine; Beauchaud, Marilyn; Attia, Joël; Mathevon, Nicolas

    2012-08-01

    While acoustic communication has been described in adults of various fish species, our knowledge about the ontogeny of fish sound production is limited. In adults, sound signals are known to be involved during aggressive interactions. However, aggressive behaviour may appear early in the life of fishes due to the possible competition for food and space. If acoustic signals are used to send information to competitors, sounds are likely to play a role during interactions between juvenile fish as well. The apparition and evolution of sound production were monitored in a group of juveniles of the cichlid fish Metriaclima zebra from hatching to 4 months of age. In addition, the link between vocalizations and agonistic behaviour was studied during dyadic interactions at three different ages. Sounds production appeared to be present early in the development of this fish and increased along with the number of aggressive behaviours. Recorded sounds consisted, in juveniles, in isolated pulses showing a decrease in frequency and duration as the fish grew. In adults, sounds became bursts of pulses but the transition from isolated to repetitive pulses was not observed. These results are compared to the existing literature on sound production ontogeny in fishes.

  16. Parasitic infections in ornamental cichlid fish in the Peruvian Amazon.

    Science.gov (United States)

    Aguinaga, Jefferson Yunis; Marcusso, Paulo Fernandes; Claudiano, Gustavo da Silva; Lima, Bruno Tadeu Marotta; Marotta, Bruno L; Sebastião, Fernanda de Alexandre; Fernandes, João Batista Kochenborger; de Moraes, Flávio Ruas; de Moraes, Julieta Rodini Engracia

    2015-01-01

    The aim of this study was to evaluate the prevalence and seasonal distribution of the main parasite species in Amazonian ornamental cichlids that affect their trade. The study was conducted from August 2007 to September 2009. We sampled 3042 specimens from 9 different species, of which 9.47% had at least one type of external parasite. 81.25% of the cases occurred in the dry season. Crenicichla anthurus (28.57%) was the most parasitized, followed by Aequidens diadema (26.32%), Pterophyllum scalare (22.69%), Cichlasoma sp. (9.52%), Apistogramma sp. (3.88%) and Symphysodon aequifasciatus (3.66%). Monogenea was the most abundant group of parasites, occurring in 66.67% of the cases, of which 96.88% occurred in the dry season. This parasite infested 95.68% of Pterophyllum scalare, 76.67% of Apistogramma sp, 33.33% of Cichlasoma sp. and 23.81% of Symphysodon aequifasciatus cases. Ichthyophthirius multifiliis infested 100% of Aequidens diadema, 76.19% of Symphysodon aequifasciatus, 66.67% of Cichlasoma sp, 41.67% of Crenicichla anthurus and 23.33% of Apistogramma sp cases. Myxosporidia infested 58.33% of Crenicichla anthurus. Trichodina infested 4.32% of Pterophyllum scalare. The prevalence of these parasites is related to the season, preferred habitat, fish behavior, individual susceptibility and handling of animals during transportation by fishermen.

  17. Parasitic infections in ornamental cichlid fish in the Peruvian Amazon

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    Jefferson Yunis Aguinaga

    Full Text Available The aim of this study was to evaluate the prevalence and seasonal distribution of the main parasite species in Amazonian ornamental cichlids that affect their trade. The study was conducted from August 2007 to September 2009. We sampled 3042 specimens from 9 different species, of which 9.47% had at least one type of external parasite. 81.25% of the cases occurred in the dry season. Crenicichla anthurus (28.57% was the most parasitized, followed by Aequidens diadema (26.32%, Pterophyllum scalare (22.69%, Cichlasoma sp. (9.52%, Apistogramma sp. (3.88% and Symphysodon aequifasciatus (3.66%. Monogenea was the most abundant group of parasites, occurring in 66.67% of the cases, of which 96.88% occurred in the dry season. This parasite infested 95.68% of Pterophyllum scalare, 76.67% of Apistogramma sp, 33.33% of Cichlasoma sp. and 23.81% of Symphysodon aequifasciatus cases. Ichthyophthirius multifiliis infested 100% of Aequidens diadema, 76.19% of Symphysodon aequifasciatus, 66.67% of Cichlasoma sp, 41.67% of Crenicichla anthurus and 23.33% of Apistogramma sp cases. Myxosporidia infested 58.33% of Crenicichla anthurus. Trichodina infested 4.32% of Pterophyllum scalare. The prevalence of these parasites is related to the season, preferred habitat, fish behavior, individual susceptibility and handling of animals during transportation by fishermen.

  18. Spawning Coordination of Mates in a Shell Brooding Cichlid

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    Dolores Schütz

    2012-01-01

    Full Text Available Aim. External fertilisation requires synchronisation of gamete release between the two sexes. Adequate synchronisation is essential in aquatic media because sperm is very short-lived in water. In the cichlid Lamprologus callipterus, fertilisation of the eggs takes place inside an empty snail shell, where females stay inside the shell and males have to ejaculate into the shell opening. This spawning pattern makes the coordination of gamete release difficult. Methods. This study examined the synchronisation of males and females during egg laying. Results. The results showed that the male initiates each spawning sequence and that sperm release and egg laying are very well synchronised. 68% of all sperm releases occurred at exactly the same time when the female laid an egg, and 99% of ejaculations occurred within ±5 seconds from egg deposition. On average 95 eggs are laid one by one with intervals of several minutes between subsequent eggs, leading to a total spawning duration in excess of six hours. Conclusions. We discuss this exceptional spawning pattern and how it might reflect a conflict between the sexes, with males attempting to induce egg laying and females extending the egg laying period to raise the chance for parasitic males to participate in spawning.

  19. Frequency-Dependent Social Dominance in a Color Polymorphic Cichlid Fish

    NARCIS (Netherlands)

    Dijkstra, Peter; Lindström, Jan; Metcalfe, Neil B.; Hemelrijk, Charlotte K.; Brendel, Mischa; Seehausen, Ole; Groothuis, Ton G.G.

    2010-01-01

    A mechanism commonly suggested to explain the persistence of color polymorphisms in animals is negative frequency-dependent selection. It could result from a social dominance advantage to rare morphs. We tested for this in males of red and blue color morphs of the Lake Victoria cichlid, Pundamilia.

  20. Habitat structure directly affects aggression in convict cich-lids Archocentrus nigrofasciatus

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    Anthony J. BARLEY, Ronald M. COLEMAN

    2010-02-01

    Full Text Available Aggressive behavior can be an important factor in determining how animals use and divide space and resources. Previous studies have shown that aggression in fishes can be influenced by a variety of factors, including water temperature and resource levels. In this study, we tested if the amount of habitat structure in the environment affected aggression levels in female convict cichlids Archocentrus nigrofasciatus. We performed a laboratory experiment in which we placed female convict cichlids into an aquarium with low or high amounts of habitat structure and monitored the dominant female's behavior toward the subordinate female. Aggressive behavior in convict cichlids primarily consists of chases and bites. We found that the total time the dominant female spent chasing the subordinate female was greater when there was a low amount of habitat structure as compared to when there was a high amount of habitat structure. We also found that both the average duration of a chasing bout and the number of bites directed at the subordinate fish increased when there was a low amount of structure, but the number of chases did not. These results indicate that increased habitat structural complexity decreases aggressive behavior in convict cichlids [Current Zoology 56 (1: 52–56, 2010].

  1. Divergent mating preferences and nuptial coloration in sibling species of cichlid fish

    NARCIS (Netherlands)

    Sluijs, Inke van der

    2008-01-01

    Mate choice by female cichlid fish from Lake Victoria plays an important role in speciation and the maintenance of species. Females are expected to select against males that are intermediate in their phenotype during the process of speciation driven by sexual selection. To test this, we hybridized t

  2. Notes on the Fishes of the Cichlid Family I. Apistogramma cacatuoides sp. n

    NARCIS (Netherlands)

    Hoedeman, J.J.

    1951-01-01

    The Dwarf-cichlid genus Apistogramma, very popular among aquarists and at present among students of animal behaviour, hitherto comprises about 16 forms, several of them hardly specifically distinguished, and probably only based on stages or sexes of other species. Nevertheless I found a new form amo

  3. An Evaluation of the Role of Sensory Drive in the Evolution of Lake Malawi Cichlid Fishes

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    Adam R. Smith

    2012-01-01

    Full Text Available Although the cichlids of Lake Malawi are an important model system for the study of sensory evolution and sexual selection, the evolutionary processes linking these two phenomena remain unclear. Prior works have proposed that evolutionary divergence is driven by sensory drive, particularly as it applies to the visual system. While evidence suggests that sensory drive has played a role in the speciation of Lake Victoria cichlids, the findings from several lines of research on cichlids of Lake Malawi are not consistent with the primary tenets of this hypothesis. More specifically, three observations make the sensory drive model implausible in Malawi: (i a lack of environmental constraint due to a broad and intense ambient light spectrum in species rich littoral habitats, (ii pronounced variation in receiver sensory characteristics, and (iii pronounced variability in male courtship signal characteristics. In the following work, we synthesize the results from recent studies to draw attention to the importance of sensory variation in cichlid evolution and speciation, and we suggest possible avenues of future research.

  4. Molecular phylogeny and revised classification of the haplotilapiine cichlid fishes formerly referred to as "Tilapia".

    Science.gov (United States)

    Dunz, Andreas R; Schliewen, Ulrich K

    2013-07-01

    African cichlids formerly referred to as "Tilapia" represent a paraphyletic species assemblage belonging to the so called haplotilapiine lineage which gave rise to the spectacular East African cichlid radiations (EARs) as well as to globally important aquaculture species. We present a comprehensive molecular phylogeny of representative haplotilapiine cichlids, combining in one data set four mitochondrial and five nuclear loci for 76 species, and compare it with phylogenetic information of a second data set of 378 mitochondrial ND2 haplotypes representing almost all important "Tilapia" or Tilapia-related lineages as well as most EAR lineages. The monophyly of haplotilapiines is supported, as is the nested sister group relationship of Etia and mouthbrooding tilapiines with the remaining haplotilapiines. The latter are consistently placed in eight monophyletic clades over all datasets and analyses, but several dichotomous phylogenetic relationships appear compromised by cytonuclear discordant phylogenetic signal. Based on these results as well as on extensive morphological evidence we propose a novel generic and suprageneric classification including a (re-)diagnosis of 20 haplotilapiine cichlid genera and nine tribes. New tribes are provided for the former subgenera Coptodon Gervais, 1853, HeterotilapiaRegan, 1920 and PelmatolapiaThys van den Audenaerde, 1969, in addition for "Tilapia" joka, Tilapia sensu stricto and Chilochromis, Etia, Steatocranus sensu stricto, the mouthbrooding tilapiines and for a clade of West African tilapiines.

  5. On gonads and reproductive behaviour in the cichlid fish Aequidens portalegrensis (Hensel)

    NARCIS (Netherlands)

    Polder, Johan Jan Willem

    1971-01-01

    In this paper on the cichlid fish Aequidensp ortalegrensis,in formation is given on 1) the anatomy and histology of the gonads, 2) the functional anatomy of the accessory organs, 3) the occurrence of cyclical changes in the gonads, 4) the mutual behaviour of male and female under different condition

  6. Colour variation in cichlid fish : Developmental mechanisms, selective pressures and evolutionary consequences

    NARCIS (Netherlands)

    Maan, Martine E.; Sefc, Kristina M.

    2013-01-01

    Cichlid fishes constitute one of the most species-rich families of vertebrates. In addition to complex social behaviour and morphological versatility, they are characterised by extensive diversity in colouration, both within and between species. Here, we review the cellular and molecular mechanisms

  7. Female mating preferences and male coloration covary with water transparency in a Lake Victoria cichlid fish

    NARCIS (Netherlands)

    Maan, Martine E.; Seehausen, Ole; Van Alphen, Jacques J. M.

    2010-01-01

    Rapid speciation in Lake Victoria cichlid fish of the genus Pundamilia may be facilitated by sexual selection: female mate choice exerts sexual selection on male nuptial coloration within species and maintains reproductive isolation between species. However, declining water transparency coincides wi

  8. Mitogenomic evaluation of the historical biogeography of cichlids toward reliable dating of teleostean divergences

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    Miya Masaki

    2008-07-01

    Full Text Available Abstract Background Recent advances in DNA sequencing and computation offer the opportunity for reliable estimates of divergence times between organisms based on molecular data. Bayesian estimations of divergence times that do not assume the molecular clock use time constraints at multiple nodes, usually based on the fossil records, as major boundary conditions. However, the fossil records of bony fishes may not adequately provide effective time constraints at multiple nodes. We explored an alternative source of time constraints in teleostean phylogeny by evaluating a biogeographic hypothesis concerning freshwater fishes from the family Cichlidae (Perciformes: Labroidei. Results We added new mitogenomic sequence data from six cichlid species and conducted phylogenetic analyses using a large mitogenomic data set. We found a reciprocal monophyly of African and Neotropical cichlids and their sister group relationship to some Malagasy taxa (Ptychochrominae sensu Sparks and Smith. All of these taxa clustered with a Malagasy + Indo/Sri Lankan clade (Etroplinae sensu Sparks and Smith. The results of the phylogenetic analyses and divergence time estimations between continental cichlid clades were much more congruent with Gondwanaland origin and Cretaceous vicariant divergences than with Cenozoic transmarine dispersal between major continents. Conclusion We propose to add the biogeographic assumption of cichlid divergences by continental fragmentation as effective time constraints in dating teleostean divergence times. We conducted divergence time estimations among teleosts by incorporating these additional time constraints and achieved a considerable reduction in credibility intervals in the estimated divergence times.

  9. The species flocks of East African cichlid fishes: recent advances in molecular phylogenetics and population genetics

    Science.gov (United States)

    Salzburger, Walter; Meyer, Axel

    With more than 3,000 species, the fish family Cichlidae is one of the most species-rich families of vertebrates. Cichlids occur in southern and central America, Africa, Madagascar, and India. The hotspot of their biodiversity is East Africa, where they form adaptive radiations composed of hundreds of endemic species in several lakes of various sizes and ages. The unparalleled species richness of East African cichlids has been something of a conundrum for evolutionary biologists and ecologists, since it has been in doubt whether these hundreds of species arose by allopatric speciation or whether it is necessary to invoke somewhat less traditional models of speciation, such as micro-allopatric, peripatric, or even sympatric speciation or evolution through sexual selection mediated by female choice. Ernst Mayr's analyses of these evolutionary uniquely diverse species assemblages have contributed to a more direct approach to this problem and have led to a deeper understanding of the patterns and processes that caused the formation of these huge groups of species. We review here recent molecular data on population differentiation and phylogenetics, which have helped to unravel, to some extent, the patterns and processes that led to the formation and ecological maintenance of cichlid species flocks. It is becoming apparent that sexually selected traits do play an important role in speciation in micro-allopatric or even sympatric settings. Species richness seems to be roughly correlated with the surface area, but not the age, of the lakes. We observe that the oldest lineages of a species flock of cichlids are often less species-rich and live in the open water or deepwater habitats. While the species flocks of the Lake Malawai and the Lake Victoria areas were shown to be monophyletic, the cichlid assemblage of Lake Tanganyika seems to consist of several independent species flocks. Cichlids emerge as an evolutionary model system in which many fundamental questions in

  10. A tribal level phylogeny of Lake Tanganyika cichlid fishes based on a genomic multi-marker approach.

    Science.gov (United States)

    Meyer, Britta S; Matschiner, Michael; Salzburger, Walter

    2015-02-01

    The species-flocks of cichlid fishes in the East African Great Lakes Victoria, Malawi and Tanganyika constitute the most diverse extant adaptive radiations in vertebrates. Lake Tanganyika, the oldest of the lakes, harbors the morphologically and genetically most diverse assemblage of cichlids and contains the highest number of endemic cichlid genera of all African lakes. Based on morphological grounds, the Tanganyikan cichlid species have been grouped into 12-16 distinct lineages, so-called tribes. While the monophyly of most of the tribes is well established, the phylogenetic relationships among the tribes remain largely elusive. Here, we present a new tribal level phylogenetic hypothesis for the cichlid fishes of Lake Tanganyika that is based on the so far largest set of nuclear markers and a total alignment length of close to 18kb. Using next-generation amplicon sequencing with the 454 pyrosequencing technology, we compiled a dataset consisting of 42 nuclear loci in 45 East African cichlid species, which we subjected to maximum likelihood and Bayesian inference phylogenetic analyses. We analyzed the entire concatenated dataset and each marker individually, and performed a Bayesian concordance analysis and gene tree discordance tests. Overall, we find strong support for a position of the Oreochromini, Boulengerochromini, Bathybatini and Trematocarini outside of a clade combining the substrate spawning Lamprologini and the mouthbrooding tribes of the 'H-lineage', which are both strongly supported to be monophyletic. The Eretmodini are firmly placed within the 'H-lineage', as sister-group to the most species-rich tribe of cichlids, the Haplochromini. The phylogenetic relationships at the base of the 'H-lineage' received less support, which is likely due to high speciation rates in the early phase of the radiation. Discordance among gene trees and marker sets further suggests the occurrence of past hybridization and/or incomplete lineage sorting in the cichlid

  11. Mating system of the amazonian cichlid angel fish, Pterophyllum scalare

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    MSRF. Cacho

    Full Text Available The species, Pterophyllum scalare distinguishes itself by its breeding behavior, involving competition for territory, sexual partners, courtship and parental care. The purpose of this study was to identify the mating system adopted by this species of fish. Twenty males and twenty females were observed under semi-natural and experimental conditions to test the hypothesis of serial monogamy. Under semi-natural conditions, after the third breeding cycle, the couples changed mates. Under experimental conditions, the couples changed partners after the first breeding cycle. Under experimental conditions, mate recognition was investigated through the preference of the females, indicated by the time they spent with the males. The females were available or not for courtship from new males, depending on their aggressiveness or submission. The larger and more aggressive males obtained new mating opportunities while the submissive males were rejected by the females. The mated fish were aggressive towards intruders in the presence of the mate, protecting their pair bond. In the interval between breeding cycles, the couples did not display aggression towards intruders, confirming the hypothesis of serial monogamy. Best mate selection by the females and the opportunity of new matings for both sexes influenced the reproductive success of this species.

  12. Molecular phylogeny and evidence for an adaptive radiation of geophagine cichlids from South America (Perciformes: Labroidei).

    Science.gov (United States)

    López-Fernández, Hernán; Honeycutt, Rodney L; Winemiller, Kirk O

    2005-01-01

    Nucleotide sequences from the mitochondrial ND4 gene and the nuclear RAG2 gene were used to derive the most extensive molecular phylogeny to date for the Neotropical cichlid subfamily Geophaginae. Previous hypotheses of relationships were tested in light of these new data and a synthesis of all existing molecular information was provided. Novel phylogenetic findings included support for : (1) a 'Big Clade' containing the genera Geophagus sensu lato, Gymnogeophagus, Mikrogeophagus, Biotodoma, Crenicara, and Dicrossus; (2) a clade including the genera Satanoperca, Apistogramma, Apistogrammoides, and Taeniacara; and (3) corroboration for Kullander's clade Acarichthyini. ND4 demonstrated saturation effects at the third code position and lineage-specific rate heterogeneity, both of which influenced phylogeny reconstruction when only equal weighted parsimony was employed. Both branch lengths and internal branch tests revealed extremely short basal nodes that add support to the idea that geophagine cichlids have experienced an adaptive radiation sensu Schluter that involved ecomorphological specializations and life history diversification.

  13. Morphology, molecules, and monogenean parasites: an example of an integrative approach to cichlid biodiversity.

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    Maarten Van Steenberge

    Full Text Available The unparalleled biodiversity of Lake Tanganyika (Africa has fascinated biologists for over a century; its unique cichlid communities are a preferred model for evolutionary research. Although species delineation is, in most cases, relatively straightforward, higher-order classifications were shown not to agree with monophyletic groups. Here, traditional morphological methods meet their limitations. A typical example are the tropheine cichlids currently belonging to Simochromis and Pseudosimochromis. The affiliations of these widespread and abundant cichlids are poorly understood. Molecular work suggested that genus and species boundaries should be revised. Moreover, previous morphological results indicated that intraspecific variation should be considered to delineate species in Lake Tanganyika cichlids. We review the genera Simochromis and Pseudosimochromis using an integrative approach. Besides a morphometric study and a barcoding approach, monogenean Cichlidogyrus (Platyhelminthes: Ancyrocephalidae gill parasites, often highly species-specific, are used as complementary markers. Six new species are described. Cichlidogyrus raeymaekersi sp. nov., C. muterezii sp. nov. and C. banyankimbonai sp. nov. infect S. diagramma. Cichlidogyrus georgesmertensi sp. nov. was found on S. babaulti and S. pleurospilus, C. franswittei sp. nov. on both S. marginatus and P. curvifrons and C. frankwillemsi sp. nov. only on P. curvifrons. As relatedness between Cichlidogyrus species usually reflects relatedness between hosts, we considered Simochromis monotypic because the three Cichlidogyrus species found on S. diagramma belonged to a different morphotype than those found on the other Simochromis. The transfer of S. babaulti, S. marginatus, S. pleurospilus and S. margaretae to Pseudosimochromis was justified by the similarity of their Cichlidogyrus fauna and the intermediate morphology of S. margaretae. Finally parasite data also supported the synonymy between S

  14. Indigenous knowledge of animal breeding and breeds

    OpenAIRE

    I. Kohler-Rollefson

    2004-01-01

    Indigenous knowledge of animal breeding (IK-AB) includes concepts and practices used to influence the genetic composition of herds. Indigenous selection is often based on preferences based on physical characteristics, vigor, social and economic insurance. This issue paper summarizes the value of indigenous knowledge and local breeds to achieve agricultural sustainability. Links to IK-AB information are also provided. Available in SANREM office, ES

  15. Alarm cue induces an antipredator morphological defense in juvenile Nicaragua cichlids Hypsophrys nicaraguensis

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    Maria E. ABATE, Andrew G. ENG, Les KAUFMAN

    2010-02-01

    Full Text Available Olfactory cues that indicate predation risk elicit a number of defensive behaviors in fishes, but whether they are sufficient to also induce morphological defenses has received little attention. Cichlids are characterized by a high level of morphological plasticity during development, and the few species that have been tested do exhibit defensive behaviors when exposed to alarm cues released from the damaged skin of conspecifics. We utilized young juvenile Nicaragua cichlids Hypsophrys nicaraguensis to test if the perception of predation risk from alarm cue (conspecific skin extract alone induces an increased relative body depth which is a defense against gape-limited predators. After two weeks of exposure, siblings that were exposed to conspecific alarm cue increased their relative body depth nearly double the amount of those exposed to distilled water (control and zebrafish Danio rerio alarm cue. We repeated our measurements over the last two weeks (12 and 14 of cue exposure when the fish were late-stage juveniles to test if the rate of increase was sustained; there were no differences in final dimensions between the three treatments. Our results show that 1 the Nicaraguan cichlid has an innate response to conspecific alarm cue which is not a generalized response to an injured fish, and 2 this innate recognition ultimately results in developing a deeper body at a stage of the life history where predation risk is high [Current Zoology 56 (1: 36–42 2010].

  16. Segregation of Species-Specific Male Attractiveness in F2 Hybrid Lake Malawi Cichlid Fish

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    Ola Svensson

    2011-01-01

    Full Text Available Among the huge radiations of haplochromine cichlid fish in Lakes Malawi and Victoria, closely related species are often reproductively isolated via female mate choice although viable fertile hybrids can be produced when females are confined only with heterospecific males. We generated F2 hybrid males from a cross between a pair of closely related sympatric cichlid fish from Lake Malawi. Laboratory mate choice experiments using microsatellite paternity analysis demonstrated that F2 hybrid males differed significantly in their attractiveness to females of the two parental species, indicating heritable variation in traits involved in mate choice that may contribute to reproductive isolation between these species. We found no significant correlation between male mating success and any measurement of male colour pattern. A simple quantitative genetic model of reproductive isolation suggests that there may be as few as two chromosomal regions controlling species-specific attractiveness. We propose that adaptive radiation of Lake Malawi cichlids could be facilitated by the presence of genes with major effects on mate choice and reproductive isolation.

  17. Investigation of Acute Toxicity Diazinon, Deltamethrin, Butachlor and pretilachlor on Zebra Cichlid (Cryptoheros nigrofasciatus

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    Ali Sadeghi

    2014-06-01

    Full Text Available Background: The presence of pesticide due to the huge demand for agricultural purposes is very prevalent in surface waters of Iran. These pesticides could finally accumulate in aquatic ecosystems and have been proved to have toxic effects on aquatic animals. The aim of this study was to assess the acute toxicity of Diazinon, Deltamethrin, Butachlor and Pretilachlor on Zebra Cichlid (Cryptoheros nigrofasciatus. Methods: Fish samples were exposed to different concentrations of Diazinon (60% (0, 2, 4, 8, 16 and 32 ppm, Deltamethrin (2.5% (0, 0.02, 0.04, 0.10, 0.20 and 0.40 ppm, butachlor (60% (0, 2, 4, 8, 16 and 32 ppm and pretilachlor (50% (0, 5, 10, 20, 30 and 40 ppm for 96 h within the 100 L glass aquaria and cumulative mortality of Zebra Cichlid fish was calculated in 24-h interval. Results: The very low LC50 obtained for diazinon (5.06±0.37 ppm, deltamethrin (0.15±0.39 ppm, butachlor (8.93±0.26 ppm and pretilachlor (20.72±0.58 ppm indicated that these are highly toxic chemicals. Conclusion: Our results demonstrate that deltamethrin and pretilachlor had the lowest and highest rate of mortality on the Zebra Cichlid respectively.

  18. Regulatory gene networks that shape the development of adaptive phenotypic plasticity in a cichlid fish.

    Science.gov (United States)

    Schneider, Ralf F; Li, Yuanhao; Meyer, Axel; Gunter, Helen M

    2014-09-01

    Phenotypic plasticity is the ability of organisms with a given genotype to develop different phenotypes according to environmental stimuli, resulting in individuals that are better adapted to local conditions. In spite of their ecological importance, the developmental regulatory networks underlying plastic phenotypes often remain uncharacterized. We examined the regulatory basis of diet-induced plasticity in the lower pharyngeal jaw (LPJ) of the cichlid fish Astatoreochromis alluaudi, a model species in the study of adaptive plasticity. Through raising juvenile A. alluaudi on either a hard or soft diet (hard-shelled or pulverized snails) for between 1 and 8 months, we gained insight into the temporal regulation of 19 previously identified candidate genes during the early stages of plasticity development. Plasticity in LPJ morphology was first detected between 3 and 5 months of diet treatment. The candidate genes, belonging to various functional categories, displayed dynamic expression patterns that consistently preceded the onset of morphological divergence and putatively contribute to the initiation of the plastic phenotypes. Within functional categories, we observed striking co-expression, and transcription factor binding site analysis was used to examine the prospective basis of their coregulation. We propose a regulatory network of LPJ plasticity in cichlids, presenting evidence for regulatory crosstalk between bone and muscle tissues, which putatively facilitates the development of this highly integrated trait. Through incorporating a developmental time-course into a phenotypic plasticity study, we have identified an interconnected, environmentally responsive regulatory network that shapes the development of plasticity in a key innovation of East African cichlids.

  19. A novel molecular marker for the study of Neotropical cichlid phylogeny.

    Science.gov (United States)

    Fabrin, T M C; Gasques, L S; Prioli, S M A P; Prioli, A J

    2015-12-22

    The use of molecular markers has contributed to phylogeny and to the reconstruction of species' evolutionary history. Each region of the genome has different evolution rates, which may or may not identify phylogenetic signal at different levels. Therefore, it is important to assess new molecular markers that can be used for phylogenetic reconstruction. Regions that may be associated with species characteristics and are subject to selective pressure, such as opsin genes, which encode proteins related to the visual system and are widely expressed by Cichlidae family members, are interesting. Our aim was to identify a new nuclear molecular marker that could establish the phylogeny of Neotropical cichlids and is potentially correlated with the visual system. We used Bayesian inference and maximum likelihood analysis to support the use of the nuclear opsin LWS gene in the phylogeny of eight Neotropical cichlid species. Their use concatenated to the mitochondrial gene COI was also tested. The LWS gene fragment comprised the exon 2-4 region, including the introns. The LWS gene provided good support for both analyses up to the genus level, distinguishing the studied species, and when concatenated to the COI gene, there was a good support up to the species level. Another benefit of utilizing this region, is that some polymorphisms are associated with changes in spectral properties of the LWS opsin protein, which constitutes the visual pigment that absorbs red light. Thus, utilization of this gene as a molecular marker to study the phylogeny of Neotropical cichlids is promising.

  20. Altering an extended phenotype reduces intraspecific male aggression and can maintain diversity in cichlid fish

    Directory of Open Access Journals (Sweden)

    Isabel Santos Magalhaes

    2013-11-01

    Full Text Available Reduced male aggression towards different phenotypes generating negative frequency-dependent intrasexual selection has been suggested as a mechanism to facilitate the invasion and maintenance of novel phenotypes in a population. To date, the best empirical evidence for the phenomenon has been provided by laboratory studies on cichlid fish with different colour polymorphisms. Here we experimentally tested the hypothesis in a natural population of Lake Malawi cichlid fish, in which males build sand-castles (bowers to attract females during seasonal leks. We predicted that if bower shape plays an important role in male aggressive interactions, aggression among conspecific males should decrease when their bower shape is altered. Accordingly, we allocated randomly chosen bowers in a Nyassachromis cf. microcephalus lek into three treatments: control, manipulated to a different shape, and simulated manipulation. We then measured male behaviours and bower shape before and after these treatments. We found that once bower shape was altered, males were involved in significantly fewer aggressive interactions with conspecific males than before manipulation. Mating success was not affected. Our results support the idea that an extended phenotype, such as bower shape, can be important in maintaining polymorphic populations. Specifically, reduced male conspecific aggression towards males with different extended phenotypes (here, bower shapes may cause negative frequency-dependent selection, allowing the invasion and establishment of a new phenotype (bower builder. This could help our understanding of mechanisms of diversification within populations, and in particular, the overall diversification of bower shapes within Lake Malawi cichlids.

  1. Tol2-mediated generation of a transgenic haplochromine cichlid, Astatotilapia burtoni.

    Directory of Open Access Journals (Sweden)

    Scott A Juntti

    Full Text Available Cichlid fishes represent one of the most species-rich and rapid radiations of a vertebrate family. These ~2200 species, predominantly found in the East African Great Lakes, exhibit dramatic differences in anatomy, physiology, and behavior. However, the genetic bases for this radiation, and for the control of their divergent traits, are unknown. A flood of genomic and transcriptomic data promises to suggest mechanisms underlying the diversity, but transgenic technology will be needed to rigorously test the hypotheses generated. Here we demonstrate the successful use of the Tol2 transposon system to generate transgenic Astatotilapia burtoni, a haplochromine cichlid from Lake Tanganyika, carrying the GFP transgene under the control of the ubiquitous EF1α promoter. The transgene integrates into the genome, is successfully passed through the germline, and the widespread GFP expression pattern is stable across siblings and multiple generations. The stable inheritance and expression patterns indicate that the Tol2 system can be applied to generate A. burtoni transgenic lines. Transgenesis has proven to be a powerful technology for manipulating genes and cells in other model organisms and we anticipate that transgenic A. burtoni and other cichlids will be used to test the mechanisms underlying behavior and speciation.

  2. Rapid sympatric ecological differentiation of crater lake cichlid fishes within historic times

    Directory of Open Access Journals (Sweden)

    Harrod Chris

    2010-05-01

    Full Text Available Abstract Background After a volcano erupts, a lake may form in the cooled crater and become an isolated aquatic ecosystem. This makes fishes in crater lakes informative for understanding sympatric evolution and ecological diversification in barren environments. From a geological and limnological perspective, such research offers insight about the process of crater lake ecosystem establishment and speciation. In the present study we use genetic and coalescence approaches to infer the colonization history of Midas cichlid fishes (Amphilophus cf. citrinellus that inhabit a very young crater lake in Nicaragua-the ca. 1800 year-old Lake Apoyeque. This lake holds two sympatric, endemic morphs of Midas cichlid: one with large, hypertrophied lips (~20% of the total population and another with thin lips. Here we test the associated ecological, morphological and genetic diversification of these two morphs and their potential to represent incipient speciation. Results Gene coalescence analyses [11 microsatellite loci and mitochondrial DNA (mtDNA sequences] suggest that crater lake Apoyeque was colonized in a single event from the large neighbouring great lake Managua only about 100 years ago. This founding in historic times is also reflected in the extremely low nuclear and mitochondrial genetic diversity in Apoyeque. We found that sympatric adult thin- and thick-lipped fishes occupy distinct ecological trophic niches. Diet, body shape, head width, pharyngeal jaw size and shape and stable isotope values all differ significantly between the two lip-morphs. The eco-morphological features pharyngeal jaw shape, body shape, stomach contents and stable isotopes (δ15N all show a bimodal distribution of traits, which is compatible with the expectations of an initial stage of ecological speciation under disruptive selection. Genetic differentiation between the thin- and thick-lipped population is weak at mtDNA sequence (FST = 0.018 and absent at nuclear

  3. Strong assortative mating by diet, color, size, and morphology but limited progress toward sympatric speciation in a classic example: Cameroon crater lake cichlids.

    Science.gov (United States)

    Martin, Christopher H

    2013-07-01

    Models predict that sympatric speciation depends on restrictive parameter ranges, such as sufficiently strong disruptive selection and assortative mating, but compelling examples in nature have rarely been used to test these predictions. I measured the strength of assortative mating within a species complex of Tilapia in Lake Ejagham, Cameroon, a celebrated example of incipient sympatric adaptive radiation. This species complex is in the earliest stages of speciation: morphological and ecological divergence are incomplete, species differ primarily in breeding coloration, and introgression is common. I captured 27 mated pairs in situ and measured the diet, color, size, and morphology of each individual. I found strong assortative mating by color, size, head depth, and dietary source of benthic or pelagic prey along two independent dimensions of assortment. Thus, Ejagham Tilapia showed strong assortative mating most conducive to sympatric speciation. Nonetheless, in contrast to a morphologically bimodal Sarotherodon cichlid species pair in the lake, Ejagham Tilapia show more limited progress toward speciation, likely due to insufficient strength of disruptive selection on morphology estimated in a previous study (γ = 0.16). This supports the predicted dependence of sympatric speciation on strong assortment and strong disruptive selection by examining a potentially stalled example in nature.

  4. Genomic dairy cattle breeding

    DEFF Research Database (Denmark)

    Mark, Thomas; Sandøe, Peter

    2010-01-01

    The aim of this paper is to discuss the potential consequences of modern dairy cattle breeding for the welfare of dairy cows. The paper focuses on so-called genomic selection, which deploys thousands of genetic markers to estimate breeding values. The discussion should help to structure...... the thoughts of breeders and other stakeholders on how to best make use of genomic breeding in the future. Intensive breeding has played a major role in securing dramatic increases in milk yield since the Second World War. Until recently, the main focus in dairy cattle breeding was on production traits......, unfavourable genetic trends for metabolic, reproductive, claw and leg diseases indicate that these attempts have been insufficient. Today, novel genome-wide sequencing techniques are revolutionising dairy cattle breeding; these enable genetic changes to occur at least twice as rapidly as previously. While...

  5. Temperature and Ca2+-dependence of the sarcoplasmic reticulum Ca2(+)-ATPase in haddock, salmon, rainbow trout and zebra cichlid

    DEFF Research Database (Denmark)

    Godiksen, Helene; Jessen, Flemming

    2002-01-01

    in the enzyme or its membrane lipid environment is still a matter of discussion. In this study we compared the temperature dependence and Ca2+-dependence of SR Ca2+-ATPase in haddock (Melanogrammus aeglefinus), salmon (Salmo, salar), rainbow trout (Oncorhynchus mykiss) and zebra cichlid (Cichlasoma...... nigrofasciatum). The Arrhenius plot of zebra cichlid showed a break point at 20 degreesC, and the haddock Arrhenius plot was non-linear with pronounced changes in slope in the. temperature area, 6-14 degreesC. In Arrhenius plot from both salmon and rainbow trout a plateau exists with an almost constant SR Ca2...

  6. Assortative mating among Lake Malawi cichlid fish populations is not simply predictable from male nuptial colour

    Directory of Open Access Journals (Sweden)

    Taylor Martin I

    2009-03-01

    Full Text Available Abstract Background Research on the evolution of reproductive isolation in African cichlid fishes has largely focussed on the role of male colours and female mate choice. Here, we tested predictions from the hypothesis that allopatric divergence in male colour is associated with corresponding divergence in preference. Methods We studied four populations of the Lake Malawi Pseudotropheus zebra complex. We predicted that more distantly-related populations that independently evolved similar colours would interbreed freely while more closely-related populations with different colours mate assortatively. We used microsatellite genotypes or mesh false-floors to assign paternity. Fisher's exact tests as well as Binomial and Wilcoxon tests were used to detect if mating departed from random expectations. Results Surprisingly, laboratory mate choice experiments revealed significant assortative mating not only between population pairs with differently coloured males, but between population pairs with similarly-coloured males too. This suggested that assortative mating could be based on non-visual cues, so we further examined the sensory basis of assortative mating between two populations with different male colour. Conducting trials under monochromatic (orange light, intended to mask the distinctive male dorsal fin hues (blue v orange of these populations, did not significantly affect the assortative mating by female P. emmiltos observed under control conditions. By contrast, assortative mating broke down when direct contact between female and male was prevented. Conclusion We suggest that non-visual cues, such as olfactory signals, may play an important role in mate choice and behavioural isolation in these and perhaps other African cichlid fish. Future speciation models aimed at explaining African cichlid radiations may therefore consider incorporating such mating cues in mate choice scenarios.

  7. Cutting the Gordian knot:Complex signaling in African cichlids is more than multimodal

    Institute of Scientific and Technical Information of China (English)

    Moira J.VAN STAADEN; Adam R.SMITH

    2011-01-01

    The active transmission of information from sender to recelver is a fundamental component of communication,and is therefore a primary facet in evolutionary models of sexual selection.Research in several systetms has underlined the importance of multiple sensory modalities in courtship signals.However,we still tend to think of individuals as having a relatively static signal in consecutive communicative events.While this may be true for certain traits such as body size or coloration,behaviorally modulated signals can quickly violate this assumption.In this work,we explore how intraspecific variation may be an important component of interspeclfic signal divergence using cichlid fishes from Lake Maiawi.Behavloral analyses were made using six species of Malawian cichlids from two divergent genera.while interspecific differences were found between congeners based on species-level analyses of both acoustic and audiovisual signais,intraspecific variation was of a similar magnitude.Specifically,individual fishes were found to possess highiy plastic signal repertoires.This finding was ubiquitous across all species and resulted in a great deal of overlap between heterospecific individuals,despite statistically distinct species means.These results demonstrate that some aspects of courtship in Malawian cichlids are more plastic than previously proposed,and that studies must account for signal variability within individuals.We propose here that bebavioral variability in signaling is important in determining the communication landscape on which signals are perceived.We review potential complexity deriving from multimodal signaling,discuss the sources for such lability,and suggest ways in which is issue may be approached experimentally.

  8. Genetic basis of continuous variation in the levels and modular inheritance of pigmentation in cichlid fishes.

    Science.gov (United States)

    Albertson, R Craig; Powder, Kara E; Hu, Yinan; Coyle, Kaitlin P; Roberts, Reade B; Parsons, Kevin J

    2014-11-01

    Variation in pigmentation type and levels is a hallmark of myriad evolutionary radiations, and biologists have long been fascinated by the factors that promote and maintain variation in coloration across populations. Here, we provide insights into the genetic basis of complex and continuous patterns of colour variation in cichlid fishes, which offer a vast diversity of pigmentation patterns that have evolved in response to both natural and sexual selection. Specifically, we crossed two divergent cichlid species to generate an F2 mapping population that exhibited extensive variation in pigmentation levels and patterns. Our experimental design is robust in that it combines traditional quantitative trait locus (QTL) analysis with population genomics, which has allowed us to move efficiently from QTL interval to candidate gene. In total, we detected 41 QTL and 13 epistatic interactions that underlie melanocyte- and xanthophore-based coloration across the fins and flanks of these fishes. We also identified 2 QTL and 1 interaction for variation in the magnitude of integration among these colour traits. This finding in particular is notable as there are marked differences both within and between species with respect to the complexity of pigmentation patterns. While certain individuals are characterized by more uniform 'integrated' colour patterns, others exhibit many more degrees of freedom with respect to the distribution of colour 'modules' across the fins and flank. Our data reveal, for the first time, a genetic basis for this difference. Finally, we implicate pax3a as a mediator of continuous variation in the levels of xanthophore-based colour along the cichlid flank.

  9. Integrating cytogenetics and genomics in comparative evolutionary studies of cichlid fish

    Directory of Open Access Journals (Sweden)

    Mazzuchelli Juliana

    2012-09-01

    Full Text Available Abstract Background The availability of a large number of recently sequenced vertebrate genomes opens new avenues to integrate cytogenetics and genomics in comparative and evolutionary studies. Cytogenetic mapping can offer alternative means to identify conserved synteny shared by distinct genomes and also to define genome regions that are still not fine characterized even after wide-ranging nucleotide sequence efforts. An efficient way to perform comparative cytogenetic mapping is based on BAC clones mapping by fluorescence in situ hybridization. In this report, to address the knowledge gap on the genome evolution in cichlid fishes, BAC clones of an Oreochromis niloticus library covering the linkage groups (LG 1, 3, 5, and 7 were mapped onto the chromosomes of 9 African cichlid species. The cytogenetic mapping data were also integrated with BAC-end sequences information of O. niloticus and comparatively analyzed against the genome of other fish species and vertebrates. Results The location of BACs from LG1, 3, 5, and 7 revealed a strong chromosomal conservation among the analyzed cichlid species genomes, which evidenced a synteny of the markers of each LG. Comparative in silico analysis also identified large genomic blocks that were conserved in distantly related fish groups and also in other vertebrates. Conclusions Although it has been suggested that fishes contain plastic genomes with high rates of chromosomal rearrangements and probably low rates of synteny conservation, our results evidence that large syntenic chromosome segments have been maintained conserved during evolution, at least for the considered markers. Additionally, our current cytogenetic mapping efforts integrated with genomic approaches conduct to a new perspective to address important questions involving chromosome evolution in fishes.

  10. Brain structure evolution in a basal vertebrate clade: evidence from phylogenetic comparative analysis of cichlid fishes

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    Kolm Niclas

    2009-09-01

    Full Text Available Abstract Background The vertebrate brain is composed of several interconnected, functionally distinct structures and much debate has surrounded the basic question of how these structures evolve. On the one hand, according to the 'mosaic evolution hypothesis', because of the elevated metabolic cost of brain tissue, selection is expected to target specific structures mediating the cognitive abilities which are being favored. On the other hand, the 'concerted evolution hypothesis' argues that developmental constraints limit such mosaic evolution and instead the size of the entire brain varies in response to selection on any of its constituent parts. To date, analyses of these hypotheses of brain evolution have been limited to mammals and birds; excluding Actinopterygii, the basal and most diverse class of vertebrates. Using a combination of recently developed phylogenetic multivariate allometry analyses and comparative methods that can identify distinct rates of evolution, even in highly correlated traits, we studied brain structure evolution in a highly variable clade of ray-finned fishes; the Tanganyikan cichlids. Results Total brain size explained 86% of the variance in brain structure volume in cichlids, a lower proportion than what has previously been reported for mammals. Brain structures showed variation in pair-wise allometry suggesting some degree of independence in evolutionary changes in size. This result is supported by variation among structures on the strength of their loadings on the principal size axis of the allometric analysis. The rate of evolution analyses generally supported the results of the multivariate allometry analyses, showing variation among several structures in their evolutionary patterns. The olfactory bulbs and hypothalamus were found to evolve faster than other structures while the dorsal medulla presented the slowest evolutionary rate. Conclusion Our results favor a mosaic model of brain evolution, as certain

  11. A COMPARATIVE-STUDY OF STIMULUS SELECTION IN THE FILIAL FOLLOWING RESPONSE OF FRY OF SUBSTRATE SPAWNING CICHLID FISH

    NARCIS (Netherlands)

    BAERENDS, GP

    1993-01-01

    This paper reports on experimental research undertaken to analyse the information processing mechanism by which the fry of substrate spawning cichlid fish visually recognise their guarding parent(s), already from the earliest time they are able to swim. The study is inspired by LORENZ' concept of 'i

  12. Intrasexual competition among females and the stabilization of a conspicuous colour polymorphism in a Lake Victoria cichlid fish

    NARCIS (Netherlands)

    Dijkstra, Peter D.; Seehausen, Ole; Groothuis, Ton G. G.

    2008-01-01

    The maintenance of colour polymorphisms within populations has been a long-standing interest in evolutionary ecology. African cichlid fish contain some of the most striking known cases of this phenomenon. Intrasexual selection can be negative frequency dependent when males bias aggression towards ph

  13. Genetic isolation and morphological divergence mediated by high-energy rapids in two cichlid genera from the lower Congo rapids

    Directory of Open Access Journals (Sweden)

    Stiassny Melanie LJ

    2010-05-01

    Full Text Available Abstract Background It is hypothesized that one of the mechanisms promoting diversification in cichlid fishes in the African Great Lakes has been the well-documented pattern of philopatry along shoreline habitats leading to high levels of genetic isolation among populations. However lake habitats are not the only centers of cichlid biodiversity - certain African rivers also contain large numbers of narrowly endemic species. Patterns of isolation and divergence in these systems have tended to be overlooked and are not well understood. Results We examined genetic and morphological divergence among populations of two narrowly endemic cichlid species, Teleogramma depressum and Lamprologus tigripictilis, from a 100 km stretch of the lower Congo River using both nDNA microsatellites and mtDNA markers along with coordinate-based morphological techniques. In L. tigripictilis, the strongest genetic break was concordant with measurable phenotypic divergence but no morphological disjunction was detected for T. depressum despite significant differentiation at mtDNA and nDNA microsatellite markers. Conclusions The genetic markers revealed patterns of philopatry and estimates of genetic isolation that are among the highest reported for any African cichlid species over a comparable geographic scale. We hypothesize that the high levels of philopatry observed are generated and maintained by the extreme hydrology of the lower Congo River.

  14. Early learning and speciation : the effects of early experience on sexual and aggressive behaviour in Lake Victoria cichlid fish

    NARCIS (Netherlands)

    Verzijden, Machteld Nicolette

    2008-01-01

    The great Lakes of East Africa are inhabited by a great number of haplochromine cichlid species, which form a diverse group in both ecology and nuptial coloration. The large number of sympatrically occuriring closely related species has raised questions about the underlying mechanism for reproductiv

  15. Welfare in horse breeding

    DEFF Research Database (Denmark)

    Campbell, M.L.H.; Sandøe, Peter

    2015-01-01

    Welfare problems related to the way horses are bred, whether by coitus or by the application of artificial reproduction techniques (ARTs), have been given no discrete consideration within the academic literature. This paper reviews the existing knowledge base about welfare issues in horse breeding...... and identifies areas in which data is lacking. We suggest that all methods of horse breeding are associated with potential welfare problems, but also that the judicious use of ARTs can sometimes help to address those problems. We discuss how negative welfare effects could be identified and limited and how...... positive welfare effects associated with breeding might be maximised. Further studies are needed to establish an evidence base about how stressful or painful various breeding procedures are for the animals involved, and what the lifetime welfare implications of ARTs are for future animal generations....

  16. Birds - Breeding [ds60

    Data.gov (United States)

    California Department of Resources — This data set provides access to information gathered on annual breeding bird surveys in California using a map layer developed by the Department. This data layer...

  17. Garlic breeding system innovations

    NARCIS (Netherlands)

    Zheng, S.J.; Kamenetsky, R.; Féréol, L.; Barandiaran, X.; Rabinowitch, H.D.; Chovelon, V.; Kik, C.

    2007-01-01

    This review outlines innovative methods for garlic breeding improvement and discusses the techniques used to increase variation like mutagenesis and in vitro techniques, as well as the current developments in florogenesis, sexual hybridization, genetic transformation and mass propagation. Sexual ste

  18. PRINCIPLES OF ANIMAL BREEDING

    OpenAIRE

    2014-01-01

    University textbook Principles of Animal Breeding is intended for students of agriculture and veterinary medicine. The material is the adapted curricula of undergraduate and graduate level studies in the framework of which the modules Principles of animal breeding as well as Basics of genetics and selection of animals attended are listened. The textbook contains 14 chapters and a glossary of terms. Its concept enables combining fundamental and modern knowledge in the ...

  19. A sensory bias has triggered the evolution of egg-spots in cichlid fishes.

    Directory of Open Access Journals (Sweden)

    Bernd Egger

    Full Text Available Although, generally, the origin of sex-limited traits remains elusive, the sensory exploitation hypothesis provides an explanation for the evolution of male sexual signals. Anal fin egg-spots are such a male sexual signal and a key characteristic of the most species-rich group of cichlid fishes, the haplochromines. Males of about 1500 mouth-brooding species utilize these conspicuous egg-dummies during courtship--apparently to attract females and to maximize fertilization success. Here we test the hypothesis that the evolution of haplochromine egg-spots was triggered by a pre-existing bias for eggs or egg-like coloration. To this end, we performed mate-choice experiments in the basal haplochromine Pseudocrenilabrus multicolor, which manifests the plesiomorphic character-state of an egg-spot-less anal fin. Experiments using computer-animated photographs of males indeed revealed that females prefer images of males with virtual ('in-silico' egg-spots over images showing unaltered males. In addition, we tested for color preferences (outside a mating context in a phylogenetically representative set of East African cichlids. We uncovered a strong preference for yellow, orange or reddish spots in all haplochromines tested and, importantly, also in most other species representing more basal lines. This pre-existing female sensory bias points towards high-quality (carotenoids-enriched food suggesting that it is adaptive.

  20. Assessment of Mercury Bioaccumulation in Zebra Cichlid (Cichlasoma Nigrofasciatum Exposed to Sublethal Concentrations of Permethrin

    Directory of Open Access Journals (Sweden)

    Mahdi Banaee

    2014-12-01

    Full Text Available Background: Aquatic ecosystems are frequently subjected to contamination by toxic heavy metals and pesticides, yet very little is known about the influence of pesticides on bioaccumulation of heavy metals in aquatic organisms. Mercury is a toxic metal with no known biological benefit to organisms. Bioavailability of mercury in aquatic environments depends on biological and non-biological parameters including other pollutants. Therefore, the objectives of this research were to determine the effects of permethrin on bioaccumulation of mercury in zebra cichlid. Methods: Acute toxicity (LC50 of permethrin and mercury chloride was evaluated by estimating mortality in Probit Model in SPSS (version 19.0 IBM. In sub-lethal toxicity, zebra cichlid (Cichlasoma nigrofasciatum was exposed to various concentrations of permethrin (0.0, 0.40, 0.80, 1.20 and 1.60 µg.L-1 combined with 20 µg.L-1 mercury chloride for 15 days. At the end of the experiment, mercury concentrations were measured using ICP-OES-Perkin elmer (optima 7300-DV. Results: 96 h LC50 values of permethrin and mercury for C. nigrofasciatum were calculated to be 17.55 µg.L-1 and 140.38 µg.L-1, respectively. Our results clearly showed that the bioaccumulation of mercury in the specimens increased with increasing concentrations of permethrin to 1.20 and 1.60 µg.L-1. Conclusion: Increasing the concentration of permethrin had synergistic effects on the bioaccumulation of mercury in fish.

  1. Color changing and behavioral context in the Amazonian Dwarf Cichlid Apistogramma hippolytae (Perciformes

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    Raoni Rosa Rodrigues

    Full Text Available Animal coloration has many functions, and fishes are noted among vertebrates for presenting a wide variety of color patterns. Although in marine fishes the relationship between body coloration and behavioral context is well documented, there's not much information about freshwater fishes. Here we describe color patterns displayed by the dwarf cichlid Apistogramma hippolytae and suggest that these patterns are dependent on different social and behavioral settings. Field observations were conducted underwater in a pond in Central Amazonia, Brazil. We recorded six body coloration patterns related to seven different kinds of behavioral activities: foraging, resting, reproductive and agonistic displays, aggression (attacking and fleeing and parental care. Changes in coloration occur rapidly and take only a few seconds. Females on parental care exhibited a unique pattern that are more persistent and probably manifests more slowly. In the shallow and clear waters of the natural environment of this dwarf cichlid, color communication seems to constitute an efficient way to display information about individual mood, social status and reproductive readiness, contributing to minimize loss of energy in unnecessary interactions.

  2. Reproductive behavior and parental roles of the cichlid fish Laetacara araguaiae

    Directory of Open Access Journals (Sweden)

    Fabrício Barreto Teresa

    Full Text Available We described the reproductive behavior of the small South American cichlid Laetacara araguaiae in streams from Brazil. We predicted that this species will show reproductive cooperation and division of labor between males and females in a similar way presented by other substrate-spawner cichlids. Thus, we studied 34 pairs in the pre-spawning (n = 11, egg/wriggler (n = 11 and fry (n = 12 phases. In the pre-spawning phase both sexes become involved in nest building and territorial defense, but females emphasizes building nest (p = 0.03, while males invest more time in territorial defense (p = 0.04. After spawning, male and female alternate between rearing eggs and defending nest in the territory. In the egg/wriggler phase females devotes more time rearing the brood while males remain defending territory (p = 0.02. These differences disappear when young are in the fry stage, and parents jointly stay closer to fry (p = 0.98. However, at this phase, there is a reduction in the frequency of threats shown by males (p<0.01 and an increase in the frequency of attacks shown by female (p<0.01 that could be a response to an increased demand for parental defense. Our results indicate that the reproductive cooperation between males and females of L. araguaiae is marked by division of labor in the early reproductive phases and by sharing of parental duties as brood develops.

  3. The Monogenean Parasite Fauna of Cichlids: A Potential Tool for Host Biogeography

    Directory of Open Access Journals (Sweden)

    Antoine Pariselle

    2011-01-01

    Full Text Available We discuss geographical distribution and phylogeny of Dactylogyridea (Monogenea parasitizing Cichlidae to elucidate their hosts' history. Although mesoparasitic Monogenea (Enterogyrus spp. show typical vicariant distribution, ectoparasitic representatives from different continents are not considered sister taxa, hence their distribution cannot result from vicariance alone. Because of the close host-parasite relationship, this might indicate that present-day cichlid distribution may also reflect dispersal through coastal or brackish waters. Loss of ectoparasites during transoceanic migration, followed by lateral transfer from other fish families might explain extant host-parasite associations. Because of its mesoparasitic nature, hence not subject to salinity variations of the host's environment, Enterogyrus could have survived marine migrations, intolerable for ectoparasites. Host-switches and salinity transitions may be invoked to explain the pattern revealed by a preliminary morphological phylogeny of monogenean genera from Cichlidae and other selected Monogenea genera, rendering the parasite distribution explicable under both vicariance and dispersal. Testable hypotheses are put forward in this parasitological approach to cichlid biogeography. Along with more comprehensive in-depth morphological phylogeny, comparison with molecular data, clarifying dactylogyridean evolution on different continents and from various fish families, and providing temporal information on host-parasite history, are needed to discriminate between the possible scenarios.

  4. Genetic structure of pelagic and littoral cichlid fishes from Lake Victoria.

    Directory of Open Access Journals (Sweden)

    Miyuki Takeda

    Full Text Available The approximately 700 species of cichlids found in Lake Victoria in East Africa are thought to have evolved over a short period of time, and they represent one of the largest known examples of adaptive radiation. To understand the processes that are driving this spectacular radiation, we must determine the present genetic structure of these species and elucidate how this structure relates to the ecological conditions that caused their adaptation. We analyzed the genetic structure of two pelagic and seven littoral species sampled from the southeast area of Lake Victoria using sequences from the mtDNA control region and 12 microsatellite loci as markers. Using a Bayesian model-based clustering method to analyze the microsatellite data, we separated these nine species into four groups: one group composed of pelagic species and another three groups composed mainly of rocky-shore species. Furthermore, we found significant levels of genetic variation between species within each group at both marker loci using analysis of molecular variance (AMOVA, although the nine species often shared mtDNA haplotypes. We also found significant levels of genetic variation between populations within species. These results suggest that initial groupings, some of which appear to have been related to habitat differences, as well as divergence between species within groups took place among the cichlid species of Lake Victoria.

  5. Broiler breeding : breeding goals, selection schemes and the usefulness of local breeds for China

    NARCIS (Netherlands)

    Jiang, X.

    1999-01-01

    This dissertation considers three aspects of broiler breeding: definition of breeding goals, selection schemes for specialized lines, and the usefulness of local breeds for China. Economic values in broiler breeding were derived based on a deterministic model. A systematic design for the application

  6. Breeding-assisted genomics.

    Science.gov (United States)

    Poland, Jesse

    2015-04-01

    The revolution of inexpensive sequencing has ushered in an unprecedented age of genomics. The promise of using this technology to accelerate plant breeding is being realized with a vision of genomics-assisted breeding that will lead to rapid genetic gain for expensive and difficult traits. The reality is now that robust phenotypic data is an increasing limiting resource to complement the current wealth of genomic information. While genomics has been hailed as the discipline to fundamentally change the scope of plant breeding, a more symbiotic relationship is likely to emerge. In the context of developing and evaluating large populations needed for functional genomics, none excel in this area more than plant breeders. While genetic studies have long relied on dedicated, well-structured populations, the resources dedicated to these populations in the context of readily available, inexpensive genotyping is making this philosophy less tractable relative to directly focusing functional genomics on material in breeding programs. Through shifting effort for basic genomic studies from dedicated structured populations, to capturing the entire scope of genetic determinants in breeding lines, we can move towards not only furthering our understanding of functional genomics in plants, but also rapidly improving crops for increased food security, availability and nutrition.

  7. Welfare in horse breeding

    DEFF Research Database (Denmark)

    Campbell, M.L.H.; Sandøe, Peter

    2015-01-01

    Welfare problems related to the way horses are bred, whether by coitus or by the application of artificial reproduction techniques (ARTs), have been given no discrete consideration within the academic literature. This paper reviews the existing knowledge base about welfare issues in horse breeding...... and identifies areas in which data is lacking. We suggest that all methods of horse breeding are associated with potential welfare problems, but also that the judicious use of ARTs can sometimes help to address those problems. We discuss how negative welfare effects could be identified and limited and how...

  8. Travelling to breed

    NARCIS (Netherlands)

    Drent, RJ; Fox, AD; Stahl, J

    2006-01-01

    Traditionally, investigation of the dynamics of avian migration has been heavily biased towards the autumn return trip to the wintering quarters. Since the migratory prelude to breeding has direct fitness consequences, the European Science Foundation recently redressed the balance and sponsored a wo

  9. Breeding kennel management.

    Science.gov (United States)

    Mullen, S

    1992-09-01

    Veterinarians and dog breeders should work together to establish protocols for health care and breeding management that are based on sound scientific principles as well as practical systems. These protocols should involve bitches, stud dogs, and puppies. Tantamount importance must be placed on record keeping so that problems may be identified and solved before they are irreversible.

  10. Penguin breeding in Edinburgh

    NARCIS (Netherlands)

    Gillespie, T.H.; F.R.S.E.,; F.Z.S.,

    1939-01-01

    The Scottish National Zoological Park at Edinburgh has been notably successful in keeping and breeding penguins. It is happy in possessing as a friend and benefactor, Mr Theodore E. Salvesen, head of the firm of Christian Salvesen & Co., Leith, to whose interest and generosity it owes the great numb

  11. Reverse breeding: a novel breeding approach based on engineered meiosis

    NARCIS (Netherlands)

    Dirks, R.; Dun, van K.P.M.; Snoo, de B.; Berg, van den M.; Lelivelt, C.L.C.; Voermans, W.; Woudenberg, L.; Wit, de J.P.C.; Reinink, K.; Schut, J.W.; Jong, de J.H.S.G.M.; Wijnker, T.G.

    2009-01-01

    Reverse breeding (RB) is a novel plant breeding technique designed to directly produce parental lines for any heterozygous plant, one of the most sought after goals in plant breeding. RB generates perfectly complementing homozygous parental lines through engineered meiosis. The method is based on re

  12. A Three-Dimensional Stereotaxic MRI Brain Atlas of the Cichlid Fish Oreochromis mossambicus

    Science.gov (United States)

    Simões, José M.; Teles, Magda C.; Oliveira, Rui F.; Van der Linden, Annemie; Verhoye, Marleen

    2012-01-01

    The African cichlid Oreochromis mossambicus (Mozambique tilapia) has been used as a model system in a wide range of behavioural and neurobiological studies. The increasing number of genetic tools available for this species, together with the emerging interest in its use for neurobiological studies, increased the need for an accurate hodological mapping of the tilapia brain to supplement the available histological data. The goal of our study was to elaborate a three-dimensional, high-resolution digital atlas using magnetic resonance imaging, supported by Nissl staining. Resulting images were viewed and analysed in all orientations (transverse, sagittal, and horizontal) and manually labelled to reveal structures in the olfactory bulb, telencephalon, diencephalon, optic tectum, and cerebellum. This high resolution tilapia brain atlas is expected to become a very useful tool for neuroscientists using this fish model and will certainly expand their use in future studies regarding the central nervous system. PMID:22984463

  13. Nuclear markers reveal that inter-lake cichlids' similar morphologies do not reflect similar genealogy.

    Science.gov (United States)

    Kassam, Daud; Seki, Shingo; Horic, Michio; Yamaoka, Kosaku

    2006-08-01

    The apparent inter-lake morphological similarity among East African Great Lakes' cichlid species/genera has left evolutionary biologists asking whether such similarity is due to sharing of common ancestor or mere convergent evolution. In order to answer such question, we first used Geometric Morphometrics, GM, to quantify morphological similarity and then subsequently used Amplified Fragment Length Polymorphism, AFLP, to determine if similar morphologies imply shared ancestry or convergent evolution. GM revealed that not all presumed morphological similar pairs were indeed similar, and the dendrogram generated from AFLP data indicated distinct clusters corresponding to each lake and not inter-lake morphological similar pairs. Such results imply that the morphological similarity is due to convergent evolution and not shared ancestry. The congruency of GM and AFLP generated dendrograms imply that GM is capable of picking up phylogenetic signal, and thus GM can be potential tool in phylogenetic systematics.

  14. Redescription of Clinostomum phalacrocoracis metacercariae (Digenea: Clinostomidae in cichlids from Lake Kinneret, Israel

    Directory of Open Access Journals (Sweden)

    Caffara Monica

    2014-01-01

    Full Text Available Clinostomidae are digeneans characterized by a complex taxonomic history, continuously under revision based on both morphological and molecular analysis. Among the 14 species considered valid so far Clinostomum phalacrocoracis has been well described only at the adult stage, whereas the morphology of the metacercarial stage has been reported only once. During a parasitological survey carried out on 262 wild cichlids sampled from Lake Kinneret (Israel metacercariae referable to C. phalacrocoracis were found in 18 fingerlings. In this study, we report this clinostomid species for the first time in wild fish from Israel describing the metacercarial stage of Clinostomum phalacrocoracis, coupling its morphological description with molecular analysis carried out on ITS rDNA and COI mtDNA sequences.

  15. Genetic linkage of distinct adaptive traits in sympatrically speciating crater lake cichlid fish

    Science.gov (United States)

    Fruciano, Carmelo; Franchini, Paolo; Kovacova, Viera; Elmer, Kathryn R.; Henning, Frederico; Meyer, Axel

    2016-01-01

    Our understanding of how biological diversity arises is limited, especially in the case of speciation in the face of gene flow. Here we investigate the genomic basis of adaptive traits, focusing on a sympatrically diverging species pair of crater lake cichlid fishes. We identify the main quantitative trait loci (QTL) for two eco-morphological traits: body shape and pharyngeal jaw morphology. These traits diverge in parallel between benthic and limnetic species in the repeated adaptive radiations of this and other fish lineages. Remarkably, a single chromosomal region contains the highest effect size QTL for both traits. Transcriptomic data show that the QTL regions contain genes putatively under selection. Independent population genomic data corroborate QTL regions as areas of high differentiation between the sympatric sister species. Our results provide empirical support for current theoretical models that emphasize the importance of genetic linkage and pleiotropy in facilitating rapid divergence in sympatry. PMID:27597183

  16. Biogeographical implications of Zambezian Cichlidogyrus species (Platyhelminthes: Monogenea: Ancyrocephalidae) parasitizing Congolian cichlids.

    Science.gov (United States)

    Vanhove, Maarten P M; Van Steenberge, Maarten; Dessein, Steven; Volckaert, Filip A M; Snoeks, Jos; Huyse, Tine; Pariselle, Antoine

    2013-01-22

    Fishes normally restricted to inland waters are valuable model systems for historical biogeography, inter alia, because of their limited dispersal abilities and concordance with the distribution patterns of other freshwater taxa (Zogaris et al. 2009). The comparison of fish species assemblages has been the major biogeographical tool for delineating African aquatic ecoregions as the fossil record is often meagre and merely offers complementary information. This is, for example, the case for the Zambezian and Congolian ichthyofaunal provinces, which display substantial contemporary fish diversity (Stewart 2001). Between both regions lies the Bangweulu-Mweru ecoregion (sensu Scott 2005), known for its high percentage of endemicity. Although hydrographically belonging to the Congo Basin, the Bangweulu-Mweru ecoregion has a high affinity with the Zambezi province (Scott 2005), due to historical river connections (Tweddle 2010). Studies comparing the Zambezi and Congo ichthyofaunal provinces are rare and hampered by lack of data from the Congo Basin. The latter harbours more than 1250 fish species (Snoeks et al. 2011) while in the Zambezi, only 120 freshwater fishes are found (Tweddle 2010). Indeed, species richness declines in all major African teleost families from the Congo Basin southwards, riverine haplochromine cichlids forming a notable exception to this rule (Joyce et al. 2005). Although it was hypothesized by Tweddle (2010) that the origin of many Zambezian fish species is in the Congo Basin, the haplochromines Serranochromis Regan, Sargochromis Regan, Pharyngochromis Greenwood and Chetia Trewavas, together forming the serranochromines, have their centre of diversity in the rivers of the Zambezian ichthyofaunal province (Joyce et al. 2005). Therefore, the biogeographical history of Cichlidae across the Zambezi- Congo watershed is not only key to cichlid biogeography on an African scale, but also complementary to biogeography of all other teleosts in the region

  17. Laboratory mating trials indicate incipient speciation by sexual selection among populations of the cichlid fish Pseudotropheus zebra from Lake Malawi.

    Science.gov (United States)

    Knight, Mairi E.; Turner, George F.

    2004-01-01

    It has been suggested that sexual selection may have played a major role in the rapid evolution of hundreds of species of cichlid fishes in Lake Malawi. We report the results of a laboratory test of assortative mating among Lake Malawi cichlid fishes from five closely related geographical populations differing in male courtship colour. Paternity of clutches was tested using microsatellite DNA typing of offspring. Out of 1955 offspring typed, 1296 (66.3%) were sired by the male from the same population as the female, which is more than three times the rate expected if females do not differentiate among males of the different populations (20%). This result indicates that mate preferences of geographical races are strongly differentiated, consistent with the races representing incipient geographical species diverging under sexual selection exerted by female preferences for different male courtship colours. PMID:15209099

  18. Phylogeography, colonization and population history of the Midas cichlid species complex (Amphilophus spp. in the Nicaraguan crater lakes

    Directory of Open Access Journals (Sweden)

    Meyer Axel

    2010-10-01

    Full Text Available Abstract Background Elucidation of the mechanisms driving speciation requires detailed knowledge about the phylogenetic relationships and phylogeography of the incipient species within their entire ranges as well as their colonization history. The Midas cichlid species complex Amphilophus spp. has been proven to be a powerful model system for the study of ecological specialization, sexual selection and the mechanisms of sympatric speciation. Here we present a comprehensive and integrative phylogeographic analysis of the complete Midas Cichlid species complex in Nicaragua (> 2000 individuals covering the entire distributional range, using two types of molecular markers (the mitochondrial DNA control region and 15 microsatellites. We investigated the majority of known lake populations of this species complex and reconstructed their colonization history in order to distinguish between alternative speciation scenarios. Results We found that the large lakes contain older and more diverse Midas Cichlid populations, while all crater lakes hold younger and genetically less variable species assemblages. The large lakes appear to have repeatedly acted as source populations for all crater lakes, and our data indicate that faunal exchange among crater lakes is extremely unlikely. Despite their very recent (often only a few thousand years old and common origin from the two large Nicaraguan lakes, all crater lake Midas Cichlid radiations underwent independent, but parallel, evolution, and comprise distinct genetic units. Indeed several of these crater lakes contain multiple genetically distinct incipient species that most likely arose through sympatric speciation. Several crater lake radiations can be traced back to a single ancestral line, but some appear to have more than one founding lineage. The timing of the colonization(s of each crater lake differs, although most of them occurred more (probably much more recently than 20,000 years ago. Conclusion The

  19. Antipredator responses by native mosquitofish to non-native cichlids: An examination of the role of prey naiveté

    Science.gov (United States)

    Rehage, Jennifer S.; Dunlop, Katherine L.; Loftus, William F.

    2009-01-01

    The strong impact of non-native predators in aquatic systems is thought to relate to the evolutionary naiveté of prey. Due to isolation and limited dispersal, this naiveté may be relatively high in freshwater systems. In this study, we tested this notion by examining the antipredator response of native mosquitofish, Gambusia holbrooki, to two non-native predators found in the Everglades, the African jewelfish,Hemichromis letourneuxi, and the Mayan cichlid, Cichlasoma urophthalmus. We manipulated prey naiveté by using two mosquitofish populations that varied in their experience with the recent invader, the African jewelfish, but had similar levels of experience with the longer-established Mayan cichlid. Specifically, we tested these predictions: (1) predator hunting modes differed between the two predators, (2) predation rates would be higher by the novel jewelfish predator, (3) particularly on the naive population living where jewelfish have not invaded yet, (4) antipredator responses would be stronger to Mayan cichlids due to greater experience and weaker and/or ineffective to jewelfish, and (5) especially weakest by the naive population. We assayed prey and predator behavior, and prey mortality in lab aquaria where both predators and prey were free-ranging. Predator hunting modes and habitat domains differed, with jewelfish being more active search predators that used slightly higher parts of the water column and less of the habitat structure relative to Mayan cichlids. In disagreement with our predictions, predation rates were similar between the two predators, antipredator responses were stronger to African jewelfish (except for predator inspections), and there was no difference in response between jewelfish-savvy and jewelfish-naive populations. These results suggest that despite the novelty of introduced predators, prey may be able to respond appropriately if non-native predator archetypes are similar enough to those of native predators, if prey rely

  20. Dealing with food and eggs in mouthbrooding cichlids: structural and functional trade-offs in fitness related traits.

    Directory of Open Access Journals (Sweden)

    Tim Tkint

    Full Text Available BACKGROUND: As in any vertebrate, heads of fishes are densely packed with functions. These functions often impose conflicting mechanical demands resulting in trade-offs in the species-specific phenotype. When phenotypical traits are linked to gender-specific parental behavior, we expect sexual differences in these trade-offs. This study aims to use mouthbrooding cichlids as an example to test hypotheses on evolutionary trade-offs between intricately linked traits that affect different aspects of fitness. We focused on the oral apparatus, which is not only equipped with features used to feed and breathe, but is also used for the incubation of eggs. We used this approach to study mouthbrooding as part of an integrated functional system with diverging performance requirements and to explore gender-specific selective environments within a species. METHODOLOGY/PRINCIPAL FINDINGS: Because cichlids are morphologically very diverse, we hypothesize that the implications of the added constraint of mouthbrooding will primarily depend on the dominant mode of feeding of the studied species. To test this, we compared the trade-off for two maternal mouthbrooding cichlid species: a "suction feeder" (Haplochromis piceatus and a "biter" (H. fischeri. The comparison of morphology and performance of both species revealed clear interspecific and intersex differences. Our observation that females have larger heads was interpreted as a possible consequence of the fact that in both the studied species mouthbrooding is done by females only. As hypothesized, the observed sexual dimorphism in head shape is inferred as being suboptimal for some aspects of the feeding performance in each of the studied species. Our comparison also demonstrated that the suction feeding species had smaller egg clutches and more elongated eggs. CONCLUSIONS/SIGNIFICANCE: Our findings support the hypothesis that there is a trade-off between mouthbrooding and feeding performance in the two

  1. The African cichlid fish Astatotilapia burtoni uses acoustic communication for reproduction: sound production, hearing, and behavioral significance.

    Science.gov (United States)

    Maruska, Karen P; Ung, Uyhun S; Fernald, Russell D

    2012-01-01

    Sexual reproduction in all animals depends on effective communication between signalers and receivers. Many fish species, especially the African cichlids, are well known for their bright coloration and the importance of visual signaling during courtship and mate choice, but little is known about what role acoustic communication plays during mating and how it contributes to sexual selection in this phenotypically diverse group of vertebrates. Here we examined acoustic communication during reproduction in the social cichlid fish, Astatotilapia burtoni. We characterized the sounds and associated behaviors produced by dominant males during courtship, tested for differences in hearing ability associated with female reproductive state and male social status, and then tested the hypothesis that female mate preference is influenced by male sound production. We show that dominant males produce intentional courtship sounds in close proximity to females, and that sounds are spectrally similar to their hearing abilities. Females were 2-5-fold more sensitive to low frequency sounds in the spectral range of male courtship sounds when they were sexually-receptive compared to during the mouthbrooding parental phase. Hearing thresholds were also negatively correlated with circulating sex-steroid levels in females but positively correlated in males, suggesting a potential role for steroids in reproductive-state auditory plasticity. Behavioral experiments showed that receptive females preferred to affiliate with males that were associated with playback of courtship sounds compared to noise controls, indicating that acoustic information is likely important for female mate choice. These data show for the first time in a Tanganyikan cichlid that acoustic communication is important during reproduction as part of a multimodal signaling repertoire, and that perception of auditory information changes depending on the animal's internal physiological state. Our results highlight the

  2. The use of multiple sources of social information in contest behavior: testing the social cognitive abilities of a cichlid fish

    OpenAIRE

    Takashi eHotta; Tomohiro eTakeyama; Dik eHeg; Satoshi eAwata; Lyndon Alexander Jordan; Masanori eKohda

    2015-01-01

    Theory suggests that living in large social groups with dynamic social interactions often favours the evolution of enhanced cognitive abilities. Studies of how animals assess their own contest ability commonly focus on a single cognitive task, and little is known about the diversity or co-occurrence of cognitive abilities in social species. We examined how a highly social cichlid fish Julidochromis transcriptus uses four major cognitive abilities in contest situations; direct experience, winn...

  3. A high-resolution map of the Nile tilapia genome: a resource for studying cichlids and other percomorphs.

    OpenAIRE

    Guyon, Richard; Rakotomanga, Michaëlle; Azzouzi, Naoual; Coutanceau, Jean-Pierre; Bonillo, Celine; D'Cotta, Helena; Pepey, Elodie; Soler, Lucile; Rodier-Goud, Marguerite; D'Hont, Angélique; Conte, Matthew,; Van Bers, Nikkie; Penman, David,; Hitte, Christophe; Crooijmans, Richard

    2012-01-01

    International audience; ABSTRACT: BACKGROUND: The Nile tilapia (Oreochromis niloticus) is the second most farmed fish species worldwide. Itis also an important model for studies of fish physiology, particularly because of its broadtolerance to an array of environments. It is a good model to study evolutionary mechanismsin vertebrates, because of its close relationship to haplochromine cichlids, which haveundergone rapid speciation in East Africa. The existing genomic resources for Nile tilapi...

  4. A high-resolution map of the Nile tilapia genome: a resource for studying cichlids and other percomorphs.

    OpenAIRE

    Guyon Richard; Rakotomanga Michaelle; Azzouzi Naoual; Coutanceau Jean Pierre; Bonillo Celine; D’Cotta Helena; Pepey Elodie; Soler Lucile; Rodier-Goud Marguerite; D’Hont Angelique; Conte Matthew A; van Bers Nikkie EM; Penman David J; Hitte Christophe; Crooijmans Richard PMA

    2012-01-01

    Abstract Background The Nile tilapia (Oreochromis niloticus) is the second most farmed fish species worldwide. It is also an important model for studies of fish physiology, particularly because of its broad tolerance to an array of environments. It is a good model to study evolutionary mechanisms in vertebrates, because of its close relationship to haplochromine cichlids, which have undergone rapid speciation in East Africa. The existing genomic resources for Nile tilapia include a genetic ma...

  5. A high-resolution map of the Nile tilapia genome: a resource for studying cichlids and other percomorphs

    OpenAIRE

    Guyon, Richard; Rakotomanga, Michaelle; Azzouzi, Naoual; Coutanceau, Jean Pierre; Bonillo, Celine; D’Cotta, Helena; Pepey, Elodie; Soler, Lucile; Rodier-Goud, Marguerite; D’Hont, Angelique; Conte, Matthew A; van Bers, Nikkie EM; Penman, David J.; Hitte, Christophe; Crooijmans, Richard Pma

    2012-01-01

    Background The Nile tilapia (Oreochromis niloticus) is the second most farmed fish species worldwide. It is also an important model for studies of fish physiology, particularly because of its broad tolerance to an array of environments. It is a good model to study evolutionary mechanisms in vertebrates, because of its close relationship to haplochromine cichlids, which have undergone rapid speciation in East Africa. The existing genomic resources for Nile tilapia include a genetic map, BAC en...

  6. A high-resolution map of the Nile tilapia genome: a resource for studying cichlids and other percomorphs

    OpenAIRE

    Guyon, Richard; Rakotomanga, Michaëlle; Azzouzi, Naoual; Coutanceau, Jean-Pierre; Bonillo, Celine; D'Cotta, Helena; Pepey, Elodie; Soler, Lucile; Rodier-Goud, Marguerite; D'Hont, Angélique; Conte, Matthew,; Van Bers, Nikkie; Penman, David,; Hitte, Christophe; Crooijmans, Richard P M A

    2012-01-01

    BACKGROUND: The Nile tilapia (Oreochromis niloticus) is the second most farmed fish species worldwide. Itis also an important model for studies of fish physiology, particularly because of its broadtolerance to an array of environments. It is a good model to study evolutionary mechanismsin vertebrates, because of its close relationship to haplochromine cichlids, which haveundergone rapid speciation in East Africa. The existing genomic resources for Nile tilapiainclude a genetic map, BAC end se...

  7. Shaping development through mechanical strain: the transcriptional basis of diet-induced phenotypic plasticity in a cichlid fish.

    Science.gov (United States)

    Gunter, Helen M; Fan, Shaohua; Xiong, Fan; Franchini, Paolo; Fruciano, Carmelo; Meyer, Axel

    2013-09-01

    Adaptive phenotypic plasticity, the ability of an organism to change its phenotype to match local environments, is increasingly recognized for its contribution to evolution. However, few empirical studies have explored the molecular basis of plastic traits. The East African cichlid fish Astatoreochromis alluaudi displays adaptive phenotypic plasticity in its pharyngeal jaw apparatus, a structure that is widely seen as an evolutionary key innovation that has contributed to the remarkable diversity of cichlid fishes. It has previously been shown that in response to different diets, the pharyngeal jaws change their size, shape and dentition: hard diets induce an adaptive robust molariform tooth phenotype with short jaws and strong internal bone structures, while soft diets induce a gracile papilliform tooth phenotype with elongated jaws and slender internal bone structures. To gain insight into the molecular underpinnings of these adaptations and enable future investigations of the role that phenotypic plasticity plays during the formation of adaptive radiations, the transcriptomes of the two divergent jaw phenotypes were examined. Our study identified a total of 187 genes whose expression differs in response to hard and soft diets, including immediate early genes, extracellular matrix genes and inflammatory factors. Transcriptome results are interpreted in light of expression of candidate genes-markers for tooth size and shape, bone cells and mechanically sensitive pathways. This study opens up new avenues of research at new levels of biological organization into the roles of phenotypic plasticity during speciation and radiation of cichlid fishes.

  8. More than Meets the Eye: Functionally Salient Changes in Internal Bone Architecture Accompany Divergence in Cichlid Feeding Mode

    Directory of Open Access Journals (Sweden)

    R. Craig Albertson

    2012-01-01

    Full Text Available African cichlids have undergone extensive and repeated adaptive radiations in foraging habitat. While the external morphology of the cichlid craniofacial skeleton has been studied extensively, biomechanically relevant changes to internal bone architecture have been largely overlooked. Here we explore two fundamental questions: (1 Do changes in the internal architecture of bone accompany shifts in foraging mode? (2 What is the genetic basis for this trait? We focus on the maxilla, which is an integral part of the feeding apparatus and an element that should be subjected to significant bending forces during biting. Analyses of μCT scans revealed clear differences between the maxilla of two species that employ alternative foraging strategies (i.e., biting versus suction feeding. Hybrids between the two species exhibit maxillary geometries that closely resemble those of the suction feeding species, consistent with a dominant mode of inheritance. This was supported by the results of a genetic mapping experiment, where suction feeding alleles were dominant to biting alleles at two loci that affect bone architecture. Overall, these data suggest that the internal structure of the cichlid maxilla has a tractable genetic basis and that discrete shifts in this trait have accompanied the evolution of alternate feeding modes.

  9. Phylogenetic relationships of Middle American cichlids (Cichlidae, Heroini) based on combined evidence from nuclear genes, mtDNA, and morphology.

    Science.gov (United States)

    Rícan, Oldrich; Zardoya, Rafael; Doadrio, Ignacio

    2008-12-01

    Heroine cichlids are the second largest and very diverse tribe of Neotropical cichlids, and the only cichlid group that inhabits Mesoamerica. The taxonomy of heroines is complex because monophyly of most genera has never been demonstrated, and many species groups are without applicable generic names after their removal from the catch-all genus Cichlasoma (sensu Regan, 1905). Hence, a robust phylogeny for the group is largely wanting. A rather complete heroine phylogeny based on cytb sequence data is available [Concheiro Pérez, G.A., Rícan O., Ortí G., Bermingham, E., Doadrio, I., Zardoya, R. 2007. Phylogeny and biogeography of 91 species of heroine cichlids (Teleostei: Cichlidae) based on sequences of the cytochrome b gene. Mol. Phylogenet. Evol. 43, 91-110], and in the present study, we have added and analyzed independent data sets (nuclear and morphological) to further confirm and strengthen the cytb-phylogenetic hypothesis. We have analyzed a combined cytb-nuclear (RAG1 and two S7 introns) data set of 48 species representing main heroine lineages to achieve further resolution of heroine higher taxonomic levels and a combined cytb-morphological data set of 92 species to stabilize generic taxonomy. The recovered phylogenies supported the circumamazonian--CAM--Heroini (sensu Concheiro Peréz et al., 2007) as a monophyletic group, that could be divided into six main clades: (1) australoheroines (the southernmost heroine genus Australoheros), (2) nandopsines (the Antillean genus Nandopsis), (3) caquetaines (including the north western Amazonian genera Caquetaia and Heroina), (4) astatheroines (including Astatheros, Herotilapia and Rocio), (5) amphilophines (including Amphilophus and related genera), and (6) herichthyines (including Herichthyis and related genera). Nuclear and mitochondrial data partitions arrived at highly congruent topologies. Suprageneric relationships were influenced mainly by the nuclear signal, as well as the most basal phylogenetic position

  10. The function of anal fin egg-spots in the cichlid fish Astatotilapia burtoni.

    Directory of Open Access Journals (Sweden)

    Anya Theis

    Full Text Available Color and pigmentation patterns of animals are often targets of sexual selection because of their role in communication. Although conspicuous male traits are typically implicated with intersexual selection, there are examples where sex-specific displays play a role in an intrasexual context, e.g. when they serve as signals for aggression level and/or status. Here, we focus on the function of a conspicuous male ornament in the most species-rich tribe of cichlid fishes, the haplochromines. A characteristic feature of these ca. 1500 species are so-called egg-spots in form of ovoid markings on the anal fins of males, which are made up of carotenoid based pigment cells. It has long been assumed that these yellow, orange or reddish egg-spots play an important role in the courtship and spawning behavior of these maternal mouth-brooding fishes by mimicking the eggs of a conspecific female. The exact function of egg-spots remains unknown, however, and there are several hypotheses about their mode of action. To uncover the function of this cichlid-specific male ornament, we used female mate choice experiments and a male aggression test in the haplochromine species Astatotilapia burtoni. We manipulated the number and arrangement of egg-spots on the anal fins of males, or removed them entirely, and tested (1 female preference with visual contact only using egg-traps, (2 female preference with free contact using paternity testing with microsatellites and (3 male aggression. We found that females did not prefer males with many egg-spots over males with fewer egg-spots and that females tended to prefer males without egg-spots over males with egg-spots. Importantly, males without egg-spots sired clutches with the same fertilization rate as males with egg-spots. In male aggression trials, however, males with fewer egg-spots received significantly more attacks, suggesting that egg-spots are an important signal in intrasexual communication.

  11. Radiation mutation breeding

    Energy Technology Data Exchange (ETDEWEB)

    Song, Hi Sup; Kim, Jae Sung; Kim, Jin Kyu; Shin, In Chul; Lim, Young Taek

    1998-04-01

    In order to develop an advanced technical knowledge for the selection of better mutants, some of the crops were irradiated and the mutation rate, the survival rate and the method for selction of a mutant were studied. Furthermore, this study aimed to obtain basic data applicable to the development of genetic resources by evaluation and analysis the specific character for selection of the superior mutant and its plant breeding. 1. selection of the mutant with a superior resistance against environment in the principal crops 1) New varieties of mutant rices such as Wonpyeongbyeo, Wongwangbyeo, Winmibyeo, and heogseon chalbeyeo (sticky forma) were registered in the national variety list and made an application to crop variety protection right. They are under review now. 2) We also keep on studying on the number of a grain of 8 lines of excellent mutant rice for the purpose of improvement of breeding . 3) We selected 3 lines which have a resistance to pod and stem blight in large soybean, 31 lines with small grain size and higher yield, 112 lines of soybean of cooking, 7 lines of low lipoxygenase content, and 12 lines with decreased phytic acid content by 20 % compared to the previous level. 2. Selection of advanced Mugunwha (Rose of Sharon) mutant 1) Bagseul, a new variety of mutant, was developed and 30 plantlets of it are being proliferated. 2) Fifty-three lines of a mutant having a various morphologies were selected.

  12. Gross morphology and histology of the alimentary tract of the convict cichlid Amatitlania nigrofasciata.

    Science.gov (United States)

    Hopperdietzel, C; Hirschberg, R M; Hünigen, H; Wolter, J; Richardson, K; Plendl, J

    2014-11-01

    The primary objectives of this study were to document the macroscopic and histological structure of the alimentary tract (AT) of the convict cichlid Amatitlania nigrofasciata, because there are no data available for this omnivorous freshwater fish of the family Cichlidae. The morphology of the AT of A. nigrofasciata resembles that of related species. While having morphological criteria of the AT typical of most omnivorous fishes, such as a blind sac stomach and medium length intestine, A. nigrofasciata also has some structural peculiarities: the oesophagus is lined by a uniform stratified squamous epithelial layer with interspersed goblet cells along its entire length. Additionally, it has well-developed layers of the tunica muscularis including muscle fibre bundles that ascend into its mucosal folds. Occasionally, taste buds are present. In the transitional area between oesophagus and stomach, a prominent torus-like closure device is present. The mucosa of the stomach cannot be divided into different regions according to mucosal and morphological properties. The simple pattern of intestinal loops of A. nigrofasciata has few variations, irrespective of sex, mass and length of the individual fish. The first segment of the intestine is characterized by the largest mucososerosal ratio and the most complex mucosal surface architecture. A distinction of midgut and hindgut was not possible in A. nigrofasciata due to lack of defining structural components as described for other fish species.

  13. Guanine-based structural coloration as an indicator of oxidative stress in a cichlid fish.

    Science.gov (United States)

    Cahn, Matthew D; Brown, Alexandria C; Clotfelter, Ethan D

    2015-07-01

    Vertebrate pigmentation is known to be influenced by oxidative stress, but few studies have tested the hypothesis that structural coloration can be similarly affected. We tested whether fish iridophores, which produce structural color using guanine stacks, might be affected by the prooxidant-antioxidant balance of the animal. Specifically, we hypothesized that convict cichlids (Amatitlania nigrofasciata) metabolize guanine present in iridophores to uric acid, an antioxidant, in response to oxidative damage. We used Hunter's contrast gloss and high performance liquid chromatography to determine whether dietary guanine supplementation allows fish to maintain their structural coloration despite oxidative stress induced via ultraviolet-B (UV-B) radiation. We found that dietary guanine was associated with greater skin gloss, and that exposure to UV-B light reduced glossiness. UV-B exposure did not increase oxidative damage (acrolein) or total antioxidant capacity in the skin or liver. Our experiment did not detect effects of dietary guanine or UV-B light on uric acid, but uric acid was positively related to antioxidant capacity. Our results support the hypothesis that structural color in fish may be altered by environmental stressors such as exposure to UV light, and highlight the need for future studies to consider the role of iridophores in condition-dependent visual signaling.

  14. Quantifying mating success of territorial males and sneakers in a bower-building cichlid fish

    Science.gov (United States)

    Magalhaes, I. S.; Smith, A. M.; Joyce, D. A.

    2017-01-01

    The strategies and traits males evolve to mate with females are incredible in their diversity. Theory on the evolution of secondary sexual characters suggests that evolving any costly trait or strategy will pay off and stabilise in the population if it is advantageous compared to the alternative less costly strategy, but quantifying the relative success of the two can be difficult. In Lake Malawi, Africa, there are >200 species of cichlid fish in which the males form leks and spend several weeks per year building sand-castle “bowers” several times their size. We tested the idea that a less costly “sneaking” strategy could be successful by quantifying the mating success of bower-holding versus non-bower-holding males. We PIT-tagged every fish in a semi-natural experimental set-up and placed tag-readers on the side of bowers to determine which fish held a bower. We then genotyped the eggs removed from females’ mouths to assign paternity of each egg. Broods were fathered by up to 3 different males. Although paternity was mostly assigned to males that held a bower, a small number of males who did not own a bower were more successful than some of those that did, indicating a role for an alternative strategy in these bower builders. PMID:28128313

  15. Reproductive-tactic-specific variation in sperm swimming speeds in a shell-brooding cichlid.

    Science.gov (United States)

    Fitzpatrick, J L; Desjardins, J K; Milligan, N; Montgomerie, R; Balshine, S

    2007-08-01

    Theory predicts that males experiencing elevated levels of sperm competition will invest more in gonads and produce faster-swimming sperm. Although there is ample evidence in support of the first prediction, few studies have examined sperm swimming speed in relation to sperm competition. In this study, we tested these predictions from sperm competition theory by examining sperm characteristics in Telmatochromis vittatus, a small shell-brooding cichlid fish endemic to Lake Tanganyika. Males exhibit four different reproductive tactics: pirate, territorial, satellite, and sneaker. Pirate males temporarily displace all other competing males from a shell nest, whereas sneaker males always release sperm in the presence of territorial and satellite males. Due to the fact that sneakers spawn in the presence of another male, sneakers face the highest levels of sperm competition and pirates the lowest, whereas satellites and territorials experience intermediate levels. In accordance with predictions, sperm from sneakers swam faster than sperm from males adopting the other reproductive tactics, whereas sperm from pirates was slowest. Interestingly, we were unable to detect any variation in sperm tail length among these reproductive tactics. Thus, sperm competition appears to have influenced sperm energetics in this species without having any influence on sperm size.

  16. Territorial males can sire more offspring in nests with smaller doors in the cichlid Lamprologus lemairii.

    Science.gov (United States)

    Ota, Kazutaka; Awata, Satoshi; Morita, Masaya; Yokoyama, Ryota; Kohda, Masanori

    2014-01-01

    To examine how territorial males counter reproductive parasites, we examined the paternity of broods guarded by territorial males using 5 microsatellite loci and factors that determine siring success in a wild population of the Lake Tanganyika cichlid Lamprologus lemairii. Females enter rock holes (nests) and spawn inside, and territorial males release milt over the nest openings. Sneakers attempt to dart into the nests, but territorial males often interrupt the attempt. The body size of territorial males (territorial defense ability) and the size of nest opening (the ability to prevent sneakers from nest intrusions) are predicted to be factors that affect paternity at the premating stage, whereas milt quality traits are factors that affect paternity at the postmating stage. Parentage analyses of 477 offspring revealed that most clutches have few or no cuckolders, and territorial males sired >80% of eggs in 7 of the 10 analyzed clutches. Larger territorial males that spawned in nests with narrower openings had greater siring success. In contrast, none of the milt traits affected the siring success. These suggest that territorial male L. lemairii adopt premating strategies whereby they effectively prevent reproductive parasitism.

  17. Quantifying mating success of territorial males and sneakers in a bower-building cichlid fish.

    Science.gov (United States)

    Magalhaes, I S; Smith, A M; Joyce, D A

    2017-01-27

    The strategies and traits males evolve to mate with females are incredible in their diversity. Theory on the evolution of secondary sexual characters suggests that evolving any costly trait or strategy will pay off and stabilise in the population if it is advantageous compared to the alternative less costly strategy, but quantifying the relative success of the two can be difficult. In Lake Malawi, Africa, there are >200 species of cichlid fish in which the males form leks and spend several weeks per year building sand-castle "bowers" several times their size. We tested the idea that a less costly "sneaking" strategy could be successful by quantifying the mating success of bower-holding versus non-bower-holding males. We PIT-tagged every fish in a semi-natural experimental set-up and placed tag-readers on the side of bowers to determine which fish held a bower. We then genotyped the eggs removed from females' mouths to assign paternity of each egg. Broods were fathered by up to 3 different males. Although paternity was mostly assigned to males that held a bower, a small number of males who did not own a bower were more successful than some of those that did, indicating a role for an alternative strategy in these bower builders.

  18. As clear as mud: Turbidity induces behavioral changes in the African cichlid Pseudocrenilabrus multicolor

    Directory of Open Access Journals (Sweden)

    Suzanne M. GRAY, Laura H. McDONNELL, Fabio G. CINQUEMANI,Lauren J. CHAPMAN

    2012-02-01

    Full Text Available Aquatic biodiversity is being lost at an unprecedented rate. One factor driving this loss is increased turbidity, an environmental stressor that can impose behavioral, morphological, and/or physiological costs on fishes. Here we describe the behavioral response of a widespread African cichlid, Pseudocrenilabrus multicolor victoriae, to turbidity. We used a split-brood rearing design to test if F1 offspring reared in turbid water, originating from river (turbid and swamp (clear populations, behave differently than full-sibs reared in clear water. We examined two facets of behavior: (1 behaviors of fish in full sib groups, including activity level and social dynamics collected during the rearing period; and (2 male aggressive behavior directed at potential male competitors after fish had reached maturity; this was done in an experimental set-up independent of the rearing aquaria. Regardless of population of origin, fish reared in turbid water were marginally less active and performed fewer social behaviors than those reared in clear water. On the other hand, when tested against a competitor in turbid water, males performed more aggressive behaviors, regardless of population of origin or rearing environment. Our results suggest a plastic behavioral response to turbidity that may allow P. multicolor to persist over a range of turbidity levels in nature by decreasing activity and general social behaviors and intensifying reproductive behaviors to ensure reproductive success [Current Zoology 58 (1: 146–157, 2012].

  19. Male mate choice scales female ornament allometry in a cichlid fish

    Directory of Open Access Journals (Sweden)

    Kullmann Harald

    2010-10-01

    Full Text Available Abstract Background Studies addressing the adaptive significance of female ornamentation have gained ground recently. However, the expression of female ornaments in relation to body size, known as trait allometry, still remains unexplored. Here, we investigated the allometry of a conspicuous female ornament in Pelvicachromis taeniatus, a biparental cichlid that shows mutual mate choice and ornamentation. Females feature an eye-catching pelvic fin greatly differing from that of males. Results We show that allometry of the female pelvic fin is scaled more positively in comparison to other fins. The pelvic fin exhibits isometry, whereas the other fins (except the caudal fin show negative allometry. The size of the pelvic fin might be exaggerated by male choice because males prefer female stimuli that show a larger extension of the trait. Female pelvic fin size is correlated with individual condition, suggesting that males can assess direct and indirect benefits. Conclusions The absence of positive ornament allometry might be a result of sexual selection constricted by natural selection: fins are related to locomotion and thus may be subject to viability selection. Our study provides evidence that male mate choice might scale the expression of a female sexual ornament, and therefore has implications for the understanding of the relationship of female sexual traits with body size in species with conventional sex-roles.

  20. Chromosomal distribution of microsatellite repeats in Amazon cichlids genome (Pisces, Cichlidae).

    Science.gov (United States)

    Schneider, Carlos Henrique; Gross, Maria Claudia; Terencio, Maria Leandra; de Tavares, Édika Sabrina Girão Mitozo; Martins, Cesar; Feldberg, Eliana

    2015-01-01

    Fish of the family Cichlidae are recognized as an excellent model for evolutionary studies because of their morphological and behavioral adaptations to a wide diversity of explored ecological niches. In addition, the family has a dynamic genome with variable structure, composition and karyotype organization. Microsatellites represent the most dynamic genomic component and a better understanding of their organization may help clarify the role of repetitive DNA elements in the mechanisms of chromosomal evolution. Thus, in this study, microsatellite sequences were mapped in the chromosomes of Cichla monoculus Agassiz, 1831, Pterophyllum scalare Schultze, 1823, and Symphysodon discus Heckel, 1840. Four microsatellites demonstrated positive results in the genome of Cichla monoculus and Symphysodon discus, and five demonstrated positive results in the genome of Pterophyllum scalare. In most cases, the microsatellite was dispersed in the chromosome with conspicuous markings in the centromeric or telomeric regions, which suggests that sequences contribute to chromosome structure and may have played a role in the evolution of this fish family. The comparative genome mapping data presented here provide novel information on the structure and organization of the repetitive DNA region of the cichlid genome and contribute to a better understanding of this fish family's genome.

  1. As clear as mud: Turbidity induces behavioral changes in the African cichlid Pseudocrenilabrus multicolor

    Institute of Scientific and Technical Information of China (English)

    Suzanne M. GRAY; Laura H. McDONNELL; Fabio G. CINQUEMANI; Lauren J. CHAPMAN

    2012-01-01

    Aquatic biodiversity is being lost at an unprecedented rate.One factor driving this loss is increased turbidity,an environmental stressor that can impose behavioral,morphological,and/or physiological costs on fishes.Here we describe the behavioral response of a widespread African cichlid,Pseudocrenilabrus multicolor victoriae,to turbidity.We used a split-brood rearing design to test if F1 offspring reared in turbid water,originating from river (turbid) and swamp (clear) populations,behave differently than full-sibs reared in clear water.We examined two facets of behavior:(1) behaviors of fish in full sib groups,including activity level and social dynamics collected during the rearing period; and (2) male aggressive behavior directed at potential male competitors after fish had reached maturity; this was done in an experimental set-up independent of the rearing aquaria.Regardless of population of origin,fish reared in turbid water were marginally less active and performed fewer social behaviors than those reared in clear water.On the other hand,when tested against a competitor in turbid water,males performed more aggressive behaviors,regardless of population of origin or rearing environment.Our results suggest a plastic behavioral response to turbidity that may allow P multicolor to persist over a range of turbidity levels in nature by decreasing activity and general social behaviors and intensifying reproductive behaviors to ensure reproductive success [ Current Zoology 58 (1):146-157,2012].

  2. Effect of mate size on maternal reproductive effort in the convict cichlid Amatitlania siquia

    Institute of Scientific and Technical Information of China (English)

    Ashley R. ROBART

    2012-01-01

    The differential allocation hypothesis predicts individuals will increase their reproductive investment when mated to a high quality partner.In many species of fish with biparental care females prefer large males due to the males' greater ability to raise more offspring to independence.I examined the relationship between mate quality,parental care and number of offspring in a natural population of convict cichlids Amatitlania siquia.The frequency of frontal displays by females was positively correlated with male standard length.Additionally,as males increased in length relative to their mate,females increased the frequency of chases towards predators,while males decreased the number of displays towards brood predators.This trade-off in parental effort within a pair due to mate quality is a key prediction of differential allocation.The number of offspring was correlated with male,but not female,standard length.These results support the differential allocation hypothesis in that females offered more parental care to offspring of a larger male,while their mates decreased the amount of care they provided.Additionally,females benefited in terms of number of offspring by pairing with higher quality mates.Increased female investment may provide an incentive to ensure male care and maintain pair bonding,which could lead to greater reproductive success through increased offspring survival [Current Zoology 58 (1):66-72,2012].

  3. Symmetry perception in bamboo sharks (Chiloscyllium griseum) and Malawi cichlids (Pseudotropheus sp.).

    Science.gov (United States)

    Schluessel, V; Beil, O; Weber, T; Bleckmann, H

    2014-09-01

    Several species have been shown to perceive symmetry as a measure of superior genetic quality, useful for assessing potential mates or mediating other visual activities such as the selection of food sources. The current study assessed whether Pseudotropheus sp. and Chiloscyllium griseum, two fish species from distantly related groups, possess symmetry perception. In alternative two choice experiments, individuals were tested for spontaneous preferences and trained to discriminate between abstract symmetrical and asymmetrical stimulus pairs. Pair discriminations were followed by extensive categorization experiments. Transfer tests elucidated whether bilaterally symmetrical and rotationally symmetrical stimuli could be distinguished. Sharks were also tested for the degree of dissimilarity between two symbols that could still be detected. While sharks showed both a spontaneous preference for symmetry as well as remarkable discrimination abilities by succeeding in all of the presented tasks, cichlids showed no spontaneous preference, had difficulties in discriminating between symbols and performed poorly in the categorization experiments. Sharks distinguished between bilaterally and rotationally symmetrical stimuli and easily differentiated between a four-armed cross (all arms 90° apart) and a cross where one of the arms was only 45° spaced from the one next to it. Performance did not decline when the separation was extended to 70°, but was significantly reduced at an 80° separation. Results indicate that the ability for symmetry perception varies across fish species and individuals, whereby some can detect even subtle differences in this respect.

  4. Immunocytochemical characterisation of neural stem-progenitor cells from green terror cichlid Aequidens rivulatus.

    Science.gov (United States)

    Wen, C M; Chen, M M; Nan, F H; Wang, C S

    2017-01-01

    In this study, cultures of neural stem-progenitor cells (NSPC) from the brain of green terror cichlid Aequidens rivulatus were established and various NSPCs were demonstrated using immunocytochemistry. All of the NSPCs expressed brain lipid-binding protein, dopamine- and cAMP-regulated neuronal phosphoprotein 32 (DARPP-32), oligodendrocyte transcription factor 2, paired box 6 and sex determining region Y-box 2. The intensity and localisation of these proteins, however, varied among the different NSPCs. Despite being intermediate cells, NSPCs can be divided into radial glial cells, oligodendrocyte progenitor cells (OPC) and neuroblasts by expressing the astrocyte marker glial fibrillary acidic protein (GFAP), OPC marker A2B5 and neuronal markers, including acetyl-tubulin, βIII-tubulin, microtubule-associated protein 2 and neurofilament protein. Nevertheless, astrocytes were polymorphic and were the most dominant cells in the NSPC cultures. By using Matrigel, radial glia exhibiting a long GFAP(+) or DARPP-32(+) fibre and neurons exhibiting a significant acetyl-tubulin(+) process were obtained. The results confirmed that NSPCs obtained from A. rivulatus brains can proliferate and differentiate into neurons in vitro. Clonal culture can be useful for further studying the distinct NSPCs.

  5. Phylogeographic Diversity of the Lower Central American Cichlid Andinoacara coeruleopunctatus (Cichlidae

    Directory of Open Access Journals (Sweden)

    S. Shawn McCafferty

    2012-01-01

    Full Text Available It is well appreciated that historical and ecological processes are important determinates of freshwater biogeographic assemblages. Phylogeography can potentially lend important insights into the relative contribution of historical processes in biogeography. However, the extent that phylogeography reflects historical patterns of drainage connection may depend in large part on the dispersal capability of the species. Here, we test the hypothesis that due to their relatively greater dispersal capabilities, the neotropical cichlid species Andinoacara coeruleopunctatus will display a phylogeographic pattern that differs from previously described biogeographic assemblages in this important region. Based on an analysis of 318 individuals using mtDNA ATPase 6/8 sequence and restriction fragment length polymorphism data, we found eight distinct clades that are closely associated with biogeographic patterns. The branching patterns among the clades and a Bayesian clock analysis suggest a relatively rapid colonization and diversification among drainages in the emergent Isthmus of Panama followed by the coalescing of some drainages due to historical connections. We also present evidence for extensive cross-cordillera sharing of clades in central Panama and the Canal region. Our results suggest that contemporary phylogeographic patterns and diversification in Lower Central American fishes reflect an interaction of historical drainage connections, dispersal, and demographic processes.

  6. Biotechnology in maize breeding

    Directory of Open Access Journals (Sweden)

    Mladenović-Drinić Snežana

    2004-01-01

    Full Text Available Maize is one of the most important economic crops and the best studied and most tractable genetic system among monocots. The development of biotechnology has led to a great increase in our knowledge of maize genetics and understanding of the structure and behaviour of maize genomes. Conventional breeding practices can now be complemented by a number of new and powerful techniques. Some of these often referred to as molecular methods, enable scientists to see the layout of the entire genome of any organism and to select plants with preferred characteristics by "reading" at the molecular level, saving precious time and resources. DNA markers have provided valuable tools in various analyses ranging from phylogenetic analysis to the positional cloning of genes. Application of molecular markers for genetic studies of maize include: assessment of genetic variability and characterization of germ plasm, identification and fingerprinting of genotypes, estimation of genetic distance, detection of monogamic and quantitative trait loci, marker assisted selection, identification of sequence of useful candidate genes, etc. The development of high-density molecular maps which has been facilitated by PCR-based markers, have made the mapping and tagging of almost any trait possible and serve as bases for marker assisted selection. Sequencing of maize genomes would help to elucidate gene function, gene regulation and their expression. Modern biotechnology also includes an array of tools for introducing or deieting a particular gene or genes to produce plants with novel traits. Development of informatics and biotechnology are resulted in bioinformatic as well as in expansion of microarrey technique. Modern biotechnologies could complement and improve the efficiency of traditional selection and breeding techniques to enhance agricultural productivity.

  7. Potato breeding in the Netherlands

    NARCIS (Netherlands)

    Haan, de H.

    1953-01-01

    A remarkable feature of potato breeding in the Netherlands is the great number of private breeders who have concentrated their efforts on the improvement of the potato. The author calls attention to some circumstances and measures that have made potato breeding attractive in the Netherlands

  8. Multispecies Outcomes of Sympatric Speciation after Admixture with the Source Population in Two Radiations of Nicaraguan Crater Lake Cichlids.

    Science.gov (United States)

    Kautt, Andreas F; Machado-Schiaffino, Gonzalo; Meyer, Axel

    2016-06-01

    The formation of species in the absence of geographic barriers (i.e. sympatric speciation) remains one of the most controversial topics in evolutionary biology. While theoretical models have shown that this most extreme case of primary divergence-with-gene-flow is possible, only a handful of accepted empirical examples exist. And even for the most convincing examples uncertainties remain; complex histories of isolation and secondary contact can make species falsely appear to have originated by sympatric speciation. This alternative scenario is notoriously difficult to rule out. Midas cichlids inhabiting small and remote crater lakes in Nicaragua are traditionally considered to be one of the best examples of sympatric speciation and lend themselves to test the different evolutionary scenarios that could lead to apparent sympatric speciation since the system is relatively small and the source populations known. Here we reconstruct the evolutionary history of two small-scale radiations of Midas cichlids inhabiting crater lakes Apoyo and Xiloá through a comprehensive genomic data set. We find no signs of differential admixture of any of the sympatric species in the respective radiations. Together with coalescent simulations of different demographic models our results support a scenario of speciation that was initiated in sympatry and does not result from secondary contact of already partly diverged populations. Furthermore, several species seem to have diverged simultaneously, making Midas cichlids an empirical example of multispecies outcomes of sympatric speciation. Importantly, however, the demographic models strongly support an admixture event from the source population into both crater lakes shortly before the onset of the radiations within the lakes. This opens the possibility that the formation of reproductive barriers involved in sympatric speciation was facilitated by genetic variants that evolved in a period of isolation between the initial founding

  9. Acquisition of Lateralized Predation Behavior Associated with Development of Mouth Asymmetry in a Lake Tanganyika Scale-Eating Cichlid Fish.

    Science.gov (United States)

    Takeuchi, Yuichi; Hori, Michio; Tada, Shinya; Oda, Yoichi

    2016-01-01

    The scale-eating cichlid Perissodus microlepis with asymmetric mouth is an attractive model of behavioral laterality: each adult tears off scales from prey fishes' left or right flanks according to the direction in which its mouth is skewed. To investigate the development of behavioral laterality and mouth asymmetry, we analyzed stomach contents and lower jaw-bone asymmetry of various-sized P. microlepis (22 ≤ SLLake Tanganyika. The shapes of the pored scales found in each specimen's stomach indicated its attack side preference. Early-juvenile specimens (SLphysical and behavioral literalities may contribute to efficient scale-eating.

  10. Haplochromis ushindi spec. nov., the largest piscivorous cichlid in the Mwanza Gulf area of Lake Victoria (East Africa) before the Nile perch upsurge

    NARCIS (Netherlands)

    Oijen, van M.J.P.

    2004-01-01

    A new species of a haplochromine cichlid (Pisces: Cichlidae: Haplochrominae) from Lake Victoria is described. It is the largest species known from the Mwanza gulf area before the Nile perch upsurge in 1986. Specimens have been collected between 1975 and 1985. Presumably, the species does not exist a

  11. RosBREED: Enabling marker-assisted breeding in Rosaceae

    NARCIS (Netherlands)

    Iezzoni, A.F.; Weebadde, C.; Luby, J.; Yue, C.; Weg, van de W.E.; Fazio, G.; Main, D.; Peace, C.P.; Bassil, N.V.; McFerson, J.

    2010-01-01

    Genomics research has not yet been translated into routine practical application in breeding Rosaceae fruit crops (peach, apple, strawberry, cherry, apricot, pear, raspberry, etc.). Through dedicated efforts of many researchers worldwide, a wealth of genomics resources has accumulated, including EST

  12. RosBREED: Enabling Marker-Assisted Breeding in Rosaceae

    Science.gov (United States)

    Genomics research has not yet been translated into routine practical application in breeding Rosaceae fruit crops (peach, apple, strawberry, cherry, apricot, pear, raspberry, etc.). Through dedicated efforts of many researchers worldwide, a wealth of genomics resources has accumulated, including ES...

  13. Two types of dominant male cichlid fish: behavioral and hormonal characteristics

    Directory of Open Access Journals (Sweden)

    Rosa M. Alcazar

    2016-08-01

    Full Text Available Male African cichlid fish, Astatotilapia burtoni, have been classified as dominant or subordinate, each with unique behavioral and endocrine profiles. Here we characterize two distinct subclasses of dominant males based on types of aggressive behavior: (1 males that display escalating levels of aggression and court females while they establish a territory, and (2 males that display a stable level of aggression and delay courting females until they have established a territory. To profile differences in their approach to a challenge, we used an intruder assay. In every case, there was a male-male confrontation between the resident dominant male and the intruder, with the intruder quickly taking a subordinate role. However, we found that dominant males with escalating aggression spent measurably more time attacking subordinates than did dominant males with stable aggression that instead increased their attention toward the females in their tank. There was no difference in the behavior of intruders exposed to either type of dominant male, suggesting that escalating aggression is an intrinsic characteristic of some dominant males and is not elicited by the behavior of their challengers. Male behavior during the first 15 min of establishing a territory predicts their aggressive class. These two types of dominant males also showed distinctive physiological characteristics. After the intruder assay, males with escalating aggression had elevated levels of 11-ketotestosterone (11-KT, testosterone, estradiol, and cortisol, while those with stable aggression did not. These observations show that the same stimulus can elicit different behavioral and endocrine responses among A. burtoni dominant males that characterize them as either escalating or stable aggressive types. Our ability to identify which individuals within a population have escalating levels of aggressive responses versus those which have stable levels of aggressive responses when exposed to

  14. Protective Effects of Silymarin Extract on Malthion-Induced Zebra Cichlid (Cichlasoma Nigrofasciatum Hepatotoxicity

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    Mahdi Banaee

    2015-03-01

    Full Text Available Background: There is much evidence indicating that natural substances from edible and medicinal plants possess powerful antioxidant and hepatoprotective activities. The objective of the present study was to investigate the potential hepatoprotective effect of silymarin in fish exposed to malathion. Methods: Zebra cichlid fish were allocated into five groups of which one group received normal feed and served as control. Fish from group 2 were treated with 0.1 mg.L-1 malathion. Fish from group 3 and 4 were fed with enriched diet with 1400 mg and 2100 mg silymarin per 1 kg feed, respectively. While fish from group 5 and 6 were fed with enriched diet with 1400 mg and 2100 mg silymarin per 1 kg feed, respectively and simultaneously were treated with 0.1 mg.L-1 malathion for 15 days. Activities of hepatic enzymes including alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and lactate dehydrogenase were evaluated. Oxidative stress was ascertained by measuring malondialdehyde as marker of lipid peroxidation and total cellular antioxidant capacity. Results: Exposure to malathion caused a significant increase in MDA levels and altered AST, ALT, ALP and LDH activities in liver tissues (p<0.05. The hepatic antioxidant capacity was significantly lowered in malathion treated fish as compared to the control group (p<0.05. Treatment with silymarin significantly ameliorated these changes in the malathion-treated groups. Conclusion: These finding demonstrated that silymarin have protective effects against the toxic influence of malathion on the examined biochemical parameters in liver tissue of fish.

  15. Mechanism of action of endosulfan as disruptor of gonadal steroidogenesis in the cichlid fish Cichlasoma dimerus.

    Science.gov (United States)

    Da Cuña, Rodrigo H; Rey Vázquez, Graciela; Dorelle, Luciana; Rodríguez, Enrique M; Guimarães Moreira, Renata; Lo Nostro, Fabiana L

    2016-09-01

    The organochlorine pesticide endosulfan (ES) is used in several countries as a wide spectrum insecticide on crops with high commercial value. Due to its high toxicity to non-target animals, its persistence in the environment and its ability to act as an endocrine disrupting compound in fish, ES use is currently banned or restricted in many other countries. Previous studies on the cichlid fish Cichlasoma dimerus have shown that waterborne exposure to ES can lead to both decreased pituitary FSH content and histological alterations of testes. As gonadotropin-stimulated sex steroids release from gonads was inhibited by ES in vitro, the aim of the present study was to elucidate possible mechanisms of disruption of ES on gonadal steroidogenesis in C. dimerus, as well as compare the action of the active ingredient (AI) with that of currently used commercial formulations (CF). Testis and ovary fragments were incubated with ES (AI or CF) and/or steroidogenesis activators or precursors. Testosterone and estradiol levels were measured in the incubation media. By itself, ES did not affect hormone levels. Co-incubation with LH and the adenylate cyclase activator forskolin caused a decrease of the stimulated sex steroids release. When co-incubated with precursors dehydroandrostenedione and 17αhydroxyprogesterone, ES did not affect the increase caused by their addition alone. No differences were observed between the AI and CFs, suggesting that the effect on steroidogenesis disruption is mainly caused by the AI. Results indicate that action of ES takes place downstream of LH-receptor activation and upstream of the studied steroidogenic enzymes.

  16. Fish embryo and juvenile size under hypoxia in the mouth- brooding African cichlid Pseudocrenilabrus multicolor

    Directory of Open Access Journals (Sweden)

    E.E. REARDON, L.J. CHAPMAN

    2012-06-01

    Full Text Available We used a field survey and a laboratory rearing experiment to (a examine response (size and survival to life-long hypoxia in offspring of the African maternal mouth-brooding cichlid Pseudocrenilabrus multicolor victoriae (Seegers and (b explore the degree to which developmental response can be environmentally-induced. Embryo size metrics were quantified in 9 field populations across a range of dissolved oxygen (DO concentrations. In the laboratory, first generation (F1 broods of low-DO origin were reared under high or low DO. Brooding period was quantified for the mothers; and egg size, egg metabolic rate and juvenile size-at-release were quantified in their (F2 offspring. The F2 offspring were split and grown for 3 months post-release under high or low DO, and juvenile size and survival were quantified. In the field survey, across stages, embryos from low-DO field populations were shorter and weighed less than embryos from high-DO populations. In the laboratory experiment, F2 eggs and juveniles-at-release from mother’s mouth did not differ in mass, length, survival regardless of development DO environment. However, juveniles diverged in size after leaving mother’s mouth, exhibiting smaller size when grown under low DO. Size differences in embryo size across field populations and divergence in embryo size after release from the mother’s mouth support predictions for smaller body size under hypoxia. There was no evidence for negative effects on survival of juveniles after 3 months. Brooding period was 16% shorter in females reared under low DO suggesting that hypoxia may accelerate embryo development. This work provides insights into how bearer fishes respond to hypoxic stress relative to fishes with no post-spawning parental care; a shorter brooding interval and smaller body size may provide an optimal solution to parent and embryo survival under hypoxia in brooding fishes [Current Zoology 58 (3: 401-412, 2012].

  17. Fish embryo and juvenile size under hypoxia in the mouth-brooding African cichlid Pseudocrenilabrus multicolor

    Institute of Scientific and Technical Information of China (English)

    E.E.REARDON; L.J.CHAPMAN

    2012-01-01

    We used a field survey and a laboratory rearing experiment to (a) examine response (size and survival) to life-long hypoxia in offspring of the African maternal mouth-brooding cichlid Pseudocrenilabrus multicolor victoriae (Seegers) and (b) explore the degree to which developmental response can be environmentally-induced.Embryo size metrics were quantified in 9 field populations across a range of dissolved oxygen (DO) concentrations.In the laboratory,first generation (F1) broods of low-DO origin were reared under high or low DO.Brooding period was quantified for the mothers; and egg size,egg metabolic rate and juvenile size-at-release were quantified in their (F2) offspring.The F2 offspring were split and grown for 3 months post-release under high or low DO,and juvenile size and survival were quantified.In the field survey,across stages,embryos from low-DO field populations were shorter and weighed less than embryos from high-DO populations.In the laboratory experiment,F2 eggs and juveniles-at-release from mother's mouth did not differ in mass,length,survival regardless of development DO environment.However,juveniles diverged in size after leaving mother's mouth,exhibiting smaller size when grown under low DO.Size differences in embryo size across field populations and divergence in embryo size after release from the mother's mouthsupport predictions for smaller body size under hypoxia.There was no evidence for negative effects on survival of juveniles after 3 months.Brooding period was 16% shorter in females reared under low DO suggesting that hypoxia may accelerate embryo development.This work provides insights into how bearer fishes respond to hypoxic stress relative to fishes with no post-spawning parental care; a shorter brooding interval and smaller body size may provide an optimal solution to parent and embryo survival under hypoxia in brooding fishes.

  18. Effect of Hypergravity on Carbonanhydrase Reactivity in inner Ear Ioncytes of developing Cichlid Fish

    Science.gov (United States)

    Beier, M.; Anken, R.; Rahmann, H.

    It has been shown earlier that hypergravity slows down inner ear otolith growth in developing fish. Otolith growth in terms of mineralisation mainly depends on the enzyme carboanhydrase (CAH), which is responsible for the provision of the pH- value necessary for calcium carbonate deposition and thus also is presumed to play a prominent role in Ménière's disease (a sensory - motor disorder inducing vertigo and kinetosis). Larval siblings of cichlid fish (Oreochromis mossambicus) were subjected to hypergravity (3g; 6 hours) during development and separated into normally and kinetotically swimming individuals following the transfer to 1g (i.e., stopping the centrifuge; kinetotically behaving fish performed spinning movements). Subsequently, CAH was histochemically demonstrated in inner ear ionocytes (cells involved in the endolymphatic ion exchange) and enzyme reactivity was determined densitometrically. The results showed that CAH-reactivity was significantly increased in normally behaving hyper-g specimens as compared to controls kept at 1g, whereas no difference in enzyme reactivity was evident between the controls and kinetotically behaving fish. On the background of earlier studies, according to which (1) hypergravity induces a decrease of otolith growth and (2) the otolithic calcium incorporation (visualized using the calcium -tracer alizarin complexone) of kinetotically swimming hyper - g fish was lower as compared to normally behaving hyper - g animals, the present study strongly supports the concept that an increase in CAH-reactivity may result in a decrease of otolithic calcium deposition. The mechanism regulating CAH-activity hitherto remains to be determined. Acknowledgement: This work was financially supported by the German Aerospace Center (DLR) (FKZ: 50 WB 9997).

  19. The role of otolith size in hearing – Insights from cichlid fishes

    Directory of Open Access Journals (Sweden)

    Tanja Schulz-Mirbach

    2015-10-01

    Full Text Available Otolithic end organs in fishes function as accelerometers and are involved in the senses of balance and hearing (e.g. Popper et al. 2005. Otolith mass and shape are likely decisive factors influencing otolith motion, but while it is largely unknown how different shapes affect otolith movement relative to the sensory epithelium (Popper et al. 2005, greater otolith mass is predicted to result in enhanced stimulation of sensory hair cells and improved hearing (Lychakov and Rebane 2005. What few studies exist on this topic, however, yielded contradicting results in that they did or did not find a correlation between increased otolith mass and enhanced hearing (see Kéver et al. 2014. We investigated the relationship between otolith morphology (including 3D-models of otoliths based on high-resolution microCT imaging and otolith weight and hearing abilities in cichlids while comparing three species (Etroplus maculatus, Hemichromis guttatus, Steatocranus tinanti with different swimbladder morphology and hearing abilities (Schulz-Mirbach et al. 2014. We predicted Etroplus maculatus—the species that displays the best hearing sensitivities—to possess larger/heavier otoliths. As swimbladder extensions in this species are connected to the lagena, we further predicted to find heavier lagenar otoliths. Compared to H. guttatus and S. tinanti, E. maculatus showed the heaviest saccular otoliths, while lagenar otoliths were significantly thinner and lighter than in the former two species, apparently contradicting the hypothesis that the lagena and its otolith are primarily involved in improved hearing abilities. Our results support the idea that there is no ‘simple’ relationship between otolith weight, ancilliary auditory structures and hearing abilities. 3D-models of inner ears and otoliths may be ideally suited for future studies modeling complex otolith motion and thus, may provide a better understanding of how otolith morphology contributes to inner

  20. Detection of artificial water flows by the lateral line system of a benthic feeding cichlid fish.

    Science.gov (United States)

    Schwalbe, Margot A B; Sevey, Benjamin J; Webb, Jacqueline F

    2016-04-01

    The mechanosensory lateral line system of fishes detects water motions within a few body lengths of the source. Several types of artificial stimuli have been used to probe lateral line function in the laboratory, but few studies have investigated the role of flow sensing in benthic feeding teleosts. In this study, we used artificial flows emerging from a sandy substrate to assess the contribution of flow sensing to prey detection in the peacock cichlid, Aulonocara stuartgranti, which feeds on benthic invertebrates in Lake Malawi. Using a positive reinforcement protocol, we trained fish to respond to flows lacking the visual and chemical cues generated by tethered prey in prior studies with A. stuartgranti Fish successfully responded to artificial flows at all five rates presented (characterized using digital particle image velocimetry), and showed a range of flow-sensing behaviors, including an unconditioned bite response. Immediately after lateral line inactivation, fish rarely responded to flows and the loss of vital fluorescent staining of hair cells (with 4-di-2-ASP) verified lateral line inactivation. Within 2 days post-treatment, some aspects of flow-sensing behavior returned and after 7 days, flow-sensing behavior and hair cell fluorescence both returned to pre-treatment levels, which is consistent with the reported timing of hair cell regeneration in other vertebrates. The presentation of ecologically relevant water flows to assess flow-sensing behaviors and the use of a positive reinforcement protocol are methods that present new opportunities to study the role of flow sensing in the feeding ecology of benthic feeding fishes.

  1. Sexual selection on color and behavior within and between cichlid populations: Implications for speciation

    Directory of Open Access Journals (Sweden)

    Michael J. PAUERS, Jeffrey S. MCKINNON

    2012-06-01

    Full Text Available Sexual selection is widely viewed as playing a central role in haplochromine cichlid speciation. Hypothetically, once divergent mate preferences evolve among populations of these fishes, reproductive isolation follows and the populations begin to behave as different species. Various studies have examined patterns of assortative mating among species and sometimes populations, but few have examined variation in directional preferences, especially among populations of the same species. We investigated mate choice behavior in two populations of Labeotropheus fuelleborni, a Lake Malawi endemic. We test whether mating preferences between populations are based on the same traits and in the same direction as preferences within populations. We examine the potential contributions of two classes of trait, color patterns and behaviors, to reproductive isolation. When females chose between either two males of their own population, or two from another, female preferences were generally similar (for the female population across the two contexts. Mate choice patterns differed between (female populations for a measure of color, but only modestly for male behavior. In a separate experiment we simultaneously offered females a male of their own population and a male from a different population. In these trials, females consistently preferred males from their own population, which were also the males that displayed more frequently than their opponents, but not necessarily those with color traits suggested to be most attractive in the previous experiment. Thus directional preferences for chroma and related aspects of color may be important when females are presented with males of otherwise similar phenotypes, but may play little role in mediating assortative mating among populations with substantially different color patterns. A preference for male behavior could play some role in speciation if males preferentially court same-population females, as we have observed

  2. Evolution of bower building in Lake Malawi cichlid fish: Phylogeny, morphology, and behavior

    Directory of Open Access Journals (Sweden)

    Ryan eYork

    2015-03-01

    Full Text Available Despite considerable research, we still know little about the proximate and ultimate causes behind behavioral evolution. This is partly because understanding the forces acting on behavioral phenotypes requires the study of species-rich clades with extensive variation in behavioral traits, of which we have few current examples. In this paper, we introduce the bower-building cichlids of the Lake Malawi adaptive radiation, a lineage with over 100 species, each possessing a distinct male extended phenotype used to signal reproductive fitness. Extended phenotypes are useful units of analysis for the study of behavior since they are static structures that can be precisely measured within populations. To this end we recognize two core types of bowers - mounds (castles and depressions (pits. We employ an established framework for the study of adaptive radiations to ask how traits related to other stages of radiations, macrohabitat and feeding morphology, are associated with the evolution of pit and castle phenotypes. We demonstrate that pits and castles are evolutionarily labile traits and have been derived numerous times in multiple Malawi genera. Using public ecological and phenotypic data sets we find significant and correlated differences in macrohabitat (depth, sensory ability (opsin expression, and feeding style (jaw morphology and biomechanics between pit-digging and castle-building species. Phylogeny-corrected comparisons also show significant differences in several measures of jaw morphology while indicating non-significant differences in depth. Finally, using laboratory observations we assay courtship behaviors in a pit-digging (Copadichromis virginalis and a castle-building species (Mchenga conophoros. Together, these results show that traits at multiple biological levels act to regulate the evolution of a courtship behavior within natural populations.

  3. Sexual selection on color and behavior within and between cichlid populations: Implications for speciation

    Institute of Scientific and Technical Information of China (English)

    Michael J.PAUERS; Jeffrey S.MCKINNON

    2012-01-01

    Sexual selection is widely viewed as playing a central role in hapiochromine cichlid speciation.Hypothetically,once divergent mate preferences evolve among populations of these fishes,reproductive isolation follows and the populations begin to behave as different species.Various studies have examined patterns of assortative mating among species and sometimes populations,but few have examined variation in directional preferences,especially among populations of the same species.We investigated mate choice behavior in two populations of Labeotropheus fuelleborni,a Lake Malawi endemic.We test whether mating.preferences between populations are based on the same traits and in the same direction as preferences within populations.We examine the potential contributions of two classes of trait,color patterns and behaviors,to reproductive isolation.When females chose between either two males of their own population,or two from another,female preferences were generally similar (for the female population) across the two contexts.Mate choice patterns differed between (female) populations for a measure of color,but only modestly for male behavior.In a separate experiment we simultaneously offered females a male of their own population and a male from a different population.In these trials,females consistently preferred males from their own population,which were also the males that displayed more frequently than their opponents,but not necessarily those with color traits suggested to be most attractive in the previous experiment.Thus directional preferences for chroma and related aspects of color may be important when females are presented with males of otherwise similar phenotypes,but may play little role in mediating assortative mating among populations with substantially different color patterns.A preference for male behavior could play some role in speciation if males preferentially court same-population females,as we have observed for the populations studied herein.

  4. Social regulation of male reproductive plasticity in an African cichlid fish.

    Science.gov (United States)

    Maruska, Karen P; Fernald, Russell D

    2013-12-01

    Social interactions with the outcome of a position in a dominance hierarchy can have profound effects on reproductive behavior and physiology, requiring animals to integrate environmental information with their internal physiological state; but how is salient information from the animal's dynamic social environment transformed into adaptive behavioral, physiological, and molecular-level changes? The African cichlid fish, Astatotilapia burtoni, is ideally suited to understand socially controlled reproductive plasticity because activity of the male reproductive (brain-pituitary-gonad) axis is tightly linked to social status. Males form hierarchies in which a small percentage of brightly colored dominant individuals have an active reproductive axis, defend territories, and spawn with females, while the remaining males are subordinate, drably colored, do not hold a territory, and have a suppressed reproductive system with minimal opportunities for spawning. These social phenotypes are plastic and quickly reversible, meaning that individual males may switch between dominant and subordinate status multiple times within a lifetime. Here, we review the rapid and remarkable plasticity that occurs along the entire reproductive axis when males rise in social rank, a transition that has important implications for the operational sex ratio of the population. When males rise in rank, transformations occur in the brain, pituitary, circulation, and testes over short time-scales (minutes to days). Changes are evident in overt behavior, as well as modifications at the physiological, cellular, and molecular levels that regulate reproductive capacity. Widespread changes triggered by a switch in rank highlight the significance of external social information in shaping internal physiology and reproductive competence.

  5. Discovery of the invasive Mayan Cichlid fish "Cichlasoma" urophthalmus (Günther 1862) in Thailand, with comments on other introductions and potential impacts

    Science.gov (United States)

    Nico, Leo G.; Beamish, William H.; Musikasinthorn, Prachya

    2007-01-01

    We report on the occurrence and possible establishment of a non-native cichlid fish in a brackish-water system in the lower Chao Phraya River delta region, Thailand. Although, the possibility of some degree of introgressive hybridization can not be ruled out, Thailand specimens agree best with Mayan Cichlid “Cichlasoma” urophthalmus (Günther 1862). Our collections represent the first records of this New World, highly-invasive, euryhaline fish from Thailand and coincides with recent collections from Singapore. Positive identification of specimens as “C.” urophthalmus requires caution due to the diversity of the Cichlidae (>1,300 species), widespread introduction of many family members, variation within species, extensive interspecific overlap in characters, and proliferation of artificial cichlid hybrids (e.g., Flowerhorns). We first became aware of the Thailand population in 2005 when “C.” urophthalmus began appearing in the catches of local fishermen. We visited the site in November 2006 and obtained and examined voucher specimens. The abundance and wide size range of juveniles and adults in local ponds and an adjacent canal is evidence of natural reproduction. Because water bodies throughout the Chao Phraya delta are interconnected and subject to flooding, it is likely that “C.” urophthalmus is already established and is dispersing, but surveys and monitoring are needed to determine their exact geographic range. The Thailand population is compared to “C.” urophthalmus introduced into Florida (USA). Based on what is known about Florida “C.” urophthalmus, it is predicted that this cichlid will further invade coastal and inland waters in Thailand and elsewhere in Southeast Asia. This cichlid has a long history in the aquarium trade in Europe. However, there are no records from the wild in European waters and, because of the colder climate, the possibility of establishment in that region is relatively low.

  6. Genetic Evidence for Multiple Sources of the Non-Native Fish Cichlasoma urophthalmus (Günther; Mayan Cichlids) in Southern Florida

    Science.gov (United States)

    Harrison, Elizabeth; Trexler, Joel C.; Collins, Timothy M.; Vazquez-Domínguez, Ella; Razo-Mendivil, Ulises; Matamoros, Wilfredo A.; Barrientos, Christian

    2014-01-01

    The number and diversity of source populations may influence the genetic diversity of newly introduced populations and affect the likelihood of their establishment and spread. We used the cytochrome b mitochondrial gene and nuclear microsatellite loci to identify the sources of a successful invader in southern Florida, USA, Cichlasoma urophthalmus (Mayan cichlid). Our cytochrome b data supported an introduction from Guatemala, while our microsatellite data suggested movement of Mayan Cichlids from the upper Yucatán Peninsula to Guatemala and introductions from Guatemala and Belize to Florida. The mismatch between mitochondrial and nuclear genomes suggests admixture of a female lineage from Guatemala, where all individuals were fixed for the mitochondrial haplotype found in the introduced population, and a more diverse but also relatively small number of individuals from Belize. The Florida cytochrome b haplotype appears to be absent from Belize (0 out of 136 fish screened from Belize had this haplotype). Genetic structure within the Florida population was minimal, indicating a panmictic population, while Mexican and Central American samples displayed more genetic subdivision. Individuals from the Upper Yucatán Peninsula and the Petén region of Guatemala were more genetically similar to each other than to fish from nearby sites and movement of Mayan Cichlids between these regions occurred thousands of generations ago, suggestive of pre-Columbian human transportation of Mayan Cichlids through this region. Mayan Cichlids present a rare example of cytonuclear disequilibrium and reduced genetic diversity in the introduced population that persists more than 30 years (at least 7–8 generations) after introduction. We suggest that hybridization occurred in ornamental fish farms in Florida and may contribute their establishment in the novel habitat. Hybridization prior to release may contribute to other successful invasions. PMID:25184569

  7. Genetic evidence for multiple sources of the non-native fish Cichlasoma urophthalmus (Günther; Mayan Cichlids) in southern Florida.

    Science.gov (United States)

    Harrison, Elizabeth; Trexler, Joel C; Collins, Timothy M; Vazquez-Domínguez, Ella; Razo-Mendivil, Ulises; Matamoros, Wilfredo A; Barrientos, Christian

    2014-01-01

    The number and diversity of source populations may influence the genetic diversity of newly introduced populations and affect the likelihood of their establishment and spread. We used the cytochrome b mitochondrial gene and nuclear microsatellite loci to identify the sources of a successful invader in southern Florida, USA, Cichlasoma urophthalmus (Mayan cichlid). Our cytochrome b data supported an introduction from Guatemala, while our microsatellite data suggested movement of Mayan Cichlids from the upper Yucatán Peninsula to Guatemala and introductions from Guatemala and Belize to Florida. The mismatch between mitochondrial and nuclear genomes suggests admixture of a female lineage from Guatemala, where all individuals were fixed for the mitochondrial haplotype found in the introduced population, and a more diverse but also relatively small number of individuals from Belize. The Florida cytochrome b haplotype appears to be absent from Belize (0 out of 136 fish screened from Belize had this haplotype). Genetic structure within the Florida population was minimal, indicating a panmictic population, while Mexican and Central American samples displayed more genetic subdivision. Individuals from the Upper Yucatán Peninsula and the Petén region of Guatemala were more genetically similar to each other than to fish from nearby sites and movement of Mayan Cichlids between these regions occurred thousands of generations ago, suggestive of pre-Columbian human transportation of Mayan Cichlids through this region. Mayan Cichlids present a rare example of cytonuclear disequilibrium and reduced genetic diversity in the introduced population that persists more than 30 years (at least 7-8 generations) after introduction. We suggest that hybridization occurred in ornamental fish farms in Florida and may contribute their establishment in the novel habitat. Hybridization prior to release may contribute to other successful invasions.

  8. Induced cytochrome P450 1A activity in cichlid fishes from Guandu River and Jacarepagua Lake, Rio de Janeiro, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Parente, Thiago E.M.; Oliveira, Ana C.A.X. de [Laboratorio de Toxicologia Ambiental, Escola Nacional de Saude Publica - FIOCRUZ, Av Brasil 4036, Predio de Expansao do Campus, Rio de Janeiro, RJ 21041-361 (Brazil); Paumgartten, Francisco J.R. [Laboratorio de Toxicologia Ambiental, Escola Nacional de Saude Publica - FIOCRUZ, Av Brasil 4036, Predio de Expansao do Campus, Rio de Janeiro, RJ 21041-361 (Brazil)], E-mail: paum@ensp.fiocruz.br

    2008-03-15

    The induction of cytochrome P4501A-mediated activity (e.g. ethoxyresorufin-O-deethylation, EROD) has been used as a biomarker for monitoring fish exposure to AhR-receptor ligands such as polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB) and polychlorinated dibenzo-dioxins/furans (PCDD/Fs). In this study we found that hepatic EROD is induced in fish ('Nile tilapia', Oreochromis niloticus and 'acara', Geophagus brasiliensis) from the Guandu River (7-17-fold) and Jacarepagua Lake (7-fold), Rio de Janeiro, Brazil. Since both cichlid fish are consumed by the local population and the Guandu River is the main source of the drinking water supply for the greater Rio de Janeiro metropolitan area, pollution by cytochrome P4501A-inducing chemicals is a cause for concern and should be further investigated in sediments, water and biota. We additionally showed that EROD activity in the fish liver post-mitochondrial supernatant-simpler, cheaper and less time consuming to prepare than the microsomal fraction-is sufficiently sensitive for monitoring purposes. - Increased EROD activity in the liver of cichlid fishes indicated that Guandu River, the source of drinking water supply for Rio de Janeiro is polluted by CYP1A-inducing chemicals.

  9. POTENSI INVASIF IKAN ZEBRA CICHLID (Amatitlania nigrofasciata Günther, 1867DI DANAU BERATAN, BALI DITINJAU DARI ASPEK BIOLOGINYA

    Directory of Open Access Journals (Sweden)

    Agus Arifin Sentosa

    2016-03-01

    Full Text Available Danau Beratan yang terletak di kawasan Bedugul, Bali telah terintroduksiikan zebra cichlid (Amatitlania nigrofasciata Günther, 1867 secara tidak sengaja. Tujuan penelitian adalah untuk mengetahui potensi ikan zebra sebagai ikan asing invasif di Danau Beratan berdasarkan kajian pada beberapa aspek biologinya. Penelitian dilakukan dengan metode survei lapang di Danau Beratan, Bali pada bulan Mei, Juli dan Oktober 2011. Contoh ikan diperoleh menggunakan jaring insang percobaan dan jaring tarik. Analisis data meliputi hubungan panjang berat, faktor kondisi, parameter pertumbuhan, kebiasaan makanan dan aspek reproduksi ikan. Hasil penelitian menunjukkan ikan zebra mendominasi hasil penangkapan. Ikan tersebut memiliki faktor kondisi yang baik dengan nilai laju pertumbuhan tahunan (K yang tinggi, bersifat generalis dalam memanfaatkan sumber daya makanan dan matang gonad pada ukuran panjang yang kecil. Karakteristik biologi inimengindikasikan ikan tersebut memiliki potensi invasif yang cukup tinggi.  Lake Beratanislocated inBedugul, Balihas been an unintentional introduction ofzebracichlid(Amatitlania nigrofasciataGünther, 1867. The aim of this research was to determine thepotential ofzebra cichlid becomeinvasivealienfish speciesinLake Beratanbasedonseveralbiological aspects.The study was carried outby field surveymethods in Lake Beratan, Bali on May, JulyandOctober 2011. Fish samples was obtained usingexperimentalgillnetsandmodification ofseine nets. Data analysis included the lengthweightrelationship, conditionfactor, growth parameters, foodhabitsand its reproduction aspects. The results showedthat zebracichliddominatethe experimental catchin LakeBeratan. Analysis showedthese fishhavea goodconditionwith ahigh growth rate, have a generalist characteristic in exploitingthe natural food resourcesandmatureat small length size. A reviewforseveral biological aspects ofthe zebra cichlidshowedthatfishhavea highinvasivepotentialinLake Beratan.

  10. Origin and evolution of B chromosomes in the cichlid fish Astatotilapia latifasciata based on integrated genomic analyses.

    Science.gov (United States)

    Valente, Guilherme T; Conte, Matthew A; Fantinatti, Bruno E A; Cabral-de-Mello, Diogo C; Carvalho, Robson F; Vicari, Marcelo R; Kocher, Thomas D; Martins, Cesar

    2014-08-01

    Approximately 15% of eukaryotes contain supernumerary B chromosomes. When present, B chromosomes frequently represent as much as 5% of the genome. Despite thousands of reports describing the distribution of supernumeraries in various taxa, a comprehensive theory for the origin, maintenance, and evolution of B chromosomes has not emerged. Here, we sequence the complete genomes of individual cichlid fish (Astatotilapia latifasciata) with and without B chromosomes, as well as microdissected B chromosomes, to identify DNA sequences on the B. B sequences were further analyzed through quantitative polymerase chain reaction and in situ hybridization. We find that the B chromosome contains thousands of sequences duplicated from essentially every chromosome in the ancestral karyotype. Although most genes on the B chromosome are fragmented, a few are largely intact, and we detect evidence that at least three of them are transcriptionally active. We propose a model in which the B chromosome originated early in the evolutionary history of Lake Victoria cichlids from a small fragment of one autosome. DNA sequences originating from several autosomes, including protein-coding genes and transposable elements, subsequently inserted into this proto-B. We propose that intact B chromosome genes involved with microtubule organization, kinetochore structure, recombination and progression through the cell cycle may play a role in driving the transmission of the B chromosome. Furthermore, our work suggests that karyotyping is an essential step prior to genome sequencing to avoid problems in genome assembly and analytical biases created by the presence of high copy number sequences on the B chromosome.

  11. Allometric shape change of the lower pharyngeal jaw correlates with a dietary shift to piscivory in a cichlid fish

    Science.gov (United States)

    Hellig, Christoph J.; Kerschbaumer, Michaela; Sefc, Kristina M.; Koblmüller, Stephan

    2010-07-01

    The morphological versatility of the pharyngeal jaw of cichlid fishes is assumed to represent a key factor facilitating their unparalleled trophic diversification and explosive radiation. It is generally believed that the functional design of an organism relates to its ecology, and thus, specializations to different diets are typically associated with distinct morphological designs, especially manifested in the cichlids’ pharyngeal jaw apparatus. Thereby, the lower pharyngeal jaw (LPJ) incorporates some of the most predictive features for distinct diet-related morphotypes. Thus, considering that piscivorous cichlids experience an ontogenetic dietary shift from typically various kinds of invertebrates to fish, concomitant morphological changes in the LPJ are expected. Using Lepidiolamprologus elongatus, a top predator in the shallow rocky habitat of Lake Tanganyika, as model, and applying geometric and traditional morphometric techniques, we demonstrate an allometric change in ontogenetic LPJ shape development coinciding with the completion of the dietary shift toward piscivory. The piscivorous LPJ morphotype is initiated in juvenile fish by increasing elongation and narrowing of the LPJ and—when the fish reach a size of 80-90 mm standard length—further refined by the elongation of the posterior muscular processes, which serve as insertion for the fourth musculus levator externus. The enlarged muscular processes of the fully mature piscivorous morphotype provide for the construction of a powerful lever system, which allows the large individuals to process large prey fish and rely on exclusive piscivory.

  12. Illinois’ 2000 breeding season report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the 2000 breeding season for grassland birds in Illinois. The report begins by summarizing weather conditions throughout the season and...

  13. Bee Queen Breeding Methods - Review

    Directory of Open Access Journals (Sweden)

    Silvia Patruica

    2016-05-01

    Full Text Available The biological potential of a bee family is mainly generated by the biological value of the queen. Whether we grow queens widely or just for our own apiaries, we must consider the acquisition of high-quality biological material, and also the creation of optimal feeding and caring conditions, in order to obtain high genetic value queens. Queen breeding technology starts with the setting of hoeing families, nurse families, drone-breeding families – necessary for the pairing of young queens, and also of the families which will provide the bees used to populate the nuclei where the next queens will hatch. The complex of requirements for the breeding of good, high-production queens is sometimes hard to met, under the application of artificial methods. The selection of breeding method must rely on all these requirements and on the beekeeper’s level of training.

  14. Atlantic Flyway Breeding Waterfowl Survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Atlantic Flyway Technical Section initiated this breeding waterfowl survey in 11 northeast states ranging from New Hampshire to Virginia.

  15. Tricolored Blackbird - Breeding [ds20

    Data.gov (United States)

    California Department of Resources — These data come from observations of breeding tricolored blackbirds throughout their range in California. NAD27 coordinates are given in the data for each record....

  16. Mutations induced in plant breeding

    Energy Technology Data Exchange (ETDEWEB)

    Barriga B, P. (Universidad Austral de Chile, Valdivia. Inst. de Produccion y Sanidad Vegetal)

    1984-10-01

    The most significant aspects of the use of ionizing radiations in plant breeding are reviewed. Aspects such as basic principles of mutation, expression and selection in obtention of mutants, methods for using induced mutations and sucess achieved with this methodology in plant breeding are reviewed. Results obtained in a program of induced mutation on wheat for high content of protein and lysine at the Universidad Austral de Chile are presented.

  17. Breeding performance in the Italian chicken breed Mericanel della Brianza

    Directory of Open Access Journals (Sweden)

    Stefano P. Marelli

    2010-11-01

    Full Text Available In Italy, 90 local avian breeds were described, the majority (61% were classified extinct and only 8.9 % still diffused. Therefore, efforts for conservation of Italian avian breeds are urgently required. The aim of this study was to record the breeding performance of the Italian breed Mericanel della Brianza and multiply a small population, in order to develop a conservation program. Fourteen females and 8 males were available at the beginning of the reproductive season in 2009 and organized in 8 families (1 male/1-2 females kept in floor pens. Birds received a photoperiod of 14L:10D and fed ad libitum. Breeding performance was recorded from March to June. Egg production and egg weight were recorded daily; eggs were set every 2 weeks and fertility, embryo mortality and hatchability were recorded. Mean egg production was 37% and mean egg weight was 34±3.49 g. High fertility values were recorded in the first three settings, from 94 to 87%, and the overall mean fertility value was 81.6%. Overall hatchability was only 49.6% due to a high proportion of dead embryos. Embryo mortality occurred mainly between day 2 and 7 of incubation and during hatch. Highest hatchability values were recorded in setting 1 and 2, 69 and 60% respectively, and a great decrease was found in the following settings. Great variations in egg production, fertility, hatchability and embryo mortality were found among families. The present results are the basic knowledge on reproductive parameters necessary to improve the reproductive efficiency of the breed within a conservation plan.

  18. Evolution, plant breeding and biodiversity

    Directory of Open Access Journals (Sweden)

    Salvatore Ceccarelli

    2011-11-01

    Full Text Available This paper deals with changes in biodiversity during the course of evolution, plant domestication and plant breeding. It shows than man has had a strong influence on the progressive decrease of biodiversity, unconscious at first and deliberate in modern times. The decrease in biodiversity in the agricultures of the North causes a severe threat to food security and is in contrasts with the conservation of biodiversity which is part of the culture of several populations in the South. The concluding section of the paper shows that man could have guided evolution in a different way and shows an example of participatory plant breeding, a type of breeding which is done in collaboration with farmers and is based on selection for specific adaptation. Even though participatory plant breeding has been practiced for only about 20 years and by relatively few groups, the effects on both biodiversity and crop production are impressive. Eventually the paper shows how participatory plant breeding can be developed into ‘evolutionary plant breeding’ to cope in a dynamic way with climate changes.

  19. Cassava Breeding I: The Value of Breeding Value

    Science.gov (United States)

    Ceballos, Hernán; Pérez, Juan C.; Joaqui Barandica, Orlando; Lenis, Jorge I.; Morante, Nelson; Calle, Fernando; Pino, Lizbeth; Hershey, Clair H.

    2016-01-01

    Breeding cassava relies on several selection stages (single row trial-SRT; preliminary; advanced; and uniform yield trials—UYT). This study uses data from 14 years of evaluations. From more than 20,000 genotypes initially evaluated only 114 reached the last stage. The objective was to assess how the data at SRT could be used to predict the probabilities of genotypes reaching the UYT. Phenotypic data from each genotype at SRT was integrated into the selection index (SIN) used by the cassava breeding program. Average SIN from all the progenies derived from each progenitor was then obtained. Average SIN is an approximation of the breeding value of each progenitor. Data clearly suggested that some genotypes were better progenitors than others (e.g., high number of their progenies reaching the UYT), suggesting important variation in breeding values of progenitors. However, regression of average SIN of each parental genotype on the number of their respective progenies reaching UYT resulted in a negligible coefficient of determination (r2 = 0.05). Breeding value (e.g., average SIN) at SRT was not efficient predicting which genotypes were more likely to reach the UYT stage. Number of families and progenies derived from a given progenitor were more efficient predicting the probabilities of the progeny from a given parent reaching the UYT stage. Large within-family genetic variation tends to mask the true breeding value of each progenitor. The use of partially inbred progenitors (e.g., S1 or S2 genotypes) would reduce the within-family genetic variation thus making the assessment of breeding value more accurate. Moreover, partial inbreeding of progenitors can improve the breeding value of the original (S0) parental material and sharply accelerate genetic gains. For instance, homozygous S1 genotypes for the dominant resistance to cassava mosaic disease (CMD) could be generated and selected. All gametes from these selected S1 genotypes would carry the desirable allele and

  20. Distribution of Endomorphin-like-immunoreactive neurones in the brain of the cichlid fish Oreochromis mossambicus.

    Science.gov (United States)

    Vijayalaxmi; Ganesh, C B

    2017-02-08

    Endomorphins are tetrapeptides involved in pain and neuroendocrine responses with high affinity for mu opioid receptors in mammals. In the present investigation, we studied the distribution of endomorphin-like-immunoreactive (EM-L-ir) neurones in the brain of the cichlid fish Oreochromis mossambicus. Application of antisera against endomorphin 1 and 2 (EM-1-2) revealed the presence of EM-L-ir somata and fibres throughout the different subdivisions of the olfactory bulb such as the olfactory nerve layer and the granule cell layer. While the extensions of EM-L-ir fibres were seen along the medial olfactory tract, intensely labeled EM-L-ir somata were found in different subdivisions of the telencephalon. In the diencephalon, intensely stained EM-L-ir neurones were noticed in the preoptic area, the nucleus preopticus pars magnocellularis, the suprachiasmatic nucleus, the nucleus lateralis tuberis pars lateralis (NLTl) and the nucleus lateralis tuberis pars medialis (NLTm) regions, whereas projections of EM-L-ir fibres were also seen along the hypothalamo-hypophyseal tract suggested a possible hypophysiotrophic role for these neurones. Intense to moderately stained EM-L-ir neurones were noticed in different subdivisions of thalamic nucleus such as the dorsal posterior thalamic nucleus, commissura posterior, ventromedial thalamic nucleus, nucleus posterior tuberis, ventrolateral thalamic nucleus and medial preglomerular nucleus. Numerous intensely stained perikarya and axonal fibres were also noticed throughout the inferior lobe, along the periventricular margin of the reccessus lateralis, and in the nucleus recesus lateralis regions. In addition, numerous moderately labeled EM-like neuronal populations were found in the secondary gustatory nucleus and rostral spinal cord. The widespread distribution of EM-L-ir neurones throughout the brain and spinal cord indicate diverse roles for these cells in neuroendocrine and neuromodulatory responses for the first time in fish

  1. Alternative reproductive tactics in snail shell-brooding cichlids diverge in energy reserve allocation.

    Science.gov (United States)

    von Kuerthy, Corinna; Tschirren, Linda; Taborsky, Michael

    2015-05-01

    Life history theory predicts that the amount of resources allocated to reproduction should maximize an individual's lifetime reproductive success. So far, resource allocation in reproduction has been studied mainly in females. Intraspecific variation of endogenous energy storage and utilization patterns of males has received little attention, although these patterns may vary greatly between individuals pursuing alternative reproductive tactics (ARTs). ARTs are characterized by systematic variation of behavioral, physiological, and often morphological traits among same-sex conspecifics. Some individuals may rely on previously accumulated reserves, because of limited foraging opportunities during reproduction. Others may be able to continue foraging during reproduction, thus relying on reserves to a lesser extent. We therefore predicted that, if male tactics involve such divergent limitations and trade-offs within a species, ARTs should correspondingly differ in energy reserve allocation and utilization. To test this prediction, we studied short-term and long-term reserve storage patterns of males in the shell-brooding cichlid Lamprologus callipterus. In this species, bourgeois males investing in territory defense, courtship, and guarding of broods coexist with two distinct parasitic male tactics: (1) opportunistic sneaker males attempting to fertilize eggs by releasing sperm into the shell opening when a female is spawning; and (2) specialized dwarf males attempting to enter the shell past the spawning female to fertilize eggs from inside the shell. Sneaker males differed from other male types by showing the highest amount of accumulated short-term and long-term fat stores, apparently anticipating their upcoming adoption of the nest male status. In contrast, nest males depleted previously accumulated energy reserves with increasing nest holding period, as they invest heavily into costly reproductive behaviors while not taking up any food. This conforms to a capital

  2. Emperor penguins breeding on iceshelves.

    Science.gov (United States)

    Fretwell, Peter T; Trathan, Phil N; Wienecke, Barbara; Kooyman, Gerald L

    2014-01-01

    We describe a new breeding behaviour discovered in emperor penguins; utilizing satellite and aerial-survey observations four emperor penguin breeding colonies have been recorded as existing on ice-shelves. Emperors have previously been considered as a sea-ice obligate species, with 44 of the 46 colonies located on sea-ice (the other two small colonies are on land). Of the colonies found on ice-shelves, two are newly discovered, and these have been recorded on shelves every season that they have been observed, the other two have been recorded both on ice-shelves and sea-ice in different breeding seasons. We conduct two analyses; the first using synthetic aperture radar data to assess why the largest of the four colonies, for which we have most data, locates sometimes on the shelf and sometimes on the sea-ice, and find that in years where the sea-ice forms late, the colony relocates onto the ice-shelf. The second analysis uses a number of environmental variables to test the habitat marginality of all emperor penguin breeding sites. We find that three of the four colonies reported in this study are in the most northerly, warmest conditions where sea-ice is often sub-optimal. The emperor penguin's reliance on sea-ice as a breeding platform coupled with recent concerns over changed sea-ice patterns consequent on regional warming, has led to their designation as "near threatened" in the IUCN red list. Current climate models predict that future loss of sea-ice around the Antarctic coastline will negatively impact emperor numbers; recent estimates suggest a halving of the population by 2052. The discovery of this new breeding behaviour at marginal sites could mitigate some of the consequences of sea-ice loss; potential benefits and whether these are permanent or temporary need to be considered and understood before further attempts are made to predict the population trajectory of this iconic species.

  3. Sounds produced by the cichlid fish Metriaclima zebra allow reliable estimation of size and provide information on individual identity.

    Science.gov (United States)

    Bertucci, F; Attia, J; Beauchaud, M; Mathevon, N

    2012-04-01

    Sounds produced by male cichlids Metriaclima zebra during aggressive interactions were recorded to conduct a detailed analysis and to search for potential individual acoustic signatures. Fish from two different size groups (small and large individuals) were analysed. The two groups were significantly different for all acoustic variables considered; six of seven features demonstrated a significant interindividual variability and most of them were correlated with the size of the emitter. A cross-validated and permuted discriminant function analysis (pDFA) separated the two groups and correctly classified around 50% of the sounds to the correct individuals. Acoustic features that best distinguished among males were the instantaneous frequency of sounds and the modulation of pulse amplitude. These results suggest that acoustic signals could bear information about individual identity. The long-term stability of this signature is likely to be weak since the signature of a growing individual may change over time.

  4. Construction of bacterial artificial chromosome libraries for the Lake Malawi cichlid (Metriaclima zebra), and the blind cavefish (Astyanax mexicanus).

    Science.gov (United States)

    Di Palma, Federica; Kidd, Celeste; Borowsky, Richard; Kocher, Thomas D

    2007-01-01

    Teleost fishes have become important models for studying the evolution of the genetic mechanisms of development. A key resource for comparative genomics and positional cloning are large-insert libraries constructed in bacterial artificial chromosomes. We have constructed bacterial artificial chromosome libraries for two species of teleost fish that are important models for the study of developmental evolution. Metriaclima zebra is one of several hundred closely related, morphologically diverse, haplochromine cichlids which have evolved over the last one million years in Lake Malawi, East Africa. The Mexican tetra, Astyanax mexicanus, is well known for adaptations related to the recent evolution of blind cave-dwelling forms. Clones and high-density filters for each library are available to the scientific community through the Hubbard Center for Genome Studies.

  5. Breeding monkeys for biomedical research

    Science.gov (United States)

    Bourne, G. H.; Golarzdebourne, M. N.; Keeling, M. E.

    1973-01-01

    Captive bred rhesus monkeys show much less pathology than wild born animals. The monkeys may be bred in cages or in an outdoor compound. Cage bred animals are not psychologically normal which makes then unsuited for some types of space related research. Compound breeding provides contact between mother and infant and an opportunity for the infants to play with their peers which are important requirements to help maintain their behavioral integrity. Offspring harvested after a year in the compound appear behaviorally normal and show little histopathology. Compound breeding is also an economical method for the rapid production of young animals. The colony can double its size about every two and a half years.

  6. Sport horses : breeding specialist from a single breeding programme?

    NARCIS (Netherlands)

    Rovere, G.A.

    2016-01-01

    Summary The general goal of this thesis was to provide information useful for the breeding programme of the Royal Dutch Warmblood Studbook (KWPN) in relation with the ongoing specialisation of the population. Data provided by KWPN consisted of records from studbook-first inspection,

  7. Disturbance cues in freshwater prey fishes: Does urea function as an‘early warning cue’in juvenile convict cichlids and rainbow trout?

    Institute of Scientific and Technical Information of China (English)

    Grant E. BROWN; Christopher D. JACKSON; Patrick H. MALKA; (E)lisa JACQUES; Marc-Andre COUTURIER

    2012-01-01

    Freshwater vertebrate and invertebrate prey species commonly rely on chemosensory information,including non-injury released disturbance cues,to assess local predation threats.We conducted laboratory studies to (1) determine if urea can function as a disturbance cue in juvenile convict cichlids and rainbow trout and (2) determine if the background level of urea influences the behavioral response to a subsequent pulse of urea ('background noise' hypothesis).In the first series of trials,juvenile cichlids and trout were exposed to urea at varying concentrations (0 to 0.5 mg L-1 for cichlids and 0 to 1.0 mg L-1 for trout).Our results suggest that both cichilds and trout exhibited functionally similar responses to urea and conspecific disturbance cues and that increasing the concentration of urea results in an increase intensity of antipredator behaviour.In the second series of trials,we pre-exposed cichlids or trout to intermediate or high concentrations of urea (or a distilled water control) and then tested for the response to a second pulse of urea at at intermediate or high concentrations (versus a distilled water control).Our results demonstrate that pre-exposure to urea reduces or eliminates the response to a second pulse of urea,supporting the background noise hypothesis.Together,our results suggest that pulses of urea,released by disturbed or stressed individuals,may function as an early warning signal in freshwater prey species [Current Zoology 58 (2):250-259,2012].

  8. A new fossil cichlid from the Middle Miocene in the East African Rift Valley (Tugen Hills, Central Kenya: First record of a putative Ectodini

    Directory of Open Access Journals (Sweden)

    Melanie Altner

    2015-11-01

    Full Text Available Identification of fossil cichlids is difficult, because the currently used diagnostic morphological characters for living cichlids are mostly soft tissue based and such characters are hardly preserved in fossils. During our recent fieldwork in the Central Kenya Rift (E-Africa, we discovered several exceptionally well-preserved fossil cichlids, which can be assigned to different lineages among the African Pseudocrenilabrinae. Here we present one of those new specimens. Its most conspicuous character is a lateral line divided into three segments. This specimen was found in the lacustrine sediments of the Middle Miocene site Waril, Tugen Hills, Kenya. The site represents the deposits of an ancient freshwater lake ca. 9-10 million years ago. Previous work on fossil leaves from the same site allow for the reconstruction of open vegetation surrounding the lake and pronounced dry seasons. Among the main further characteristics of the new fossil cichlid is a lachrimal with six lateral line canals, big cycloid scales and a low number of dorsal fin spines (XIII. The latter two characters are traceable in several members of tribes within the Pseudocrenilabrinae. However, a lachrimal with six lateral line canals is exclusively found in certain tribes of the EAR (East African Radiation within the Pseudocrenilabrinae. Moreover, the unique lateral line pattern is solely present in two genera of the EAR tribe Ectodini. However, the fossil shows cycloid scales, while modern Ectodini have ctenoid scales. Taken all evidence together, this fossil may perhaps represent an ancient lineage related to the Ectodini. Up to date, there is no definite fossil record of the members of the EAR. Our fossil may represent the first reliable calibration point for this group, which would be consistent with the previously reconstructed diversification time of the H-lineage (EAR tribes, except Boulengerochromini, Bathybatini, Trematocarini and Lamprologini and the Lamprologini ca

  9. Bentho-pelagic divergence of cichlid feeding architecture was prodigious and consistent during multiple adaptive radiations within African rift-lakes.

    Directory of Open Access Journals (Sweden)

    W James Cooper

    Full Text Available BACKGROUND: How particular changes in functional morphology can repeatedly promote ecological diversification is an active area of evolutionary investigation. The African rift-lake cichlids offer a calibrated time series of the most dramatic adaptive radiations of vertebrate trophic morphology yet described, and the replicate nature of these events provides a unique opportunity to test whether common changes in functional morphology have repeatedly facilitated their ecological success. METHODOLOGY/PRINCIPAL FINDINGS: Specimens from 87 genera of cichlid fishes endemic to Lakes Tanganyka, Malawi and Victoria were dissected in order to examine the functional morphology of cichlid feeding. We quantified shape using geometric morphometrics and compared patterns of morphological diversity using a series of analytical tests. The primary axes of divergence were conserved among all three radiations, and the most prevalent changes involved the size of the preorbital region of the skull. Even the fishes from the youngest of these lakes (Victoria, which exhibit the lowest amount of skull shape disparity, have undergone extensive preorbital evolution relative to other craniofacial traits. Such changes have large effects on feeding biomechanics, and can promote expansion into a wide array of niches along a bentho-pelagic ecomorphological axis. CONCLUSIONS/SIGNIFICANCE: Here we show that specific changes in trophic anatomy have evolved repeatedly in the African rift lakes, and our results suggest that simple morphological alterations that have large ecological consequences are likely to constitute critical components of adaptive radiations in functional morphology. Such shifts may precede more complex shape changes as lineages diversify into unoccupied niches. The data presented here, combined with observations of other fish lineages, suggest that the preorbital region represents an evolutionary module that can respond quickly to natural selection when fishes

  10. The evolution of potato breeding

    Science.gov (United States)

    Potato cultivars in most regions of the world are tetraploid and clonally propagated. For over a century, the breeding strategy has been phenotypic recurrent selection. However, the polyploid nature of the crop prevents breeders from eliminating deleterious alleles and assembling positive alleles fo...

  11. Rose breeding: past, present, prospects

    NARCIS (Netherlands)

    Vries, de D.P.; Dubois, L.A.M.

    1996-01-01

    In this review the PAST, PRESENT and PROSPECT will be considered as three separate periods in the history of the breeding and development of rose cultivars. The recurring theme is the genetic variation. This theme was chosen because there is justified doubt as to sufficient genetic variation availab

  12. Conservation priorities for Ethiopian sheep breeds combining threat status, breed merits and contributions to genetic diversity

    Directory of Open Access Journals (Sweden)

    Windig Jack J

    2008-07-01

    Full Text Available Abstract Prioritizing livestock breeds for conservation needs to incorporate both genetic and non-genetic aspects important for the survival of the breeds. Here, we apply a maximum-utility-strategy to prioritize 14 traditional Ethiopian sheep breeds based on their threat status, contributions to farmer livelihoods (current breed merits and contributions to genetic diversity. Contributions of the breeds to genetic diversity were quantified using Eding's marker-estimated kinship approaches. Non-genetic aspects included threats (e.g. low population size, low preferences by farmers and current merits (economic, ecological and cultural merits. Threat analysis identified eight of the 14 breeds as threatened. Analysis of current merits showed that sub-alpine and arid-lowland breeds contribute most to farmer livelihoods in comparison to other breeds. The highest contribution to the genetic diversity conserved was from the Simien breed. Simien showed high between-breed (low between-breed kinship = 0.04 as well as high within-breed diversity (low within-breed kinship = 0.09 and high HE = 0.73 and allelic richness = 6.83. We combined the results on threat status, current breed merits and contributions to genetic diversity to produce a ranking of the 14 breeds for conservation purposes. Our results balance the trade-offs between conserving breeds as insurance against future uncertainties and current sustainable utilization. The ranking of breeds provides a basis for conservation strategies for Ethiopian sheep and contributes to a regional or global conservation plan.

  13. Native Pig and Chicken Breed Database: NPCDB.

    Science.gov (United States)

    Jeong, Hyeon-Soo; Kim, Dae-Won; Chun, Se-Yoon; Sung, Samsun; Kim, Hyeon-Jeong; Cho, Seoae; Kim, Heebal; Oh, Sung-Jong

    2014-10-01

    Indigenous (native) breeds of livestock have higher disease resistance and adaptation to the environment due to high genetic diversity. Even though their extinction rate is accelerated due to the increase of commercial breeds, natural disaster, and civil war, there is a lack of well-established databases for the native breeds. Thus, we constructed the native pig and chicken breed database (NPCDB) which integrates available information on the breeds from around the world. It is a nonprofit public database aimed to provide information on the genetic resources of indigenous pig and chicken breeds for their conservation. The NPCDB (http://npcdb.snu.ac.kr/) provides the phenotypic information and population size of each breed as well as its specific habitat. In addition, it provides information on the distribution of genetic resources across the country. The database will contribute to understanding of the breed's characteristics such as disease resistance and adaptation to environmental changes as well as the conservation of indigenous genetic resources.

  14. Selective breeding in organic dairy production

    NARCIS (Netherlands)

    Nauta, W.J.

    2009-01-01

    Organic dairy farming started to take off in the early 1990s, when the European Union laid down organic standards for animal production. Until now, however, only incidental steps have been taken towards organic breeding and organic farmers mainly use breeding stock from conventional breeding program

  15. Grooming relationships between breeding females and adult group members in cooperatively breeding moustached tamarins (Saguinus mystax).

    Science.gov (United States)

    Löttker, Petra; Huck, Maren; Zinner, Dietmar P; Heymann, Eckhard W

    2007-10-01

    Grooming is the most common form of affiliative behavior in primates that apart from hygienic and hedonistic benefits offers important social benefits for the performing individuals. This study examined grooming behavior in a cooperatively breeding primate species, characterized by single female breeding per group, polyandrous matings, dizygotic twinning, delayed offspring dispersal, and intensive helping behavior. In this system, breeding females profit from the presence of helpers but also helpers profit from staying in a group and assisting in infant care due to the accumulation of direct and indirect fitness benefits. We examined grooming relationships of breeding females with three classes of partners (breeding males, potentially breeding males, (sub)adult non-breeding offspring) during three reproductive phases (post-partum ovarian inactivity, ovarian activity, pregnancy) in two groups of wild moustached tamarins (Saguinus mystax). We investigated whether grooming can be used to regulate group size by either "pay-for-help" or "pay-to-stay" mechanisms. Grooming of breeding females with breeding males and non-breeding offspring was more intense and more balanced than with potentially breeding males, and most grooming occurred during the breeding females' pregnancies. Grooming was skewed toward more investment by the breeding females with breeding males during the phases of ovarian activity, and with potentially breeding males during pregnancies. Our results suggest that grooming might be a mechanism used by female moustached tamarins to induce mate association with the breeding male, and to induce certain individuals to stay in the group and help with infant care.

  16. Emperor penguins breeding on iceshelves.

    Directory of Open Access Journals (Sweden)

    Peter T Fretwell

    Full Text Available We describe a new breeding behaviour discovered in emperor penguins; utilizing satellite and aerial-survey observations four emperor penguin breeding colonies have been recorded as existing on ice-shelves. Emperors have previously been considered as a sea-ice obligate species, with 44 of the 46 colonies located on sea-ice (the other two small colonies are on land. Of the colonies found on ice-shelves, two are newly discovered, and these have been recorded on shelves every season that they have been observed, the other two have been recorded both on ice-shelves and sea-ice in different breeding seasons. We conduct two analyses; the first using synthetic aperture radar data to assess why the largest of the four colonies, for which we have most data, locates sometimes on the shelf and sometimes on the sea-ice, and find that in years where the sea-ice forms late, the colony relocates onto the ice-shelf. The second analysis uses a number of environmental variables to test the habitat marginality of all emperor penguin breeding sites. We find that three of the four colonies reported in this study are in the most northerly, warmest conditions where sea-ice is often sub-optimal. The emperor penguin's reliance on sea-ice as a breeding platform coupled with recent concerns over changed sea-ice patterns consequent on regional warming, has led to their designation as "near threatened" in the IUCN red list. Current climate models predict that future loss of sea-ice around the Antarctic coastline will negatively impact emperor numbers; recent estimates suggest a halving of the population by 2052. The discovery of this new breeding behaviour at marginal sites could mitigate some of the consequences of sea-ice loss; potential benefits and whether these are permanent or temporary need to be considered and understood before further attempts are made to predict the population trajectory of this iconic species.

  17. Breeding quinoa (Chenopodium quinoa Willd.)

    DEFF Research Database (Denmark)

    Zurita-Silva, Andrés; Fuentes, Francisco; Zamora, Pablo

    2014-01-01

    Quinoa (Chenopodium quinoa Willd.) originated in the Andean region of South America; this species is associated with exceptional grain nutritional quality and is highly valued for its ability to tolerate abiotic stresses. However, its introduction outside the Andes has yet to take off on a large...... scale. In the Andes, quinoa has until recently been marginally grown by small-scale Andean farmers, leading to minor interest in the crop from urban consumers and the industry. Quinoa breeding programs were not initiated until the 1960s in the Andes, and elsewhere from the 1970s onwards. New molecular...... tools available for the existing quinoa breeding programs, which are critically examined in this review, will enable us to tackle the limitations of allotetraploidy and genetic specificities. The recent progress, together with the declaration of "The International Year of the Quinoa" by the Food...

  18. SOYBEAN - MOLECULAR ASPECTS OF BREEDING

    Directory of Open Access Journals (Sweden)

    Aleksandra Sudarić

    2012-12-01

    Full Text Available The book Soybean: Molecular Aspects of Breeding focuses recent progress in our understanding of the genetics and molecular biology of soybean. This book is divided into four parts and contains 22 chapters. Part I, Molecular Biology and Biotechnology focuses advances in molecular biology and laboratory procedures that have been developed recently to manipulate DNA. Part II, Breeding for abiotic stress covers proteomics approaches form as a powerful tool for investigating the molecular mechanisms of the plant responses to various types of abiotic stresses. Part III, Breeding for biotic stress addresses issues related to application of molecular based strategies in order to increase soybean resistance to various biotic factors. Part IV, Recent Technology reviews recent technologies into the realm of soybean monitoring, processing and product use. While the information accumulated in this book is of primary interest for plant breeders, valuable insights are also offered to agronomists, molecular biologists, physiologists, plant pathologists, food scientists and students. The book is a result of efforts made by many experts from different countries (USA, Japan, Croatia, Serbia, China, Canada, Malawi, Iran, Hong Kong, Brasil, Mexico.

  19. Charge Breeding of Radioactive Ions

    CERN Document Server

    Wenander, F J C

    2013-01-01

    Charge breeding is a technique to increase the charge state of ions, in many cases radioactive ions. The singly charged radioactive ions, produced in an isotope separator on-line facility, and extracted with a low kinetic energy of some tens of keV, are injected into a charge breeder, where the charge state is increased to Q. The transformed ions are either directed towards a dedicated experiment requiring highly charged ions, or post-accelerated to higher beam energies. In this paper the physics processes involved in the production of highly charged ions will be introduced, and the injection and extraction beam parameters of the charge breeder defined. A description of the three main charge-breeding methods is given, namely: electron stripping in gas jet or foil; external ion injection into an electron-beam ion source/trap (EBIS/T); and external ion injection into an electron cyclotron resonance ion source (ECRIS). In addition, some preparatory devices for charge breeding and practical beam delivery aspects ...

  20. Genetic diversity of eleven European pig breeds

    Directory of Open Access Journals (Sweden)

    Foulley Jean-Louis

    2000-03-01

    Full Text Available Abstract A set of eleven pig breeds originating from six European countries, and including a small sample of wild pigs, was chosen for this study of genetic diversity. Diversity was evaluated on the basis of 18 microsatellite markers typed over a total of 483 DNA samples collected. Average breed heterozygosity varied from 0.35 to 0.60. Genotypic frequencies generally agreed with Hardy-Weinberg expectations, apart from the German Landrace and Schwäbisch-Hällisches breeds, which showed significantly reduced heterozygosity. Breed differentiation was significant as shown by the high among-breed fixation index (overall FST = 0.27, and confirmed by the clustering based on the genetic distances between individuals, which grouped essentially all individuals in 11 clusters corresponding to the 11 breeds. The genetic distances between breeds were first used to construct phylogenetic trees. The trees indicated that a genetic drift model might explain the divergence of the two German breeds, but no reliable phylogeny could be inferred among the remaining breeds. The same distances were also used to measure the global diversity of the set of breeds considered, and to evaluate the marginal loss of diversity attached to each breed. In that respect, the French Basque breed appeared to be the most "unique" in the set considered. This study, which remains to be extended to a larger set of European breeds, indicates that using genetic distances between breeds of farm animals in a classical taxonomic approach may not give clear resolution, but points to their usefulness in a prospective evaluation of diversity.

  1. Breeding without breeding: is a complete pedigree necessary for efficient breeding?

    Directory of Open Access Journals (Sweden)

    Yousry A El-Kassaby

    Full Text Available Complete pedigree information is a prerequisite for modern breeding and the ranking of parents and offspring for selection and deployment decisions. DNA fingerprinting and pedigree reconstruction can substitute for artificial matings, by allowing parentage delineation of naturally produced offspring. Here, we report on the efficacy of a breeding concept called "Breeding without Breeding" (BwB that circumvents artificial matings, focusing instead on a subset of randomly sampled, maternally known but paternally unknown offspring to delineate their paternal parentage. We then generate the information needed to rank those offspring and their paternal parents, using a combination of complete (full-sib: FS and incomplete (half-sib: HS analyses of the constructed pedigrees. Using a random sample of wind-pollinated offspring from 15 females (seed donors, growing in a 41-parent western larch population, BwB is evaluated and compared to two commonly used testing methods that rely on either incomplete (maternal half-sib, open-pollinated: OP or complete (FS pedigree designs. BwB produced results superior to those from the incomplete design and virtually identical to those from the complete pedigree methods. The combined use of complete and incomplete pedigree information permitted evaluating all parents, both maternal and paternal, as well as all offspring, a result that could not have been accomplished with either the OP or FS methods alone. We also discuss the optimum experimental setting, in terms of the proportion of fingerprinted offspring, the size of the assembled maternal and paternal half-sib families, the role of external gene flow, and selfing, as well as the number of parents that could be realistically tested with BwB.

  2. A high-resolution map of the Nile tilapia genome: a resource for studying cichlids and other percomorphs

    Directory of Open Access Journals (Sweden)

    Guyon Richard

    2012-06-01

    Full Text Available Abstract Background The Nile tilapia (Oreochromis niloticus is the second most farmed fish species worldwide. It is also an important model for studies of fish physiology, particularly because of its broad tolerance to an array of environments. It is a good model to study evolutionary mechanisms in vertebrates, because of its close relationship to haplochromine cichlids, which have undergone rapid speciation in East Africa. The existing genomic resources for Nile tilapia include a genetic map, BAC end sequences and ESTs, but comparative genome analysis and maps of quantitative trait loci (QTL are still limited. Results We have constructed a high-resolution radiation hybrid (RH panel for the Nile tilapia and genotyped 1358 markers consisting of 850 genes, 82 markers corresponding to BAC end sequences, 154 microsatellites and 272 single nucleotide polymorphisms (SNPs. From these, 1296 markers could be associated in 81 RH groups, while 62 were not linked. The total size of the RH map is 34,084 cR3500 and 937,310 kb. It covers 88% of the entire genome with an estimated inter-marker distance of 742 Kb. Mapping of microsatellites enabled integration to the genetic map. We have merged LG8 and LG24 into a single linkage group, and confirmed that LG16-LG21 are also merged. The orientation and association of RH groups to each chromosome and LG was confirmed by chromosomal in situ hybridizations (FISH of 55 BACs. Fifty RH groups were localized on the 22 chromosomes while 31 remained small orphan groups. Synteny relationships were determined between Nile tilapia, stickleback, medaka and pufferfish. Conclusion The RH map and associated FISH map provide a valuable gene-ordered resource for gene mapping and QTL studies. All genetic linkage groups with their corresponding RH groups now have a corresponding chromosome which can be identified in the karyotype. Placement of conserved segments indicated that multiple inter-chromosomal rearrangements have occurred

  3. Group-size-dependent punishment of idle subordinates in a cooperative breeder where helpers pay to stay.

    Science.gov (United States)

    Fischer, Stefan; Zöttl, Markus; Groenewoud, Frank; Taborsky, Barbara

    2014-08-22

    In cooperative breeding systems, dominant breeders sometimes tolerate unrelated individuals even if they inflict costs on the dominants. According to the 'pay-to-stay' hypothesis, (i) subordinates can outweigh these costs by providing help and (ii) dominants should be able to enforce help by punishing subordinates that provide insufficient help. This requires that dominants can monitor helping and can recognize group members individually. In a field experiment, we tested whether cooperatively breeding cichlid Neolamprologus pulcher subordinates increase their help after a forced 'idle' period, how other group members respond to a previously idle helper, and how helper behaviour and group responses depend on group size. Previously, idle helpers increased their submissiveness and received more aggression than control helpers, suggesting that punishment occurred to enforce help. Subordinates in small groups increased their help more than those in large groups, despite receiving less aggression. When subordinates were temporarily removed, dominants in small groups were more likely to evict returning subordinates. Our results suggest that only in small groups do helpers face a latent threat of punishment by breeders as predicted by the pay-to-stay hypothesis. In large groups, cognitive constraints may prevent breeders from tracking the behaviour of a large number of helpers.

  4. Breeding schemes in reindeer husbandry

    Directory of Open Access Journals (Sweden)

    Lars Rönnegård

    2003-04-01

    Full Text Available The objective of the paper was to investigate annual genetic gain from selection (G, and the influence of selection on the inbreeding effective population size (Ne, for different possible breeding schemes within a reindeer herding district. The breeding schemes were analysed for different proportions of the population within a herding district included in the selection programme. Two different breeding schemes were analysed: an open nucleus scheme where males mix and mate between owner flocks, and a closed nucleus scheme where the males in non-selected owner flocks are culled to maximise G in the whole population. The theory of expected long-term genetic contributions was used and maternal effects were included in the analyses. Realistic parameter values were used for the population, modelled with 5000 reindeer in the population and a sex ratio of 14 adult females per male. The standard deviation of calf weights was 4.1 kg. Four different situations were explored and the results showed: 1. When the population was randomly culled, Ne equalled 2400. 2. When the whole population was selected on calf weights, Ne equalled 1700 and the total annual genetic gain (direct + maternal in calf weight was 0.42 kg. 3. For the open nucleus scheme, G increased monotonically from 0 to 0.42 kg as the proportion of the population included in the selection programme increased from 0 to 1.0, and Ne decreased correspondingly from 2400 to 1700. 4. In the closed nucleus scheme the lowest value of Ne was 1300. For a given proportion of the population included in the selection programme, the difference in G between a closed nucleus scheme and an open one was up to 0.13 kg. We conclude that for mass selection based on calf weights in herding districts with 2000 animals or more, there are no risks of inbreeding effects caused by selection.

  5. Social and reproductive physiology and behavior of the Neotropical cichlid fish Cichlasoma dimerus under laboratory conditions

    Directory of Open Access Journals (Sweden)

    Felipe Alonso

    Full Text Available In this work we describe for the first time the social and reproductive behavior of the Neotropical fish Cichlasoma dimerus (Heckel, 1840 [Perciformes: Cichlidae], endemic to the Paraná River basin, using a comprehensive-integral approach, including morphological and physiological features. This substrate breeding fish has biparental care of the fry and presents a dominance hierarchy that determines access to breeding territories among males, and to males with territories among females. Gregarious behavior associated with a pale body color, was observed before reproductive behaviors started. Afterwards, a dominance hierarchy was established through aggressive interactions. Territorial individuals had bright body color patterns and non territorial an opaque grey one. Black ventral coloration was associated with reproductive individuals. Courtship displays, which were similar to threatening displays, had the common effect of increasing the visible area of the individual. The dominant male was always the largest one suggesting that size is probably a major factor determining the hierarchy establishment and that these intra-sexually selected traits may have been reinforced by inter-sexual selection. Reproductive males had higher pituitary levels of β-follicle stimulating hormone (β-FSH and somatolactin (SL than non reproductive ones, while no differences were found among females. No differences were found among male gonadosomatic indexes. Non reproductive individuals had higher plasma cortisol levels for both sexes. It is possible that dominant reproductive individuals may be inhibiting reproduction of subordinate fish through physical contact, increasing their cortisol levels and diminishing FSH and SL pituitary content. However, this was not reflected as an inhibition at the gonadal level in our experimental design.

  6. High frequency of multiple paternity in broods of a socially monogamous cichlid fish with biparental nest defence.

    Science.gov (United States)

    Sefc, Kristina M; Mattersdorfer, Karin; Sturmbauer, Christian; Koblmüller, Stephan

    2008-05-01

    In several animal taxa, genetic analyses have demonstrated that social monogamy and biparental brood care do not preclude polygamous reproduction. Few studies have been conducted in fish, but in fish species without alternative reproductive phenotypes, social monogamy was largely congruent with genetic parentage. In contrast to these findings, we report an exceptionally high level of multiple paternity in a socially monogamous cichlid fish with biparental nest defence (Variabilichromis moorii), inferred from microsatellite and mitochondrial data of 10 broods. Whereas all offspring in a nest shared a common mother, each brood was sired by 2 to > 10 males. None of the inferred sires was assigned a large proportion of the brood. Paternity was estimated as the minimum number of sires required to explain multilocus offspring genotypes, and as the maximum-likelihood number of sires given population allele frequencies. Analysis of simulated brood genotypes suggested that, although these two methods tend to under- and overestimate, respectively, the true number of sires, primary sires with many offspring in a brood would have been detected. Hence, the genetic data indicate that the nest tending males suffer substantial cuckoldry and provide alloparental care for a large number of unrelated fry. We have no data on the social status of the cuckolding males, but due to synchronous spawning of pairs and commitment to brood care of paired males, it is possible that most of the parasitic spawners are solitary males.

  7. Acquisition of Lateralized Predation Behavior Associated with Development of Mouth Asymmetry in a Lake Tanganyika Scale-Eating Cichlid Fish.

    Directory of Open Access Journals (Sweden)

    Yuichi Takeuchi

    Full Text Available The scale-eating cichlid Perissodus microlepis with asymmetric mouth is an attractive model of behavioral laterality: each adult tears off scales from prey fishes' left or right flanks according to the direction in which its mouth is skewed. To investigate the development of behavioral laterality and mouth asymmetry, we analyzed stomach contents and lower jaw-bone asymmetry of various-sized P. microlepis (22 ≤ SL<115 mm sampled in Lake Tanganyika. The shapes of the pored scales found in each specimen's stomach indicated its attack side preference. Early-juvenile specimens (SL<45 mm feeding mainly on zooplankton exhibited slight but significant mouth asymmetry. As the fish acquired scale-eating (45 mm ≤ SL, attack side preference was gradually strengthened, as was mouth asymmetry. Among size-matched individuals, those with more skewed mouths ate more scales. These findings show that behavioral laterality in scale-eating P. microlepis is established in association with development of mouth asymmetry which precedes the behavioral acquisition, and that this synergistic interaction between physical and behavioral literalities may contribute to efficient scale-eating.

  8. High levels of interspecific gene flow in an endemic cichlid fish adaptive radiation from an extreme lake environment.

    Science.gov (United States)

    Ford, Antonia G P; Dasmahapatra, Kanchon K; Rüber, Lukas; Gharbi, Karim; Cezard, Timothee; Day, Julia J

    2015-07-01

    Studying recent adaptive radiations in isolated insular systems avoids complicating causal events and thus may offer clearer insight into mechanisms generating biological diversity. Here, we investigate evolutionary relationships and genomic differentiation within the recent radiation of Alcolapia cichlid fish that exhibit extensive phenotypic diversification, and which are confined to the extreme soda lakes Magadi and Natron in East Africa. We generated an extensive RAD data set of 96 individuals from multiple sampling sites and found evidence for genetic admixture between species within Lake Natron, with the highest levels of admixture between sympatric populations of the most recently diverged species. Despite considerable environmental separation, populations within Lake Natron do not exhibit isolation by distance, indicating panmixia within the lake, although individuals within lineages clustered by population in phylogenomic analysis. Our results indicate exceptionally low genetic differentiation across the radiation despite considerable phenotypic trophic variation, supporting previous findings from smaller data sets; however, with the increased power of densely sampled SNPs, we identify genomic peaks of differentiation (FST outliers) between Alcolapia species. While evidence of ongoing gene flow and interspecies hybridization in certain populations suggests that Alcolapia species are incompletely reproductively isolated, the identification of outlier SNPs under diversifying selection indicates the radiation is undergoing adaptive divergence.

  9. Indirect mate choice, direct mate choice and species recognition in a bower-building cichlid fish lek.

    Science.gov (United States)

    Genner, M J; Young, K A; Haesler, M P; Joyce, D A

    2008-09-01

    Sexual selection arising through female mate choice typically favours males with larger, brighter and louder signals. A critical challenge in sexual selection research is to determine the degree to which this pattern results from direct mate choice, where females select individual males based on variation in signalling traits, or indirect mate choice, where male competition governs access to reproductively active females. We investigated female mate choice in a lekking Lake Malawi cichlid fish, Hemitilapia oxyrhynchus, in which males build and aggressively defend sand 'bowers'. Similar to previous studies, we found that male reproductive success was positively associated with bower height and centrality on the lek. However, this pattern resulted from males holding these territories encountering more females, and thus their greater success was due to indirect mate choice. Following initial male courtship, an increase in the relative mating success of some males was observed, but this relative increase was unrelated to bower size or position. Crucially, experimentally manipulating bowers to resemble those of a co-occurring species had no appreciable effect on direct choice by females or male spawning success. Together, these results suggest indirect mate choice is the dominant force determining male-mating success in this species, and that bowers are not signals used in direct mate choice by females. We propose that, in this species, bowers have a primary function in intraspecific male competition, with the most competitive males maintaining larger and more central bowers that are favoured by sexual selection due to higher female encounter rates.

  10. Breeding for behavioural change in farm animails

    DEFF Research Database (Denmark)

    Sandøe, Peter; D'eath, RB; Lawrence, AB

    2009-01-01

    examples, such as breeding for good maternal behaviour, could enhance welfare, production and naturalness, although dilemmas emerge where improved welfare could result from breeding away from natural behaviour. Selection against certain behaviours may carry a risk of creating animals which are generally......In farm animal breeding, behavioural traits are rarely included in selection programmes despite their potential to improve animal production and welfare. Breeding goals have been broadened beyond production traits in most farm animal species to include health and functional traits......, and opportunities exist to increase the inclusion of behaviour in breeding indices. On a technical level, breeding for behaviour presents a number of particular challenges compared to physical traits. It is much more difficult and time-consuming to directly measure behaviour in a consistent and reliable manner...

  11. Breeding of speciality maize for industrial purposes

    OpenAIRE

    2010-01-01

    The breeding programme on speciality maize with specific traits was established at the Maize Research Institute, Zemun Polje, several decades ago. The initial material was collected, new methods applying to breeding of speciality maize, i.e. popping maize, sweet maize and white-seeded maize, were introduced. The aim was to enhance and improve variability of the initial material for breeding these three types of maize. Then, inbred lines of good combining abilities were developed and used as c...

  12. Development Of Space Breeding In China

    Institute of Scientific and Technical Information of China (English)

    Liu Luxiang

    2009-01-01

    @@ Space breeding provides a new technical platform for Chinese agricaltural scientists to explore the mechanism of crop mutation induced during spaceflight and breeds new varieties of crops. It is important for China to develop the space breeding industry,maintain China's lead position in this field,serve agricultural production better,promote China's sustainable and healthy agricultural development,and ensure national food safety.

  13. The Breeding Bird Survey, 1966

    Science.gov (United States)

    Robbins, C.S.; Van Velzen, W.T.

    1967-01-01

    A Breeding Bird Survey of a large section on North America was conducted during June 1966. Cooperators ran a total of 585 Survey routes in 26 eastern States and 4 Canadian Provinces. Future coverage of established routes will enable changes in the abundance of North American breeding birds to be measured. Routes are selected at random on the basis of one-degree blocks of latitude and longitude. Each 241/2-mile route, with 3-minute stops spaced one-half mile apart, is driven by automobile. All birds heard or seen at the stops are recorded on special forms and the data are then transferred to machine punch cards. The average number of birds per route is tabulated by State, along with the total number of each species and the percent of routes and stops upon which they were recorded. Maps are presented showing the range and abundance of selected species. Also, a year-to-year comparison is made of populations of selected species on Maryland routes in 1965 and 1966.

  14. Genomics-assisted breeding in fruit trees.

    Science.gov (United States)

    Iwata, Hiroyoshi; Minamikawa, Mai F; Kajiya-Kanegae, Hiromi; Ishimori, Motoyuki; Hayashi, Takeshi

    2016-01-01

    Recent advancements in genomic analysis technologies have opened up new avenues to promote the efficiency of plant breeding. Novel genomics-based approaches for plant breeding and genetics research, such as genome-wide association studies (GWAS) and genomic selection (GS), are useful, especially in fruit tree breeding. The breeding of fruit trees is hindered by their long generation time, large plant size, long juvenile phase, and the necessity to wait for the physiological maturity of the plant to assess the marketable product (fruit). In this article, we describe the potential of genomics-assisted breeding, which uses these novel genomics-based approaches, to break through these barriers in conventional fruit tree breeding. We first introduce the molecular marker systems and whole-genome sequence data that are available for fruit tree breeding. Next we introduce the statistical methods for biparental linkage and quantitative trait locus (QTL) mapping as well as GWAS and GS. We then review QTL mapping, GWAS, and GS studies conducted on fruit trees. We also review novel technologies for rapid generation advancement. Finally, we note the future prospects of genomics-assisted fruit tree breeding and problems that need to be overcome in the breeding.

  15. Chemical classification of cattle. 1. Breed groups.

    Science.gov (United States)

    Baker, C M; Manwell, C

    1980-01-01

    From approximately 1000 papers with data on protein polymorphism in some 216 breeds of cattle, 10 polymorphic proteins were compared in means and variances of gene frequencies (arcsin p 1/2) for ten well-recognized breed groups for 196 of the breeds. The polymorphic proteins were alpha-lactalbumin, beta-lactoglobulin, caseins (alpha s1, beta and chi), serum albumin, transferrin, haemoglobin, amylase I and carbonic anhydrase II. The breed groups were North European, Pied Lowland, European Red brachyceros, Channel Island brachyceros, Upland brachyceros, primigenius-brachyceros mixed, primigenius, Indian Zebu, African Humped (with Zebu admixture), and African Humped (Sanga). The coherence within groups and the differences between groups are often impressive. Only carbonic anhydrase II fails to differentiate at least some of the major breed groups. In some cases paradoxical distributions of rare genetic variants can be explained by a more detailed inspection of breed history. The chemical data support the morphological and geographical divisions of cattle into major breed groups. There are three distinct but related brachyceros groups; for some polymorphisms the two Channel Island breeds, the Jersey and the Guernsey, are quite divergent. Although some authorities have considered the Pied Lowland as primigenius, it is a very distinct breed group.

  16. Genetic mapping of horizontal stripes in Lake Victoria cichlid fishes: benefits and pitfalls of using RAD markers for dense linkage mapping.

    Science.gov (United States)

    Henning, Frederico; Lee, Hyuk Je; Franchini, Paolo; Meyer, Axel

    2014-11-01

    The genetic dissection of naturally occurring phenotypes sheds light on many fundamental and longstanding questions in speciation and adaptation and is a central research topic in evolutionary biology. Until recently, forward-genetic approaches were virtually impossible to apply to nonmodel organisms, but the development of next-generation sequencing techniques eases this difficulty. Here, we use the ddRAD-seq method to map a colour trait with a known adaptive function in cichlid fishes, well-known textbook examples for rapid rates of speciation and astonishing phenotypic diversification. A suite of phenotypic key innovations is related to speciation and adaptation in cichlids, among which body coloration features prominently. The focal trait of this study, horizontal stripes, evolved in parallel in several cichlid radiations and is associated with piscivorous foraging behaviour. We conducted interspecific crosses between Haplochromis sauvagei and H. nyererei and constructed a linkage map with 867 SNP markers distributed on 22 linkage groups and total size of 1130.63 cM. Lateral stripes are inherited as a Mendelian trait and map to a single genomic interval that harbours a paralog of a gene with known function in stripe patterning. Dorsolateral and mid-lateral stripes were always coinherited and are thus under the same genetic control. Additionally, we directly quantify the genotyping error rates in RAD markers and offer guidelines for identifying and dealing with errors. Uncritical marker selection was found to severely impact linkage map construction. Fortunately, by applying appropriate quality control steps, a genotyping accuracy of >99.9% can be reached, thus allowing for efficient linkage mapping of evolutionarily relevant traits.

  17. The productivity of various pure breed and cross breed of imported pigs during lactation period

    Directory of Open Access Journals (Sweden)

    Djamuara Aritonang

    2001-03-01

    Full Text Available A study has been conducted to evaluate the productivity of pure breeds and cross breeds of imported pigs. Sixteen strains of pigs with five best sows were selected based on litter size and birth weight on the second parity. The results of the study showed that the pure breed performance was better than the cross breeds, as shown by the litter size, birth and weaned weight, less mortality, better mothering ability and better feed efficiency. Between pure breed, the Landrace and Yorkshire were better than other sows and between the cross breed, the LH and YL performed better than other crossbreeds. It is recommended that the pure breed especially Landrace and Yorkshire and LH and YL of cross breed are better than others

  18. The effect of high rearing densities on the growth of juveniles of the cichlid, cichlasoma managuense (Günther, 1869 (ESP

    Directory of Open Access Journals (Sweden)

    Jorge Günther Nonell

    2016-03-01

    Full Text Available The effect of high density culture on the growth of juvenile jaguar cichlids was investigated. Mean growth rate decrease with density, while the growth rate of the largest fishes was not affected. Reduction in mean growth resulted from a greater number of stunted individuals as well as from a higher degree of stunting. Skewness appears to be a better indicator of competitive effects than the coefficient of variation. It is concluded that at least in stagnant waters, even high densities do not affect the strong dominance hierarchy which establishes among guapote juveniles.

  19. Across Breed QTL Detection and Genomic Prediction in French and Danish Dairy Cattle Breeds

    DEFF Research Database (Denmark)

    van den Berg, Irene; Guldbrandtsen, Bernt; Hozé, C

    Our objective was to investigate the potential benefits of using sequence data to improve across breed genomic prediction, using data from five French and Danish dairy cattle breeds. First, QTL for protein yield were detected using high density genotypes. Part of the QTL detected within breed was...

  20. 78 FR 45494 - Plant Breeding Listening Session meeting

    Science.gov (United States)

    2013-07-29

    ...; ] DEPARTMENT OF AGRICULTURE Plant Breeding Listening Session meeting ACTION: Notice of a Plant Breeding... Agriculture (USDA) announces a Plant Breeding Listening Session stakeholder meeting for all interested plant breeding and cultivar development stakeholders. DATES: The Plant Breeding Listening Session will be...

  1. Breeding for Grass Seed Yield

    DEFF Research Database (Denmark)

    Boelt, Birte; Studer, Bruno

    2010-01-01

    Seed yield is a trait of major interest for many fodder and amenity grass species and has received increasing attention since seed multiplication is economically relevant for novel grass cultivars to compete in the commercial market. Although seed yield is a complex trait and affected...... by agricultural practices as well as environmental factors, traits related to seed production reveal considerable genetic variation, prerequisite for improvement by direct or indirect selection. This chapter first reports on the biological and physiological basics of the grass reproduction system, then highlights...... important aspects and components affecting the seed yield potential and the agronomic and environmental aspects affecting the utilization and realization of the seed yield potential. Finally, it discusses the potential of plant breeding to sustainably improve total seed yield in fodder and amenity grasses....

  2. Plant Breeding: Surprisingly, Less Sex Is Better.

    Science.gov (United States)

    van Dijk, Peter J; Rigola, Diana; Schauer, Stephen E

    2016-02-01

    Introduction of apomixis, asexual reproduction through seeds, into crop species has the potential to dramatically transform plant breeding. A new study demonstrates that traits can be stably transferred between generations in newly produced apomictic lines, and heralds a breeding revolution needed to increase food production for the growing planet.

  3. Lily breeding research in the Netherlands

    NARCIS (Netherlands)

    Tuyl, van J.M.; Holsteijn, van H.M.C.

    1996-01-01

    At the Centre for Plant Breeding and Reproduction Research (CPRO-DLO) in Wageningen lily breeding research in the Netherlands is concentrated. To this end sources of germplasm (genetic material) are maintained in a lily species and cultivar collection. Research is done on long term storage of this c

  4. Breeding for behavioural change in farm animals

    DEFF Research Database (Denmark)

    D'Eath, R.B.; Conington, J.; Lawrence, A.B.

    2010-01-01

    In farm animal breeding, behavioural traits are rarely included in selection programmes despite their potential to improve animal production and welfare. Breeding goals have been broadened beyond production traits in most farm animal species to include health and functional traits, and opportunit...

  5. Breed predisposition to canine gastric carcinoma

    DEFF Research Database (Denmark)

    Seim-Wikse, Tonje; Jörundsson, Einar; Nødtvedt, Ane;

    2013-01-01

    Previous research has indicated a breed predisposition to gastric carcinoma in dogs. However, results to date are inconsistent since several studies have failed to prove such a predisposition. Better knowledge of breeds at risk could facilitate early detection of gastric carcinoma in dogs. The ai...

  6. Genetic diversity of 11 European pig breeds

    NARCIS (Netherlands)

    Lavall, G.; Iannuccelli, N.; Legault, C.; Milan, D.; Groenen, M.A.M.; Andersson, L.; Fredholm, M.; Geldermann, H.; Foulley, J.L.; Chevalet, C.; Ollivier, L.

    2000-01-01

    A set of eleven pig breeds originating from six European countries, and including a small sample of wild pigs, was chosen for this study of genetic diversity. Diversity was evaluated on the basis of 18 microsatellite markers typed over a total of 483 DNA samples collected. Average breed heterozygosi

  7. Cattle breeding goals and production circumstances.

    NARCIS (Netherlands)

    Groen, A.F.

    1989-01-01

    This thesis gives the results of a study on the relationship between cattle breeding goals and production circumstances. The relationship between breeding goals and production circumstances mostly arises from the influences of production circumstances on the economic values of geneticim

  8. Impact of selective breeding on European aquaculture

    NARCIS (Netherlands)

    Janssen, K.; Chavanne, H.; Berentsen, P.; Komen, H.

    2016-01-01

    Objectives of this study were to determine the combined market share of breeding companies in aquaculture production in Europe, to describe the main characteristics of breeding companies and their programs, and to provide per species estimates on cumulative genetic gain in growth performance. Sur

  9. Breed predisposition to canine gastric carcinoma

    DEFF Research Database (Denmark)

    Seim-Wikse, Tonje; Jörundsson, Einar; Nødtvedt, Ane

    2013-01-01

    Previous research has indicated a breed predisposition to gastric carcinoma in dogs. However, results to date are inconsistent since several studies have failed to prove such a predisposition. Better knowledge of breeds at risk could facilitate early detection of gastric carcinoma in dogs. The ai...... of the study was to retrospectively investigate the proportion and possible breed predisposition to canine gastric carcinoma using the Norwegian Canine Cancer Register for calculations of proportional morbidity ratios (PMRs) for the period 1998-2009.......Previous research has indicated a breed predisposition to gastric carcinoma in dogs. However, results to date are inconsistent since several studies have failed to prove such a predisposition. Better knowledge of breeds at risk could facilitate early detection of gastric carcinoma in dogs. The aim...

  10. Selection criteria in organic cattle breeding

    Directory of Open Access Journals (Sweden)

    Savić Mila

    2014-01-01

    Full Text Available The central issue in process of organizing organic cattle breeding is the knowledge about specificities of this kind of production, good knowledge of breed characteristics (body composition, immune tolerance, expressed predisposition towards some diseases, production properties. Research centres, in collaboration with producers, have defined the essential features on which the selection programmes in organic cattle breeding are based on. Of the greatest importance for veterinary service is the fact that selection programmes in organic cattle breeding are in the first place based on giving priority to healthy animals, with strong immune system, good reproductive characteristics, which can be in production system for a long period. Additional important selective criteria is specific body resistance and adaptability of autochtonous breeds to environmental conditions. [Projekat Ministarstva nauke Republike Srbije, br. TP 31085

  11. Patterns of molecular genetic variation among cat breeds.

    Science.gov (United States)

    Menotti-Raymond, Marilyn; David, Victor A; Pflueger, Solveig M; Lindblad-Toh, Kerstin; Wade, Claire M; O'Brien, Stephen J; Johnson, Warren E

    2008-01-01

    Genetic variation in cat breeds was assessed utilizing a panel of short tandem repeat (STR) loci genotyped in 38 cat breeds and 284 single-nucleotide polymorphisms (SNPs) genotyped in 24 breeds. Population structure in cat breeds generally reflects their recent ancestry and absence of strong breed barriers between some breeds. There is a wide range in the robustness of population definition, from breeds demonstrating high definition to breeds with as little as a third of their genetic variation partitioning into a single population. Utilizing the STRUCTURE algorithm, there was no clear demarcation of the number of population subdivisions; 16 breeds could not be resolved into independent populations, the consequence of outcrossing in established breeds to recently developed breeds with common ancestry. These 16 breeds were divided into 6 populations. Ninety-six percent of cats in a sample set of 1040 were correctly assigned to their classified breed or breed group/population. Average breed STR heterozygosities ranged from moderate (0.53; Havana, Korat) to high (0.85; Norwegian Forest Cat, Manx). Most of the variation in cat breeds was observed within a breed population (83.7%), versus 16.3% of the variation observed between populations. The hierarchical relationships of cat breeds is poorly defined as demonstrated by phylogenetic trees generated from both STR and SNP data, though phylogeographic grouping of breeds derived completely or in part from Southeast Asian ancestors was apparent.

  12. Variable light environments induce plastic spectral tuning by regional opsin coexpression in the African cichlid fish, Metriaclima zebra.

    Science.gov (United States)

    Dalton, Brian E; Lu, Jessica; Leips, Jeff; Cronin, Thomas W; Carleton, Karen L

    2015-08-01

    Critical behaviours such as predation and mate choice often depend on vision. Visual systems are sensitive to the spectrum of light in their environment, which can vary extensively both within and among habitats. Evolutionary changes in spectral sensitivity contribute to divergence and speciation. Spectral sensitivity of the retina is primarily determined by visual pigments, which are opsin proteins bound to a chromophore. We recently discovered that photoreceptors in different regions of the retina, which view objects against distinct environmental backgrounds, coexpress different pairs of opsins in an African cichlid fish, Metriaclima zebra. This coexpression tunes the sensitivity of the retinal regions to the corresponding backgrounds and may aid in detection of dark objects, such as predators. Although intraretinal regionalization of spectral sensitivity in many animals correlates with their light environments, it is unknown whether variation in the light environment induces developmentally plastic alterations of intraretinal sensitivity regions. Here, we demonstrate with fluorescent in situ hybridization and qPCR that the spectrum and angle of environmental light both influence the development of spectral sensitivity regions by altering the distribution and level of opsins across the retina. Normally, M. zebra coexpresses LWS opsin with RH2Aα opsin in double cones of the ventral but not the dorsal retina. However, when illuminated from below throughout development, adult M. zebra coexpressed LWS and RH2Aα in double cones both dorsally and ventrally. Thus, environmental background spectra alter the spectral sensitivity pattern that develops across the retina, potentially influencing behaviours and related evolutionary processes such as courtship and speciation.

  13. Fighting and assessment in male cichlid fish: the effects of asymmetries in gonadal state and body size.

    Science.gov (United States)

    Neat; Huntingford; Beveridge

    1998-04-01

    In fights between animals over limited resources, the larger contestant often wins. Game theoretical models of animal fighting predict that relative body size is assessed during the fight and thus determines fight duration and intensity. In addition, if the contestants differ in the value they place on the disputed resource, this can also influence the outcome, duration and intensity of the fight. We studied territorial fighting in a cichlid fish, Tilapia zillii, in relation to relative body size and gonad weight. Relative gonad weight was a much stronger predictor of fight outcome than relative body size, even when body weight asymmetries were as large as 30%. This suggested that males with large gonads were fighting harder to defend their territory, perhaps because the value of a territory correlates with the gonadal state of the individual. A detailed analysis of mouth wrestling observed during fighting suggested that relative body size is assessed. However, contestants smaller than their opponent often continued to fight in spite of their size disadvantage. Weight disadvantaged winners appeared to fight more fiercely as suggested by a negative correlation between weight asymmetry and the proportion of bites inflicted by the winner. During escalated fighting, winners and losers differed consistently with regard to a behaviour termed mouth locking. Although neither biting nor persistence in mouth locking was related to gonad weight, we propose that the fish may have been assessing asymmetries unrelated to relative body size and possibly more related to levels of cost and the motivation to persist. Copyright 1998 The Association for the Study of Animal Behaviour. Copyright 1998 The Association for the Study of Animal Behaviour.

  14. Experimentally increased temperature and hypoxia affect stability of social hierarchy and metabolism of the Amazonian cichlid Apistogramma agassizii.

    Science.gov (United States)

    Kochhann, Daiani; Campos, Derek Felipe; Val, Adalberto Luis

    2015-12-01

    The primary goal of this study was to understand how changes in temperature and oxygen could influence social behaviour and aerobic metabolism of the Amazonian dwarf cichlid Apistogramma agassizii. Social hierarchies were established over a period of 96h by observing the social interactions, feeding behaviour and shelter use in groups of four males. In the experimental environment, temperature was increased to 29°C in the high-temperature treatment, and oxygen lowered to 1.0mg·L(-1)O2 in the hypoxia treatment. Fish were maintained at this condition for 96h. The control was maintained at 26°C and 6.6mg·L(-1)O2. After the experimental exposure, metabolism was measured as routine metabolic rate (RMR) and electron transport system (ETS) activity. There was a reduction in hierarchy stability at high-temperature. Aggression changed after environmental changes. Dominant and subdominant fish at high temperatures increased their biting, compared with control-dominant. In contrast, hypoxia-dominant fish decreased their aggressive acts compared with all other fish. Shelter use decreased in control and hypoxic dominant fish. Dominant fish from undisturbed environments eat more than their subordinates. There was a decrease of RMR in fish exposed to the hypoxic environment when compared with control or high-temperature fish, independent of social position. Control-dominant fish had higher RMR than their subordinates. ETS activity increased in fish exposed to high temperatures; however, there was no effect on social rank. Our study reinforces the importance of environmental changes for the maintenance of hierarchies and their characteristics and highlights that most of the changes occur in the dominant position.

  15. A new cichlid fish in the Sahara: The Ounianga Serir lakes (Chad), a biodiversity hotspot in the desert.

    Science.gov (United States)

    Trape, Sébastien

    In the rare perennial bodies of water of the Sahara desert, only a few fish species have survived to increasing aridification since the end of the last humid period at the Holocene, approximately 5000 years BP. Here, I report the occurrence of an undescribed haplochomine cichlid fish in Lake Boukou, one of the seven Ounianga Serir lakes (Chad). These lakes are located in one of the most arid areas of the Sahara desert, but they persist by virtue of subsurface inflow of fresh groundwater from a large fossil aquifer. Astatotilapia tchadensis sp. nov. is characterized by a black bar between eye and corner of mouth, rounded orange spots on anal fin, scales ctenoid, lower limb of first gill arch with 7-8 gill rackers, dorsal fin with 13-14 spines and 9-11 soft rays, anal fin with 3 spines and 8-9 soft rays, 29 or 30 lateral line scales, and lower pharyngeal dentition with enlarged molariform teeth. The new species is easily distinguished from A. desfontainii and A. flaviijosephii, the northernmost haplochromine species currently isolated from its other group members, and appears close to an unnamed species of Lake Chad basin. Ounianga Serir lakes and especially Lake Boukou present a remarkable diversity of fish, the highest known in the Sahara desert with a total of at least six fish species belonging to six genera and three families. They also constitute an exceptional natural landscape inscribed on the UNESCO world heritage list in 2012 and a biodiversity hotspot for desert vertebrate species.

  16. Evidence for the involvement of dopamine in stress-induced suppression of reproduction in the cichlid fish Oreochromis mossambicus.

    Science.gov (United States)

    Chabbi, A; Ganesh, C B

    2015-05-01

    In the present study, we examined whether stress-induced suppression of reproduction is mediated through the catecholaminergic neurotransmitter dopamine (DA) in the female cichlid fish Oreochromis mossambicus. In the first experiment, application of antibody against tyrosine hydroxylase (TH; a marker for DA) in brain sections revealed the presence of intensely stained TH immunoreactive cells in the preoptic area (POA) and nucleus preopticus (NPO) during the previtellogenic phase. These cells showed weak immunoreactivity during the vitellogenic and prespawning phases concomitant with darkly stained luteinising hormone (LH) immunoreactive content in the proximal pars distalis (PPD) of the pituitary gland and fully ripened follicles (stage V) in the ovary of control fish. However, in fish exposed to aquacultural stressors, TH secreting cells remained intensely stained in POA and NPO regions during the prespawning phase, indicating increased synthetic and secretory activity, which was reflected by a significantly higher DA content compared to controls. Increased DA activity as a result of stress was associated with a decrease in the LH immunoreactive content in the PPD and an absence of stage V follicles in the ovary. In the second experiment, administration of DA caused effects similar to those in stressed fish, whereas DA receptor antagonist domperidone (DOM) treatment significantly increased the LH content in the PPD and the number of stage V follicles in unstressed fish. On the other hand, treatment of stressed fish with DOM resulted in dark accumulations of LH immunoreactive content in the PPD accompanied by the presence of stage V follicles in the ovary. Taken together, these results suggest an additional pathway for the inhibitory effects of stress through dopaminergic neurones along the reproductive axis.

  17. Cytogenetic mapping of the retroelements Rex1, Rex3 and Rex6 among cichlid fish: new insights on the chromosomal distribution of transposable elements.

    Science.gov (United States)

    Valente, G T; Mazzuchelli, J; Ferreira, I A; Poletto, A B; Fantinatti, B E A; Martins, C

    2011-01-01

    To enhance our understanding of the organization of the genome and chromosome evolution of cichlid fish species, we have isolated and physically mapped onto the chromosomes the transposable elements (TEs) Rex1, Rex3 and Rex6, which are conserved in teleost fish, in the chromosomes of African and South American cichlid species. The physical mapping of different Rex elements showed that they are primarily compartmentalized in the pericentromeric heterochromatic regions, although dispersed or clustered signals in euchromatic regions were also observed. The presence of TEs in heterochromatin can be correlated with their role in the structure and organization of heterochromatic areas (such as centromeres) or with the lower selective pressure that act on these gene-poor regions. The Rex elements were also concentrated in the largest chromosome pair of the Nile tilapia, Oreochromis niloticus. This chromosome pair is supposed to have originated by fusions, demonstrating the possible involvement of TEs with chromosome rearrangements. Besides general patterns of chromosomal distribution, comparative analysis suggests that Rex elements could differ in their chromosomal distribution among different fish groups or species and that intrinsic aspects of the genomes could influence the spread, accumulation or elimination of TEs.

  18. Breeding objectives for Targhee sheep.

    Science.gov (United States)

    Borg, R C; Notter, D R; Kuehn, L A; Kott, R W

    2007-11-01

    Breeding objectives were developed for Targhee sheep under rangeland production conditions. Traits considered were those for which EPD were available from the US National Sheep Improvement Program and included direct and maternal effects on 120-d weaning weight (WW and MM, respectively); yearling weight (YW); yearling fleece weight, fiber diameter, and staple length; and percent lamb crop (PLC), measured as the number of lambs born per 100 ewes lambing. A bioeconomic model was used to predict the effects of a change of 1 additive SD in EPD for each trait, holding all other traits constant at their mean, on animal performance, feed requirements, feed costs, and economic returns. Resulting economic weightings were then used to derive selection indexes. Indexes were derived separately for 3 prolificacy levels (1.41, 1.55, and 1.70 lambs/ewe lambing), 2 triplet survival levels (50 and 67%), 2 lamb pricing policies (with or without discounting of prices for heavy feeder lambs), and 3 forage cost scenarios (renting pasture, purchasing hay, or reducing flock size to accommodate increased nutrient requirements for production). Increasing PLC generally had the largest impact on profitability, although an increase in WW was equally important, with low feed costs and no discounting of prices for heavy feeder lambs. Increases in PLC were recommended at all 3 prolificacy levels, but with low triplet survival the value of increasing PLC eventually declined as the mean litter size increased to approximately 2.15 lambs/ewe lambing and above. Increasing YW (independent of WW) increased ewe maintenance costs and reduced profitability. Predicted changes in breeding values for WW and YW under index selection varied with lamb pricing policy and feed costs. With low feed costs or no discounts for heavy lambs, YW increased at a modest rate in association with increasing WW, but with high feed costs or discounting of heavy lambs, genetic trends in WW were reduced by approximately 50% to

  19. Advances in Japanese pear breeding in Japan.

    Science.gov (United States)

    Saito, Toshihiro

    2016-01-01

    The Japanese pear (Pyrus pyrifolia Nakai) is one of the most widely grown fruit trees in Japan, and it has been used throughout Japan's history. The commercial production of pears increased rapidly with the successive discoveries of the chance seedling cultivars 'Chojuro' and 'Nijisseiki' around 1890, and the development of new cultivars has continued since 1915. The late-maturing, leading cultivars 'Niitaka' and 'Shinko' were released during the initial breeding stage. Furthermore, systematic breeding by the Horticultural Research Station (currently, NARO Institute of Fruit Tree Science, National Agriculture and Food Research Organization (NIFTS)) began in 1935, which mainly aimed to improve fruit quality by focusing on flesh texture and black spot disease resistance. To date, 22 cultivars have been released, including 'Kosui', 'Hosui', and 'Akizuki', which are current leading cultivars from the breeding program. Four induced mutant cultivars induced by gamma irradiation, which exhibit some resistance to black spot disease, were released from the Institute of Radiation Breeding. Among these cultivars, 'Gold Nijisseiki' has become a leading cultivar. Moreover, 'Nansui' from the Nagano prefectural institute breeding program was released, and it has also become a leading cultivar. Current breeding objectives at NIFTS mainly combine superior fruit quality with traits related to labor and cost reduction, multiple disease resistance, or self-compatibility. Regarding future breeding, marker-assisted selection for each trait, QTL analyses, genome-wide association studies, and genomic selection analyses are currently in progress.

  20. LINE CONSTRUCTION OF NONIUS BREED IN SLOVAKIA

    Directory of Open Access Journals (Sweden)

    Eva Mlyneková

    2013-12-01

    Full Text Available Nowadays breeding has become the problem often solved in European states and it has been paid much attention by breeding organizations. In terms of hippology as well as some urgent requirements from the side of nonius breeders we have focussed on this particular breed especially from the reason of its further survival and development in Slovakia. The aim of this paper was to evaluate the growth indicators as well as the achievement level of the stallions since 1927 to the present. Based on our research of the nonius body lines we can state that at present there are 3 stallions that are followers of the N VIII horse line founder. In general, there are 12 stallions that are active within this breed in Slovakia. It was statistically confirmed that this particular breed grew much stronger through the goal-directed breeding work, improved nutrition as well as the immediate breeding site. It was quite complicated to evaluate the performance tests because the individual indicators were significantly influenced by the subjective views of the commitee members performing the evaluation. The next factor which prevents the objective evaluation is the fact that in the period up to 1979, the performance tests were valued by the 100 point system and from the year 1980 by the 10 point system. That is why we take the performance test results into account only as supplemental ones, which can provide a kind of amendment to the observed biological parameters.

  1. Breeding Practices in Sheep Farming

    Directory of Open Access Journals (Sweden)

    M.A. Shejal

    2009-02-01

    Full Text Available The sheep is an important economic livestock species, contributing greatly to the Indian economy, especially in arid, semi arid and mountain areas. The current population in world is 1110.78 millions, around 44.85 millions (1987 sheeps in India (ICAR., 2002. Sheeps are mostly reared for meat and wool. The average annual wool production per sheep is between 3.5 to 5.5 kg of fine quality wool in Australia, New Zealand and U.S.S.R., where as in India except Magra sheep which annually yield more than 2 kg wool having staple length 5.8 cm, the average of rest of the wool produced is less than 1.0 kg per sheep of inferior quality (Banerjee G.C., 1998. Therefore many farmers in southern India adapted sheep rearing for meat production than for wool production. For yielding more production from sheep farming one should have sound knowledge of general information related to the reproduction and different breeding practices. [Vet. World 2009; 2(1.000: 43-44

  2. Management and Breeding Soundness of Mature Bulls.

    Science.gov (United States)

    Palmer, Colin W

    2016-07-01

    Mature bulls must be fed a balanced ration, vaccinated appropriately, and undergo a breeding soundness evaluation to ensure they meet what is required of a short, but intense breeding season. To be classified as a satisfactory potential breeder, minimum standards for physical soundness, scrotal circumference, sperm motility, and sperm morphology must be achieved using an accepted bull-breeding soundness evaluation format. Sperm production requires approximately 70 days. Heat and stress are the most common insults to spermatogenesis, causing an increase in morphologic abnormalities with obesity-associated scrotal fat accumulation being the most frequent cause of elevated testicular temperature in mature bulls.

  3. The ascent of cat breeds: genetic evaluations of breeds and worldwide random-bred populations.

    Science.gov (United States)

    Lipinski, Monika J; Froenicke, Lutz; Baysac, Kathleen C; Billings, Nicholas C; Leutenegger, Christian M; Levy, Alon M; Longeri, Maria; Niini, Tirri; Ozpinar, Haydar; Slater, Margaret R; Pedersen, Niels C; Lyons, Leslie A

    2008-01-01

    The diaspora of the modern cat was traced with microsatellite markers from the presumed site of domestication to distant regions of the world. Genetic data were derived from over 1100 individuals, representing 17 random-bred populations from five continents and 22 breeds. The Mediterranean was reconfirmed to be the probable site of domestication. Genetic diversity has remained broad throughout the world, with distinct genetic clustering in the Mediterranean basin, Europe/America, Asia and Africa. However, Asian cats appeared to have separated early and expanded in relative isolation. Most breeds were derived from indigenous cats of their purported regions of origin. However, the Persian and Japanese bobtail were more aligned with European/American than with Mediterranean basin or Asian clusters. Three recently derived breeds were not distinct from their parental breeds of origin. Pure breeding was associated with a loss of genetic diversity; however, this loss did not correlate with breed popularity or age.

  4. Waterfowl Breeding Population and Habitat Survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Waterfowl Breeding Population and Habitat Survey was initiated experimentally in 1947 and became operational in 1955. It is conducted cooperatively by the U.S....

  5. Waterfowl breeding population survey: Southern Manitoba: 1983

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for southern Manitoba during 1983. The primary purpose of the survey is to provide...

  6. Final Performance Report : Snowy Plover Breeding Distribution

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Surveys of breeding populations and nesting habitat of the snowy plover were conducted from January to August, 1989 along the Gulf Coast of Florida and Alabama....

  7. Waterfowl breeding population survey for Montana: 1993

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for Montana during 1993. The primary purpose of the survey is to provide information on...

  8. Western Ontario: Waterfowl breeding population survey: 1986

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for western Ontario during 1986. The primary purpose of the survey is to provide...

  9. Waterfowl breeding population survey for Montana: 1998

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for Montana during 1998. The primary purpose of the survey is to provide information on...

  10. Waterfowl breeding pair survey: Southern Alberta: 1981

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for southern Alberta during 1981. The primary purpose of the survey is to provide...

  11. California Least Tern Breeding Survey 1995 Season

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Sterna antillarum browni) nested at 37 sites along the coast of California. This 7% decrease in breeding population size from 1994 brings to an end the trend since...

  12. Western Ontario: Waterfowl breeding population survey: 1989

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for western Ontario during 1989. The primary purpose of the survey is to provide...

  13. Western Ontario: Waterfowl breeding population survey: 1995

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for western Ontario during 1995. The primary purpose of the survey is to provide...

  14. Western Ontario: Waterfowl breeding population survey: 1993

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for western Ontario during 1993. The primary purpose of the survey is to provide...

  15. Western Ontario: Waterfowl breeding population survey: 1994

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for western Ontario during 1994. The primary purpose of the survey is to provide...

  16. Western Ontario: Waterfowl breeding population survey: 1996

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for western Ontario during 1996. The primary purpose of the survey is to provide...

  17. Western Ontario: Waterfowl breeding population survey: 1987

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for western Ontario during 1987. The primary purpose of the survey is to provide...

  18. Western Ontario: Waterfowl breeding population survey: 1992

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for western Ontario during 1992. The primary purpose of the survey is to provide...

  19. Western Ontario: Waterfowl breeding population survey: 1990

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for western Ontario during 1990. The primary purpose of the survey is to provide...

  20. Western Ontario: Waterfowl breeding population survey: 1997

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for western Ontario during 1997. The primary purpose of the survey is to provide...

  1. Western Ontario: Waterfowl breeding population survey: 1988

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for western Ontario during 1988. The primary purpose of the survey is to provide...

  2. Prunus transcription factors: Breeding perspectives

    Directory of Open Access Journals (Sweden)

    Valmor João Bianchi

    2015-06-01

    Full Text Available Many plant processes depend on differential gene expression, which is generally controlled by complex proteins called transcription factors (TFs. In peach, 1,533 TFs have been identified, accounting for about 5.5% of the 27,852 protein-coding genes. These TFs are the reference for the rest of the Prunus species. TF studies in Prunus have been performed on the gene expression analysis of different agronomic traits, including control of the flowering process, fruit quality, and biotic and abiotic stress resistance. These studies, using quantitative RT-PCR, have mainly been performed in peach, and to a lesser extent in other species, including almond, apricot, black cherry, Fuji cherry, Japanese apricot, plum, and sour and sweet cherry. Other tools have also been used in TF studies, including cDNA-AFLP, LC-ESI-MS, RNA and DNA blotting or mapping. More recently, new tools assayed include microarray and high-throughput DNA sequencing (DNA-Seq and RNA sequencing (RNA-Seq. New functional genomics opportunities include genome resequencing and the well-known synteny among Prunus genomes and transcriptomes. These new functional studies should be applied in breeding programs in the development of molecular markers. With the genome sequences available, some strategies that have been used in model systems (such as SNP genotyping assays and genotyping-by-sequencing may be applicable in the functional analysis of Prunus TFs as well. In addition, the knowledge of the gene functions and position in the peach reference genome of the TFs represents an additional advantage. These facts could greatly facilitate the isolation of genes via QTL (quantitative trait loci map-based cloning in the different Prunus species, following the association of these TFs with the identified QTLs using the peach reference genome.

  3. Prospects for Hybrid Breeding in Bioenergy Grasses

    DEFF Research Database (Denmark)

    Aguirre, Andrea Arias; Studer, Bruno; Frei, Ursula

    2012-01-01

    of different hybrid breeding schemes to optimally exploit heterosis for biomass yield in perennial ryegrass (Lolium perenne L.) and switchgrass (Panicum virgatum), two perennial model grass species for bioenergy production. Starting with a careful evaluation of current population and synthetic breeding methods...... and MS for the two bioenergy grass species, and discuss how molecular tools and synteny can be used to transfer relevant information for genes controlling these biological mechanisms across grass species...

  4. [Pain caused by breeding: definition, judgment, pathogenesis].

    Science.gov (United States)

    Herzog, A

    1997-02-01

    Special terms of the "German Animal Protection Law (section 11b)"and the "European Agreement for Protection of Domestic Animals" particularly "torture-breeding, genetic characteristics, well-being, soundness, pains, injuries and specific use" are commented. Examples of torture-breedings are discussed: Dog (Merle-faktor, brachycephalie, atrichosis), cat (Mans-factor, W-gene, folded-ears), birds (tuffs, ear-drops, tailesness, hypertrophy of bill-warts, abnormal position of tarsal-joints, hypertrophy of imposing behavior).

  5. Citrus breeding, genetics and genomics in Japan.

    Science.gov (United States)

    Omura, Mitsuo; Shimada, Takehiko

    2016-01-01

    Citrus is one of the most cultivated fruits in the world, and satsuma mandarin (Citrus unshiu Marc.) is a major cultivated citrus in Japan. Many excellent cultivars derived from satsuma mandarin have been released through the improvement of mandarins using a conventional breeding method. The citrus breeding program is a lengthy process owing to the long juvenility, and it is predicted that marker-assisted selection (MAS) will overcome the obstacle and improve the efficiency of conventional breeding methods. To promote citrus molecular breeding in Japan, a genetic mapping was initiated in 1987, and the experimental tools and resources necessary for citrus functional genomics have been developed in relation to the physiological analysis of satsuma mandarin. In this paper, we review the progress of citrus breeding and genome researches in Japan and report the studies on genetic mapping, expression sequence tag cataloguing, and molecular characterization of breeding characteristics, mainly in terms of the metabolism of bio-functional substances as well as factors relating to, for example, fruit quality, disease resistance, polyembryony, and flowering.

  6. Testicular Histomorphometric Evaluation of Zebu Bull Breeds

    Directory of Open Access Journals (Sweden)

    Paulo Antônio Terrabuio Andreussi

    2014-12-01

    Full Text Available The objective of this study was to evaluate the quantitative histology and testicular biometrics in zebu bulls of different breeds. Testicular fragments of Nelore (n=10, Polled Nelore (n=6, Gir (n=5, Guzerat (n=5 and Tabapuã bulls (n=5 were used. The fragments were perfusion-fixed in Karnovsky solution, embedded in glycol methacrylate and stained with toluidine blue-1% sodium borate. The Nelore animals had a higher tubular volumetric proportion (85.2% and greater height of the seminiferous epithelium (73.2 µm than the Gir, Guzerat and Tabapuã breeds. The Nelore animals also had a higher volumetric proportion of Leydig cells (5.2% than the Guzerat and Tabapuã breeds. There was no significant difference for any of these parameters between the Nelore and Polled Nelore breeds. The gonadosomatic index, seminiferous tubule diameter, cross-sectional area of the seminiferous tubule and tubule length (total length and length per gram of testicular parenchyma did not vary among the breeds studied. The morphometric parameters evaluated suggested that the genetic selection applied to the Nelore and Polled Nelore breeds improved the efficiency of spermatogenesis in these breeders.

  7. Neutronic Comparison of Tritium-Breeding Performance of Candidate Tritium-Breeding Materials

    Institute of Scientific and Technical Information of China (English)

    郑善良; 吴宜灿

    2003-01-01

    Tritium self-sustainment, which will meet the fuel requirement of fusion reactor, isone of the key issues of fusion power development. The tritium breeding performances of varioustritium-breeding materials are compared based on a series of neutronics calculations using three-dimensional Monte Carlo neutron-photon transport code MCNP/4C with the IAEA FENDL-2data library. The effects of the dimensions of the tritium-breeding zone and the enrichment of 6Lion Tritium Breeding Ratio (TBR) are analyzed. The effects of Be as a neutron multiplier on TBRare also calculated.

  8. 50 CFR 15.24 - Permits for cooperative breeding.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Permits for cooperative breeding. 15.24... PLANTS WILD BIRD CONSERVATION ACT Permits and Approval of Cooperative Breeding Programs § 15.24 Permits for cooperative breeding. (a) Application requirements for permits for cooperative breeding....

  9. Strategy and Opportunity for The Development of Duck Breeding Farm

    Directory of Open Access Journals (Sweden)

    L Hardy Prasetyo

    2006-09-01

    Full Text Available The recent development of duck farming requires the availability of good quality breeding stocks commercially in order to improve productivity and efficiency . Presently, there is no commercial duck breeding farm which can produce good quality breeding stocks . This article presents information on alternatives in developing duck breeding farm, particularly for layer ducks . There are two alternative approaches in duck breeding farms : (1 Group breeding farm, which belongs to duck farmers' group, as part of a group production system, and (2 Commercial breeding farm, by an individual private company/Semi-Government Institution in a commercial scale and particularly for export market . A good breeding farm requires appropriate systems for selection and mating of the animals in order to guarantee the quality of the breeding stocks being produced . A breeding farm must be economically and technically feasible as an economic entity, so that economic analysis and marketing must be prepared seriously.

  10. Influence of altered gravity on the cytochemical localization of cytochrome oxidase activity in central and peripheral gravisensory systems in developing cichlid fish

    Science.gov (United States)

    Paulus, U.; Nindl, G.; Körtje, K. H.; Slenzka, K.; Neubert, J.; Rahmann, H.

    Cichlid fish larvae were reared from hatching to active free swimming under different gravity conditions: natural environment, increased acceleration in a centrifuge, simulated weightlessness in a clinostat and near weightlessness during space flight. Cytochrome oxidase activity was analyzed semiquantitatively on the ultrastructural level as a marker of regional neuronal activity in a primary, vestibular brainstem nucleus and in gravity receptive epithelia in the inner ear. Our results show, that gravity seems to be positively correlated with cytochrome oxidase activity in the magnocellular nucleus of developing fish brain. In the inner ear the energy metabolism is decreased under microgravity concerning utricle but not saccule. Hypergravity has not effect on cytochrome oxidase activity in sensory inner ear epithelia.

  11. Breeding programmes for smallholder sheep farming systems: II. Optimization of cooperative village breeding schemes.

    Science.gov (United States)

    Gizaw, S; van Arendonk, J A M; Valle-Zárate, A; Haile, A; Rischkowsky, B; Dessie, T; Mwai, A O

    2014-10-01

    A simulation study was conducted to optimize a cooperative village-based sheep breeding scheme for Menz sheep of Ethiopia. Genetic gains and profits were estimated under nine levels of farmers' participation and three scenarios of controlled breeding achieved in the breeding programme, as well as under three cooperative flock sizes, ewe to ram mating ratios and durations of ram use for breeding. Under fully controlled breeding, that is, when there is no gene flow between participating (P) and non-participating (NP) flocks, profits ranged from Birr 36.9 at 90% of participation to Birr 21.3 at 10% of participation. However, genetic progress was not affected adversely. When there was gene flow from the NP to P flocks, profits declined from Birr 28.6 to Birr -3.7 as participation declined from 90 to 10%. Under the two-way gene flow model (i.e. when P and NP flocks are herded mixed in communal grazing areas), NP flocks benefited from the genetic gain achieved in the P flocks, but the benefits declined sharply when participation declined beyond 60%. Our results indicate that a cooperative breeding group can be established with as low as 600 breeding ewes mated at a ratio of 45 ewes to one ram, and the rams being used for breeding for a period of two years. This study showed that farmer cooperation is crucial to effect genetic improvement under smallholder low-input sheep farming systems.

  12. Breeding barnacle geese in Kolokolkova Bay, Russia : number of breeding pairs, reproductive success and morphology

    NARCIS (Netherlands)

    van der Jeugd, HP; Gurtovaya, E; Eichhorn, G; Litvin, KY; Mineev, OY; van Eerden, M

    2003-01-01

    We report the results of an expedition to a barnacle-goose (Branta leucopsis) breeding area in Kolokolkova Bay, west of the lower Pechora delta in northern Russia, undertaken in July 2002. In total, 6 breeding colonies were found within the study area, harbouring 1,324 nests. Mean clutch size was 2.

  13. Motives and values in farming local cattle breeds in Europe: a survey on 15 breeds

    NARCIS (Netherlands)

    Gandini, G.; Avon, L.; Bohte-Wilhelmus, D.I.; Bay, E.; Colinet, F.G.; Choroszy, Z.; Diaz, C.; Duclos, D.; Fernandez, J.; Gengler, N.; Hoving-Bolink, A.H.; Kearney, F.; Lilja, T.; Mäki-Tanila, A.; Martin-Collado, D.; Maurice - Van Eijndhoven, M.H.T.; Musella, M.; Pizzi, F.; Soini, K.; Toro, M.; Turri, F.; Viinalas, H.; Hiemstra, S.J.

    2010-01-01

    Within the EURECA project (Towards self-sustainable EUropean REgional CAttle breeds), we interviewed a total of 371 farmers of 15 local cattle breeds in eight European countries. Besides collecting data on farmers, land use, herd composition and economic role of cattle, we aimed at understanding far

  14. Participatory definition of breeding objectives and selection indexes for sheep breeding in traditional systems

    NARCIS (Netherlands)

    Gizaw, S.; Lemma, S.; Komen, J.; Arendonk, van J.A.M.

    2010-01-01

    A farmer participatory approach was used to define breeding objectives and selection indexes for short-fat-tailed sheep in sheep–barley systems and Black Head Somali sheep in pastoral systems in Ethiopia. Breeding-objective traits were identified based on producers' preferences for traits collected

  15. The sub-annual breeding cycle of a tropical seabird.

    Science.gov (United States)

    Reynolds, S James; Martin, Graham R; Dawson, Alistair; Wearn, Colin P; Hughes, B John

    2014-01-01

    Breeding periodicity allows organisms to synchronise breeding attempts with the most favourable ecological conditions under which to raise offspring. For most animal species, ecological conditions vary seasonally and usually impose an annual breeding schedule on their populations; sub-annual breeding schedules will be rare. We use a 16-year dataset of breeding attempts by a tropical seabird, the sooty tern (Onychoprion fuscatus), on Ascension Island to provide new insights about this classical example of a population of sub-annually breeding birds that was first documented in studies 60 years previously on the same island. We confirm that the breeding interval of this population has remained consistently sub-annual. By ringing >17,000 birds and re-capturing a large sample of them at equivalent breeding stages in subsequent seasons, we reveal for the first time that many individual birds also consistently breed sub-annually (i.e. that sub-annual breeding is an individual as well as a population breeding strategy). Ascension Island sooty terns appear to reduce their courtship phase markedly compared with conspecifics breeding elsewhere. Our results provide rare insights into the ecological and physiological drivers of breeding periodicity, indicating that reduction of the annual cycle to just two life-history stages, breeding and moult, is a viable life-history strategy and that moult may determine the minimum time between breeding attempts.

  16. EFFECT OF BREED, SEX AND SOURCE WITHIN BREED ON THE HEAMATOGICAL PARAMETERS OF THE NIGERIAN GOATS

    Directory of Open Access Journals (Sweden)

    J.C. OKONKWO

    2011-01-01

    Full Text Available Effect of breed, sex and source within breed, together with their interactions on the haematological parameters of Nigerian goats were studied using 81 goats (comprising 9 males and 18 females per breed, objective being to characterize and outline the differences and similarities between the breeds in blood parameters. The goats were derived from different geo-ecological zones in the country based on the areas of preponderance of each breed. The breeds studied were: the Sahel goat (SG, Red Sokoto goat (RSG, and West African Dwarf goat (WADG and hematological values obtained per breed were: 22.52±1.48, 23.04±3.56, and 29.22±4.76 (%PCV; 7.52±0.50, 7.82±1.25 and 9.48±1.60 (g/dl Hb; 2.71±0.23, 3.09±0.64, and 4.10±0.42 (x1012/l RBC; 11.94±1.10, 11.32±2.03 and 9.23±0.63 (x109cells/l WBC, and 83.22±1.67, 76.72±2.30 and 73.34±3.40 (x106/mm3 MCV, respectively. Significant differences (P0.05 for all the breeds. The WADGs were superior to the RSGs and SGs in PCV, Hb, and RBC counts, but lower in WBC counts and MCV. The SGs were similar in most of the haematological profiles examined, irrespective of geo-ecological distance, indicating homogeneity of the breed. The sahelian goat breed also outscored other breeds in MCV, showing that the breed has greater propensity to transport oxygen and in situation occasioning oxygen starvation, the breed survives better. This explains the reason for the survival of the breed in arid and semi-arid zone. Gender has no effect on the MCV and the values of 83.22±1.67x106/mm3, 76.72±2.30x106/mm3 and 73.34±3.40x106/mm3 were observed for the SG, RSG, and WADG, respectively.

  17. Developments in breeding cereals for organic agriculture

    DEFF Research Database (Denmark)

    Wolfe, M.S.; Baresel, J.P.; Desclaux, D.

    2008-01-01

    The need for increased sustainability of performance in cereal varieties, particularly in organic agriculture (OA), is limited by the lack of varieties adapted to organic conditions. Here, the needs for breeding are reviewed in the context of three major marketing types, global, regional, local......, in European OA. Currently, the effort is determined, partly, by the outcomes from trials that compare varieties under OA and CA (conventional agriculture) conditions. The differences are sufficiently large and important to warrant an increase in appropriate breeding. The wide range of environments within OA...... into the crop can be helped by diversification within the crop, allowing complementation and compensation among plants. Although the problems of breeding cereals for organic farming systems are large, there is encouraging progress. This lies in applications of ecology to organic crop production, innovations...

  18. Selective breeding for scrapie resistance in sheep

    Directory of Open Access Journals (Sweden)

    Cristina Santos Sotomaior

    2012-11-01

    Full Text Available It is well known that the susceptibility of sheep to scrapie is determined by the host’s prion protein gene (PRNP. PRNP polymorphisms at codons 136 (alanine, A/valine, V, 154 (histidine, H/arginine, R and 171 (glutamine, Q/histidine, H/arginine, R are the main determinants of sheep susceptibility/resistance to classical scrapie. There are four major variants of the wild-type ARQ allele: VRQ, AHQ, ARH and ARR. Breeding programs have been developed in the European Union and the USA to increase the frequency of the resistant ARR allele while decreasing the frequency of the susceptible VRQ allele in sheep populations. In Brazil, little PRNP genotyping data are available for sheep, and thus far, no controlled breeding scheme for scrapie has been implemented. This review will focus on important epidemiological aspects of scrapie and the use of genetic resistance as a tool in breeding programs to control the disease.

  19. Under-forest Breeding Pattern and the Practice Form

    Institute of Scientific and Technical Information of China (English)

    SHEN Zhong-ming

    2012-01-01

    Through the development in recent years, China’s under-forest breeding pattern can be divided into four kinds of practice form of under-forest breeding pattern (the pattern of breeding driven by leading enterprises; the pattern of breeding driven by intermediary economic organizations; the pattern of breeding driven by the professional wholesale market; the pattern of breeding driven by the modern animal husbandry demonstration areas), according to difference in the main body participating in signing the operation contract in breeding pattern. In the production practice of under-forest breeding pattern, the most widely used and successful pattern is the pattern of breeding driven by leading enterprises and its derivative forms.

  20. MARKER ASSISTED SELECTION IN DISEASE RESISTANCE BREEDING

    Directory of Open Access Journals (Sweden)

    Narasimhulu Ragimekula

    2013-08-01

    Full Text Available Feeding ever-increasing population is the main challenge faced by the agricultural scientists and to meet this plant breeders have to put continuous efforts to develop new crop varieties on fast track basis. DNA based polymorphism, commonly known as DNA markers can be used for genetic improvement through selection for favourable traits such as disease resistance. Molecular markers are becoming an essential component in backcross breeding programs for tracking the resistance genes in gene pyramiding. Marker assisted selection (MAS, is expected to increase genetic response by affecting efficiency and accuracy of selection. Even though marker-assisted selection now plays a prominent role in the field of plant breeding, examples of successful, practical outcomes are rare. MAS, with few exceptions, has not yet delivered its expected benefits in commercial breeding. It is clear that DNA markers hold great promise, but realizing that promise remains elusive. The economic and biological constraints such as a low return of investment in small-grain cereal breeding, lack of diagnostic markers, and the prevalence of QTL-background effects hinder the broad implementation of MAS. Until complex traits can be fully dissected, the application of MAS will be limited to genes of moderate-to-large effect and to applications that do not endanger the response to conventional selection. Till then, observable phenotype will remain an important component of genetic improvement programmes, because it takes in to account the collective effect of all genes. In future, chip-based, high-throughput genotyping platforms and the introduction of genomic selection will reduce the current problems of integrating MAS in practical breeding programs and open new avenues for a molecular-based resistance breeding.

  1. Estimating superpopulation size and annual probability of breeding for pond-breeding salamanders

    Science.gov (United States)

    Kinkead, K.E.; Otis, D.L.

    2007-01-01

    It has long been accepted that amphibians can skip breeding in any given year, and environmental conditions act as a cue for breeding. In this paper, we quantify temporary emigration or nonbreeding probability for mole and spotted salamanders (Ambystoma talpoideum and A. maculatum). We estimated that 70% of mole salamanders may skip breeding during an average rainfall year and 90% may skip during a drought year. Spotted salamanders may be more likely to breed, with only 17% avoiding the breeding pond during an average rainfall year. We illustrate how superpopulations can be estimated using temporary emigration probability estimates. The superpopulation is the total number of salamanders associated with a given breeding pond. Although most salamanders stay within a certain distance of a breeding pond for the majority of their life spans, it is difficult to determine true overall population sizes for a given site if animals are only captured during a brief time frame each year with some animals unavailable for capture at any time during a given year. ?? 2007 by The Herpetologists' League, Inc.

  2. Phylogeny and biogeography of 91 species of heroine cichlids (Teleostei: Cichlidae) based on sequences of the cytochrome b gene.

    Science.gov (United States)

    Pérez, Gustavo A Concheiro; Rícan, Oldrich; Ortí, Guillermo; Bermingham, Eldredge; Doadrio, Ignacio; Zardoya, Rafael

    2007-04-01

    Heroini constitute the second largest tribe of Neotropical cichlids and show their greatest diversity in Mesoamerica. Although heroine species are morphologically and ecologically very diverse, they were all historically assigned to one single genus, Cichlasoma that was never formally revised from a phylogenetic point of view. Here, we present the most comprehensive molecular phylogeny of the tribe Heroini to date, based on the complete DNA sequence of the mitochondrial gene cytochrome b, and the analysis of 204 individuals representing 91 species. Phylogenetic analyses did not support the monophyly of heroines because the genus Pterophyllum was placed as the sister group of all remaining heroines plus cichlasomatines. However, the recovered relative position of Pterophyllum was without strong statistical support. Within the remaining heroines, Hyspelecara and Hoplarchus are recovered with low support in a basal position with respect to a clade that includes Heros, Uaru, Mesonauta, and Symphysodon, and the circumamazonian (CAM) heroines. The first clade is restricted to South America. The largest clade of heroines, the CAM heroines, include more than 85% of the species within the tribe. This clade is mostly Mesoamerican, but also contains four species found in the Greater Antilles (Nandopsis), and three genera found in South America (the 'Heros' festae group, Australoheros, and Caquetaia). Up to eight major lineages can be recovered within the CAM heroines, but the phylogenetic relationships among them remain unresolved. Two large suprageneric groups can be distinguished, the amphilophines and the herichthyines. The amphilophines include Amphilophus, Archocentrus, Hypsophrys, Neetroplus, Parachromis, Petenia, and five additional unnamed genera (the 'Heros' istlanus group, the 'Amphilophus' calobrensis group, the 'Heros' urophthalmus group, the 'Heros' wesseli group, and the 'Heros' sieboldii group). The herichthyines include the crown-group herichthyines

  3. Costs Associated with Equine Breeding in Kentucky

    Science.gov (United States)

    Walker, Cassandra L.

    There were approximately 9 million horses in the United States having a 102 billion impact on the U.S. economy (AHC, 2005). Over 1 million of those horses were involved in the breeding sector. In Kentucky, nearly 18% of the horse population have been involved in breeding. Managing an equine enterprise can be difficult, particularly given that many who undertake such endeavors do not have a background or education in business management. Kentucky Cooperative Extension has produced interactive spreadsheets to help horse owners better understand the costs associated with owning horses or managing certain equine businesses, including boarding and training operations. However, there has been little support for breeders. Therefore, the objectives of this study were to provide owners with a list of services offered for breeding and the costs associated with those services. Survey questions were created from a list of topics pertinent to equine breeding and from that list of questions, an electronic survey was created. The survey was sent via Qualtrics Survey Software to collect information on stallion and mare management costs as well as expenses related to owning and breeding. Question topics included veterinary and housing costs, management and advertising expenses, and membership fees. A total of 78 farms were selected from the 2013 breeder's listings for the Kentucky Quarter Horse Association (n = 39) and the Kentucky Thoroughbred Farm Managers' Club (n = 26), and other breed association contacts (n = 13). These farms were selected from the lists by outside individuals who were not related to the project. Participants were asked to answer all questions relevant to the farm. After the initial survey distribution, follow-up e-mails and phone calls were conducted in order to answer any questions participants might have had about the survey. Survey response rate was 32.1% (25 of 78 surveys returned). Farms in Kentucky had an average of two farm-owned and two outside

  4. Analysis of Plant Breeding on Hadoop and Spark

    Directory of Open Access Journals (Sweden)

    Shuangxi Chen

    2016-01-01

    Full Text Available Analysis of crop breeding technology is one of the important means of computer-assisted breeding techniques which have huge data, high dimensions, and a lot of unstructured data. We propose a crop breeding data analysis platform on Spark. The platform consists of Hadoop distributed file system (HDFS and cluster based on memory iterative components. With this cluster, we achieve crop breeding large data analysis tasks in parallel through API provided by Spark. By experiments and tests of Indica and Japonica rice traits, plant breeding analysis platform can significantly improve the breeding of big data analysis speed, reducing the workload of concurrent programming.

  5. Breed differences in calving interval in the humid Mexican tropic.

    Science.gov (United States)

    Murillo Medina, Aída Lorena; Córdova-Izquierdo, Alejandro; Soriano Robles, Ramón; Mendoza Martínez, Germán David; Castillo-Juárez, Héctor

    2009-10-01

    The objective of this study was to evaluate the influence of breed, breed and sex of the calf, farm, calving number (CN), type of calving, and their interactions on CI using records from four different beef breeds performing in the humid tropical environment of Mexico. The influence of these factors on CN was also evaluated. CI and CN varied with farm, breed of the dam, and with breed of the dam by calf breed interaction (PAngus cows, although with an apparent unexpected negative impact on CN.

  6. Analysis of the performance test results of young pure breed boars from the Bydgoszcz breeding region in Poland

    Directory of Open Access Journals (Sweden)

    Grażyna MICHALSKA

    2016-02-01

    Full Text Available The aim of presented paper was analysis of the performance test results of young pure breed boars coming from The Bydgoszcz Breeding Region (located in Poland in Kujawy-Pomorze Province. The research covered the results concerning 4190 young boars of following breeds: Polish Large White, Polish Landrace, Hampshire, Duroc and Pietrain. Young pure breed boars were performance tested in 2009 and 2010 in The Bydgoszcz Breeding Region according to the actual methodology. Among young pure breed boars performance tested in The Bydgoszcz Breeding Region in tested years animals of Hampshire breed had the higher growth rate. The pigs of Pietrain breed had the highest meat content. Regarding to the most important parameter of performance test, i.e. selection index in analyzed years 2009 and 2010 the best results had young boars of Hampshire then Pietrain, Duroc, PLW and PL.

  7. Development and application of biological technologies in fish genetic breeding.

    Science.gov (United States)

    Xu, Kang; Duan, Wei; Xiao, Jun; Tao, Min; Zhang, Chun; Liu, Yun; Liu, ShaoJun

    2015-02-01

    Fish genetic breeding is a process that remolds heritable traits to obtain neotype and improved varieties. For the purpose of genetic improvement, researchers can select for desirable genetic traits, integrate a suite of traits from different donors, or alter the innate genetic traits of a species. These improved varieties have, in many cases, facilitated the development of the aquaculture industry by lowering costs and increasing both quality and yield. In this review, we present the pertinent literatures and summarize the biological bases and application of selection breeding technologies (containing traditional selective breeding, molecular marker-assisted breeding, genome-wide selective breeding and breeding by controlling single-sex groups), integration breeding technologies (containing cross breeding, nuclear transplantation, germline stem cells and germ cells transplantation, artificial gynogenesis, artificial androgenesis and polyploid breeding) and modification breeding technologies (represented by transgenic breeding) in fish genetic breeding. Additionally, we discuss the progress our laboratory has made in the field of chromosomal ploidy breeding of fish, including distant hybridization, gynogenesis, and androgenesis. Finally, we systematically summarize the research status and known problems associated with each technology.

  8. Rapid cyling plant breeding in citrus

    Science.gov (United States)

    Resistance or tolerance to huanglongbing (HLB) and other important traits have been identified in several citrus types and relatives and associated markers should be identified soon. What is urgently needed in addition is an accelerated strategy for citrus variety breeding. Identification and use of...

  9. Breeding and Cytogenetics in the Genus Tulipa

    NARCIS (Netherlands)

    Marasek Ciolakowska, A.R.; Ramanna, M.S.; Arens, P.; Tuyl, van J.M.

    2012-01-01

    Tulip (Tulipa) is one of the most important ornamental bulbous plants, which has been cultivated for cut flower, potted plant, garden plant and for landscaping. Species from the different sections display complementary agronomic characteristics and breeding techniques are used to combine desired fea

  10. Breeding for trypanotolerance in African cattle

    NARCIS (Netherlands)

    Waaij, van der E.H.

    2001-01-01

    Trypanosomosis, or sleeping sickness, is one of the most important livestock diseases in Africa. Some West African cattle breeds show a degree of resistance to a trypanosome infection: they are trypanotolerant. At the International Livestock Research Institute (ILRI) in Nairobi, Kenya, an F2 experim

  11. Breeding for feed intake capacity in pigs

    NARCIS (Netherlands)

    Eissen, J.J.

    2000-01-01

    This thesis deals with feed intake capacity of pigs. By selection, breeding organizations try to achieve genetic improvement in production and reproduction efficiency. Future genetic improvement may become constrained by a limited feed intake capacity of growing pigs and lactating sows, respectively

  12. Breed differences in behavioural development in kittens.

    Science.gov (United States)

    Marchei, P; Diverio, S; Falocci, N; Fatjó, J; Ruiz-de-la-Torre, J L; Manteca, X

    2009-03-23

    Differences in behaviour of pure breed cats have been suggested but not wholly investigated. Oriental/Siamese/Abyssinian (OSA) kittens (n=43) were weekly compared with Norwegian Forest (NFO) kittens (n=39) from the 4th to the 10th week of age in a repeated Open Field Test (OFT) paradigm. Heart rate (HR) and rectal temperature (RT) before and after the test, and behavioural responses during the OFT were recorded. Behaviours registered were analysed by focal animal sampling. Significant breed differences were found; cats of the northern zones (NFO) seem to develop earlier thermoregulatory abilities. Precocious opening of eyes, higher locomotion scores and longer time spent standing, observed in OSA kittens may indicate an earlier neurological development. Inter breed differences recorded for exploration and locomotion seem to indicate coping style divergences: in the OFT challenging situation OSA kittens presented higher emotional tachycardia and performed more passively, with a faster decline in exploration and locomotion scores. NFO kittens exerted a more active behaviour as they spent more time exploring the arena and in escape attempts. Notwithstanding OSA and NFO cat selection was mainly aimed to improve divergent morphological traits, some different behavioural and physiological traits seem to have been maintained or co-selected within each breed.

  13. San Diego Zoo:Success in Breeding

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Giant pandas have become very popular in U.S.zoos. One in particular, the San Diego Zoo, has been extremely successful at making the pandas feel at home and getting them to breed. In 1999, it became home tothe first surviving panda cub born in the United States.

  14. Evaluation of charge breeding options for EURISOL

    CERN Document Server

    Delahaye, P; Lamy, T; Marie-Jeanne, M; Kester, O; Wenander, F

    2010-01-01

    A comprehensive study of charge breeding techniques for the most ambitious ISOL-facility project, EURISOL, is presented here. It is based on results obtained during the past years at CERN-ISOLDE and LPSC Grenoble with charge breeders of both ECR and EBIS types.

  15. Marketing potential of advanced breeding clones

    Science.gov (United States)

    The accumulation of reducing sugars during cold storage of potato tubers is a serious and costly problem for producers and processors. The degree to which cultivars accumulate reducing sugars during storage determines their processing and market potential. Cultivars or advanced breeding lines with...

  16. Computerized management support for swine breeding farms.

    NARCIS (Netherlands)

    Huirne, R.B.M.

    1990-01-01

    1. INTRODUCTIONThe investigations described in this thesis have been directed towards computerized management support for swine breeding farms, focused on sow productivity and profitability. The study is composed of three basic parts: (1) basic description and definition of farm man

  17. Applied Genetics and Genomics in Alfalfa Breeding

    Directory of Open Access Journals (Sweden)

    E. Charles Brummer

    2012-03-01

    Full Text Available Alfalfa (Medicago sativa L., a perennial and outcrossing species, is a widely planted forage legume for hay, pasture and silage throughout the world. Currently, alfalfa breeding relies on recurrent phenotypic selection, but alternatives incorporating molecular marker assisted breeding could enhance genetic gain per unit time and per unit cost, and accelerate alfalfa improvement. Many major quantitative trait loci (QTL related to agronomic traits have been identified by family-based QTL mapping, but in relatively large genomic regions. Candidate genes elucidated from model species have helped to identify some potential causal loci in alfalfa mapping and breeding population for specific traits. Recently, high throughput sequencing technologies, coupled with advanced bioinformatics tools, have been used to identify large numbers of single nucleotide polymorphisms (SNP in alfalfa, which are being developed into markers. These markers will facilitate fine mapping of quantitative traits and genome wide association mapping of agronomic traits and further advanced breeding strategies for alfalfa, such as marker-assisted selection and genomic selection. Based on ideas from the literature, we suggest several ways to improve selection in alfalfa including (1 diversity selection and paternity testing, (2 introgression of QTL and (3 genomic selection.

  18. Plant Breeding by Using Radiation Mutation

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Si Yong; Kim, Dong Sub; Lee, Geung Joo (and others)

    2007-06-15

    A mutation breeding is to use physical or chemical mutagens to induce mutagenesis, followed by individual selections with favorable traits. The mutation breeding has many advantages over other breeding methods, which include the usefulness for improving one or two inferior characteristics, applications to broad species with different reproductive systems or to diverse plant materials, native or plant introduction with narrow genetic background, time and cost-effectiveness, and valuable mutant resources for genomic researches. Recent applications of the radiation breeding techniques to developments of flowering plants or food crops with improved functional constituents heightened the public's interests in agriculture and in our genetic resources and seed industries. The goals of this project, therefore, include achieving advances in domestic seed industries and agricultural productivities by developing and using new radiation mutants with favored traits, protecting an intellectual property right of domestic seeds or germplasm, and sharing the valuable mutants and mutated gene information for the genomic and biotech researches that eventually leads to economic benefits.

  19. Seabird metapopulations: searching for alternative breeding habitats

    NARCIS (Netherlands)

    Schippers, P.; Snep, R.P.H.; Schotman, A.G.M.; Jochem, R.; Stienen, E.W.M.; Slim, P.A.

    2009-01-01

    Today, many seabird species nest in port areas, which are also necessary for human economic activity. In this paper, we evaluate, using a metapopulation model, the possibilities for creating alternative breeding sites for the Common Tern (Sterna hirundo) in the Rhine¿Meuse¿Scheldt estuary. We explor

  20. MODELING REGIONAL SYSTEMS OF BREEDING PIGS

    Directory of Open Access Journals (Sweden)

    Svinarev I. Y.

    2015-12-01

    Full Text Available The article contains the experience of the development of the methodology and the computer program for calculation of regional and local systems of pigs hybridization at the example of the Rostov region (Russia. Crossing the GP lines for F1 should be organized in multiplier farm, which may be separate farms and to be part of large commercial farms. For the production of F1 in a multiplier farm, we must breed a purebred specialized paternal and a maternal line, selected on the effect of combining ability. For the successful functioning of the system of hybridization, it is necessary to build a genetic pyramid, including breeding and genetic centers (nucleus farm, multiplier farm, reproducing the baseline. The article gives a detailed calculation of sow population of levels of P, GP, GGP for maternal and paternal breeds of pigs. The program uses user-defined parameters of pigs productivity, of the simulated population, and the parameters characterizing the intensity of selection of young animals. To ensure annual production of 1,822 million pigs in the Rostov region it is necessary to provide the availability of brood stock in the amount of 89 thousand heads, 6 800 heads in the structure of grandparent flocks (GP, 730 heads in the structure of the Grand-Grand-parent stock (GGP, excluding sows second maternal and paternal breeds

  1. Breeding for longevity in Italian Chianina cattle

    NARCIS (Netherlands)

    Forabosco, F.

    2005-01-01

    The objective of this thesis was to evaluate genetic aspects of longevity (LPL) in the Chianina beef cattle population in order to define how to include this trait in selection criteria. The Chianina breed has been raised for over twenty-two centuries inItaly

  2. Pericardial effusion in a mixed breed dog.

    OpenAIRE

    2001-01-01

    A 7-year-old, spayed female mixed breed dog was evaluated for labored breathing, lethargy, and a distended abdomen. Pericardial effusion was diagnosed after radiographic and echocardiographic interpretation. Treatment consisted of thoracocentesis and a single pericardiocentesis. Follow-up examinations indicate that the dog's condition has remained stable.

  3. Relevance of test information in horse breeding

    NARCIS (Netherlands)

    Ducro, B.J.

    2011-01-01

      The aims of this study were 1) to determine the role of test results of young horses in selection for sport performance, 2) to assess the genetic diversity of a closed horse breed and 3) the consequences of inbreeding for male reproduction. The study was performed using existing databases

  4. Artificial Breeding Techniques of Whitmania pigra

    Institute of Scientific and Technical Information of China (English)

    Zhao; Nan; Xu; Ziliang

    2014-01-01

    The artificial breeding technology for juvenile of Whitmania pigra was introduced in the paper,including selection of sites and water quality,construction of spawning pool,hatching pool and escape proof facilities,key technology of leech selection,feeding,cocoon hatching,juvenile feeding and management.

  5. The role of water in animal breeding

    Directory of Open Access Journals (Sweden)

    Monica Serrantoni

    2006-07-01

    Full Text Available The role of water in animal breeding must be extended to a wider context than the animal production area, considering that 70% of the water used in the world is consumed by the whole production chain (agriculture and animal production. Therefore has a great importance the connection with other fields of the chain, as the fodder-growing and the cereal-growing, together with the evaluation and quantification of the environmental impacts. Water, that plays an essential role in the breeding, assumes different importance in relation to the animal class (birds, fish and mammals and to the animal species. Therefore are extremely different the water requirements and the water consumptions, that are moreover strongly influenced by many factors, such as the dry matter, the climatic breeding conditions, together with the individual animal features. All that represents the starting point to determine the strategies and the ways of the water giving in animal breeding, related to the technological, project and management aspects. Besides the quantitative aspects, water must be considered as food, because it is necessary to animal survival. The importance of the quality of water used in animal breeding and its nutritional role is closely related to the qualitative characteristics and to the presence of residual and polluting substances. The animal production chain, moreover, can produce environmental impacts on the aquatic ecosystems and therefore a particular attention goes to end uses of water as output of the whole animal production chain and to the quantification of the impacts, that is extremely complicate and difficult, depending on many variables. The considerations related to animal production chain assume a different value in the productive context of the management of the water resources in the third countries.

  6. Breeding productivity of Smith Island black ducks

    Science.gov (United States)

    Haramis, G.M.; Jorde, D.G.; Olsen, G.H.; Stotts, D.B.; Harrison, M.K.; Perry, M.C.

    2002-01-01

    We investigated the breeding performance of American black ducks (Anas rubripes) on Smith Island, Chesapeake Bay, to improve our understanding of island black duck breeding ecology and to make management recommendations to enhance productivity. During 1995-96, we implanted 56 female black ducks with 20-g radio transmitters and tracked 35 of the individuals through the breeding season to locate nests, determine nest fate, and identify brood habitat. We also increased preseason banding efforts and compared capture characteristics over 12 years with those from the Deal Island Wildlife Management Area, a banding site on the mainland of Tangier Sound. A low rate of nesting (37%), lack of renesting, and poor hatching success (31%) indicated that island salt marsh habitats present a harsh environment for breeding black ducks. Black ducks located 11 of 13 nests (85%) in black needlerush (Juncus roemerianus) marsh where they were vulnerable to flooding from extreme tides and to egg predators. No nests were found on forested tree hammocks, a feature that distinguishes Smith Island from nearby South Marsh and Bloodsworth Islands. Nest predators included red foxes (Vulpes vulpes), herring gulls (Larus argentams), fish crows (Corvus ossifragus), and, potentially, Norway rats (Rattus norvegicus). Unlike mainland red foxes, foxes radio tracked on Smith Island were found to be capable swimmers and effective low marsh predators. We found shoreline meadows of widgeon grass (Ruppia maritima) to be important foraging sites for black ducks and suspected that the virtual absence of fresh water in this high salinity environment (1217+ ppt) to incur some cost in terms of growth and survival of ducklings. Preseason bandings revealed a high proportion of banded adults and a strong positive correlation in age ratios with the Deal Island banding site. This latter finding strongly suggests a negative universal effect of storm tides on nest success for Tangier Sound black ducks. Management to

  7. Across Breed QTL Detection and Genomic Prediction in French and Danish Dairy Cattle Breeds

    DEFF Research Database (Denmark)

    van den Berg, Irene; Guldbrandtsen, Bernt; Hozé, C;

    was shared across breed. Second, sequence data was used to quantify the loss in prediction reliabilities that results from using genomic markers rather than the causal variants. 50, 100 or 250 causative mutations were simulated and different sets of prediction markers were used to predict genomic...... relationships at causative mutations. Prediction of genomic relationships at causative mutations was most accurate when predicted by a selective number of markers within 1 Kb of the causative mutations. Whole-genome sequence data can help to get closer to the causative mutations and therefore improve genomic......Our objective was to investigate the potential benefits of using sequence data to improve across breed genomic prediction, using data from five French and Danish dairy cattle breeds. First, QTL for protein yield were detected using high density genotypes. Part of the QTL detected within breed...

  8. BREED PREFERENCES AND EFFECTIVENESS OF BEEKEEPING IN THE SOUTH URAL

    Directory of Open Access Journals (Sweden)

    A. Mashenkov

    2012-12-01

    Full Text Available Efficiency of beekeeping is defined by breed of bees and melliferous herbs. In the conditions of sharply continental climate of South Ural, duration of success of beekeeping is provided with breed of bees.

  9. New trends in plant breeding - example of soybean

    Directory of Open Access Journals (Sweden)

    Miladinović Jegor

    2015-01-01

    Full Text Available Soybean breeding and selection is a continual process designed to increase yield levels and improve resistance to biotic and abiotic stresses. Soybean breeders have been successful in producing a large number of varieties using conventional breeding methods, the Single Seed Descent method in particular. In recent decades, with the increased use of genetic transformations, backcrossing is more frequent though the only trait that has been commercialized is glyphosate tolerance. Physiological breeding poses a particular challenge, as well as phenotyping and development of useful criteria and techniques suitable for plant breeding. Using modern remote sensing techniques provides great opportunity for collecting a large amount of physiological data in real environment, which is necessary for physiological breeding. Molecular based plant breeding methods and techniques are a conceptual part of any serious breeding program. Among those methods, the most extensively used is marker-assisted selection, as a supplement to conventional breeding methods. [Projekat Ministarstva nauke Republike Srbije, br. TR-31022

  10. Four Square Mile Survey breeding population report for 2001

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Production report of Four Square Mile Survey breeding population estimates for 13 species of ducks. Data includes summaries of breeding population estimates...

  11. Breeding objectives, selection criteria and breeding system of indigenous goat types in bale zone, oromia, Ethiopia

    Directory of Open Access Journals (Sweden)

    Belete Asefa

    2015-12-01

    Full Text Available The study was undertaken in bale zone to assess farmer’s selective breeding objectives, trait preferences, selection criteria and breeding system October 2012 to November 2013. A purposive and multistage sampling technique was applied for selection of 3 district and 9 kebeles. Then 360 households were selected by using simple random sampling techniques after the list of pastoralist having goats was identified. Statistical analysis system version 9.1 was used for analysis of data. Indices, effective population size and rate of inbreeding were calculated on average each respondent holds about 14 goats. Milk production is the main reason of goat keeping in the study area. Appearance is the first rank as selection criteria for male and female in all studies area. About 47.8% of the respondents have their own buck. The main use of breeding buck in the study area was for mating purpose (76.2%. Mean estimate of effective population size and mean rate of inbreeding was 2.43 and 0.21, respectively when a household flock is herded alone and under random mating. Therefore, any breed improvement strategies that are intended to be implemented in the study area and else- where should consider the traditional breeding practices and breeding objectives of the community.

  12. Breeding biology and nestling development of the Grasshopper Buzzard

    OpenAIRE

    Buij, R.; Kortekaas, K.; Folkertsma, I.; Van Der Velde, M.; Komdeur, J.; H. H. de Iongh; A. Monadjem

    2012-01-01

    Research into the effect of environmental variables on reproductive success of tropical raptors is often constrained by the lack of information on breeding biology. We provide the first detailed information of the breeding biology and nestling development of the Grasshopper Buzzard Butastur rufipennis, an Afrotropical migratory raptor threatened by extensive land transformation in its breeding range. Breeding coincided with the transition from the dry to the wet season. The mean incubation pe...

  13. 50 CFR 15.26 - Approval of cooperative breeding programs.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Approval of cooperative breeding programs... WILDLIFE AND PLANTS WILD BIRD CONSERVATION ACT Permits and Approval of Cooperative Breeding Programs § 15.26 Approval of cooperative breeding programs. Upon receipt of a complete application, the...

  14. Maternal genealogical patterns of chicken breeds sampled in Europe.

    Science.gov (United States)

    Lyimo, C M; Weigend, A; Msoffe, P L; Hocking, P M; Simianer, H; Weigend, S

    2015-08-01

    The aim of this study was to investigate the maternal genealogical pattern of chicken breeds sampled in Europe. Sequence polymorphisms of 1256 chickens of the hypervariable region (D-loop) of mitochondrial DNA (mtDNA) were used. Median-joining networks were constructed to establish evolutionary relationships among mtDNA haplotypes of chickens, which included a wide range of breeds with different origin and history. Chicken breeds which have had their roots in Europe for more than 3000 years were categorized by their founding regions, encompassing Mediterranean type, East European type and Northwest European type. Breeds which were introduced to Europe from Asia since the mid-19th century were classified as Asian type, and breeds based on crossbreeding between Asian breeds and European breeds were classified as Intermediate type. The last group, Game birds, included fighting birds from Asia. The classification of mtDNA haplotypes was based on Liu et al.'s (2006) nomenclature. Haplogroup E was the predominant clade among the European chicken breeds. The results showed, on average, the highest number of haplotypes, highest haplotype diversity, and highest nucleotide diversity for Asian type breeds, followed by Intermediate type chickens. East European and Northwest European breeds had lower haplotype and nucleotide diversity compared to Mediterranean, Intermediate, Game and Asian type breeds. Results of our study support earlier findings that chicken breeds sampled in Europe have their roots in the Indian subcontinent and East Asia. This is consistent with historical and archaeological evidence of chicken migration routes to Europe.

  15. Genomic prediction across dairy cattle populations and breeds

    DEFF Research Database (Denmark)

    Zhou, Lei

    Genomic prediction is successful in single breed genetic evaluation. However, there is no achievement in acoress breed prediction until now. This thesis investigated genomic prediction across populations and breeds using Chinese Holsterin, Nordic Holstein, Norwgian Red, and Nordic Red. Nordic Red...

  16. The Evolution and Ecology of Cooperative Breeding in Vertebrates

    NARCIS (Netherlands)

    Komdeur, Jan; Eikenaar, Cas; Brouwer, Lyanne; Richardson, David S.

    2008-01-01

    Cooperative breeding – in which some adults forgo independent breeding and remain as subordinates within a group helping to raise the offspring of others – occurs in between 3% and 10% of vertebrates. The structure of such systems varies greatly, from pairs with helpers-at-the-nest to communal breed

  17. The use of clones in dairy cattle breeding.

    NARCIS (Netherlands)

    Boer, de I.J.M.

    1994-01-01

    The aim of this thesis was to determine a breeding scheme that optimally uses large scale production of genetically identical individuals (clones) in dairy cattle. Such a breeding scheme should optimize the continuous genetic improvement of the breeding population (genetic response), and the selecti

  18. Genetics and breeding of brewers yeast

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson-Tillgren, T.; Gjermansen, C.; Petersen, J.G.L.; Holmberg, S.; Kielland-Brandt, M.C.

    1984-01-01

    Yeasts, used for beer production, can be divided into two groups, top fermenters and bottom fermenters and Saccharomyces carlsbergensis has been chosen as the name for the bottom fermenting yeasts which are used in lager beer production. The key for the analysis of the chromosomes of Saccharomyces carlsbergensis was provided by the discovery that single chromosomes of meiotic segregants of these strains can be transferred to genetically marked Saccharomyces cerevisiae strains and subsequently analyzed by tetrad analysis and molecular hybridization. It is proposed that Saccharomyces carlsbergensis is composed of two rather divergent genotypes. Breeding can be accomplished by cross breeding and mutagenesis and possibly by introducing in vitro modified cloned genes into meiotic segregants of Saccharomyces carlsbergensis.

  19. Vertebral heart scores in eight dog breeds.

    Science.gov (United States)

    Jepsen-Grant, K; Pollard, R E; Johnson, L R

    2013-01-01

    The vertebral heart score (VHS) measurement is commonly used to provide a more objective measurement of cardiomegaly in canines. However, several studies have shown significant breed variations from the value previously established by Buchanan and Bücheler (9.7 ± 0.5). This study describes VHS measurements in Pug, Pomeranian, Yorkshire Terrier, Dachshund, Bulldog, Shih Tzu, Lhasa Apso, and Boston Terrier dog breeds. Dogs with two or three view thoracic radiographs, no subjective radiographic evidence of cardiomegaly, and no physical examination findings of heart murmurs or gallop rhythms were included in the study. The Pug, Pomeranian, Bulldog, and Boston Terrier groups were found to have a VHS significantly greater than 9.7 ± 0.5 (P Bulldog (P = 0.028) and Boston Terrier (P = 0.0004) groups. Thoracic depth to width ratio did not have a significant effect on VHS.

  20. ITER breeding blanket module design and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kuroda, Toshimasa; Enoeda, Mikio; Kikuchi, Shigeto [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment] [and others

    1998-11-01

    The ITER breeding blanket employs a ceramic breeder and Be neutron multiplier both in small spherical pebble form. Radial-poloidal cooling panels are arranged in the blanket box to remove the nuclear heating in these materials and to reinforce the blanket structure. At the first wall, Be armor is bonded onto the stainless steel (SS) structure to provide a low Z plasma-compatible surface and to protect the first wall/blanket structure from the direct contact with the plasma during off-normal events. Thermo-mechanical analyses and investigation of fabrication procedure have been performed for this breeding blanket. To evaluate thermo-mechanical behavior of the pebble beds including the dependency of the effective thermal conductivity on stress, analysis methods have been preliminary established by the use of special calculation option of ABAQUS code, which are briefly summarized in this report. The structural response of the breeding blanket module under internal pressure of 4 MPa (in case of in-blanket LOCA) resulted in rather high stress in the blanket side (toroidal end) wall, thus addition of a stiffening rib or increase of the wall thickness will be needed. Two-dimensional elasto-plastic analyses have been performed for the Be/SS bonded interface at the first wall taking a fabrication process based on HIP bonding and thermal cycle due to pulsed plasma operation into account. The stress-strain hysteresis during these process and operation was clarified, and a procedure to assess and/or confirm the bonding integrity was also proposed. Fabrication sequence of the breeding blanket module was preliminarily developed based on the procedure to fabricate part by part and to assemble them one by one. (author)

  1. Detection of Breeding Blankets Using Antineutrinos

    Science.gov (United States)

    Cogswell, Bernadette; Huber, Patrick

    2016-03-01

    The Plutonium Management and Disposition Agreement between the United States and Russia makes arrangements for the disposal of 34 metric tons of excess weapon-grade plutonium. Under this agreement Russia plans to dispose of its excess stocks by processing the plutonium into fuel for fast breeder reactors. To meet the disposition requirements this fuel would be burned while the fast reactors are run as burners, i.e., without a natural uranium blanket that can be used to breed plutonium surrounding the core. This talk discusses the potential application of antineutrino monitoring to the verification of the presence or absence of a breeding blanket. It is found that a 36 kg antineutrino detector, exploiting coherent elastic neutrino-nucleus scattering and made of silicon, could determine the presence of a breeding blanket at a liquid sodium cooled fast reactor at the 95% confidence level within 90 days. Such a detector would be a novel non-intrusive verification tool and could present a first application of coherent elastic neutrino-nucleus scattering to a real-world challenge.

  2. Beef cattle breeding à la Jefferson.

    Science.gov (United States)

    Hohenboken, W D

    1982-03-01

    ?Even more than most disciplines in the Animal Sciences, quantitative genetics is dependent upon models. Models, by definition, are abstractions of reality. Invariably they require simplifying assumptions, which should be but sometimes are not clearly specified. One thesis of this article, illustrated by examples, is that many of the assumptions upon which animal breeding theory and practice are based are not valid. Some proportion of research resources should be devoted to challenging or verifying those assumptions and following up those areas of enquiry suggested by the outcome of such research. A further thesis is that the selection of topics and priorities for animal breeding research should be a matter of choice by individual scientists and should not be determined by steering committees or directed by administrative fiat. Hopefully, the resultant mutation, cross-fertilization, assortment, recombination and selection of ideas that would result would bestow upon our discipline higher fitness from multiple-peak epistasis, and minimal danger of extinction (or petrification) from over-specialization. A final thesis is that true creativity by research scientists should be nurtured and rewarded and that work in traditional areas of breeding and quantitative genetics should be continued-but done better.

  3. The development of beef breeding bulls.

    Science.gov (United States)

    Engelken, T J

    2008-08-01

    Management of the bull battery will have a dramatic impact on profitability of the cow/calf enterprise. It is critical that young bulls be selected and developed to maximize longevity and productivity for the eventual buyer. Bulls must be structurally sound, healthy, and have adequate libido in order to service the required number of females. Once bulls complete their first breeding season, special care must be taken in order to ensure that they recover and regain needed body condition and pass a bull breeding soundness examination (BBSE). Mature bulls that have reached their genetic potential for growth require less intensive management, but the health program and annual BBSE cannot be overlooked. Mature bulls are also more likely to carry venereal disease and should be screened according to local disease incidence and state regulations. All bulls, regardless of age, should be observed early during the breeding season to ensure that they are physically capable of mounting and servicing females. The establishment of a complete management program, especially for young bulls, is essential to ensure that ranch resources are used efficiently, including maintenance of a high level of reproductive performance of the cow herd.

  4. Cytogenetical characterization of bovine breeds Caracu, Junqueira, Pantaneiro and Patua

    Directory of Open Access Journals (Sweden)

    Rita Maria Ladeira Pires

    2014-10-01

    Full Text Available During the adaptive process to Brazilian conditions, the native cattle breeds acquired physiological and phenotypic characteristics wich differs them from European breeds, from which they derive. The objectives of present study were to compare the sex chromosomes morphologies between four Brazilian native cattle breeds as well as the incidence of chromosomal abnormalities. The karyotype of 332 animals from four breeds were analyzed: Caracu (115 females and 159 males, Junqueira (13 females and 3 males, Pantaneiro (8 males and Patua (21 females and 13 males. The Giemsa coloring were used to read the chromosome. All cattle breeds studied showed the normal chromosome (2n=60 consisting of 58 acrocentric autosomes and two submetacentric X chromosomes in females, and one X and one Y in males. In Caracu breed, selected for dairy or beef, it was developed by animals dimorphism carriers of Y chromosome (acrocentric and submetacentric, and the beef bloodlines showed higher percentage of acrocentric Y chromosome. There was 1% significant difference in Chi-Square test. In two females and two male born from twin birth of Caracu breed it was observed chemerism 60, XX/ 60, XY, and in other female from same breed it was observed 60, XX/ 61 XXY. For other three breeds, no chromosomal abnormality was observed. The Y chromosome morphology of the Pantaneiro and Patua breeds showed dimorphism of Y chromosome (submetacentric an acrocentric. In the Junqueira breed, only submetacentric morphology was observed.

  5. The different breeding strategies of penguins: a review.

    Science.gov (United States)

    Ancel, André; Beaulieu, Michaël; Gilbert, Caroline

    2013-01-01

    The 18 penguin species are exclusively and widely distributed in the Southern hemisphere, from the Equator to the Antarctic continent, and are thus submitted to various ecological constraints in their reproductive strategy. This results in a high variability in all aspects of the breeding biology of the different species. Although penguins appear primarily adapted for a marine existence, they remain dependent on land for breeding, rearing young, and moulting. Here we describe and compare the breeding cycle of all the penguin species, highlighting the characteristics of each species in terms of breeding range, population status, threats induced by environmental changes, duration of the different phases of the breeding cycle, mate fidelity, body mass, body height, egg mass and duration of egg formation. We also focus on the breeding cycle of the genus Aptenodytes, since it largely differs from the breeding cycle of most of the other penguin species.

  6. Life histories and the evolution of cooperative breeding in mammals.

    Science.gov (United States)

    Lukas, Dieter; Clutton-Brock, Tim

    2012-10-07

    While the evolution of cooperative breeding systems (where non-breeding helpers participate in rearing young produced by dominant females) has been restricted to lineages with socially monogamous mating systems where coefficients of relatedness between group members are usually high, not all monogamous lineages have produced species with cooperative breeding systems, suggesting that other factors constrain the evolution of cooperative breeding. Previous studies have suggested that life-history parameters, including longevity, may constrain the evolution of cooperative breeding. Here, we show that transitions to cooperative breeding across the mammalian phylogeny have been restricted to lineages where females produce multiple offspring per birth. We find no support for effects of longevity or of other life-history parameters. We suggest that the evolution of cooperative breeding has been restricted to monogamous lineages where helpers have the potential to increase the reproductive output of breeders.

  7. Status and Prospects of Hybrid Rice Breeding in Jiangsu, China

    Institute of Scientific and Technical Information of China (English)

    WANG Cai-lin

    2005-01-01

    Research on hybrid rice in Jiangsu Province, China began in 1970. Great progress has been made since then, which can be divided into three stages according to the development of hybrid rice breeding and production in Jiangsu Province. The first stage was beginning stage from 1970 to 1980, when progress was mainly made in cytoplasmic male sterile line breeding. The second stage could be described as developing stage, from 1980 to 1995, when indica hybrid rice was rapidly popularized, and japonica hybrid rice became popular later. From 1996, hybrid rice breeding in Jiangsu Province entered the third stage, when both indica and japonica hybrid rice breeding in the three-line system or intersubspecific hybrid rice breeding in the two-line system made a great breakthrough with the successful breeding of the hybrids Teyou 559, 9 You 138 and Liangyoupeijiu. The developing trend of hybrid rice breeding in Jiangsu Province is also discussed.

  8. Spatial scale of local breeding habitat quality and adjustment of breeding decisions.

    Science.gov (United States)

    Doligez, Blandine; Berthouly, Anne; Doligez, Damien; Tanner, Marion; Saladin, Verena; Bonfils, Danielle; Richner, Heinz

    2008-05-01

    Experimental studies provide evidence that, in spatially and temporally heterogeneous environments, individuals track variation in breeding habitat quality to adjust breeding decisions to local conditions. However, most experiments consider environmental variation at one spatial scale only, while the ability to detect the influence of a factor depends on the scale of analysis. We show that different breeding decisions by adults are based on information about habitat quality at different spatial scales. We manipulated (increased or decreased) local breeding habitat quality through food availability and parasite prevalence at a small (territory) and a large (patch) scale simultaneously in a wild population of Great Tits (Parus major). Females laid earlier in high-quality large-scale patches, but laying date did not depend on small-scale territory quality. Conversely, offspring sex ratio was higher (i.e., biased toward males) in high-quality, small-scale territories but did not depend on large-scale patch quality. Clutch size and territory occupancy probability did not depend on our experimental manipulation of habitat quality, but territories located at the edge of patches were more likely to be occupied than central territories. These results suggest that integrating different decisions taken by breeders according to environmental variation at different spatial scales is required to understand patterns of breeding strategy adjustment.

  9. Induced cytochrome P450 1A activity in cichlid fishes from Guandu River and Jacarepaguá Lake, Rio de Janeiro, Brazil.

    Science.gov (United States)

    Parente, Thiago E M; De-Oliveira, Ana C A X; Paumgartten, Francisco J R

    2008-03-01

    The induction of cytochrome P4501A-mediated activity (e.g. ethoxyresorufin-O-deethylation, EROD) has been used as a biomarker for monitoring fish exposure to AhR-receptor ligands such as polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB) and polychlorinated dibenzo-dioxins/furans (PCDD/Fs). In this study we found that hepatic EROD is induced in fish ("Nile tilapia", Oreochromis niloticus and "acará", Geophagus brasiliensis) from the Guandu River (7-17-fold) and Jacarepaguá Lake (7-fold), Rio de Janeiro, Brazil. Since both cichlid fish are consumed by the local population and the Guandu River is the main source of the drinking water supply for the greater Rio de Janeiro metropolitan area, pollution by cytochrome P4501A-inducing chemicals is a cause for concern and should be further investigated in sediments, water and biota. We additionally showed that EROD activity in the fish liver post-mitochondrial supernatant-simpler, cheaper and less time consuming to prepare than the microsomal fraction-is sufficiently sensitive for monitoring purposes.

  10. Intermediate number of major histocompatibility complex class IIB length variants relates to enlarged perivisceral fat deposits in the blunt-head cichlid Tropheus moorii.

    Science.gov (United States)

    Hablützel, P I; Vanhove, M P M; Grégoir, A F; Hellemans, B; Volckaert, F A M; Raeymaekers, J A M

    2014-10-01

    Studying the genetic basis of host-parasite interactions represents an outstanding opportunity to observe eco-evolutionary processes. Established candidates for such studies in vertebrates are immunogenes of the major histocompatibility complex (MHC). The MHC has been reported to reach high intra- and interindividual diversity, and a diverse MHC might be advantageous when facing infections from multiple parasites. However, other studies indicated that individuals with an intermediate number of MHC alleles are less infected with parasites or have other fitness advantages. In this study, we assessed the optimal number of MHC alleles in the blunt-head cichlid Tropheus moorii from Lake Tanganyika. We investigated the influence of the interindividual variation in number of MHC length variants on parasite infection and body condition, measured by the amount of perivisceral fat reserves. Surprisingly, there was no correlation between parasite infection and number of MHC length variants or perivisceral fat deposits. However, the individual number of MHC length variants significantly correlated with the amount of perivisceral fat deposits in males, suggesting that male individuals with an intermediate number of alleles might be able to use their fat reserves more efficiently.

  11. Redescription of Neoechinorhynchus (Neoechinorhynchus) golvani Salgado-Maldonado, 1978 (Acanthocephala: Neoechinorhynchidae) and description of a new species from freshwater cichlids (Teleostei: Cichlidae) in Mexico.

    Science.gov (United States)

    Salgado-Maldonado, Guillermo

    2013-05-01

    A redescription of Neoechinorhynchus (Neoechinorhynchus) golvani Salgado-Maldonado (An Inst Biol Univ Nal Autón Méx, Ser Zool 49:35-47, 1978) is presented, based on adult specimens collected from the type host Paraneetroplus fenestratus from the type location, the Lago de Catemaco lake, Veracruz state, Mexico, and its presence is recorded in other cichlids. Detailed studies of N. (N.) golvani using light microscopy revealed some taxonomically important, previously unreported features, such as the size and shape of fully developed adult males and females, and the structure of the eggs. Morphological variability in N. (N.) golvani is described. Based on these data, the geographic distribution of this species is documented. Neoechinorhynchus (Neoechinorhynchus) panucensis n. sp. is described from Herichthys labridens (Pellegrin), Amatitlania nigrofasciata (Günther), and Herichthys cyanoguttatus Baird and Girard (all of them Cichlidae), collected in the Río Atlapexco, a tributary to the upper Río Panuco basin, Hidalgo State, Mexico. This new species stand up alone because of its minute proboscis (♂ 50 × 60, ♀ 42-55 (48.5) × 48-63 (57.7)) and anterior hooks (♂ 27-30 (28.8) × 3-5 (4), ♀ 28-32 (30) × 5 (5)). A key to the species of Neoechinorhynchus recorded from freshwater fishes in Central and South America is included.

  12. A sex-specific trade-off between mating preferences for genetic compatibility and body size in a cichlid fish with mutual mate choice.

    Science.gov (United States)

    Thünken, Timo; Meuthen, Denis; Bakker, Theo C M; Baldauf, Sebastian A

    2012-08-01

    Mating preferences for genetic compatibility strictly depend on the interplay of the genotypes of potential partners and are therein fundamentally different from directional preferences for ornamental secondary sexual traits. Thus, the most compatible partner is on average not the one with most pronounced ornaments and vice versa. Hence, mating preferences may often conflict. Here, we present a solution to this problem while investigating the interplay of mating preferences for relatedness (a compatibility criterion) and large body size (an ornamental or quality trait). In previous experiments, both sexes of Pelvicachromis taeniatus, a cichlid fish with mutual mate choice, showed preferences for kin and large partners when these criteria were tested separately. In the present study, test fish were given a conflicting choice between two potential mating partners differing in relatedness as well as in body size in such a way that preferences for both criteria could not simultaneously be satisfied. We show that a sex-specific trade-off occurs between mating preferences for body size and relatedness. For females, relatedness gained greater importance than body size, whereas the opposite was true for males. We discuss the potential role of the interplay between mating preferences for relatedness and body size for the evolution of inbreeding preference.

  13. Effects on milk production in F1 crossbred of Alpine goat breed (♂ and Albanian goat breed (♀

    Directory of Open Access Journals (Sweden)

    Luan Hajno

    2012-07-01

    Full Text Available About 950,000 goats, farmed mostly in hilly and mountainous areas of Albania, contribute about 8% of the country’s total milk production. In order to increase milk production, farmers are currently using crosses of the local goat breed with exotic breeds, mainly the Alpine breed from France. This study examines milk production data of first lactation from 45 goats of the local breed, 82 goats of the Alpine breed and 58 F1 crosses (♂Alpine breed x ♀local breed. The goats were kept on small-scale farms according to the traditional Albanian system. Milking was carried out in the morning and evening. Kids were weaned at 65 days of age after which milking started. Milk yield was recorded twice with a 15-day interval between the two readings. Total milk yield was calculated using the Fleischmann method. The F1 goats produced 37.8 kg more milk than local breed goats although the lactation length (P<0.05 of F1 goats was six days shorter compared to that of local breed goats (P<0.05. Analysis of variance showed a highly significant effect (P<0.01 of the genotype factor on milk production. The average Cappio-Borlino curves of three genotypes indicated that the lactation curves of local breed and F1 crosses were similar. Although the F1 cross goats had 50% of their genomes from a genetically improved breed they were still able to deal with the difficult conditions that characterize the traditional extensive farming systems in Albania. Breeding pure Alpine breed or its crosses with the local goat breed improved milk production in an extensive traditional system.

  14. Breeding blanket design for ITER and prototype (DEMO) fusion reactors and breeding materials issues

    Energy Technology Data Exchange (ETDEWEB)

    Takatsu, H.; Enoeda, M. [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    1998-03-01

    Current status of the designs of the ITER breeding blanket and DEMO blankets is introduced placing emphasis on the breeding materials selection and related issues. The former design is based on the up-to-date design activities, as of October 1997, being performed jointly by Joint Central Team (JCT) and Home Teams (HT`s), while the latter is based on the DEMO blanket test module designs being proposed by each Party at the TBWG (Test Blanket Working Group) meetings. (J.P.N.)

  15. Simulation Modeling in Plant Breeding: Principles and Applications

    Institute of Scientific and Technical Information of China (English)

    WANG Jian-kang; Wolfgang H Pfeiffer

    2007-01-01

    Conventional plant breeding largely depends on phenotypic selection and breeder's experience, therefore the breeding efficiency is low and the predictions are inaccurate. Along with the fast development in molecular biology and biotechnology, a large amount of biological data is available for genetic studies of important breeding traits in plants,which in turn allows the conduction of genotypic selection in the breeding process. However, gene information has not been effectively used in crop improvement because of the lack of appropriate tools. The simulation approach can utilize the vast and diverse genetic information, predict the cross performance, and compare different selection methods. Thus,the best performing crosses and effective breeding strategies can be identified. QuLine is a computer tool capable of defining a range, from simple to complex genetic models, and simulating breeding processes for developing final advanced lines. On the basis of the results from simulation experiments, breeders can optimize their breeding methodology and greatly improve the breeding efficiency. In this article, the underlying principles of simulation modeling in crop enhancement is initially introduced, following which several applications of QuLine are summarized, by comparing the different selection strategies, the precision parental selection, using known gene information, and the design approach in breeding. Breeding simulation allows the definition of complicated genetic models consisting of multiple alleles, pleiotropy, epistasis, and genes, by environment interaction, and provides a useful tool for breeders, to efficiently use the wide spectrum of genetic data and information available.

  16. Fitness consequences of timing of migration and breeding in cormorants.

    Directory of Open Access Journals (Sweden)

    Phillip Gienapp

    Full Text Available In most bird species timing of breeding affects reproductive success whereby early breeding is favoured. In migratory species migration time, especially arrival at the breeding grounds, and breeding time are expected to be correlated. Consequently, migration time should also have fitness consequences. However, in contrast to breeding time, evidence for fitness consequences of migration time is much more limited. Climate change has been shown to negatively affect the synchrony between trophic levels thereby leading to directional selection on timing but again direct evidence in avian migration time is scarce. We here analysed fitness consequences of migration and breeding time in great cormorants and tested whether climate change has led to increased selection on timing using a long-term data set from a breeding colony on the island of Vorsø (Denmark. Reproductive success, measured as number of fledglings, correlated with breeding time and arrival time at the colony and declined during the season. This seasonal decline became steeper during the study period for both migration and breeding time and was positively correlated to winter/spring climate, i.e. selection was stronger after warmer winters/springs. However, the increasing selection pressure on timing seems to be unrelated to climate change as the climatic variables that were related to selection strength did not increase during the study period. There is indirect evidence that phenology or abundances of preferred prey species have changed which could have altered selection on timing of migration and breeding.

  17. Breeding implications resulting from classification of patellae luxation in dogs.

    Science.gov (United States)

    van Grevenhof, E M; Hazewinkel, H A W; Heuven, H C M

    2016-08-01

    Patellar luxation (PL) is one of the major hereditary orthopaedic abnormalities observed in a variety of dog breeds. When the patellae move sideways out of the trochlear groove, this is called PL. The PL score varies between dogs from normal to very severe. Reducing the prevalence of PL by breeding could prevent surgery, thereby improve welfare. Orthopaedic specialists differentiate between normal and loose patellae, where the patellae can be moved to the edge of the trochlear groove, considering scoring loose patellae as normal in the future. Loose patellae are considered acceptable for breeding so far by the breeding organization. The aim of this study was to analyse the genetic background of PL to decide on the importance of loose patellae when breeding for healthy dogs. Data are available from two dog breeds, that is Flat-coated Retrievers (n = 3808) and Kooiker dogs (n = 794), with a total of 4602 dogs. Results show that loose patellae indicate that dogs are genetically more susceptible to develop PL because family members of the dogs with loose patellae showed more severe PL. In addition, the estimated breeding values for dogs with loose patellae indicate that breeding values of dogs with loose patellae were worse than breeding values obtained for dogs with a normal score. Given these results, it is advised to orthopaedic specialists to continue to score loose patellae as a separate class and to dog breeders to minimize the use of dogs in breeding with a genetically higher susceptibility for PL.

  18. Studies on mutation breeding of hibiscus syriacuse

    Energy Technology Data Exchange (ETDEWEB)

    Song, Hee Sub; Kim, Jin Kyu; Lee, Ki Un; Lim, Yong Taek [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-12-01

    Hibiscus has been known as a national flower of Korea. Hibiscus has ahch a characteristic of self-incompatibility that all the plants exist as natural hybrids and have heterogeneous genes. Thirth two domestic varieties were propagated. Radiosensitivity of H. syriacus irradiated with gamma ray was investigated in plant cuttings. The plant height was reduced by 45 percent in 5 kR irradiated group compared to control group. The radiation dose of 5 kR could be rrecommended for mutation breeding of Hibiscus cuttings. Promising mutant lines were selected form the varieties of Hwarang Wolsan 176, I1pyondansim and Emille. 6 tabs., 2 figs., 13 refs., 4 ills. (Author).

  19. Breeding Potential in Danish Apple Cultivar

    DEFF Research Database (Denmark)

    Larsen, Bjarne

    , including several rare alleles. Using historical gene bank records, including aroma volatile analysis, sugar and acid data and other fruit- and tree character records, we established genotype-phenotype relationships, performing a genome-wide association study. A number of SNP markers are presented that can...... be used directly for marker-assisted selection. In addition, we suggest a number of candidate genes involved in the control of several important fruit quality traits. Future studies and breeding attempts can therefore benefit from the results, including genetic fingerprints and pedigree reconstruction...

  20. Advances in Japanese pear breeding in Japan

    OpenAIRE

    Saito, Toshihiro

    2016-01-01

    The Japanese pear (Pyrus pyrifolia Nakai) is one of the most widely grown fruit trees in Japan, and it has been used throughout Japan’s history. The commercial production of pears increased rapidly with the successive discoveries of the chance seedling cultivars ‘Chojuro’ and ‘Nijisseiki’ around 1890, and the development of new cultivars has continued since 1915. The late-maturing, leading cultivars ‘Niitaka’ and ‘Shinko’ were released during the initial breeding stage. Furthermore, systemati...

  1. Milk yield of some Croatian sheep breeds

    OpenAIRE

    Kristijan Pandek; Boro Mioč; Zdravko Barać; Vesna Pavić; Neven Antunac; Zvonimir Prpić

    2005-01-01

    Among the most important breeds of sheep, used for the milk production in Croatia, are the sheep from Pag, Brač, Cres, Istrian and Travnik΄s sheep, different crossbreeds and, recently, East Friesian sheep. The aim of the research was to determine the genotype effect on lactation period, milk yield and protein and fat content, which are important in cheese making. The longest lactation period (213 days) had East Friesian sheep, while the highest total milk production (294 kg) and the highest p...

  2. Veal fatty acid composition of different breeds

    Directory of Open Access Journals (Sweden)

    Ivica Kos

    2010-01-01

    Full Text Available Veal fatty acid composition in M. Longissimus thoracis was investigated in different calf breeds (Simmental, Holstein, Simmental x Holstein. Calves were reared on the same farm under identical feeding and handling conditions. Simmental calves had higher polyunsaturated fatty acid (PUFA but lower saturated fatty acid (SFA and monounsaturated fatty acid (MUFA values than Holstein and crossbreed calves (P<0,05. The PUFA/SFA ratio was the highest in Simmental calves and the lowest in Holstein calves. Simmental calves also had the highest n-6/n-3 ratio while the crossbreed calves had the lowest n-6/n-3 ratio.

  3. Strategy for larch breeding in Iceland

    Energy Technology Data Exchange (ETDEWEB)

    Eysteinsson, T. [Iceland Forest Service, Egilsstadir (Iceland)

    1995-12-31

    An accelerated breeding program for Siberian larch was initiated in Iceland in 1992. Siberian larch is an important exotic species, but not fully adapted to Icelandic conditions. Selections are made based on adaptive traits such as growth rhythm and resistance to damage as well as form and growth rate. Seed will be produced in containerised, greenhouse orchards, necessitating selection for fecundity to best use expensive greenhouse space. Research will concentrate on developing flower induction treatments for Siberian larch and ways to maximize seed production and viability. 19 refs

  4. Review: Towards the agroecological management of ruminants, pigs and poultry through the development of sustainable breeding programmes. II. Breeding strategies.

    Science.gov (United States)

    Phocas, F; Belloc, C; Bidanel, J; Delaby, L; Dourmad, J Y; Dumont, B; Ezanno, P; Fortun-Lamothe, L; Foucras, G; Frappat, B; González-García, E; Hazard, D; Larzul, C; Lubac, S; Mignon-Grasteau, S; Moreno, C R; Tixier-Boichard, M; Brochard, M

    2016-11-01

    Agroecology uses ecological processes and local resources rather than chemical inputs to develop productive and resilient livestock and crop production systems. In this context, breeding innovations are necessary to obtain animals that are both productive and adapted to a broad range of local contexts and diversity of systems. Breeding strategies to promote agroecological systems are similar for different animal species. However, current practices differ regarding the breeding of ruminants, pigs and poultry. Ruminant breeding is still an open system where farmers continue to choose their own breeds and strategies. Conversely, pig and poultry breeding is more or less the exclusive domain of international breeding companies which supply farmers with hybrid animals. Innovations in breeding strategies must therefore be adapted to the different species. In developed countries, reorienting current breeding programmes seems to be more effective than developing programmes dedicated to agroecological systems that will struggle to be really effective because of the small size of the populations currently concerned by such systems. Particular attention needs to be paid to determining the respective usefulness of cross-breeding v. straight breeding strategies of well-adapted local breeds. While cross-breeding may offer some immediate benefits in terms of improving certain traits that enable the animals to adapt well to local environmental conditions, it may be difficult to sustain these benefits in the longer term and could also induce an important loss of genetic diversity if the initial pure-bred populations are no longer produced. As well as supporting the value of within-breed diversity, we must preserve between-breed diversity in order to maintain numerous options for adaptation to a variety of production environments and contexts. This may involve specific public policies to maintain and characterize local breeds (in terms of both phenotypes and genotypes), which could

  5. Characterization of the genetic profile of five Danish dog breeds

    DEFF Research Database (Denmark)

    Pertoldi, Cino; Kristensen, Torsten Nygaard; Loeschcke, Volker

    2013-01-01

    was determined by means of principal component analysis (PCA) and through a Bayesian clustering method. Both the PCA and the Bayesian clustering method revealed a clear genetic separation of the 5 breeds. The level of genetic variation within the breeds varied. The expected heterozygosity (H) as well......This investigation presents results from a genetic characterization of 5 Danish dog breeds genotyped on the CanineHD BeadChip microarray with 170,000 SNP. The breeds investigated were 1) Danish Spitz (DS; n = 8), 2) Danish-Swedish Farm Dog (DSF; n = 18), 3) Broholmer (BR; n = 22), 4) Old Danish...... Pointing Dog (ODP; n = 24), and 5) Greenland Dog (GD; n = 23). The aims of the investigation were to characterize the genetic profile of the abovementioned dog breeds by quantifying the genetic differentiation among them and the degree of genetic homogeneity within breeds. The genetic profile...

  6. Genome-wide genetic changes during modern breeding of maize.

    Science.gov (United States)

    Jiao, Yinping; Zhao, Hainan; Ren, Longhui; Song, Weibin; Zeng, Biao; Guo, Jinjie; Wang, Baobao; Liu, Zhipeng; Chen, Jing; Li, Wei; Zhang, Mei; Xie, Shaojun; Lai, Jinsheng

    2012-06-03

    The success of modern maize breeding has been demonstrated by remarkable increases in productivity over the last four decades. However, the underlying genetic changes correlated with these gains remain largely unknown. We report here the sequencing of 278 temperate maize inbred lines from different stages of breeding history, including deep resequencing of 4 lines with known pedigree information. The results show that modern breeding has introduced highly dynamic genetic changes into the maize genome. Artificial selection has affected thousands of targets, including genes and non-genic regions, leading to a reduction in nucleotide diversity and an increase in the proportion of rare alleles. Genetic changes during breeding happen rapidly, with extensive variation (SNPs, indels and copy-number variants (CNVs)) occurring, even within identity-by-descent regions. Our genome-wide assessment of genetic changes during modern maize breeding provides new strategies as well as practical targets for future crop breeding and biotechnology.

  7. Elephant reproduction: improvement of breeding efficiency and development of a breeding strategy

    NARCIS (Netherlands)

    Thitaram, C.

    2009-01-01

    The efficiency of reproduction of the Asian elephant (Elephas maximus) has become of major concern. Captive breeding programs worldwide have met with limited success and few ex situ elephant populations are self-sustaining. The low birth rate and high mortality cause the captive population to declin

  8. Combining Breeding Bird Survey and distance sampling to estimate density of migrant and breeding birds

    Science.gov (United States)

    Somershoe, S.G.; Twedt, D.J.; Reid, B.

    2006-01-01

    We combined Breeding Bird Survey point count protocol and distance sampling to survey spring migrant and breeding birds in Vicksburg National Military Park on 33 days between March and June of 2003 and 2004. For 26 of 106 detected species, we used program DISTANCE to estimate detection probabilities and densities from 660 3-min point counts in which detections were recorded within four distance annuli. For most species, estimates of detection probability, and thereby density estimates, were improved through incorporation of the proportion of forest cover at point count locations as a covariate. Our results suggest Breeding Bird Surveys would benefit from the use of distance sampling and a quantitative characterization of habitat at point count locations. During spring migration, we estimated that the most common migrant species accounted for a population of 5000-9000 birds in Vicksburg National Military Park (636 ha). Species with average populations of 300 individuals during migration were: Blue-gray Gnatcatcher (Polioptila caerulea), Cedar Waxwing (Bombycilla cedrorum), White-eyed Vireo (Vireo griseus), Indigo Bunting (Passerina cyanea), and Ruby-crowned Kinglet (Regulus calendula). Of 56 species that bred in Vicksburg National Military Park, we estimated that the most common 18 species accounted for 8150 individuals. The six most abundant breeding species, Blue-gray Gnatcatcher, White-eyed Vireo, Summer Tanager (Piranga rubra), Northern Cardinal (Cardinalis cardinalis), Carolina Wren (Thryothorus ludovicianus), and Brown-headed Cowbird (Molothrus ater), accounted for 5800 individuals.

  9. Extent of linkage disequilibrium in large breed dogs: chromosomal and breed variation

    Science.gov (United States)

    Purpose: Understanding extent of linkage disequilibrium (LD) is a crucial component for successful utilization of genome-wide association studies (GWAS). The extent of LD in the dog has been described based upon small marker sets in multiple breeds and studies. Understanding variation in LD on a per...

  10. Genetic Diversity of Some Tomato Cultivars and Breeding Lines Commonly Used in Pakistani Breeding Program

    Directory of Open Access Journals (Sweden)

    Muhammad Azhar Shah

    2014-10-01

    Full Text Available Genetic diversity present in gene pool is an important determination for breeding programs, and characterization is useful of building crop plant collections primarily based on the knowledge of the presence of valuable genes and traits. Developing successful varieties for increasing the future yield and quality of tomato depend mainly on the genetic diversity of parents used in the breeding program. Molecular characterization of 21 tomato genotypes used in in Pakistani breeding program was studied using random amplified polymorphic DNA (RAPD markers. Total 102 bands were amplified among 21 genotypes using 20 RAPD primers. Overall 73.5% polymorphism was shown as 75 out of 102 loci were polymorphic. High degree of divergence between varieties was indicated by low level of monomorphic bands. The number of PCR products per primer varied from 2-8 with an average of 5.1 bands per primer. Primer GL J-20 and GL C-09 produced maximum number of bands whereas the primers GL A-09 produced the lowest. The polymorphism per RAPD primer ranged from 50% to 100% with an average of 73.5%. The accumulative analysis of amplified products generated by RAPD’s was enough to assess the genetic diversity among the genotypes. The information would be helpful for formulating future breeding and genome mapping programs. This study will also work as an indicator for tomato breeders to evolve varieties with genetic diverse back ground to achieve sustainability in tomato production in the country.

  11. Binucleation to breed new plant species adaptable to their environments

    OpenAIRE

    Moustafa, Khaled

    2015-01-01

    Classical plant breeding approaches may fall short to breed new plant species of high environmental and ecological interests. Biotechnological and genetic manipulations, on the other hand, may hold more effective capabilities to circumvent the limitations of sexual incompatibility and conventional breeding programs. Given that plant cells encompass multiple copies of organellar genomes (mitochondrial and plastidial genomes), an important question could be raised about whether an artificial at...

  12. Characterization of the genetic profile of five Danish dog breeds

    DEFF Research Database (Denmark)

    Pertoldi, Cino; Kristensen, T. N.; Loeschcke, Volker;

    2013-01-01

    This investigation presents results from a genetic characterization of 5 Danish dog breeds genotyped on the CanineHD BeadChip microarray with 170,000 SNP. The breeds investigated were 1) Danish Spitz (DS; n = 8), 2) Danish-Swedish Farm Dog (DSF; n = 18), 3) Broholmer (BR; n = 22), 4) Old Danish P...... strategies for the preservation of the genetic pool of these dog breeds. © 2013 American Society of Animal Science. All rights reserved....

  13. Hybrid reactors: Nuclear breeding or energy production?

    Energy Technology Data Exchange (ETDEWEB)

    Piera, Mireia [UNED, ETSII-Dp Ingenieria Energetica, c/Juan del Rosal 12, 28040 Madrid (Spain); Lafuente, Antonio; Abanades, Alberto; Martinez-Val, J.M. [ETSII-UPM, c/Jose Gutierrez Abascal 2, 28006 Madrid (Spain)

    2010-09-15

    After reviewing the long-standing tradition on hybrid research, an assessment model is presented in order to characterize the hybrid performance under different objectives. In hybrids, neutron multiplication in the subcritical blanket plays a major role, not only for energy production and nuclear breeding, but also for tritium breeding, which is fundamental requirement in fusion-fission hybrids. All three objectives are better achieved with high values of the neutron multiplication factor (k-eff) with the obvious and fundamental limitation that it cannot reach criticality under any event, particularly, in the case of a loss of coolant accident. This limitation will be very important in the selection of the coolant. Some general considerations will be proposed, as guidelines for assessing the hybrid potential in a given scenario. Those guidelines point out that hybrids can be of great interest for the future of nuclear energy in a framework of Sustainable Development, because they can contribute to the efficient exploitation of nuclear fuels, with very high safety features. Additionally, a proposal is presented on a blanket specially suited for fusion-fission hybrids, although this reactor concept is still under review, and new work is needed for identifying the most suitable blanket composition, which can vary depending on the main objective of the hybrid. (author)

  14. The Breeding Bird Survey, 1967 and 1968

    Science.gov (United States)

    Robbins, C.S.; Van Velzen, W.T.

    1969-01-01

    In the Breeding Bird Survey of North America, cooperators ran 982 survey routes in 1967 and 1,174 in 1968. All States except Hawaii and all Canadian Provinces except Newfoundland were included. Roadside routes are selected at random within 1-degree blocks of latitude and longitude. Each 24 1/2-mile route, with 3-minute stops spaced half a mile apart, is driven by automobile. All birds heard or seen at the stops are recorded on special forms, and the data are transferred to magnetic tape for analysis. The average number of birds of each species per route is tabulated by State and Province, presenting for the first time a record of the comparative abundance of each species across the continent. The sample size is given for each species recorded. A sophisticated analysis program, here employed for the first time, is used to compute weighted mean values of the survey results for selected species at the State, stratum, regional, and continental level. The statistical significance of year-to-year changes at the 80, 90, 95, and 99 percent levels of probability are part of the computer output. An index for comparing populations of each species from year to year is established, with 1968 as the base year. Maps show the breeding range and comparative abundance of selected species.

  15. Nutrient reserve dynamics of breeding canvasbacks

    Science.gov (United States)

    Barzen, J.A.; Serie, J.R.

    1990-01-01

    We compared nutrients in reproductive and nonreproductive tissues of breeding Canvasbacks (Aythya valisineria) to assess the relative importance of endogenous reserves and exogenous foods. Fat reserves of females increased during rapid follicle growth and varied more widely in size during the early phase of this period. Females began laying with ca. 205 g of fat in reserve and lost 1.8 g of carcass fat for every 1 g of fat contained in their ovary and eggs. Females lost body mass (primarily fat) at a declining rate as incubation advanced. Protein reserves increased directly with dry oviduct mass during rapid follicle growth. This direct relationship was highly dependent upon data from 2 birds and likely biased by structural size. During laying, protein reserves did not vary with the combined mass of dry oviduct and dry egg protein. Between laying and incubation, mean protein reserves decreased by an amount equal to the protein found in 2.1 Canvasback eggs. Calcium reserves did not vary with the cumulative total of calcium deposited in eggs. Mean calcium reserve declined by the equivalent content of 1.2 eggs between laying and incubation. We believe that protein and calcium were stored in small amounts during laying, and that they were supplemented continually by exogenous sources. In contrast, fat was stored in large amounts and contributed significantly to egg production and body maintenance. Male Canvasbacks lost fat steadily--but not protein or calcium--as the breeding season progressed.

  16. Tornadic storm avoidance behavior in breeding songbirds.

    Science.gov (United States)

    Streby, Henry M; Kramer, Gunnar R; Peterson, Sean M; Lehman, Justin A; Buehler, David A; Andersen, David E

    2015-01-05

    Migration is a common behavior used by animals of many taxa to occupy different habitats during different periods. Migrant birds are categorized as either facultative (i.e., those that are forced to migrate by some proximal cue, often weather) or obligate (i.e., those that migrate on a regular cycle). During migration, obligate migrants can curtail or delay flights in response to inclement weather or until favorable winds prevail, and they can temporarily reorient or reverse direction when ecological or meteorological obstacles are encountered. However, it is not known whether obligate migrants undertake facultative migrations and make large-scale movements in response to proximal cues outside of their regular migration periods. Here, we present the first documentation of obligate long-distance migrant birds undertaking a facultative migration, wherein breeding golden-winged warblers (Vermivora chrysoptera) carrying light-level geolocators performed a >1,500 km 5-day circumvention of a severe tornadic storm. The birds evacuated their breeding territories >24 hr before the arrival of the storm and atmospheric variation associated with it. The probable cue, radiating >1,000 km from tornadic storms, perceived by birds and influencing bird behavior and movements, is infrasound (i.e., sound below the range of human hearing). With the predicted increase in severity and frequency of similar storms as anthropogenic climate change progresses, understanding large-scale behavioral responses of animals to such events will be an important objective of future research.

  17. Breeding programs for smallholder sheep farming systems: I. Evaluation of alternative designs of breeding schemes.

    Science.gov (United States)

    Gizaw, S; Rischkowsky, B; Valle-Zárate, A; Haile, A; van Arendonk, J A M; Mwai, A O; Dessie, T

    2014-10-01

    Village- and central nucleus-based schemes were simulated and evaluated for their relative bio-economic efficiencies, using Ethiopia's Menz sheep as example. The schemes were: village-based 2-tier (Scheme-1) and 1-tier (Scheme-2) cooperative village breeding schemes, dispersed village-based nuclei scheme (Scheme-3), conventional 2-tier central nucleus-based scheme (Scheme-4), and schemes linking a central nucleus and village multiplier nuclei with selection in central nucleus (Scheme-5) or in both central and village nuclei (Scheme-6). Among village-based schemes, Scheme-1 gave the highest genetic progress, while Scheme-2 was economically the most efficient with genetic gain in the breeding objective of Birr 5.6 and a profit of Birr 37.2/ewe/year. The central nucleus schemes were more efficient than the village schemes. Scheme-4 was the most efficient with genetic gain in the breeding objective of Birr 13.5 and a profit of Birr 71.2, but is operationally more difficult as it requires a very large central nucleus. The choice between village and central nucleus-based schemes would depend on local conditions (availability of infrastructure, logistics and technical knowhow and support). Linking central nucleus with village-based nuclei (Scheme-6) would be a feasible option to overcome the operational difficulties of the conventional central nucleus scheme. If a village-based breeding program is envisaged as should be the 1st step in most low-input systems, then Scheme-2 is the most efficient. To scale out to an entire Menz breed level, Scheme-3 would be recommended.

  18. Repeat breeding: Incidence, risk factors and diagnosis in buffaloes

    Directory of Open Access Journals (Sweden)

    Chandra Shekher Saraswat

    2016-04-01

    Full Text Available Repeat breeding in buffaloes was evaluated in terms of incidence, risk factors and diagnosis. The incidence of repeat breeding is low in buffaloes however in different studies the incidence varied from 0.70% to 30%. Because of seasonal suppression of fertility repeat breeding in buffaloes should be limited to the breeding season. Spring and winter calving, first parity, peri-parturient disease and lactation are significant risk factors for repeat breeding in buffaloes. The etiologies of repeat breeding in buffaloes can be failure of fertilization and early embryonic deaths. Only a few of causes of failure of fertilization have been identified in buffaloes. Ovulatory disturbances and ovarian cysts are uncommon in buffaloes and cysts have poor clinical manifestation. Endometritis is the common female cause of fertilization failures in buffaloes whereas poor semen quality and improper insemination are the bull side factors for fertilization failures. Early embryonic deaths are common in buffaloes mated/inseminated during the end of the breeding season due to a low luteal progesterone however embryonic deaths occur late (<25 days in buffaloes. Diagnostic approaches for repeat breeding include vaginoscopic and transrectal examination and uterine cytology for genital health. More precise evaluations of the ovarian and uterine function can be obtained by ultrasonographic and hysteroscopic examinations performed sequentially however, precise diagnosis of the cause of repeat breeding seems difficult.

  19. Development of Circular Economy of Characteristic Breeding Industry in Guangxi

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    In order to achieve characteristic,high-quality,high-efficiency,low-consumption,healthy and intensive breeding,we use the ecology method to analyze the status quo of development of characteristic breeding industry in Guangxi,from advantages in resources,industrial development,characteristic breeding,and standardized construction.There are some problems existing in the development of characteristic breeding industry in Guangxi:prominent contradiction among human,land and grain;outdated breeding mode;low comprehensive utilization rate of resources;increasingly deteriorating ecological environment.We put forth the following recommendations:based on the ecological and economic principles,introducing"reduce,reuse,recycle"idea of circular economy;striving to choose the development pattern of circular economy adapting to local resource characteristics,planting and breeding habits;in terms of realization path,paying close attention to construction of standardized breeding farm,cultivation of organic fertilizer industry,infrastructure construction,environmental law enforcement,and other parts;reinforcing the policy guidance,adjusting and optimizing industrial structure,strengthening scientific and technological innovation,and advancing industrialization management,to promote steady development of circular economy of characteristic breeding industry in Guangxi,and accelerate the process of rejuvenating province by breeding industry,enriching the people and building up Guangxi.

  20. Owner perceived differences between mixed-breed and purebred dogs

    Science.gov (United States)

    Turcsán, Borbála; Miklósi, Ádám; Kubinyi, Enikő

    2017-01-01

    Studies about the behaviours of mixed-breed dogs are rare, although mixed-breeds represent the majority of the world’s dog population. We have conducted two surveys to investigate the behavioural, demographic, and dog keeping differences between purebred and mixed-breed companion dogs. Questionnaire data were collected on a large sample of dogs living in Germany (N = 7,700 purebred dogs representing more than 200 breeds, and N = 7,691 mixed-breeds). We found that according to their owners, mixed-breeds were (1) less calm, (2) less sociable toward other dogs, and (3) showed more problematic behaviour than purebreds (p 10%) differences: neutering was more frequent among mixed-breeds, and they were acquired at older ages than purebreds (p < 0.001 for both), which could result in the observed behaviour differences. After controlling for the distribution of the demographic and dog keeping factors, we found that mixed-breeds were (1) more trainable than purebreds, (2) less calm, and (3) showed more problematic behaviour than purebreds (p < 0.001 for all). We discuss that these differences at least partly might be due to selective forces. Our results suggest that instead of being the “average” dogs, mixed-breeds represent a special group with characteristic behavioural traits. PMID:28222103

  1. Population viability analysis on domestic horse breeds (Equus caballus)

    DEFF Research Database (Denmark)

    Thirstrup, Janne Pia; Bach, Lars; Loeschcke, Volker

    2009-01-01

    management scenarios in which one of the studbooks was closed. According to the Vortex analysis, 2 of the breeds (Knabstrupper and Jutland) will persist for the next 200 yr, whereas the smaller breed (Frederiksborg) could become extinct within 40 yr. The sensitivity analyses indicated that the variables...... (Frederiksborg ) at its present 30% level. Monitoring of the breeds in the future, however, may be exploited to adjust the breeding strategies. We suggest that the large amount of data required by Vortex makes it very useful for analyzing domestic animals because of the comprehensive data material often...

  2. Evaluation of breeding objectives for purebred and crossbred selection schemes for adoption in indigenous chicken breeding programmes.

    Science.gov (United States)

    Okeno, T O; Kahi, A K; Peters, K J

    2013-01-01

    1. The aim of the study was to evaluate the genetic and economic breeding objectives for an indigenous chicken (IC) breeding programme in Kenya. 2. A closed three-tier nucleus breeding programme with three breeding objectives and two selection schemes was simulated. The breeding objectives included IC dual-purpose (ICD) for both eggs and meat, IC layer (ICL) for eggs and IC broiler (ICB) for meat production. 3. Pure line selection scheme (PLS) for development of IC pure breeds and crossbreeding scheme (CBS) for the production of hybrids were considered. Two-and three-way crossbreeding strategies were evaluated under CBS and the impact of nucleus size on genetic gains and profitability of the breeding programme were investigated. 4. Males were the main contributors to genetic gains. The highest genetic gains for egg number (2·71 eggs) and growth traits (1·74 g average daily gain and 57·96 g live weight at 16 weeks) were realised under PLS in ICL and ICB, respectively. 5. The genetic response for age at first egg was desirable in all the breeding objectives, while that for fertility and hatchability were only favourable under ICL and PLS in ICD. Faecal egg count and immune antibody response had low, but positive gains except under PLS where the later was unfavourable. ICB was the most profitable breeding objective, followed by ICD and ICL under all the selection schemes. 6. Although PLS was superior in genetic gains and profitability and recommended in breeding programmes targeting ICL and ICB, a three line CBS should be considered in development of a dual-purpose breed. 7. Increasing the nucleus size beyond 5% of the IC population was not attractive as it resulted in declining profitability of the breeding programme.

  3. Mitochondrial DNA of seven Italian sheep breeds shows faint signatures of domestication and suggests recent breed formation.

    Science.gov (United States)

    Mariotti, Marco; Valentini, Alessio; Marsan, Paolo Ajmone; Pariset, Lorraine

    2013-10-01

    Italy represented a crucial zone for migration and formation of sheep breeds. However, few data on Italian breeds have been published so far. We analysed seven Italian sheep breeds using mitochondrial DNA (mtDNA) sequencing to gain information on their genetic diversity and history. A 721 bp mtDNA control region fragment was amplified and sequenced in a total of 138 samples belonging to seven breeds and to Italian mohuflon (Ovis orientalis musimon) to investigate genetic diversity and phylogenetic evolution. We retrieved 68 variable sites and 79 haplotypes. The sheep breeds in our study are quite diverse, and phylogenetic analyses resulted in 3.6% of the samples belonging to A, 2.2% to D and 94.2% to B mtDNA haplogroups. Principal Component Analysis (PCA) showed a separation of breeds on both dimensions. The results of this study provide data on Italian breeds, presently scarcely investigated, and contribute to the knowledge of Italian sheep breeds and will be useful to the understanding of population genetics and breed evolution.

  4. A test of genetic association among male nuptial coloration, female mating preference, and male aggression bias within a polymorphic population of cichlid fish

    Directory of Open Access Journals (Sweden)

    Inke van der SLUIJS, Peter D. DIJKSTRA, Charlotte M. LINDEYER et al.

    2013-04-01

    Full Text Available Both inter- and intrasexual selection have been implicated in the origin and maintenance of species-rich taxa with diverse sexual traits. Simultaneous disruptive selection by female mate choice and male-male competition can, in theory, lead to speciation without geographical isolation if both act on the same male trait. Female mate choice can generate discontinuities in gene flow, while male-male competition can generate negative frequency-dependent selection stabilizing the male trait polymorphism. Speciation may be facilitated when mating preference and/or aggression bias are physically linked to the trait they operate on. We tested for genetic associations among female mating preference, male aggression bias and male coloration in the Lake Victoria cichlid Pundamilia. We crossed females from a phenotypically variable population with males from both extreme ends of the phenotype distribution in the same population (blue or red. Male offspring of a red sire were significantly redder than males of a blue sire, indicating that intra-population variation in male coloration is heritable. We tested mating preferences of female offspring and aggression biases of male offspring using binary choice tests. There was no evidence for associations at the family level between female mating preferences and coloration of sires, but dam identity had a significant effect on female mate preference. Sons of the red sire directed significantly more aggression to red than blue males, whereas sons of the blue sire did not show any bias. There was a positive correlation among individuals between male aggression bias and body coloration, possibly due to pleiotropy or physical linkage, which could facilitate the maintenance of color polymorphism [Current Zoology 59 (2: 221-229, 2013].

  5. A test of genetic association among male nuptial coloration,female mating preference, and male aggression bias within a polymorphic population of cichlid fish

    Institute of Scientific and Technical Information of China (English)

    Inke van der SLUIJS; Peter D.DIJKSTRA; Charlotte M.LINDEYER; Bertanne VISSER; Alan M.SMITH; Ton G.G.GROOTHUIS; Jacques J.M.van ALPHEN

    2013-01-01

    Both inter-and intrasexual selection have been implicated in the origin and maintenance of species-rich taxa with diverse sexual traits.Simultaneous disruptive selection by female mate choice and male-male competition can,in theory,lead to speciation without geographical isolation if both act on the same male trait.Female mate choice can generate discontinuities in gene flow,while male-male competition can generate negative frequency-dependent selection stabilizing the male trait polymorphism.Speciation may be facilitated when mating preference and/or aggression bias are physically linked to the trait they operate on.We tested for genetic associations among female mating preference,male aggression bias and male coloration in the Lake Victoria cichlid Pundamilia.We crossed females from a phenotypically variable population with males from both extreme ends of the phenotype distribution in the same population (blue or red).Male offspring of a red sire were significantly redder than males of a blue sire,indicating that intra-population variation in male coloration is heritable.We tested mating preferences of female offspring and aggression biases of male offspring using binary choice tests.There was no evidence for associations at the family level between female mating preferences and coloration of sires,but dam identity had a significant effect on female mate preference.Sons of the red sire directed significantly more aggression to red than blue males,whereas sons of the blue sire did not show any bias.There was a positive correlation among individuals between male aggression bias and body coloration,possibly due to pleiotropy or physical linkage,which could facilitate the maintenance of color polymorphism.

  6. Cholistan and Cholistani Breed of Cattle

    Directory of Open Access Journals (Sweden)

    U. Farooq, H. A. Samad*, F. Sher1, M. Asim1 and M. Arif Khan2

    2010-04-01

    Full Text Available Cholistan, once a green and prosperous land with the source of water being the ancient Hakra River, was also the cradle of great Hakra Valley Civilization. It is sprawled at an area of 26,000 Km2, located between the latitudes 27º42´and 29º45´North and longitudes 69º52´and 75º24´East. The bioclimatic system of Cholistan falls under the category of “tropical desert” with very scanty rainfall. Geomorphologically, the soils of Cholistan are a complex blend of river alluvium and Aeolin sands. Based on topography, type of soil and vegetation, this desert is divided into two geomorphic regions: the Lesser Cholistan (the Northern 7,770 Km² region and the Greater Cholistan (the Southern 18,130 Km² region. The primary source of water is rainfall which is utilized through natural depressions or man-made ponds called “Tobas” and “Dahars.” The secondary source is underground water which is brackish and salty and not fit for human/animal consumption. Two livestock production systems prevail under pastoralism in Cholistan viz. transhumanie and nomadic. Despite an uncertain, unpredictable rainfall, low humidity and extremes in temperatures, Cholistan has long been famous for raising different breeds of livestock, contributing a significant share to national milk, meat and wool output. The total livestock population estimated during 2006 was 12,09528, out of which 47% were cattle. Cholistani cattle are considered to be ancestor of the Sahiwal and are a thermo-tolerant, tick-resistant breed. Preliminary data on some productive and reproductive traits of Cholistani cows maintained at Govt. Livestock Station, Jugait Peer, Bahawalpur during the period 2005 to 2009 revealed the avergae values for the productive traits i.e. lactation length, lactation yield, dry period, service period and fat percentage in milk as 165 days, 1235 liters, 155 days, 121 days and 4.8%, respectively. Similarly, the average values for reproductive traits i.e. age at

  7. Optimizing breeding decisions for Finnish dairy herds.

    Science.gov (United States)

    Rajala-Schultz, P J; Gröhn, Y T; Allore, H G

    2000-01-01

    The purpose of this study was to determine the effect of reproductive performance on profitability and optimal breeding decisions for Finnish dairy herds. We used a dynamic programming model to optimize dairy cow insemination and replacement decisions. This optimization model maximizes the expected net revenues from a given cow and her replacements over a decision horizon. Input values and prices reflecting the situation in 1998 in Finland were used in the study. Reproductive performance was reflected in the model by overall pregnancy rate, which was a function of heat detection and conception rate. Seasonality was included in conception rate. The base run had a pregnancy rate of 0.49 (both heat detection and conception rate of 0.7). Different scenarios were modeled by changing levels of conception rate, heat detection, and seasonality in fertility. Reproductive performance had a considerable impact on profitability of a herd; good heat detection and conception rates provided an opportunity for management control. When heat detection rate decreased from 0.7 to 0.5, and everything else was held constant, net revenues decreased approximately 2.6%. If the conception rate also decreased to 0.5 (resulting in a pregnancy rate of 0.25), net revenues were approximately 5% lower than with a pregnancy rate of 0.49. With lower fertility, replacement percentage was higher and the financial losses were mainly from higher replacement costs. Under Finnish conditions, it is not optimal to start breeding cows calving in spring and early summer immediately after the voluntary waiting period. Instead, it is preferable to allow the calving interval to lengthen for these cows so that their next calving is in the fall. However, cows calving in the fall should be bred immediately after the voluntary waiting period. Across all scenarios, optimal solutions predicted most calvings should occur in fall and the most profitable time to bring a replacement heifer into a herd was in the fall. It

  8. CAGE BREEDING OF WARM WATER FRESHWATER FISH SPECIES

    Directory of Open Access Journals (Sweden)

    Roman Safner

    2008-10-01

    Full Text Available In the 1970s, Croatia became actively involved in the contemporary trend of breeding fish in floating cages. In addition to various species of marine fishes, breeding was attempted with trout, carp, catfish, cisco and salmon. Of the above freshwater fish species, specific standards were established only for the cage breeding of rainbow trout. Cage breeding of the remaining species remained at the level of occasional attempts, with more of an experimental than a commercial character. The regular attempts to master this technique for cage breeding of warm water freshwater fish species were aimed at achieving the known benefits of such breeding, such as simplicity of implementing technological measures, easier establishment of the breeding system, simpler manipulation, the possibility of denser colonies per unit volume with a high level of production, easier adaptations to market conditions and fewer initial structural investments. Despite the many advantages, the main reasons for the lack of greater implementation of the cage breeding technology for warm water species of freshwater fish include problems in obtaining the appropriate category and quantity of healthy fry, the specificity and applicability of physical and chemical properties of the recipients and human error. In evaluating the advantages and disadvantages, the final decision on the justification of cage breeding for individual warm water freshwater species must be based on both biological and economic factors. Based on the knowledge of cage breeding acquired to date, the rule for virtually all intensive breeding systems is that it is only recommended for those species with high market demand and a high market price. The technology that demands nutrition with highly concentrated feed and other production expenditures is costly, and is therefore not profitable with less expensive fish species. Furthermore, production must be market oriented, i.e. the appropriate market research measures

  9. Is income breeding an appropriate construct for waterfowl?

    Science.gov (United States)

    Janke, Adam K.; Anteau, Michael J.; Markl, Nicholas; Stafford, Joshua D.

    2015-01-01

    Breeding birds use a range of nutrient accumulation and allocation strategies to meet the nutritional demands of clutch formation and incubation. On one end of the spectrum, capital breeders use stored nutrients acquired prior to clutch formation and incubation to sustain metabolism during reproduction, while on the opposite end, income breeders derive nutrients solely from exogenous sources on the breeding grounds. Blue-winged Teal (Anas discors) are an ideal candidate to test for adoption of an income strategy among migratory waterfowl because of their small body size, temperate breeding range, and timing of reproduction relative to pulses in nutrient availability within breeding habitats. We collected migrating and pre-breeding Blue-winged Teal (n = 110) during the warmest spring in over a century in the southern edge of the species’ breeding range, which produced ideal conditions to test for adoption of an income breeding strategy among migratory waterfowl. Regression analyses revealed that females accumulated protein and fat reserves early in follicle development and appeared to mobilize at least some reserves coincident with the onset of clutch formation. Accumulation and subsequent mobilization of nutrient reserves was inconsistent with adherence to an income breeding strategy and suggested breeding Blue-winged Teal used capital (albeit locally acquired) for reproduction. Our results add to existing knowledge on the ubiquity of endogenous nutrient reserve accumulation prior to and during reproduction by waterfowl, perhaps suggesting endogenous nutrient reserves are universally used for clutch formation or incubation to some degree. If indeed Blue-winged Teal and other waterfowl universally use capital for breeding, research and conservation efforts should shift from evaluating whether an income breeding strategy is used and focus on when and where necessary capital is acquired prior to clutch formation.

  10. Issues and perspectives in dairy sheep breeding

    Directory of Open Access Journals (Sweden)

    Pierlorenzo Secchiari

    2010-01-01

    Full Text Available The present review consists of two parts. In the first part, the authors briefly describe the state of the art of breedingprogrammes for Italian dairy sheep; then they report new models for genetic evaluation and consider the problem ofgenotype x environment interaction and the impact of farming systems on the genetic merit of animals. In the secondpart new breeding goals regarding the evolution of milk quality concept and the increasing importance of functional traitsare reported. Regarding milk quality, the authors especially focus on the traits related to cheese-making ability and onthe nutraceutical aspects of milk. Among functional traits, resistance to diseases (mastitis and Scrapie has been highlightedfor its great importance in livestock species. Finally, the perspectives of marker-assisted selection have also beenreported.

  11. Studies on mutation breeding of hibiscus Syriacus

    Energy Technology Data Exchange (ETDEWEB)

    Song, Heui Sub; Lee, Ki Woon; Im, Yong Taek [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1994-12-01

    Hibiscus(Hibiscus syracuse L.) has been know as a national flower of Korea science old times. Although there are some ancient records that the Hibiscus had been planted in large quantities in Korea, Japanese had dug out all the good plants of Hibiscus in this country during their colonial period. But Hibiscus has such a characteristics of self-incompatibility that all the plants exist as a hybrid naturally and have heterogeneous genes. Therefore many good characters can be taken out from the surviving plants. Many domestic 78 varieties of Hibiscus syracuse were collected and propagated 26 varieties cuttings. Radiosensitivity of gamma-ray irradiated Hibiscus syracuse were investigated the germination rate, survival rate, plant height was with the increase of 4 kR better than control. The radiation doses of 10-12 kR are recommended for mutation breeding of Hibiscus. 6 figs, 11 tabs, 41 refs. (Author).

  12. Breeding return times and abundance in capture-recapture models.

    Science.gov (United States)

    Pledger, Shirley; Baker, Edward; Scribner, Kim

    2013-12-01

    For many long-lived animal species, individuals do not breed every year, and are often not accessible during non-breeding periods. Individuals exhibit site fidelity if they return to the same breeding colony or spawning ground when they breed. If capture and recapture is only possible at the breeding site, temporary emigration models are used to allow for only a subset of the animals being present in any given year. Most temporary emigration models require the use of the robust sampling design, and their focus is usually on probabilities of annual survival and of transition between breeding and non-breeding states. We use lake sturgeon (Acipenser fulvescens) data from a closed population where only a simple (one sample per year) sampling scheme is possible, and we also wish to estimate abundance as well as sex-specific survival and breeding return time probabilities. By adding return time parameters to the Schwarz-Arnason version of the Jolly-Seber model, we have developed a new likelihood-based model which yields plausible estimates of abundance, survival, transition and return time parameters. An important new finding from investigation of the model is the overestimation of abundance if a Jolly-Seber model is used when Markovian temporary emigration is present.

  13. Litter size variation in Polish selected small dog breeds

    Directory of Open Access Journals (Sweden)

    Małgorzata Goleman

    2015-08-01

    Full Text Available In breeders’ general opinion small breed females produce less numerous litters. The aim of the study was to analyse the litter size and the frequency of the gender ratio in selected small dog breeds in view of their popularity in Poland. The data set comprised information on 639 litters (in total 2578 puppies of eight breeds, which were born between January 2003 and end December 2014. The results were statistically analysed using statistical program SPSS 20.0. Medium-size litters were observed in the analysed small dog breeds (4.034±0.1. Comparison of the selected breeds of the Fédération Cynologique Internationale (FCI Groups showed that the mean litter size in Group IX was higher (4.36±0.08 than that in Group III (3.87±0.14 and the differences were statistically significant. The study has confirmed the hypothesis that larger females produce more numerous litters, but there are large intra-individual variations in the number of pups born in individual breeds. Additionally, the gender ratio in the puppies born in the analysed breeds was equal, despite the fluctuations in the individual breeds.

  14. Felinine excretion in domestic cat breeds: a preliminary investigation

    NARCIS (Netherlands)

    Hagen-Plantinga, E.A.; Bosch, G.; Hendriks, W.H.

    2014-01-01

    The aim of this study was to determine possible differences in felinine excretion between domesticated cat breeds. For this purpose, urine was collected from a total of 83 privately owned entire male cats from eight different breeds in the Netherlands during the period of November 2010 till November

  15. Felinine excretion in domestic cat breeds: a preliminary investigation.

    NARCIS (Netherlands)

    Hagen - Plantinga, Esther; Hendriks, Wouter; Bosch, Guido

    2014-01-01

    The aim of this study was to determine possible differences in felinine excretion between domesticated cat breeds. For this purpose, urine was collected from a total of 83 privately owned entire male cats from eight different breeds in the Netherlands during the period of November 2010 till November

  16. Breeding biology and nestling development of the Grasshopper Buzzard

    NARCIS (Netherlands)

    Buij, R.; Kortekaas, K.; Folkertsma, I.; van der Velde, M.; Komdeur, J.; de Iongh, H. H.; Monadjem, A.

    2012-01-01

    Research into the effect of environmental variables on reproductive success of tropical raptors is often constrained by the lack of information on breeding biology. We provide the first detailed information of the breeding biology and nestling development of the Grasshopper Buzzard Butastur rufipenn

  17. Prevalence of genetic disorders in dog breeds: a literature review

    NARCIS (Netherlands)

    Wirth, J.

    2015-01-01

    Genetic disorders are common in dogs and in the media it is reported that genetic disorders are more frequent in pedigree dogs than in look-a-likes or in mixed-breed dogs. Here, we consider pedigree dogs as purebred dogs (i.e. matching a breed-specific morphology) with a registered and certified ped

  18. Developing a typology for local cattle breed farmers in Europe

    NARCIS (Netherlands)

    Soini, K.; Diaz, C.; Gandini, G.; Haas, de Y.; Lilja, T.; Martin-Collado, D.; Pizzi, F.; Hiemstra, S.J.

    2012-01-01

    Recognizing cultural diversity among local breed farmers is crucial for the successful development and implementation of farm animal genetic resources FAnGr conservation policies and programmes. In this study based on survey data collected in the EUropean REgional CAttle breeds project from six Euro

  19. Creating new middle breeding materials by utilizing new techniques

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ A new breeding program" Creating new middle breeding materials by utilizing new techniques", cooperated by China National Rice Research Institute (CNRRI) and Japan International Research Center for Agricultural Science (JIRCAS)", started in Hangzhou, China in 1999.The study led by Dr Kunihiro Y. (Japan) and Dr QIAN Qian (China) now advances smoothly.

  20. Short communication: casein haplotype variability in sicilian dairy goat breeds.

    Science.gov (United States)

    Gigli, I; Maizon, D O; Riggio, V; Sardina, M T; Portolano, B

    2008-09-01

    In the Mediterranean region, goat milk production is an important economic activity. In the present study, 4 casein genes were genotyped in 5 Sicilian goat breeds to 1) identify casein haplotypes present in the Argentata dell'Etna, Girgentana, Messinese, Derivata di Siria, and Maltese goat breeds; and 2) describe the structure of the Sicilian goat breeds based on casein haplotypes and allele frequencies. In a sample of 540 dairy goats, 67 different haplotypes with frequency >or=0.01 and 27 with frequency >or=0.03 were observed. The most common CSN1S1-CSN2-CSN1S2-CSN3 haplotype for Derivata di Siria and Maltese was FCFB (0.17 and 0.22, respectively), whereas for Argentata dell'Etna, Girgentana and Messinese was ACAB (0.06, 0.23, and 0.10, respectively). According to the haplotype reconstruction, Argentata dell'Etna, Girgentana, and Messinese breeds presented the most favorable haplotype for cheese production, because the casein concentration in milk of these breeds might be greater than that in Derivata di Siria and Maltese breeds. Based on a cluster analysis, the breeds formed 2 main groups: Derivata di Siria, and Maltese in one group, and Argentata dell'Etna and Messinese in the other; the Girgentana breed was between these groups but closer to the latter.

  1. Signatures of diversifying selection in European pig breeds.

    Directory of Open Access Journals (Sweden)

    Samantha Wilkinson

    2013-04-01

    Full Text Available Following domestication, livestock breeds have experienced intense selection pressures for the development of desirable traits. This has resulted in a large diversity of breeds that display variation in many phenotypic traits, such as coat colour, muscle composition, early maturity, growth rate, body size, reproduction, and behaviour. To better understand the relationship between genomic composition and phenotypic diversity arising from breed development, the genomes of 13 traditional and commercial European pig breeds were scanned for signatures of diversifying selection using the Porcine60K SNP chip, applying a between-population (differentiation approach. Signatures of diversifying selection between breeds were found in genomic regions associated with traits related to breed standard criteria, such as coat colour and ear morphology. Amino acid differences in the EDNRB gene appear to be associated with one of these signatures, and variation in the KITLG gene may be associated with another. Other selection signals were found in genomic regions including QTLs and genes associated with production traits such as reproduction, growth, and fat deposition. Some selection signatures were associated with regions showing evidence of introgression from Asian breeds. When the European breeds were compared with wild boar, genomic regions with high levels of differentiation harboured genes related to bone formation, growth, and fat deposition.

  2. Signatures of Diversifying Selection in European Pig Breeds

    NARCIS (Netherlands)

    Wilkinson, S.; Lu, Z.H.; Megens, H.J.W.C.; Archibald, A.L.; Haley, C.; Jackson, I.J.; Groenen, M.A.M.; Crooijmans, R.P.M.A.; Ogden, R.; Wiener, P.

    2013-01-01

    Following domestication, livestock breeds have experienced intense selection pressures for the development of desirable traits. This has resulted in a large diversity of breeds that display variation in many phenotypic traits, such as coat colour, muscle composition, early maturity, growth rate, bod

  3. Fitness consequences of cooperative breeding in the Seychelles warbler

    NARCIS (Netherlands)

    Komdeur, Jan; Richardson, David; Burke, Terry

    2006-01-01

    Inclusive fitness benefits have been suggested as the selective force behind the evolution of cooperative breeding. Assessing the benefits accrued to individual males and females is crucial to understanding the sex-specific helping behavior observed in many cooperatively breeding species. We investi

  4. CATTLE BREEDING AND TERRITORY: A SURVEY ON THE MAREMMANA BREED RAISED IN TUSCANY

    Directory of Open Access Journals (Sweden)

    Roberto FRATINI

    2014-07-01

    Full Text Available This study aims to highlight the importance of a cattle race native in an area of the territory of Tuscany. The Maremmana breed is a valuable breed raised in the pastures that stretch between southern Tuscany and northern Lazio. A sample of 12 farms was analyzed through direct interview, carried out at the farm. The farms surveyed implement organic farming, according to precise rules. The aspect that mostly catches in the interviews is that the only livestock activity is not sufficient for economic development of this rural area; in fact most of the farms perform multi-functional, practicing agritourism activities. In terms of remuneration of the factors of production used in animal husbandry it seems that especially farms with few animals require the integration of agricultural income with other business activities.

  5. Plasma hormone levels and semen quality in male cats during non-breeding and breeding seasons.

    Science.gov (United States)

    Tsutsui, T; Onodera, F; Oba, H; Mizutani, T; Hori, T

    2009-07-01

    Female cats are known to be seasonal breeders and male cats annual breeders. Despite this, there are limited data on the influence of breeding season (BS) on hormone concentration and semen quality in the male cat. This study compared plasma concentrations of LH and testosterone (T), and semen quality during the non-breeding season (NBS) and BS in five male cats subject to natural hours of daylight but a constant environmental temperature. Plasma LH and T concentrations were higher during the BS in 2/35 and 3/5 cats, respectively, although when comparing both hormones combined, values were higher during the BS than the NBS in all cats (p hormone secretion and semen quality, during the NBS all cats were likely to have been fertile.

  6. Changes in sunflower breeding over the last fifty years

    Directory of Open Access Journals (Sweden)

    Vear Felicity

    2016-03-01

    Full Text Available This article discusses changes in sunflower breeding objectives since the introduction of hybrid varieties 50 years ago. After a reminder of the importance of some early programmes, Canadian in particular, the present situation for each breeding objective is compared with those encountered earlier. Breeding for yield has changed from maximum possible yield under intensive agriculture to yield with resistance to abiotic stresses, moderate droughts and shallow soils in particular, helped by collaboration with agronomists to produce crop models. Breeding for oil has changed from quantity to quality and the value of seed meal is again becoming economically important. Necessary disease resistances vary with agronomic practises and selection pressure on pathogens according to varietal genetics. The possibilities of new types of sunflower are also discussed. Advances in genomics will change breeding procedures, but with rapidly changing molecular techniques, international collaboration is particularly important.

  7. MILK COAGULATION PROPERTIES OF CATTLE BREEDS REARED IN ALPINE AREA

    Directory of Open Access Journals (Sweden)

    Giulio Visentin

    2015-09-01

    Full Text Available The aim of the present study was to apply mid-infrared spectroscopy prediction models developed for milk coagulation properties (MCP to a spectral dataset of 123,240 records collected over a 2-year period in the Alpine area, and to investigate sources of variation of the predicted MCP. Mixed linear models included fixed effects of breed, month and year of sampling, days in milk, parity, and the interactions between the main effects. Random effects were herd nested within breed, cow nested within breed, and the residual. All fixed effects were significant (P<0.05 in explaining the variation of MCP. In particular, milk clotting characteristics varied significantly among breeds, and local Alpine Grey breed exhibited the most favourable processing characteristics. Milk coagulation properties varied across lactation and were at their worst after the peak.

  8. Breed differences in natriuretic peptides in healthy dogs

    DEFF Research Database (Denmark)

    Sjöstrand, K.; Wess, G.; Ljungvall, I.

    2014-01-01

    BACKGROUND: Measurement of plasma concentration of natriuretic peptides (NPs) is suggested to be of value in diagnosis of cardiac disease in dogs, but many factors other than cardiac status may influence their concentrations. Dog breed potentially is 1 such factor. OBJECTIVE: To investigate breed...... variation in plasma concentrations of pro-atrial natriuretic peptide 31-67 (proANP 31-67) and N-terminal B-type natriuretic peptide (NT-proBNP) in healthy dogs. ANIMALS: 535 healthy, privately owned dogs of 9 breeds were examined at 5 centers as part of the European Union (EU) LUPA project. METHODS: Absence...... the median concentration in Doberman Pinschers. CONCLUSIONS AND CLINICAL IMPORTANCE: Considerable interbreed variation in plasma NP concentrations was found in healthy dogs. Intrabreed variation was large in several breeds, especially for NT-proBNP. Additional studies are needed to establish breed...

  9. Characteristics important for organic breeding of vegetable crops

    Directory of Open Access Journals (Sweden)

    Zdravković Jasmina

    2010-01-01

    Full Text Available The remarkable development and application of new genetic The Institute for Vegetable Crops possesses a rich germplasm collection of vegetables, utilized as gene resource for breeding specific traits. Onion and garlic breeding programs are based on chemical composition improvement. There are programs for identification and use of genotypes characterized by high tolerance to economically important diseases. Special attention is paid to breeding cucumber and tomato lines tolerant to late blight. As a result, late blight tolerant pickling cucumber line, as well as late blight tolerant tomato lines and hybrids are realized. Research on bean drought stress tolerance is initiated. Lettuce breeding program including research on spontaneous flora is started and interspecies hybrids were observed as possible genetic variability source. It is important to have access to a broad range of vegetable genotypes in order to meet the needs of organic agriculture production. Appreciating the concept of sustainable agriculture, it is important to introduce organic agriculture programs in breeding institutions.

  10. Domestic estimated breeding values and genomic enhanced breeding values of bulls in comparison with their foreign genomic enhanced breeding values.

    Science.gov (United States)

    Přibyl, J; Bauer, J; Čermák, V; Pešek, P; Přibylová, J; Šplíchal, J; Vostrá-Vydrová, H; Vostrý, L; Zavadilová, L

    2015-10-01

    Estimated breeding values (EBVs) and genomic enhanced breeding values (GEBVs) for milk production of young genotyped Holstein bulls were predicted using a conventional BLUP - Animal Model, a method fitting regression coefficients for loci (RRBLUP), a method utilizing the realized genomic relationship matrix (GBLUP), by a single-step procedure (ssGBLUP) and by a one-step blending procedure. Information sources for prediction were the nation-wide database of domestic Czech production records in the first lactation combined with deregressed proofs (DRP) from Interbull files (August 2013) and domestic test-day (TD) records for the first three lactations. Data from 2627 genotyped bulls were used, of which 2189 were already proven under domestic conditions. Analyses were run that used Interbull values for genotyped bulls only or that used Interbull values for all available sires. Resultant predictions were compared with GEBV of 96 young foreign bulls evaluated abroad and whose proofs were from Interbull method GMACE (August 2013) on the Czech scale. Correlations of predictions with GMACE values of foreign bulls ranged from 0.33 to 0.75. Combining domestic data with Interbull EBVs improved prediction of both EBV and GEBV. Predictions by Animal Model (traditional EBV) using only domestic first lactation records and GMACE values were correlated by only 0.33. Combining the nation-wide domestic database with all available DRP for genotyped and un-genotyped sires from Interbull resulted in an EBV correlation of 0.60, compared with 0.47 when only Interbull data were used. In all cases, GEBVs had higher correlations than traditional EBVs, and the highest correlations were for predictions from the ssGBLUP procedure using combined data (0.75), or with all available DRP from Interbull records only (one-step blending approach, 0.69). The ssGBLUP predictions using the first three domestic lactation records in the TD model were correlated with GMACE predictions by 0.69, 0.64 and 0

  11. Influence of production circumstances and economic evaluation criteria on economic comparison of breeds and breed-crosses.

    NARCIS (Netherlands)

    Kahi, A.K.; Koskey, I.S.; Cardoso, V.L.; Arendonk, van J.A.M.

    1998-01-01

    The ranking of genotypes (i.e., breeds and breed crosses) for economic performance depends on the production circumstances of the herd and the criteria for economic evaluation. In this study, the effects of evaluation criteria and production circumstance are quantified using data from the literature

  12. Breeding business : the future of plant breeding in the light of developments in patent rights and plant breeder's rights

    NARCIS (Netherlands)

    Louwaars, N.P.; Dons, J.J.M.; Overwalle, van G.; Raven, H.; Arundel, A.; Eaton, D.; Nelis, A.

    2009-01-01

    Plant breeding serves an important public interest. Two intellectual property (IP) systems are relevant for the protection of innovations in this sector: plant breeder's rights and patent rights. Some exemptions play an important role in plant breeding, such as the 'breeder's exemption', which is un

  13. Call for Papers--Molecular Plant Breeding (ISSN 1923-8266)

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Molecular Plant Breeding (ISSN 1923-8266, online, http://mpb.sophiapublisher.com/) is an open access and peer reviewed journal, which publishes original research papers involving the transgenic breeding and marker assisted breeding in plants.

  14. The lifetime production of Bovec and Improved Bovec sheep breeds

    Directory of Open Access Journals (Sweden)

    Gregor Gorjanc

    2009-06-01

    Full Text Available Production data of Bovec and Improved (with East-Friesian Bovec sheep born between years 1989 and 2006 were used for the analysis of culling dynamics and lifetime production. Lifetime production was calculated as the sum of production at each lambing (number of born and liveborn lambs and litter birth weight, weaning (number of weaned lambs and litter weaning weight or during each lactation (milk yield, fat (6.5 % and protein (5.8 % corrected milk yield (FPC; Pulina et al., 2005., and fat and protein yield for culled sheep. Animals with any missing records from the first till the last lambing, weaning or lactation were removed from the analysis. Animals that left the system of animal recording alive, due to selling or the cancellation of recording by a breeder were also excluded. Dataset included records for 2254 sheep: 1734 of Bovec and 520 of Improved Bovec breed. Data preparation and statistical analysis were performed with the use of a statistical program R (R Development Core Team, 2007. and additional packages Zelig (Imai et al., 2007; Bailey and Alimadhi, 2007; Imai et al., 2008 and lme4 (Bates and DebRoy, 2004; Bates, 2007. Results have shown that in the period ≤1996 Bovec breed had on average 4.4 lactations in their lifetime, which was almost one lactation more than in Improved Bovec breed. In the period after the year 1996 the highest proportion of animals were culled in the first lactation (as expected due to culling dynamics, with slightly higher proportion in Improved Bovec breed than in Bovec breed. Lifetime number of born, liveborn and weaned lambs was higher for about one lamb in Improved Bovec breed. Lifetime lamb weight gain did not differ between breeds, due to the high frequency of early weaning in Improved Bovec breed. During lifetime, Improved Bovec sheep produced around 200 kg (~34 % more milk, around 190 kg (~32 % more FPC milk, around 12 kg (~32 % more milk fat, and around 10 kg (~34 % more milk protein than Bovec

  15. Captive breeding programs based on family groups in polyploid sturgeons.

    Science.gov (United States)

    Boscari, Elisa; Pujolar, Jose Martin; Dupanloup, Isabelle; Corradin, Riccardo; Congiu, Leonardo

    2014-01-01

    In species with long life cycles and discontinuous availability of individuals to reproduction, implementing a long-term captive breeding program can be difficult or impossible. In such cases, managing diversity among familiar groups instead of individuals could become a suitable approach to avoid inbreeding and increase the possibility to accomplish a breeding scheme. This is the case of several sturgeon species including the Adriatic sturgeon, whose recovery depends on the management of a few captive stocks directly descended from the same group of wild parents. In the present study, relatedness among 445 potential breeders was inferred with a novel software for pedigree reconstruction in tetraploids ("BreedingSturgeons"). This information was used to plan a breeding scheme considering familiar groups as breeding units and identifying mating priorities. A two-step strategy is proposed: a short-term breeding program, relying on the 13 remaining F0 individuals of certain wild origin; and a long-term plan based on F1 families. Simulations to evaluate the loss of alleles in the F2 generation under different pairing strategies and assess the number of individuals to breed, costs and logistical aquaculture constraints were performed. The strategy proposed is transferable to the several other tetraploid sturgeon species on the brink of extinction.

  16. Brain size-related breeding strategies in a seabird.

    Science.gov (United States)

    Jaatinen, Kim; Öst, Markus

    2016-01-01

    The optimal compromise between decision speed and accuracy may depend on cognitive ability, associated with the degree of encephalization: larger brain size may select for accurate but slow decision-making, beneficial under challenging conditions but costly under benign ones. How this brain size-dependent selection pressure shapes avian breeding phenology and reproductive performance remains largely unexplored. We predicted that (1) large-brained individuals have a delayed breeding schedule due to thorough nest-site selection and/or prolonged resource acquisition, (2) good condition facilitates early breeding independent of relative brain size, and (3) large brain size accrues benefits mainly to individuals challenged by environmental or intrinsic constraints. To test these predictions, we examined how the relative head volume of female eiders (Somateria mollissima) of variable body condition correlated with their breeding schedule, hatching success and offspring quality. The results were consistent with our predictions. First, large head size was associated with a progressively later onset of breeding with increasing breeding dispersal distance. Second, increasing body condition advanced the timing of breeding, but this effect was significantly weaker in large-brained females. Third, larger head volume was associated with increased hatching success mainly among late breeders and those in poor body condition, and duckling body condition was positively related to maternal head volume, but only in poor-condition mothers. Our study is, to our knowledge, the first to demonstrate the presence of brain size-related differences in reproductive strategies within a single natural population.

  17. PRODUCTION PARAMETERS OF SLOVAK NATIONAL HEN’S BREED ORAVKA

    Directory of Open Access Journals (Sweden)

    J. WEIS

    2013-07-01

    Full Text Available Our work describes the results of egg production and egg weight of hen’s breed Oravka in years 2004 - 2008. Observation of production parameters of hen’s breed Oravka realised in special poultry house for controlled breeds of poultry at University Experimental Farm in Kolíňany. In analyzed period 2004 to 2008 we observed flock of breed Oravka with ten females and one male. This poultry flock was selecting from young birds per year. The egg production we evaluated as average number of eggs for accelerated 7-month laying period (1 month - 30 days. The eggs were weighed individually from every hen for period 10 days in each month. On basic of achieved results we observed progressive increase of egg production and egg weight. The egg production of breed Oravka increased about 3.10 eggs/hen (2.06 % between years 2004 and 2008. Massive improvement we recorded at parameter of egg weight (3.30 g - 6.30 % in analyzed period. The selection programme of breed Oravka will target the increase of egg production and egg weight in accordance with standard of breed (egg production 180 - 200 eggs, egg weight 58 g.

  18. Biotechnological approach in crop improvement by mutation breeding in Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Soeranto, H.; Sobrizal; Sutarto, Ismiyati; Manurung, Simon; Mastrizal [National Nuclear Energy Agency, Center for Research and Development of Isotope and Radiation Technology, Jakarta (Indonesia)

    2002-02-01

    Mutation breeding has become a proven method of improving crop varieties. Most research on plant mutation breeding in Indonesia is carried out at the Center for Research and Development of Isotope and Radiation Technology, National Nuclear Energy Agency (BATAN). Nowadays, a biotechnological approach has been incorporated in some mutation breeding researches in order to improve crop cultivars. This approach is simply based on cellular totipotency, or the ability to regenerate whole, flowering plants from isolated organs, pieces of tissue, individual cells, and protoplasts. Tissue culture technique has bee extensively used for micro propagation of disease-free plants. Other usage of this technique involves in various steps of the breeding process such as germplasm preservation, clonal propagation, and distant hybridization. Mutation breeding combined with tissue culture technique has made a significant contribution in inducing plant genetic variation, by improving selection technology, and by accelerating breeding time as for that by using anther or pollen culture. In Indonesia, research on mutation breeding combined with tissue culture techniques has been practiced in different crop species including rice, ginger, banana, sorghum etc. Specially in rice, a research on identification of DNA markers linked to blast disease resistance is now still progressing. A compiled report from some research activities is presented in this paper. (author)

  19. Improving Charging-Breeding Simulations with Space-Charge Effects

    Science.gov (United States)

    Bilek, Ryan; Kwiatkowski, Ania; Steinbrügge, René

    2016-09-01

    Rare-isotope-beam facilities use Highly Charged Ions (HCI) for accelerators accelerating heavy ions and to improve measurement precision and resolving power of certain experiments. An Electron Beam Ion Trap (EBIT) is able to create HCI through successive electron impact, charge breeding trapped ions into higher charge states. CBSIM was created to calculate successive charge breeding with an EBIT. It was augmented by transferring it into an object-oriented programming language, including additional elements, improving ion-ion collision factors, and exploring the overlap of the electron beam with the ions. The calculation is enhanced with the effects of residual background gas by computing the space charge due to charge breeding. The program assimilates background species, ionizes and charge breeds them alongside the element being studied, and allows them to interact with the desired species through charge exchange, giving fairer overview of realistic charge breeding. Calculations of charge breeding will be shown for realistic experimental conditions. We reexamined the implementation of ionization energies, cross sections, and ion-ion interactions when charge breeding.

  20. Evidence of selection signatures that shape the Persian cat breed.

    Science.gov (United States)

    Bertolini, Francesca; Gandolfi, Barbara; Kim, Eui Soo; Haase, Bianca; Lyons, Leslie A; Rothschild, Max F

    2016-04-01

    The Persian cat is mainly characterized by an extremely brachycephalic face as part of the standard body conformation. Despite the popularity, world-wide distribution, and economic importance of the Persian cat as a fancy breed, little is known about the genetics of their hallmark morphology, brachycephaly. Over 800 cats from different breeds including Persian, non-Persian breeds (Abyssinian, Cornish Rex, Bengal, La Perm, Norwegian Forest, Maine Coon, Manx, Oriental, and Siamese), and Persian-derived breeds (British Shorthair, Scottish Fold, Selkirk Rex) were genotyped with the Illumina 63 K feline DNA array. The experimental strategy was composed of three main steps: (i) the Persian dataset was screened for runs of homozygosity to find and select highly homozygous regions; (ii) selected Persian homozygous regions were evaluated for the difference of homozygosity between Persians and those considered non-Persian breeds, and, (iii) the Persian homozygous regions most divergent from the non-Persian breeds were investigated by haplotype analysis in the Persian-derived breeds. Four regions with high homozygosity (H > 0.7) were detected, each with an average length of 1 Mb. Three regions can be considered unique to the Persian breed, with a less conservative haplotype pattern in the Persian-derived breeds. Moreover, two genes, CHL1 and CNTN6 known to determine face shape modification in humans, reside in one of the identified regions and therefore are positional candidates for the brachycephalic face in Persians. In total, the homozygous regions contained several neuronal genes that could be involved in the Persian cat behavior and can provide new insights into cat domestication.

  1. Localization of canine brachycephaly using an across breed mapping approach.

    Directory of Open Access Journals (Sweden)

    Danika Bannasch

    Full Text Available The domestic dog, Canis familiaris, exhibits profound phenotypic diversity and is an ideal model organism for the genetic dissection of simple and complex traits. However, some of the most interesting phenotypes are fixed in particular breeds and are therefore less tractable to genetic analysis using classical segregation-based mapping approaches. We implemented an across breed mapping approach using a moderately dense SNP array, a low number of animals and breeds carefully selected for the phenotypes of interest to identify genetic variants responsible for breed-defining characteristics. Using a modest number of affected (10-30 and control (20-60 samples from multiple breeds, the correct chromosomal assignment was identified in a proof of concept experiment using three previously defined loci; hyperuricosuria, white spotting and chondrodysplasia. Genome-wide association was performed in a similar manner for one of the most striking morphological traits in dogs: brachycephalic head type. Although candidate gene approaches based on comparable phenotypes in mice and humans have been utilized for this trait, the causative gene has remained elusive using this method. Samples from nine affected breeds and thirteen control breeds identified strong genome-wide associations for brachycephalic head type on Cfa 1. Two independent datasets identified the same genomic region. Levels of relative heterozygosity in the associated region indicate that it has been subjected to a selective sweep, consistent with it being a breed defining morphological characteristic. Genotyping additional dogs in the region confirmed the association. To date, the genetic structure of dog breeds has primarily been exploited for genome wide association for segregating traits. These results demonstrate that non-segregating traits under strong selection are equally tractable to genetic analysis using small sample numbers.

  2. The early social environment affects social competence in a cooperative breeder

    Science.gov (United States)

    Taborsky, Barbara; Arnold, Cornelia; Junker, Julian; Tschopp, Andreas

    2012-01-01

    Social competence is defined as the ability of an animal to optimize the expression of social behaviour as a function of the available social information. The social environment encountered early in life can affect the expression of various social behaviours later in life. We investigated whether early social experience can affect social competence. In the cooperatively breeding cichlid Neolamprologus pulcher, we tested whether individuals reared with older brood-caring conspecifics persistently perform better in a series of tasks (1) simulating different social contexts, (2) assigning individuals different social roles and (3) exposing them to an unknown social situation. Fish that had been reared together with older conspecifics showed more appropriate behaviours both as winners (more aggressive displays) and as losers (more submissive displays) when aggressively competing with peers over a resource, and when trying to be accepted as subordinate group member and prospective brood care helper by an unfamiliar dominant pair (more submissive displays near shelters), a situation they had never encountered before. In both tasks fish that had grown up with older fish were tolerated better by conspecifics than fish reared with same-age siblings only. We detected effects of the early environment on social behaviour in the juvenile and adult stages of the test fish. Our results suggest that growing up in more complex social groups fosters a general social ability (i.e. social competence) in N. pulcher that improves their performance across different social roles and contexts, and which may provide fitness benefits. PMID:22536004

  3. Genotype by environment interaction in maize breeding

    Directory of Open Access Journals (Sweden)

    Babić Milosav

    2008-01-01

    Full Text Available Because proximity measures occur in pairs where both, similarity and dissimilarity measures exploit the same type of information, companion classification and ordination techniques can be applied. They complement each other in analysis of genotype by environment interaction (GxE data. Choice of method, companion diagnostics and graphical presentation are required within each of methodologies. By clustering of 12 genotypes into 5 groups, 96.26% of variability for genotypes contained in original data is kept. By applying same analysis for environments, 96.45% of variability contained in original data matrix is kept with grouping of 31 environments into 11 groups. Caused by genotypes and environments grouping 78.10% of GxE variability contained in original data matrix remained in analysis of such two-way reduced data. Based on shown results, it is not possible to define smaller growing regions. Clustering of environment can be useful not only for defining mega environments but also for smaller growing regions defining only in combination with some of additional analysis (AMMI, discrimination analysis, correspondent analysis etc.. In such kind of analysis experience of investigator would be of great importance. Choice of test sites for breeding programme can be made based on obtained grouping to a limited extent (rather for restructuring existing test sites network in order to obtain 'better' information with same number of test sites then for its rationalization with number of test sites decreasing.

  4. Most frequent calf diseases in industrial breeding

    Directory of Open Access Journals (Sweden)

    Lazić Sava

    2004-01-01

    Full Text Available It is possible to conduct an analysis of the incidence of viral diseases in calves if these diseases are divided into two basic groups. One group comprises diseases of respiratory organs which are manifested by symptoms of a respiratory syndrome, and the second group comprises diseases of digestive tract organs in the form of a gastrointestinal syndrome. It is considered that viruses have the dominant role in the complex etiology of the respiratory syndrome, primarily the IBR virus or the Bovine Herpes Virus-1 (BHV-1, followed by the parainfluenza 3 virus (RSV, the Bovine Viral Diahrrea Virus (BVDV, the bovine Respiratory Syncytial Virus (RSV, but also other viruses, such as adenoviruses, rhinoviruses, coronaviruses, can also influence the appearance of the respiratory syndrome. The respiratory syndrome is rarely caused by a single viral agent, but most frequently by mixed viruses, but also by bacterial infections. Mixed viral infections often have a lethal outcome. Investigations of the etiology of the gastrointestinal syndrome so far indicate that, in addition to bacteria, viruses can also be a significant etiological factor. Rotaviruses, coronaviruses, adenoviruses parvoviruses, herpesviruses (the IBR virus, pestiviruses (BVDV, can be the causes of a gastrointestinal syndrome. It is believed that viruses can be the cause in about 10% cases in the ethiopathogenesis of this syndrome. The paper describes the etiopathogenesis of calf diseases of viral etiology which are most often found in the local conditions of industrial breeding of calves.

  5. Breeding of Biomphalaria tenagophila in mass scale

    Directory of Open Access Journals (Sweden)

    Florence Mara Rosa

    2013-02-01

    Full Text Available An efficient method for breeding Biomphalaria tenagophila (Taim lineage/RS was developed over a 5-year-period (2005-2010. Special facilities were provided which consisted of four cement tanks (9.4 x 0.6 x 0.22 m, with their bottom covered with a layer of sterilized red earth and calcium carbonate. Standard measures were adopted, as follows: each tank should contain an average of 3000 specimens, and would be provided with a daily ration of 35,000 mg complemented with lettuce. A green-house effect heating system was developed which constituted of movable dark canvas covers, which allowed the temperature to be controlled between 20 - 24 ºC. This system was essential, especially during the coldest months of the year. Approximately 27,000 specimens with a diameter of 12 mm or more were produced during a 14-month-period. The mortality rates of the newly-hatched and adult snails were 77% and 37%, respectively. The follow-up of the development system related to 310 specimens of B. tenagophila demonstrated that 70-day-old snails reached an average of 17.0 ± 0.9 mm diameter. The mortality rates and the development performance of B. tenagophila snails can be considered as highly satisfactory, when compared with other results in literature related to works carried out with different species of the genus Biomphalaria, under controlled laboratory conditions.

  6. Application of molecular markers in apple breeding

    Directory of Open Access Journals (Sweden)

    Marić Slađana

    2010-01-01

    Full Text Available Apple is economically the most important species of genus Malus Miller. In respect of production, trade and consumption, it ranks first among deciduous fruit and third on a global scale among all fruit species. Apple breeding is carried out on a large scale in several scientific institutes throughout the world. Due to this activity, apple is a fruit species with the highest number of described monogenic traits; 76 genes, encoding morphological traits, pest and disease resistance, as well as 69 genes encoding enzymes. The development of molecular markers (RFLPs, AFLPs, SCARs and SSRs has allowed the mapping of the apple genome and the development of several saturated genetic maps, to which genes controlling important traits are assigned. Markers flanking these genes not only play an important role in selecting parental combinations and seedlings with positive traits, but they are also particularly important in detecting recessive traits, such as seedless fruit. In addition they enable pre-selection for polygenic quantitative traits. In recent years, particular attention has been paid to biochemical and physiological processes involved in the pathway of important traits e.g., ripening and the storage capability of apple fruit.

  7. Feeding and Breeding Biology of Amblypharyngodon mola – A Review

    Directory of Open Access Journals (Sweden)

    Sandipan Gupta

    2014-05-01

    Full Text Available Amblypharyngodon mola is a popular food fish of Indian sub-continent due to its high nutritional value. Earlier many workers have carried out studies on feeding and breeding biology of this fish species but consolidated information on the same is not available. So, a survey of published literatures on the feeding and breeding biology of A. mola has been carried out to consolidate the available information.  Lacunae of information has been pointed out for further study mainly on age group wise variation in food preference and correlation of breeding periodicity with hydrological parameters and photoperiod.

  8. Genetic distinctiveness of the Herdwick sheep breed and two other locally adapted hill breeds of the UK.

    Directory of Open Access Journals (Sweden)

    Dianna Bowles

    Full Text Available There is considerable interest in locally adapted breeds of livestock as reservoirs of genetic diversity that may provide important fitness traits for future use in agriculture. In marginal areas, these animals contribute to food security and extract value from land unsuitable for other systems of farming. In England, close to 50% of the national sheep flock is farmed on grassland designated as disadvantaged areas for agricultural production. Many of these areas are in the uplands, where some native breeds of sheep continue to be commercially farmed only in highly localised geographical regions to which they are adapted. This study focuses on three of these breeds, selected for their adaptation to near identical environments and their geographical concentration in regions close to one another. Our objective has been to use retrotyping, microsatellites and single nucleotide polymorphisms to explore the origins of the breeds and whether, despite their similar adaptations and proximity, they are genetically distinctive. We find the three breeds each have a surprisingly different pattern of retrovirus insertions into their genomes compared with one another and with other UK breeds. Uniquely, there is a high incidence of the R0 retrotype in the Herdwick population, characteristic of a primitive genome found previously in very few breeds worldwide and none in the UK mainland. The Herdwick and Rough Fells carry two rare retroviral insertion events, common only in Texels, suggesting sheep populations in the northern uplands have a historical association with the original pin-tail sheep of Texel Island. Microsatellite data and analyses of SNPs associated with RXFP2 (horn traits and PRLR (reproductive performance traits also distinguished the three breeds. Significantly, an SNP linked to TMEM154, a locus controlling susceptibility to infection by Maedi-Visna, indicated that all three native hill breeds have a lower than average risk of infection to the

  9. Breeding biology of a winter-breeding procellariiform in the North Atlantic, the Macaronesian shearwater Puffinus lherminieri baroli.

    Science.gov (United States)

    Fagundes, Ana Isabel; Ramos, Jaime A; Ramos, Urtelinda; Medeiros, Renata; Paiva, Vitor H

    2016-10-01

    The breeding success of burrow-nesting seabirds may be influenced by both nest site characteristics and oceanographic conditions influencing food availability at sea. In this study we describe the breeding biology of the winter-breeding Macaronesian shearwater (Puffinus lherminieri baroli), including nest site characteristics and interspecific competition. We also evaluate the possible effects of changing oceanographic conditions on breeding phenology and breeding success. The study was carried out over two breeding seasons on two islands in the North Atlantic Ocean, Cima Islet and Selvagem Grande. Oceanographic characteristics differed between years. On a regional scale, the North Atlantic Oscillation (NAO) index was low and negative in 2011, and on a local scale, birds used areas with significantly lower values of chlorophyll a concentration and significantly higher values of sea surface temperature anomalies. Hatching success was higher in 2012 than in 2011. At both colonies, egg cracking was the main cause of hatching failure, but in 2011 several eggs on Selvagem Grande were deserted. In 2012 birds laid earlier and chicks had longer wings and were heavier. At both colonies, nests that were deeper, were sheltered from prevailing winds and had small chambers and a soil substrate had a higher probability of being used successfully by the birds. Nests occupied solely by Macaronesian shearwaters were much deeper and had less volume than nests shared with other species. Our study suggests that the breeding success of Macaronesian shearwaters is strongly related to nest site characteristics and that at-sea environmental conditions exert a strong influence on reproductive parameters, with birds breeding in a poor year (evaluated in terms of lower marine productivity) laying much later and their chicks growing at a slower rate than in a good year. The influence of nest site characteristics and environmental conditions may be very important for understanding the breeding

  10. Does genomic selection have a future in plant breeding?

    Science.gov (United States)

    Jonas, Elisabeth; de Koning, Dirk-Jan

    2013-09-01

    Plant breeding largely depends on phenotypic selection in plots and only for some, often disease-resistance-related traits, uses genetic markers. The more recently developed concept of genomic selection, using a black box approach with no need of prior knowledge about the effect or function of individual markers, has also been proposed as a great opportunity for plant breeding. Several empirical and theoretical studies have focused on the possibility to implement this as a novel molecular method across various species. Although we do not question the potential of genomic selection in general, in this Opinion, we emphasize that genomic selection approaches from dairy cattle breeding cannot be easily applied to complex plant breeding.

  11. Future perspectives of in vitro culture and plant breeding

    DEFF Research Database (Denmark)

    Kuligowska, Katarzyna; Lütken, Henrik Vlk; Hegelund, Josefine Nymark

    2015-01-01

    Conventional breeding and plant improvement increasingly become inadequate to keep up with progression and high quality demands. Thus biotechnological techniques are more and more adopted. Initially, biotechnological tools have supported conventional breeding by in vitro culture techniques......, comprising micropropagation, speeding up multiplication and improving uniformity. Also, crossing barriers of incompatible plants have been overcome using in vitro methods and embryo rescue techniques in wide hybridization approaches. Marker-assisted breeding is employed for targeted selection of DNA...... breeding in Europe is still marginal due to investment costs, legal approval and public acceptance. As a result, natural transformation using wild type bacteria and thus avoiding recombinant DNA technology has attracted attention of ornamental plant breeders in Europe. However, during the last decades...

  12. Dusky Canada goose breeding population survey, May 16 1989

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Dusky Canada goose breeding ground surveys were initiated on the Copper River Delta near Cordova, Alaska during the 1970's by the Waterfowl Division of the Alaska...

  13. Dusky Canada goose breeding population survey, May 18 1990

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Dusky Canada goose breeding ground surveys were initiated on the Copper River Delta near Cordova, Alaska during the 1970's by the Waterfowl Division of the Alaska...

  14. Waterfowl breeding population survey: Southern Alberta: May 1991

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for southern Alberta during 1991. The primary purpose of the survey is to provide...

  15. [Breeding bird survey authorization : Audubon National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This letter authorizes Larry Igl and Chris Johnson to conduct population estimates of breeding birds on Audubon National Wildlife Refuge. This study is in...

  16. Maine & the Maritimes: Waterfowl breeding population survey: 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for Maine and the Maritimes during 2000. The primary purpose of the survey is to provide...

  17. Breeding bird study in the Mississippi River Floodplain

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A breeding bird study was initiated in 1992 to census birds on the Gardner Division of Mark Twain NWR. The division is located in the Mississippi River floodplain...

  18. Reindeer breeding along the Finno-Ugric tribes

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This paper discusses the reindeer breeding practices among the Finno-Urgic tribes located in the northern territories of the Soviet Union and frontier districts...

  19. Waterfowl breeding population survey: Southern and central Alberta: May 1995

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for southern and central Alberta during 1995. The primary purpose of the survey is to...

  20. Predicting breeding values in animals by kalman filter

    DEFF Research Database (Denmark)

    Karacaören, Burak; Janss, Luc; Kadarmideen, Haja

    2012-01-01

    The aim of this study was to investigate usefulness of Kalman Filter (KF) Random Walk methodology (KF-RW) for prediction of breeding values in animals. We used body condition score (BCS) from dairy cattle for illustrating use of KF-RW. BCS was measured by Swiss Holstein Breeding Association during...... May 2004-March 2005 for 7 times approximately at monthly intervals from dairy cows (n=80) stationed at the Chamau research farm of Eidgenössische Technische Hochschule (ETH), Switzerland. Benefits of KF were demonstrated using random walk models via simulations. Breeding values were predicted over...... for variance components were found (with standard errors) 0.03 (0.006) for animal genetic variance 0.04 (0.007) for permanent environmental variance and 0.21 (0.02) for error variance. Since KF gives online estimation of breeding values and does not need to store or invert matrices, this methodology could...

  1. Usefulness of portable near infrared spectroscopy in olive breeding programs

    Energy Technology Data Exchange (ETDEWEB)

    Leon-Moreno, L.

    2012-11-01

    The usefulness of portable near infrared (NIR) spectroscopy as a simple and efficient method to determine some of the main selection traits in olive breeding is evaluated in this work. Calibration models were developed and evaluated using partial least squares (PLS) regression from samples collected in different selection steps of the breeding work and under different experimental conditions. The results showed that accurate enough models (values of correlation between actual and predicted constituent higher than 0.9) were obtained for oil and moisture content in both cross validation and prediction results. Portable NIR spectroscopy could be used for selection of genotypes on the basis of these characters, providing similar ranking of genotypes than reference methods both in different selection steps of the breeding process (progenies and selection plots) and different experimental conditions (on-tree or under laboratory conditions). The advantages of this technique to improve the efficiency of the evaluation process in olive breeding programs are discussed. (Author) 21 refs.

  2. Relative Abundance of Breeding Birds in the Dismal Swamp 1982

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — To obtain an idea of the relative abundance of breeding birds in the predominant mixed swamp hardwoods forest of the Dismal Swamp in southeastern Virginia, a...

  3. Survey of breeding birds Walnut Creek National Wildlife Refuge 1995

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report is a summary of the results of the second annual survey of breeding birds of Walnut Creek National Wildlife Refuge conducted in 1995. This series of...

  4. Survey of breeding birds, Walnut Creek National Wildlife Refuge, 1996

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report is a summary of the results of the third annual survey of breeding birds of Walnut Creek National Wildlife Refuge conducted in 1996. Information on...

  5. INTEGRATION IN ANTLER REINDEER BREEDING OF THE ALTAI REPUBLIC

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    Glotko A. V.

    2014-12-01

    Full Text Available In this article the questions of vertical integration which is necessary to bring the company of antler reindeer breeding out of crisis are considered. We have presented a scheme of participant of "supplier – consumer” integral interaction

  6. GENETIC CHARACTERIZATION OF ROMANIAN CATTLE BREEDS USING BIOCHEMICAL MARKERS

    Directory of Open Access Journals (Sweden)

    MARIANA REBEDEA

    2013-12-01

    Full Text Available The paper presents a genetic characterization of cattle breeds in Romania based onbiochemical markers in the blood and the milk. The surveyed breeds are: RomanianBlack Spotted Cattle (BNR, Romanian Spotted Cattle (BR, Romanian Brown (Band Romanian Steppe, and the markers identified are represented by some proteins,serum transferrin (Tf, serum albumins (Al, hemoglobin (Hb respectively-from theblood and beta-lactoglobulin (βLg-from the milk. In order to determine thegenotypes in the studied populations electrophoresis was used in three differentvariations, depending on the type of the protein, and the migration substrates usedwere starch and polyacrylamide. The identified genetic structures in the individualsfrom the surveyed breeds allowed their genetic characterization based on gene andgenotype frequencies, as well as using these data in establishing the identity andpaternity of the individuals in the surveyed breeds.

  7. Waterfowl breeding pair survey: Ontario, Quebec, and New York: 1997

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for Ontario, Quebec, and New York during 1997. The primary purpose of the survey is to...

  8. Western and Central Ontario: Waterfowl breeding population survey: 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the Waterfowl Breeding Population and Habitat Survey for Western and Central Ontario during 2000. The primary purpose of the survey is to...

  9. Hybrid recreation by reverse breeding in Arabidopsis thaliana.

    Science.gov (United States)

    Wijnker, Erik; Deurhof, Laurens; van de Belt, Jose; de Snoo, C Bastiaan; Blankestijn, Hetty; Becker, Frank; Ravi, Maruthachalam; Chan, Simon W L; van Dun, Kees; Lelivelt, Cilia L C; de Jong, Hans; Dirks, Rob; Keurentjes, Joost J B

    2014-04-01

    Hybrid crop varieties are traditionally produced by selecting and crossing parental lines to evaluate hybrid performance. Reverse breeding allows doing the opposite: selecting uncharacterized heterozygotes and generating parental lines from them. With these, the selected heterozygotes can be recreated as F1 hybrids, greatly increasing the number of hybrids that can be screened in breeding programs. Key to reverse breeding is the suppression of meiotic crossovers in a hybrid plant to ensure the transmission of nonrecombinant chromosomes to haploid gametes. These gametes are subsequently regenerated as doubled-haploid (DH) offspring. Each DH carries combinations of its parental chromosomes, and complementing pairs can be crossed to reconstitute the initial hybrid. Achiasmatic meiosis and haploid generation result in uncommon phenotypes among offspring owing to chromosome number variation. We describe how these features can be dealt with during a reverse-breeding experiment, which can be completed in six generations (∼1 year).

  10. Integrating genomic selection into dairy cattle breeding programmes: a review.

    Science.gov (United States)

    Bouquet, A; Juga, J

    2013-05-01

    Extensive genetic progress has been achieved in dairy cattle populations on many traits of economic importance because of efficient breeding programmes. Success of these programmes has relied on progeny testing of the best young males to accurately assess their genetic merit and hence their potential for breeding. Over the last few years, the integration of dense genomic information into statistical tools used to make selection decisions, commonly referred to as genomic selection, has enabled gains in predicting accuracy of breeding values for young animals without own performance. The possibility to select animals at an early stage allows defining new breeding strategies aimed at boosting genetic progress while reducing costs. The first objective of this article was to review methods used to model and optimize breeding schemes integrating genomic selection and to discuss their relative advantages and limitations. The second objective was to summarize the main results and perspectives on the use of genomic selection in practical breeding schemes, on the basis of the example of dairy cattle populations. Two main designs of breeding programmes integrating genomic selection were studied in dairy cattle. Genomic selection can be used either for pre-selecting males to be progeny tested or for selecting males to be used as active sires in the population. The first option produces moderate genetic gains without changing the structure of breeding programmes. The second option leads to large genetic gains, up to double those of conventional schemes because of a major reduction in the mean generation interval, but it requires greater changes in breeding programme structure. The literature suggests that genomic selection becomes more attractive when it is coupled with embryo transfer technologies to further increase selection intensity on the dam-to-sire pathway. The use of genomic information also offers new opportunities to improve preservation of genetic variation. However

  11. RESEARCH STUDY ON THE BREEDING AVIFAUNA OF THE BASCOV RESERVOIR

    Directory of Open Access Journals (Sweden)

    Maria Denisa Conete

    2015-12-01

    Full Text Available The author conducted an ornithological study in the Bascov Reservoir area (a square of 2x2 km and observed 102 breeding species; 83 (81% of them are certain breeding species and 19 (19% are probable breeding species. The results of the research were cumulated with those found in the Atlas of the breeding species of Romania. By relating them with the Atlas data, we noted that 83 of the 100 breeding species cited in the Atlas were again recorded during our study. Nineteen new breeding species were identified. Among the species dependent on wetlands, mention should be made of Ixobrychus minutus, Anas platyrhynchos, Fulica atra, Gallinula chloropus, Aythya ferina, etc., with relatively large numbers of individuals. The analysis showed a relatively larger number (66 of euconstant and constant species, which confirmed the wealth of food resources in the area during the nesting period. The specific richness on the Bascov Lake is represented by 119 species, a number that is consistent with the availability of the food resources and nesting places, as well as the somewhat fluctuating presence of predators (stray dogs, and the anthropocentric disturbance (sound and chemical pollution, etc.. The yearly increase in the number of reed clusters, the expansion of the surface of the islets, the emergence of bushes and trees, the ageing of the existing trees have led to a certain yearly increase in the number of breeding individuals in 45 species. But the anthropogenic influence in the area has eventually contributed to a decrease in the number of birds, both as a number of species and as a number of individuals. The study has also shown that in the farmland bird species the number of individuals is in decline. Most of the breeding species - 75 (representing 74% in the area under research are migratory. Eighteen breeding species (17.64% are listed in Annex I of the Birds Directive. The presence of the key breeding species in the area under research must be

  12. Eradication of scrapie with selective breeding: are we nearly there?

    Directory of Open Access Journals (Sweden)

    Davidse Aart

    2010-05-01

    Full Text Available Abstract Background Following EU decision 2003/100/EC Member States have recently implemented sheep breeding programmes to reduce the prevalence of sheep with TSE susceptible prion genotypes. The present paper investigates the progress of the breeding programme in the Netherlands. The PrP genotype frequencies were monitored through time using two sets of random samples: one set covers the years 2005 to 2008 and is taken from national surveillance programme; the other is taken from 168 random sheep farms in 2007. The data reveal that although the level of compliance to the breeding programme has been high, the frequency of susceptible genotypes varies substantially between farms. The 168 sheep farms are a subset of 689 farms participating in a postal survey inquiring about management and breeding strategies. This survey aimed to identify how much these strategies varied between farms, in order to inform assessment of the expected future progress towards eradication of classical scrapie. Results On the one hand, we found that compliance to the national breeding program has been high, and the frequency of resistant genotypes is expected to increase further in the next few years. On the other hand, we observed a large variation in prevalence of the scrapie resistant PrP genotype ARR between farms, implicating a large variation of genetic resistance between farms. Substantial between-flock differences in management and breeding strategies were found in the postal survey, suggesting considerable variation in risk of scrapie transmission between farms. Conclusions Our results show that although there has been a good progress in the breeding for scrapie resistance and the average farm-level scrapie susceptibility in the Netherlands has been significantly reduced, still a considerable proportion of farms contain high frequencies of susceptible genotypes in their sheep population. Since 2007 the breeding for genetic resistance is voluntarily again, and

  13. Genome wide selection in Citrus breeding.

    Science.gov (United States)

    Gois, I B; Borém, A; Cristofani-Yaly, M; de Resende, M D V; Azevedo, C F; Bastianel, M; Novelli, V M; Machado, M A

    2016-10-17

    Genome wide selection (GWS) is essential for the genetic improvement of perennial species such as Citrus because of its ability to increase gain per unit time and to enable the efficient selection of characteristics with low heritability. This study assessed GWS efficiency in a population of Citrus and compared it with selection based on phenotypic data. A total of 180 individual trees from a cross between Pera sweet orange (Citrus sinensis Osbeck) and Murcott tangor (Citrus sinensis Osbeck x Citrus reticulata Blanco) were evaluated for 10 characteristics related to fruit quality. The hybrids were genotyped using 5287 DArT_seq(TM) (diversity arrays technology) molecular markers and their effects on phenotypes were predicted using the random regression - best linear unbiased predictor (rr-BLUP) method. The predictive ability, prediction bias, and accuracy of GWS were estimated to verify its effectiveness for phenotype prediction. The proportion of genetic variance explained by the markers was also computed. The heritability of the traits, as determined by markers, was 16-28%. The predictive ability of these markers ranged from 0.53 to 0.64, and the regression coefficients between predicted and observed phenotypes were close to unity. Over 35% of the genetic variance was accounted for by the markers. Accuracy estimates with GWS were lower than those obtained by phenotypic analysis; however, GWS was superior in terms of genetic gain per unit time. Thus, GWS may be useful for Citrus breeding as it can predict phenotypes early and accurately, and reduce the length of the selection cycle. This study demonstrates the feasibility of genomic selection in Citrus.

  14. One hundred years of statistical developments in animal breeding.

    Science.gov (United States)

    Gianola, Daniel; Rosa, Guilherme J M

    2015-01-01

    Statistical methodology has played a key role in scientific animal breeding. Approximately one hundred years of statistical developments in animal breeding are reviewed. Some of the scientific foundations of the field are discussed, and many milestones are examined from historical and critical perspectives. The review concludes with a discussion of some future challenges and opportunities arising from the massive amount of data generated by livestock, plant, and human genome projects.

  15. Competitor phenology as a social cue in breeding site selection.

    Science.gov (United States)

    Samplonius, Jelmer M; Both, Christiaan

    2017-05-01

    Predicting habitat quality is a major challenge for animals selecting a breeding patch, because it affects reproductive success. Breeding site selection may be based on previous experience, or on social information from the density and success of competitors with an earlier phenology. Variation in animal breeding phenology is often correlated with variation in habitat quality. Generally, animals breed earlier in high-quality habitats that allow them to reach a nutritional threshold required for breeding earlier or avoid nest predation. In addition, habitat quality may affect phenological overlap between species and thereby interspecific competition. Therefore, we hypothesized that competitor breeding phenology can be used as social cue by settling migrants to locate high-quality breeding sites. To test this hypothesis, we experimentally advanced and delayed hatching phenology of two resident tit species on the level of study plots and studied male and female settlement patterns of migratory pied flycatchers Ficedula hypoleuca. The manipulations were assigned at random in two consecutive years, and treatments were swapped between years in sites that were used in both years. In both years, males settled in equal numbers across treatments, but later arriving females avoided pairing with males in delayed phenology plots. Moreover, male pairing probability declined strongly with arrival date on the breeding grounds. Our results demonstrate that competitor phenology may be used to assess habitat quality by settling migrants, but we cannot pinpoint the exact mechanism (e.g. resource quality, predation pressure or competition) that has given rise to this pattern. In addition, we show that opposing selection pressures for arrival timing may give rise to different social information availabilities between sexes. We discuss our findings in the context of climate warming, social information use and the evolution of protandry in migratory animals.

  16. Genetic Diversity of Old Chicken Breeds Kept in Poland

    Directory of Open Access Journals (Sweden)

    Fabio Maretto

    2013-09-01

    Full Text Available The aim of this study was to compare the genetic variation of five local chicken breeds reared in Poland. Twenty-seven microsatellite markers were investigated in 138 birds belonging to five breeds: Miniature Cochin (MCO, Gold Italian (GI, Green Legged Partridge (GLP, Silver Italian (SI and White Leghorn (WL. One hundred eighty five alleles were detected in the overall population, with a mean number of 6.85 ± 3.32 alleles per locus. For the local breeds, the observed and expected heterozygosity ranged from a minimum of 0.287 to a maximum of 0.458 and from 0.397 to 0.499 for the GI and SI breeds, respectively. The overall population heterozygote deficiency was 0.430, the average Wright’s inbreeding coefficient (FIS was 0.061 and the heterozygote deficiency due to breed subdivision was 0.393. Wright’s fixation index was slightly positive for all breeds excluding MCO (FIS = -0.476 and the estimated molecular inbreeding (fij within breed ranged from 0.296 (GLP and SI to 0.361 (WL evidencing limited coancestry. Mean allelic richness, obtained with rarefaction method based on sixteen observations, was 2.12 being the WL the less variable (1.79. Tomiuk and Loeschcke’s DTL genetic distance values were used to draw a neighbornet network which separated the cluster made of MCO and GLP from the cluster of GI, WL and SI. The results arising from our microsatellites analysis represent a starting point for the valorization of these local Polish chicken breeds for monitoring and preserving their genetic variability.

  17. Radiographic liver size in Pekingese dogs versus other dog breeds.

    Science.gov (United States)

    Choi, Jihye; Keh, Seoyeon; Kim, Hyunwook; Kim, Junyoung; Yoon, Junghee

    2013-01-01

    Differential diagnoses for canine liver disease are commonly based on radiographic estimates of liver size, however little has been published on breed variations. Aims of this study were to describe normal radiographic liver size in Pekingese dogs and to compare normal measurements for this breed with other dog breeds and Pekingese dogs with liver disease. Liver measurements were compared for clinically normal Pekingese (n = 61), normal non-Pekingese brachycephalic (n = 45), normal nonbrachycephalic (n = 71), and Pekingese breed dogs with liver disease (n = 22). For each dog, body weight, liver length, T11 vertebral length, thoracic depth, and thoracic width were measured on right lateral and ventrodorsal abdominal radiographs. Liver volume was calculated using a formula and ratios of liver length/T11 vertebral length and liver volume/body weight ratio were determined. Normal Pekingese dogs had a significantly smaller liver volume/body weight ratio (16.73 ± 5.67, P dogs (19.54 ± 5.03) and normal nonbrachycephalic breed dogs (18.72 ± 6.52). The liver length/T11 vertebral length ratio in normal Pekingese (4.64 ± 0.65) was significantly smaller than normal non-Pekingese brachycephalic breed dogs (5.16 ± 0.74) and normal nonbrachycephalic breed dogs (5.40 ± 0.74). Ratios of liver volume/body weight and liver length/T11 vertebral length in normal Pekingese were significantly different from Pekingese with liver diseases (P dogs have a smaller normal radiographic liver size than other breeds. We recommend using 4.64× the length of the T11 vertebra as a radiographic criterion for normal liver length in Pekingese dogs.

  18. Captive breeding, reintroduction, and the conservation of amphibians.

    Science.gov (United States)

    Griffiths, Richard A; Pavajeau, Lissette

    2008-08-01

    The global amphibian crisis has resulted in renewed interest in captive breeding as a conservation tool for amphibians. Although captive breeding and reintroduction are controversial management actions, amphibians possess a number of attributes that make them potentially good models for such programs. We reviewed the extent and effectiveness of captive breeding and reintroduction programs for amphibians through an analysis of data from the Global Amphibian Assessment and other sources. Most captive breeding and reintroduction programs for amphibians have focused on threatened species from industrialized countries with relatively low amphibian diversity. Out of 110 species in such programs, 52 were in programs with no plans for reintroduction that had conservation research or conservation education as their main purpose. A further 39 species were in programs that entailed captive breeding and reintroduction or combined captive breeding with relocations of wild animals. Nineteen species were in programs with relocations of wild animals only. Eighteen out of 58 reintroduced species have subsequently bred successfully in the wild, and 13 of these species have established self-sustaining populations. As with threatened amphibians generally, amphibians in captive breeding or reintroduction programs face multiple threats, with habitat loss being the most important. Nevertheless, only 18 out of 58 reintroduced species faced threats that are all potentially reversible. When selecting species for captive programs, dilemmas may emerge between choosing species that have a good chance of surviving after reintroduction because their threats are reversible and those that are doomed to extinction in the wild as a result of irreversible threats. Captive breeding and reintroduction programs for amphibians require long-term commitments to ensure success, and different management strategies may be needed for species earmarked for reintroduction and species used for conservation

  19. Breeding sunflower (Helianthus annuus L.) for drought tolerance

    OpenAIRE

    Saeed Rauf

    2008-01-01

    Productivity of sunflower is strongly regulated by the availability of water and greatest yield losses occur when water shortage occurs at flowering. Therefore, it is critical to manage the deleterious effect of drought stress at this stage. Evolving crop genotypes which have enhanced drought tolerance are the most successful and cheapest strategy to cope with drought. However, progress in drought tolerance breeding is slow due to inappropriate selection criteria and faulty breeding strategie...

  20. Network Candidate Genes in Breeding for Drought Tolerant Crops

    OpenAIRE

    Christoph Tim Krannich; Lisa Maletzki; Christina Kurowsky; Renate Horn

    2015-01-01

    Climate change leading to increased periods of low water availability as well as increasing demands for food in the coming years makes breeding for drought tolerant crops a high priority. Plants have developed diverse strategies and mechanisms to survive drought stress. However, most of these represent drought escape or avoidance strategies like early flowering or low stomatal conductance that are not applicable in breeding for crops with high yields under drought conditions. Even though a gr...

  1. Larvivorous fishes in controlling mosquito breeding from draw wells.

    Science.gov (United States)

    Joshi, R D; Chakraverty, R K; Rai, R N; Dey, K P; Sharma, R S

    1989-12-01

    Culex quinquefasciatus have been found to breed in about 29 per cent of the wells in semi-urban area and 14 per cent of the wells in rural areas of Varanasi at one time or other. Majority of such wells are used-ones. Effectiveness of Poecillia reticulata, Esomus danrica and Trichogaster fasciatus in controlling well breeding is evaluated in the present study with successful results.

  2. Breeding ecology of ground tits in northeastern Tibetan plateau, with special reference to cooperative breeding system

    Institute of Scientific and Technical Information of China (English)

    Xin LU; Ran HUO; Yang LI; Wenbo LIAO; Chen WANG

    2011-01-01

    Data on breeding ecology of a color-band marked population of the ground tit Parus humilis were collected in north Qinghai on the Tibetan plateau,during 2008 and 2009.In spring the birds excavated 0.8-3.2 m long nesting burrows under the ground.First-egg laying occurred between late April and late June during which a pair produced one brood.Incubation was done by female alone for 15-16 days and nestling-feeding by both sexes and helpers in any for 23-25 days.Average brood size at fledging was 5.8 (± 1.4 SD,3-8) and all the 27 observed nesting attempts fledged at least one young.At the population level,brood sex ratio did not differ from 1∶1.The birds are a territory-living resident,with annual resight rates being 48% (22 of 46) in adult breeders and 10% (7 of 67) in yearlings.Pairs were socially monogamous,of which 23% (9 of 40) contained one and sometimes two male helpers,most likely being philopatric sons of the breeders.The formation of cooperative groups is similar to the population in central Tibet but differs from that in south Guansu where breeding ground tits exhibit a high level of annual turnover [Current Zoology 57 (6):751-757,2011].

  3. Breeding ecology of ground tits in northeastern Tibetan plateau, with special reference to cooperative breeding system

    Directory of Open Access Journals (Sweden)

    Xin LU, Ran HUO, Yang LI, Wenbo LIAO, Chen WANG

    2011-12-01

    Full Text Available Data on breeding ecology of a color-band marked population of the ground tit Parus humilis were collected in north Qinghai on the Tibetan plateau, during 2008 and 2009. In spring the birds excavated 0.8-3.2 m long nesting burrows under the ground. First-egg laying occurred between late April and late June during which a pair produced one brood. Incubation was done by female alone for 15-16 days and nestling-feeding by both sexes and helpers in any for 23-25 days. Average brood size at fledging was 5.8 (± 1.4 SD, 3-8 and all the 27 observed nesting attempts fledged at least one young. At the population level, brood sex ratio did not differ from 1:1. The birds are a territory-living resident, with annual resight rates being 48% (22 of 46 in adult breeders and 10% (7 of 67 in yearlings. Pairs were socially monogamous, of which 23% (9 of 40 contained one and sometimes two male helpers, most likely being philopatric sons of the breeders. The formation of cooperative groups is similar to the population in central Tibet but differs from that in south Guansu where breeding ground tits exhibit a high level of annual turnover [Current Zoology 57 (6: 751–757, 2011].

  4. Estimating the annual number of breeding attempts from breeding dates using mixture models.

    Science.gov (United States)

    Cornulier, Thomas; Elston, David A; Arcese, Peter; Benton, Tim G; Douglas, David J T; Lambin, Xavier; Reid, Jane; Robinson, Robert A; Sutherland, William J

    2009-11-01

    Well-established statistical methods exist to estimate variation in a number of key demographic rates from field data, including life-history transition probabilities and reproductive success per attempt. However, our understanding of the processes underlying population change remains incomplete without knowing the number of reproductive attempts individuals make annually; this is a key demographic rate for which we have no satisfactory method of estimating. Using census data to estimate this parameter from requires disaggregating the overlying temporal distributions of first and subsequent breeding attempts. We describe a Bayesian mixture method to estimate the annual number of reproductive attempts from field data to provide a new tool for demographic inference. We validate our method using comprehensive data on individually-marked song sparrows Melospiza melodia, and then apply it to more typical nest record data collected over 45 years on yellowhammers Emberiza citrinella. We illustrate the utility of our method by testing, and rejecting, the hypothesis that declines in UK yellowhammer populations have occurred concurrently with declines in annual breeding frequency.

  5. Opposing selection and environmental variation modify optimal timing of breeding.

    Science.gov (United States)

    Tarwater, Corey E; Beissinger, Steven R

    2013-09-17

    Studies of evolution in wild populations often find that the heritable phenotypic traits of individuals producing the most offspring do not increase proportionally in the population. This paradox may arise when phenotypic traits influence both fecundity and viability and when there is a tradeoff between these fitness components, leading to opposing selection. Such tradeoffs are the foundation of life history theory, but they are rarely investigated in selection studies. Timing of breeding is a classic example of a heritable trait under directional selection that does not result in an evolutionary response. Using a 22-y study of a tropical parrot, we show that opposing viability and fecundity selection on the timing of breeding is common and affects optimal breeding date, defined by maximization of fitness. After accounting for sampling error, the directions of viability (positive) and fecundity (negative) selection were consistent, but the magnitude of selection fluctuated among years. Environmental conditions (rainfall and breeding density) primarily and breeding experience secondarily modified selection, shifting optimal timing among individuals and years. In contrast to other studies, viability selection was as strong as fecundity selection, late-born juveniles had greater survival than early-born juveniles, and breeding later in the year increased fitness under opposing selection. Our findings provide support for life history tradeoffs influencing selection on phenotypic traits, highlight the need to unify selection and life history theory, and illustrate the importance of monitoring survival as well as reproduction for understanding phenological responses to climate change.

  6. Genetic diversity revealed by AFLP markers in Albanian goat breeds

    Directory of Open Access Journals (Sweden)

    Hoda Anila

    2012-01-01

    Full Text Available The amplified fragment length polymorphism (AFLP technique with three EcoRI/TaqI primer combinations was used in 185 unrelated individuals, representative of 6 local goat breeds of Albania, and 107 markers were generated. The mean Nei’s expected heterozygosity value for the whole population was 0.199 and the mean Shannon index was 0.249, indicating a high level of within-breed diversity. Wright’s FST index, Nei’s unbiased genetic distance and Reynolds’ genetic distance were calculated. Pairwise Fst values among the populations ranged from 0.019 to 0.047. A highly significant average FST of 0.031 was estimated, showing a low level of breed subdivision. Most of the variation is accounted for by differences among individuals. Cluster analysis based on Reynolds’ genetic distance between breeds and PCA were performed. An individual UPGMA tree based on Jaccard’s similarity index showed clusters with individuals from all goat breeds. Analysis of population structure points to a high level of admixture among breeds.

  7. Nest ectoparasites increase physiological stress in breeding birds: an experiment

    Science.gov (United States)

    Martínez-de La Puente, Josué; Merino, Santiago; Tomás, Gustavo; Moreno, Juan; Morales, Judith; Lobato, Elisa; Martínez, Javier

    2011-02-01

    Parasites are undoubtedly a biotic factor that produces stress. Heat shock proteins (HSPs) are important molecules buffering cellular damage under adverse conditions. During the breeding season, blue tit Cyanistes caeruleus (L.) adults are affected by blood parasites, nest-dwelling parasites and biting flies, potentially affecting their HSP-mediated responses. Here, we treated females with primaquine to reduce blood parasites and fumigated nests with permethrin to reduce nest-dwelling parasites to test whether these treatments affect HSP60 level during the breeding season. Medicated females, but not controls, had a significant reduction of the intensity of infection by Haemoproteus spp. blood parasites. However, final intensity of infection did not differ significantly between groups, and we did not find an effect of medication on change in HSP60 level. Fumigation reduced the abundance of nest-dwelling parasites (mites, fleas and blowfly larvae) and engorged biting midges in nests. Females breeding in non-fumigated nests increased HSP60 levels during the season more than those breeding in fumigated nests. Furthermore, the change in HSP60 level was positively correlated with the abundance of biting midges. These results show how infections by nest ectoparasites during the breeding period can increase the level of HSPs and suggest that biting midges impose physiological costs on breeding female blue tits. Although plausible, the alternative that biting midges prefer to feed on more stressed birds is poorly supported by previous studies.

  8. Dog Breed Differences in Visual Communication with Humans.

    Science.gov (United States)

    Konno, Akitsugu; Romero, Teresa; Inoue-Murayama, Miho; Saito, Atsuko; Hasegawa, Toshikazu

    2016-01-01

    Domestic dogs (Canis familiaris) have developed a close relationship with humans through the process of domestication. In human-dog interactions, eye contact is a key element of relationship initiation and maintenance. Previous studies have suggested that canine ability to produce human-directed communicative signals is influenced by domestication history, from wolves to dogs, as well as by recent breed selection for particular working purposes. To test the genetic basis for such abilities in purebred dogs, we examined gazing behavior towards humans using two types of behavioral experiments: the 'visual contact task' and the 'unsolvable task'. A total of 125 dogs participated in the study. Based on the genetic relatedness among breeds subjects were classified into five breed groups: Ancient, Herding, Hunting, Retriever-Mastiff and Working). We found that it took longer time for Ancient breeds to make an eye-contact with humans, and that they gazed at humans for shorter periods of time than any other breed group in the unsolvable situation. Our findings suggest that spontaneous gaze behavior towards humans is associated with genetic similarity to wolves rather than with recent selective pressure to create particular working breeds.

  9. Candidate genes for idiopathic epilepsy in four dog breeds

    Directory of Open Access Journals (Sweden)

    Mickelson James R

    2011-04-01

    Full Text Available Abstract Background Idiopathic epilepsy (IE is a naturally occurring and significant seizure disorder affecting all dog breeds. Because dog breeds are genetically isolated populations, it is possible that IE is attributable to common founders and is genetically homogenous within breeds. In humans, a number of mutations, the majority of which are genes encoding ion channels, neurotransmitters, or their regulatory subunits, have been discovered to cause rare, specific types of IE. It was hypothesized that there are simple genetic bases for IE in some purebred dog breeds, specifically in Vizslas, English Springer Spaniels (ESS, Greater Swiss Mountain Dogs (GSMD, and Beagles, and that the gene(s responsible may, in some cases, be the same as those already discovered in humans. Results Candidate genes known to be involved in human epilepsy, along with selected additional genes in the same gene families that are involved in murine epilepsy or are expressed in neural tissue, were examined in populations of affected and unaffected dogs. Microsatellite markers in close proximity to each candidate gene were genotyped and subjected to two-point linkage in Vizslas, and association analysis in ESS, GSMD and Beagles. Conclusions Most of these candidate genes were not significantly associated with IE in these four dog breeds, while a few genes remained inconclusive. Other genes not included in this study may still be causing monogenic IE in these breeds or, like many cases of human IE, the disease in dogs may be likewise polygenic.

  10. Breed susceptibility for developmental orthopedic diseases in dogs.

    Science.gov (United States)

    LaFond, Elizabeth; Breur, Gert J; Austin, Connie C

    2002-01-01

    A large-scale epidemiological study was conducted to determine breeds at risk for 12 developmental orthopedic diseases (DODs). Developmental orthopedic diseases investigated included canine hip dysplasia (CHD); craniomandibular osteopathy (CMO); fragmented coronoid process; hypertrophic osteodystrophy; Legg-Calvé-Perthes disease; osteochondrosis of the medial humeral condyle, caudal humeral head, femoral condyles, and talar trochlear ridges; panosteitis; patella luxation; and ununited anconeal process. Dogs that were diagnosed with any one of the diseases of interest at any of 10 veterinary teaching hospitals participating in the Veterinary Medical Database from 1986 to 1995 were included as cases. Odds ratios and corresponding 95% confidence intervals were calculated to determine risk. Frequency of diagnosis during the 10-year period ranged from 35 cases (CMO) to 10,637 cases (CHD). The number of breeds at increased risk for a disease ranged from one (CMO) to 35 (CHD). Breed susceptibility for a DOD may suggest a genetic component in the disease etiology. The results of this study serve to increase veterinarians' awareness of breeds susceptible to DODs and may facilitate the control of such diseases by identifying breeds that might benefit from breeding programs or environmental intervention such as dietary modification.

  11. Dog Breed Differences in Visual Communication with Humans

    Science.gov (United States)

    Konno, Akitsugu; Romero, Teresa; Inoue-Murayama, Miho; Saito, Atsuko; Hasegawa, Toshikazu

    2016-01-01

    Domestic dogs (Canis familiaris) have developed a close relationship with humans through the process of domestication. In human-dog interactions, eye contact is a key element of relationship initiation and maintenance. Previous studies have suggested that canine ability to produce human-directed communicative signals is influenced by domestication history, from wolves to dogs, as well as by recent breed selection for particular working purposes. To test the genetic basis for such abilities in purebred dogs, we examined gazing behavior towards humans using two types of behavioral experiments: the ‘visual contact task’ and the ‘unsolvable task’. A total of 125 dogs participated in the study. Based on the genetic relatedness among breeds subjects were classified into five breed groups: Ancient, Herding, Hunting, Retriever-Mastiff and Working). We found that it took longer time for Ancient breeds to make an eye-contact with humans, and that they gazed at humans for shorter periods of time than any other breed group in the unsolvable situation. Our findings suggest that spontaneous gaze behavior towards humans is associated with genetic similarity to wolves rather than with recent selective pressure to create particular working breeds. PMID:27736990

  12. Breed- and age-related differences in canine mammary tumors.

    Science.gov (United States)

    Kim, Hyun-Woo; Lim, Ha-Young; Shin, Jong-Il; Seung, Byung-Joon; Ju, Jung-Hyung; Sur, Jung-Hyang

    2016-04-01

    Triple-negative breast cancer is a type of breast cancer that does not express the genes for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER-2). It is an important and clinically relevant condition as it has a poor prognosis and is difficult to treat. Basal-like triple-negative cancer is highly prevalent in both African-Americans and adolescents. We therefore examined whether such a cancer likewise occurs in specific breeds and age groups in dogs, focusing on basal-like triple-negative cancer in particular. In this study, 181 samples from dogs with malignant mammary carcinoma from the 5 most common breeds and 2 age groups in Korea were analyzed. Histological classification and molecular subtyping, including assessment of immunohistochemical findings, were carried out. Twenty-five of 28 (89.3%) triple-negative carcinomas were identified as basal-like triple-negative carcinomas. Analysis of associations of classified factors revealed that the shih tzu breed (9/25, 36.0%) and advanced-age (19/25, 76.0%) groups were characterized by higher prevalence of basal-like triple-negative tumors with diverse histological types and of a higher grade. These results suggest that breed- and age-related differences can be identified in canine mammary carcinoma and, notably, in the shih tzu breed and at older ages. Further investigation of these distinguishing characteristics of the shih tzu breed is warranted.

  13. Behaviour characteristics estimation tool of genetic distance between sheep breeds

    Directory of Open Access Journals (Sweden)

    Eko Handiwirawan

    2014-12-01

    Full Text Available Information on the estimation of genetic distances and differentiation among sheep breeds are needed in crossing and conservation programs. This research aims to study of utilizing behaviour characteristic variables to differentiate and estimate genetic distance between the sheep breeds. The study was conducted at Cilebut and Bogor Animal House of Indonesian Research Institute for Animal Production. Five sheep breeds used were Barbados Black Belly Cross (BC, Garut Composite (KG, Garut Local (LG, Sumatera Composite (KS and St. Croix Cross (SC, with total sample of 50 heads. A total of 10 variables of behavior traits were observed in this study. Analysis of variances and significance tests were applied to compare between sheep breeds and performed for all of behavior traits using PROC GLM of SAS Program ver. 9.0. PROC CANDISC was used for canonical discriminant analyses, the hierarchical clustering was performed using the PROC CLUSTER by Average Linkage method (Unweighted Pair-Group Method Using Arithmetic Averages, UPGMA, and the dendogram for the five sheep breeds was described using PROC TREE. The differentiator variables for the behavior traits were standing and feeding duration. The canonical plotting based on behavioral characteristics could differentiate BC, KS and LG (with KG and SC sheeps. Estimation of genetic distance based on the behavior traits is less accurate for grouping of sheep breeds.

  14. 9 CFR 151.3 - Application for certificate of pure breeding.

    Science.gov (United States)

    2010-01-01

    ... breeding. 151.3 Section 151.3 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL BREEDS RECOGNITION OF BREEDS AND BOOKS OF RECORD OF PUREBRED ANIMALS Certification of Purebred Animals § 151.3 Application for certificate of pure breeding. An application for...

  15. Breeding Livestock. A Unit for Teachers of Vocational Agriculture. Production Agriculture Curriculum Materials Project.

    Science.gov (United States)

    O'Bryan, Robert C.

    Designed to provide instructional materials for use by vocational agriculture teachers, this unit on breeding livestock contains materials for use in teaching the importance of breeding, the physiology of livestock breeding, reproductive processes, sire selection, and breeding systems. Lessons on each of these competencies contain the following:…

  16. 9 CFR 151.2 - Issuance of a certificate of pure breeding.

    Science.gov (United States)

    2010-01-01

    ... breeding. 151.2 Section 151.2 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL BREEDS RECOGNITION OF BREEDS AND BOOKS OF RECORD OF PUREBRED ANIMALS Certification of Purebred Animals § 151.2 Issuance of a certificate of pure breeding. The Administrator...

  17. 9 CFR 151.10 - Recognition of additional breeds and books of record.

    Science.gov (United States)

    2010-01-01

    ... books of record. 151.10 Section 151.10 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL BREEDS RECOGNITION OF BREEDS AND BOOKS OF RECORD OF PUREBRED ANIMALS Recognition of Breeds and Books of Record § 151.10 Recognition of additional breeds and books...

  18. Genetic characterization of Egyptian and Italian sheep breeds using mitochondrial DNA

    Directory of Open Access Journals (Sweden)

    Othman E. Othman

    2015-06-01

    The matrix of pairwise differences among breeds was used to perform a Principal Component Analysis (PCA. This analysis showed that the Italian breeds are clearly separated from the Egyptian breeds; moreover the Egyptian Barki breed is separated from Ossimi and Rahmani.

  19. Potato breeding in the Netherlands: a successful participatory model with collaboration between farmers and commercial breeders

    NARCIS (Netherlands)

    Almekinders, C.J.M.; Mertens, L.; Loon, van J.P.; Lammerts Van Bueren, E.

    2014-01-01

    Participatory Plant Breeding (PPB) is mostly considered relevant to smallholder agriculture in developing countries. PPB involves getting farmers to participate in plant breeding to overcome shortcomings in the formal plant breeding system. The potato breeding system in the Netherlands has a long st

  20. Production objectives and breeding goals of Sahiwal cattle keepers in Kenya and implications for a breeding programme.

    Science.gov (United States)

    Ilatsia, Evans D; Roessler, Regina; Kahi, Alexander K; Piepho, Hans-Peter; Zárate, Valle

    2012-03-01

    The Sahiwal breed has been used for upgrading the East African Zebu (EAZ) for improved milk production and growth performance in the southern rangelands of Kenya. Main users of this breed are Maasai pastoralists. Until now, there has been no deliberate effort to understand why these pastoralists specifically prefer to keep Sahiwal genetic resources as well as which traits are considered important by them and what is the underlying reason for this. However, this information is regarded vital for further development of the breed. A survey was conducted between May and October 2009 among Maasai pastoralists in Kajiado and Narok counties in the Southern part of Kenya, and private ranches and government farms to identify production objectives and breeding goals of Sahiwal cattle producers. Sahiwal genetic resources were mainly kept for domestic milk production and for revenue generation through milk sales and live animals. To a limited extent, they were kept for breeding and also for multiple objectives that included insurance against risks and social functions. Production aims were influenced to varying extents by various household and farmer characteristics. Sahiwal cattle and their crosses were generally perceived to be better with respect to productive traits and fertility traits when compared to the EAZ. However, the EAZ was rated higher with respect to adaptation traits. The breeding objective traits of primary importance were high milk yield and big body size, good reproductive efficiency and relatively good adaptation to local production conditions. Performance and functional traits are important breeding goals that play a major role in fulfilling the multiple production objectives. This forms the basis for the optimisation of a breeding programme for sustainable utilisation to meet the needs of Sahiwal cattle producers.

  1. Post-breeding migration of Dutch-breeding black-tailed godwits: timing, routes, use of stopovers, and nonbreeding destinations

    Science.gov (United States)

    Hooijmeijer, Jos C. E. W.; Senner, Nathan R.; Tibbitts, T. Lee; Gill, Robert E.; Douglas, David C.; Bruinzeel, Leo W.; Wymenga, Eddy; Piersma, Theunis

    2014-01-01

    Conservation of long-distance migratory shorebirds is complex because these species use habitats spread across continents and hemispheres, making identification of critical habitats and potential bottlenecks in the annual cycle especially difficult. The population of Black-tailed Godwits that breeds in Western Europe, Limosa limosa limosa, has declined precipitously over the past few decades. Despite significant efforts to identify the root causes of this decline, much remains unclear. To better understand the migratory timing, use of stopover and nonbreeding sites, and the potential impact of breeding success on these parameters, we attached 15 Argos satellite transmitters and 10 geolocation tracking devices to adult godwits nearing completion of incubation at breeding sites in southwest Friesland, The Netherlands during the spring of 2009. We successfully tracked 16 adult godwits for their entire southward migration and two others for part of it. Three migration patterns and four regions of use were apparent. Most godwits left their breeding sites and proceeded south directly to stopover sites in the Mediterranean — e.g. Spain, Portugal, and Morocco — before flying on to non-breeding sites in West Africa. Other individuals spent the entire nonbreeding season in the Mediterranean. A third pattern included a few individuals that flew nonstop from their Dutch breeding sites to nonbreeding sites in West Africa. Tracking data from this study will be immediately useful for conservation efforts focused on preserving the dispersed network of sites used by godwits during their southward migration.

  2. An Overview of Ten Italian Horse Breeds through Mitochondrial DNA

    Science.gov (United States)

    Capodiferro, Marco Rosario; Capomaccio, Stefano; Buttazzoni, Luca; Biggio, Giovanni Paolo; Cherchi, Raffaele; Albertini, Emidio; Olivieri, Anna; Cappelli, Katia; Achilli, Alessandro; Silvestrelli, Maurizio

    2016-01-01

    Background The climatic and cultural diversity of the Italian Peninsula triggered, over time, the development of a great variety of horse breeds, whose origin and history are still unclear. To clarify this issue, analyses on phenotypic traits and genealogical data were recently coupled with molecular screening. Methodology To provide a comprehensive overview of the horse genetic variability in Italy, we produced and phylogenetically analyzed 407 mitochondrial DNA (mtDNA) control-region sequences from ten of the most important Italian riding horse and pony breeds: Bardigiano, Esperia, Giara, Lipizzan, Maremmano, Monterufolino, Murgese, Sarcidano, Sardinian Anglo-Arab, and Tolfetano. A collection of 36 Arabian horses was also evaluated to assess the genetic consequences of their common use for the improvement of some local breeds. Conclusions In Italian horses, all previously described domestic mtDNA haplogroups were detected as well as a high haplotype diversity. These findings indicate that the ancestral local mares harbored an extensive genetic diversity. Moreover, the limited haplotype sharing (11%) with the Arabian horse reveals that its impact on the autochthonous mitochondrial gene pools during the final establishment of pure breeds was marginal, if any. The only significant signs of genetic structure and differentiation were detected in the geographically most isolated contexts (i.e. Monterufolino and Sardinian breeds). Such a geographic effect was also confirmed in a wider breed setting, where the Italian pool stands in an intermediate position together with most of the other Mediterranean stocks. However, some notable exceptions and peculiar genetic proximities lend genetic support to historical theories about the origin of specific Italian breeds. PMID:27054850

  3. Tracing cattle breeds with principal components analysis ancestry informative SNPs.

    Directory of Open Access Journals (Sweden)

    Jamey Lewis

    Full Text Available The recent release of the Bovine HapMap dataset represents the most detailed survey of bovine genetic diversity to date, providing an important resource for the design and development of livestock production. We studied this dataset, comprising more than 30,000 Single Nucleotide Polymorphisms (SNPs for 19 breeds (13 taurine, three zebu, and three hybrid breeds, seeking to identify small panels of genetic markers that can be used to trace the breed of unknown cattle samples. Taking advantage of the power of Principal Components Analysis and algorithms that we have recently described for the selection of Ancestry Informative Markers from genomewide datasets, we present a decision-tree which can be used to accurately infer the origin of individual cattle. In doing so, we present a thorough examination of population genetic structure in modern bovine breeds. Performing extensive cross-validation experiments, we demonstrate that 250-500 carefully selected SNPs suffice in order to achieve close to 100% prediction accuracy of individual ancestry, when this particular set of 19 breeds is considered. Our methods, coupled with the dense genotypic data that is becoming increasingly available, have the potential to become a valuable tool and have considerable impact in worldwide livestock production. They can be used to inform the design of studies of the genetic basis of economically important traits in cattle, as well as breeding programs and efforts to conserve biodiversity. Furthermore, the SNPs that we have identified can provide a reliable solution for the traceability of breed-specific branded products.

  4. Genomic tools in cowpea breeding programs: status and perspectives

    Directory of Open Access Journals (Sweden)

    Ousmane eBoukar

    2016-06-01

    Full Text Available Cowpea is one of the most important grain legumes in sub-Saharan Africa (SSA. It provides strong support to the livelihood of small-scale farmers through its contributions to their nutritional security, income generation and soil fertility enhancement. Worldwide about 6.5 million metric tons of cowpea are produced annually on about 14.5 million hectares. The low productivity of cowpea is attributable to numerous abiotic and biotic constraints. The abiotic stress factors comprise drought, low soil fertility, and heat while biotic constraints include insects, diseases, parasitic weeds and nematodes. Cowpea farmers also have limited access to quality seeds of improved varieties for planting. Some progress has been made through conventional breeding at international and national research institutions in the last three decades. Cowpea improvement could also benefit from modern breeding methods based on molecular genetic tools. A number of advances in cowpea genetic linkage maps, and quantitative trait loci associated with some desirable traits such as resistance to Striga, Macrophomina, Fusarium wilt, bacterial blight, root-knot nematodes, aphids and foliar thrips have been reported. An improved consensus genetic linkage map has been developed and used to identify QTLs of additional traits. In order to take advantage of these developments single nucleotide polymorphism (SNP genotyping is being streamlined to establish an efficient workflow supported by genotyping support service (GSS-client interactions. About 1100 SNPs mapped on the cowpea genome were converted by LGC Genomics to KASP assays. Several cowpea breeding programs have been exploiting these resources to implement molecular breeding, especially for MARS and MABC, to accelerate cowpea variety improvement. The combination of conventional breeding and molecular breeding strategies, with workflow managed through the CGIAR breeding management system (BMS, promises an increase in the number of

  5. Genomic Tools in Cowpea Breeding Programs: Status and Perspectives.

    Science.gov (United States)

    Boukar, Ousmane; Fatokun, Christian A; Huynh, Bao-Lam; Roberts, Philip A; Close, Timothy J

    2016-01-01

    Cowpea is one of the most important grain legumes in sub-Saharan Africa (SSA). It provides strong support to the livelihood of small-scale farmers through its contributions to their nutritional security, income generation and soil fertility enhancement. Worldwide about 6.5 million metric tons of cowpea are produced annually on about 14.5 million hectares. The low productivity of cowpea is attributable to numerous abiotic and biotic constraints. The abiotic stress factors comprise drought, low soil fertility, and heat while biotic constraints include insects, diseases, parasitic weeds, and nematodes. Cowpea farmers also have limited access to quality seeds of improved varieties for planting. Some progress has been made through conventional breeding at international and national research institutions in the last three decades. Cowpea improvement could also benefit from modern breeding methods based on molecular genetic tools. A number of advances in cowpea genetic linkage maps, and quantitative trait loci associated with some desirable traits such as resistance to Striga, Macrophomina, Fusarium wilt, bacterial blight, root-knot nematodes, aphids, and foliar thrips have been reported. An improved consensus genetic linkage map has been developed and used to identify QTLs of additional traits. In order to take advantage of these developments single nucleotide polymorphism (SNP) genotyping is being streamlined to establish an efficient workflow supported by genotyping support service (GSS)-client interactions. About 1100 SNPs mapped on the cowpea genome were converted by LGC Genomics to KASP assays. Several cowpea breeding programs have been exploiting these resources to implement molecular breeding, especially for MARS and MABC, to accelerate cowpea variety improvement. The combination of conventional breeding and molecular breeding strategies, with workflow managed through the CGIAR breeding management system (BMS), promises an increase in the number of improved

  6. Hybridization among wild boars, local breeds and commercial breeds - preliminary results

    DEFF Research Database (Denmark)

    Iacolina, Laura; Bakan, Jana; Cubric-Curik, Vlatka

    . Hybridization with the domestic pig is known to occur in Europe, however the degree and extent of the phenomenon is not fully understood yet. Introgression is considered to be a treat to biodiversity and could lead to loss of local adaptation or introgression in the wild population of human selected genes....... A better understanding of the hybridization levels at European scale would provide an important tool for the development of management plans aimed at reducing human conflict but also at preserving biodiversity and genetic differentiation. Additionally, this information would provide new perspectives...... gradients in variability levels among the analysed wild and domestic populations. This preliminary results will be further investigated to address the possible presence of hybrid zone(s) in Europe and the possible implications for conservation and management of both wild populations and local pig breeds...

  7. The scurs inheritance: new insights from the French Charolais breed

    Directory of Open Access Journals (Sweden)

    Gautier Mathieu

    2009-07-01

    Full Text Available Abstract Background Polled animals are valued in cattle industry because the absence of horns has a significant economic impact. However, some cattle are neither polled nor horned but have so-called scurs on their heads, which are corneous growths loosely attached to the skull. A better understanding of the genetic determinism of the scurs phenotype would help to fine map the polled locus. To date, only one study has attempted to map the scurs locus in cattle. Here, we have investigated the inheritance of the scurs phenotype in the French Charolais breed and examined whether the previously proposed localisation of the scurs locus on bovine chromosome 19 could be confirmed or not. Results Our results indicate that the inheritance pattern of the scurs phenotype in the French Charolais breed is autosomal recessive with complete penetrance in both sexes, which is different from what is reported for other breeds. The frequency of the scurs allele (Sc reaches 69.9% in the French Charolais population. Eleven microsatellite markers on bovine chromosome 19 were genotyped in 267 offspring (33 half-sib and full-sib families. Both non-parametric and parametric linkage analyses suggest that in the French Charolais population the scurs locus may not map to the previously identified region. A new analysis of an Angus-Hereford and Hereford-Hereford pedigree published in 1978 enabled us to calculate the frequency of the Sc allele in the Hereford breed (89.4% and to study the penetrance of this allele in males heterozygous for both polled and scurs loci (40%. This led us to revise the inheritance pattern of the scurs phenotype proposed for the Hereford breed and to suggest that allele Sc is not fully but partially dominant in double heterozygous males while it is always recessive in females. Crossbreeding involving the Charolais breed and other breeds gave results similar to those reported in the Hereford breed. Conclusion Our results suggest the existence of

  8. Practices and Prospects of Super Hybrid Rice Breeding

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The great progress in super rice breeding both in China and other countries has been made in recent years.However, there were three main problems in super rice breeding: 1) the super rice varieties were still rare; 2) most super rice varieties exhibited narrow adaptability; and 3) current breeding theories emphasized too much on the rice growth model, but they were unpractical in guidance for rice breeding. According to the authors' experience on the rice breeding, the breeding strategies including three steps (super parent breeding, super hybrid rice breeding and super hybrid rice seed production)were proposed, and the objectives of each step and the key technologies to achieve the goals were elucidated in detail. The super parent of hybrid rice should exhibit excellent performance in all agronomic traits, with the yield or sink capacity reached the level of the hybrid rice control in regional trials. The super hybrid rice combination should meet the following criteria: good rice quality, wide adaptation, lodging resistance, resistance to main insects and diseases, and the yield exceeded above 8%over the control varieties in the national and provincial regional trials. To achieve the goal, the technical strategies, such as selecting optimal combination of the parents, increasing selection pressure, paying more attention to harmony of ideal plant type, excellent physiological traits and all the agronomic traits, should be emphasized. The yield of seed production should reach 3.75 t/ha and 5.25 t/ha for the super hybrid rice combinations derived from early-season and middle-season types of male sterile lines, respectively. The main technologies for raising seed production yield included selecting optimum seed production site, using the male sterile line with large sink capacity and good outcrossing characteristics, and improving the amount of the pollen by intensive cultivation of the male parent. According to the technologies of the three-step breeding on super

  9. Genetic characterization of four native Italian shepherd dog breeds and analysis of their relationship to cosmopolitan dog breeds using microsatellite markers

    DEFF Research Database (Denmark)

    Bigi, D.; Marelli, S. P.; Randi, Ettore

    2015-01-01

    -defined cosmopolitan dog breeds. As the Border Collie seems closer to the Italian breeds than the other cosmopolitan shepherd dogs considered here, a possible utilization of this breed to improve working performance in Italian traditional working shepherd dogs cannot be ignored. The data and information found here can...

  10. Proximate drivers of spatial segregation in non-breeding albatrosses.

    Science.gov (United States)

    Clay, Thomas A; Manica, Andrea; Ryan, Peter G; Silk, Janet R D; Croxall, John P; Ireland, Louise; Phillips, Richard A

    2016-07-21

    Many animals partition resources to avoid competition, and in colonially-breeding species this often leads to divergent space or habitat use. During the non-breeding season, foraging constraints are relaxed, yet the patterns and drivers of segregation both between and within populations are poorly understood. We modelled habitat preference to examine how extrinsic (habitat availability and intra-specific competition) and intrinsic factors (population, sex and breeding outcome) influence the distributions of non-breeding grey-headed albatrosses Thalassarche chrysostoma tracked from two major populations, South Georgia (Atlantic Ocean) and the Prince Edward Islands (Indian Ocean). Spatial segregation was greater than expected, reflecting distinct seasonal differences in habitat selection and accessibility, and avoidance of intra-specific competition with local breeders. Previously failed birds segregated spatially from successful birds during summer, when they used less productive waters, suggesting a link between breeding outcome and subsequent habitat selection. In contrast, we found weak evidence of sexual segregation, which did not reflect a difference in habitat use. Our results indicate that the large-scale spatial structuring of albatross distributions results from interactions between extrinsic and intrinsic factors, with important implications for population dynamics. As habitat preferences differed substantially between colonies, populations should be considered independently when identifying critical areas for protection.

  11. North European short-tailed breeds of sheep: a review.

    Science.gov (United States)

    Dýrmundsson, O R; Niżnikowski, R

    2010-08-01

    The short-tailed sheep, native of an area stretching from Russia to Iceland, are generally considered a primitive type. These robust northern sheep seem to have been spread by Norse vikings to several countries in this area from the late eighth century to the middle of the eleventh century ad. They have several common characteristics in addition to the fluke-shaped and tapered short tail, such as a wide range of colour patterns, dual-coated wool and the ability to thrive under harsh environmental conditions, often in isolated marginal areas. While 34 short-tailed breeds of North European origin can still be identified, it is clear that their population sizes have declined in most cases and several of them are now rare and endangered. Although these breeds have mainly been confined to certain localities, some of them have gained considerable distribution due to their genetic merits, such as prolificacy. Of these, the Finnsheep and the Romanov are best known being exported to several countries in the world where their genetic material has been utilized through crossbreeding with local sheep. This has resulted in the production of some new synthetic breeds. Meat is now generally the main product of the North European short-tailed breeds and their crossbreds, whereas wool, skins and milk are normally regarded as byproducts, yet of considerable economic importance in some cases. Such breeds have clearly a role to play in sustainable grassland-based production systems in the future.

  12. MATING DESIGNS: HELPFUL TOOL FOR QUANTITATIVE PLANT BREEDING ANALYSIS

    Directory of Open Access Journals (Sweden)

    Athanase Nduwumuremyi

    2013-12-01

    Full Text Available Selection of parental materials and good mating designs in conventional plant breeding are the keys to the successful plant breeding programme. However, there are several factors affecting the choices of mating designs. Mating design refers to the procedure of producing the progenies, in plant breeding, plant breeders and geneticists, theoretically and practically, they use different form of mating designs and arrangements for targeted purpose. The choice of a mating design for estimating genetic variances should be dictated by the objectives of the study, time, space, cost and other biological limitations. In all mating designs, the individuals are taken randomly and crossed to produce progenies which are related to each other as half-sibs or full-sibs. A form of multivariate analysis or the analysis of variance can be adopted to estimate the components of variances. Therefore, this review aimed at highlighting the most used mating design in plant breeding and genetics studies. It provides easy and quick insight of the different form of mating designs and some statistical components for successful plant breeding.

  13. Genomic breeding value estimation using nonparametric additive regression models

    Directory of Open Access Journals (Sweden)

    Solberg Trygve

    2009-01-01

    Full Text Available Abstract Genomic selection refers to the use of genomewide dense markers for breeding value estimation and subsequently for selection. The main challenge of genomic breeding value estimation is the estimation of many effects from a limited number of observations. Bayesian methods have been proposed to successfully cope with these challenges. As an alternative class of models, non- and semiparametric models were recently introduced. The present study investigated the ability of nonparametric additive regression models to predict genomic breeding values. The genotypes were modelled for each marker or pair of flanking markers (i.e. the predictors separately. The nonparametric functions for the predictors were estimated simultaneously using additive model theory, applying a binomial kernel. The optimal degree of smoothing was determined by bootstrapping. A mutation-drift-balance simulation was carried out. The breeding values of the last generation (genotyped was predicted using data from the next last generation (genotyped and phenotyped. The results show moderate to high accuracies of the predicted breeding values. A determination of predictor specific degree of smoothing increased the accuracy.

  14. Genetic diversity in Spanish donkey breeds using microsatellite DNA markers

    Directory of Open Access Journals (Sweden)

    Jordana Jordi

    2001-07-01

    Full Text Available Abstract Genetic diversity at 13 equine microsatellite loci was compared in five endangered Spanish donkey breeds: Andaluza, Catalana, Mallorquina, Encartaciones and Zamorano-Leonesa. All of the equine microsatellites used in this study were amplified and were polymorphic in the domestic donkey breeds with the exception of HMS1, which was monomorphic, and ASB2, which failed to amplify. Allele number, frequency distributions and mean heterozygosities were very similar among the Spanish donkey breeds. The unbiased expected heterozygosity (HE over all the populations varied between 0.637 and 0.684 in this study. The low GST value showed that only 3.6% of the diversity was between breeds (P A distance matrix showed little differentiation between Spanish breeds, but great differentiation between them and the Moroccan ass and also with the horse, used as an outgroup. These results confirm the potential use of equine microsatellite loci as a tool for genetic studies in domestic donkey populations, which could also be useful for conservation plans.

  15. Corticosterone mediated costs of reproduction link current to future breeding.

    Science.gov (United States)

    Crossin, Glenn T; Phillips, Richard A; Lattin, Christine R; Romero, L Michael; Williams, Tony D

    2013-11-01

    Life-history theory predicts that costs are associated with reproduction. One possible mediator of costs involves the secretion of glucocorticoid hormones, which in birds can be measured in feathers grown during the breeding period. Glucocorticoids mediate physiological responses to unpredictable environmental or other stressors, but they can also function as metabolic regulators during more predictable events such as reproduction. Here we show that corticosterone ("Cort") in feathers grown during the breeding season reflects reproductive effort in two Antarctic seabird species (giant petrels, Macronectes spp.). In females of both species, but not males, feather Cort ("fCort") was nearly 1.5-fold higher in successful than failed breeders (those that lost their eggs/chicks), suggesting a cost of successful reproduction, i.e., high fCort levels in females reflect the elevated plasma Cort levels required to support high metabolic demands of chick-rearing. Successful breeding also led to delayed moult prior to winter migration. The fCort levels and pre-migration moult score that we measured at the end of current breeding were predictive of subsequent reproductive effort in the following year. Birds with high fCort and a delayed initiation of moult were much more likely to defer breeding in the following year. Cort levels and the timing of moult thus provide a potential mechanism for the tradeoff between current and future reproduction.

  16. Molecular Breeding of Sorghum bicolor, A Novel Energy Crop.

    Science.gov (United States)

    Ordonio, Reynante; Ito, Yusuke; Morinaka, Yoichi; Sazuka, Takashi; Matsuoka, Makoto

    2016-01-01

    Currently, molecular breeding is regarded as an important tool for the improvement of many crop species. However, in sorghum, recently heralded as an important bioenergy crop, progress in this field has been relatively slow and limited. In this review, we present existing efforts targeted at genetic characterization of sorghum mutants. We also comprehensively review the different attempts made toward the isolation of genes involved in agronomically important traits, including the dissection of some sorghum quantitative trait loci (QTLs). We also explore the current status of the use of transgenic techniques in sorghum, which should be crucial for advancing sorghum molecular breeding. Through this report, we provide a useful benchmark to help assess how much more sorghum genomics and molecular breeding could be improved.

  17. Reliabilities of genomic estimated breeding values in Danish Jersey

    DEFF Research Database (Denmark)

    Thomasen, Jørn Rind; Guldbrandtsen, Bernt; Su, Guosheng;

    2012-01-01

    In order to optimize the use of genomic selection in breeding plans, it is essential to have reliable estimates of the genomic breeding values. This study investigated reliabilities of direct genomic values (DGVs) in the Jersey population estimated by three different methods. The validation methods...... of DGV. The data set consisted of 1003 Danish Jersey bulls with conventional estimated breeding values (EBVs) for 14 different traits included in the Nordic selection index. The bulls were genotyped for Single-nucleotide polymorphism (SNP) markers using the Illumina 54 K chip. A Bayesian method was used...... index pre-selection only. Averaged across traits, the estimates of reliability of DGVs ranged from 0.20 for validation on the most recent 3 years of bulls and up to 0.42 for expected reliabilities. Reliabilities from the cross-validation were on average 0.24. For the individual traits, the reliability...

  18. REPRODUCTIVE TRAITS OF BLACK SLAVONIAN PIG - ENDANGERED BREED

    Directory of Open Access Journals (Sweden)

    Đ. Senčić

    2001-12-01

    Full Text Available Black Slavonian pig is an autochtonous Croatian breed originated by crossing of the breeds Mangulica, Berkshire and Poland Chine at the end of 19th and beginning of 20th century. It belongs to the group of fat-meaty breeds. Due to a small number of the animals (153 sows, 45 gilts and 15 boars – Report HSSP, 2000 it is subjected to extinction danger. The investigation was conducted with 60 sows, inseminated by the total of ten boars at a family farm in eastern Slavonia. Black Slavonian sows farrowed 7.10 piglets per litter of which 6.31 were alive. They reared 5.71 piglets, aged two months, in a litter. Significant variability of the reproductive traits and their statistically important phenotypic correlation (r were determined in the analysed sows.

  19. Understanding Swedish dairy farmers’ view on breeding goals

    DEFF Research Database (Denmark)

    Röcklinsberg, H.; Gamborg, Christian; Gjerris, Mickey;

    2016-01-01

    , but also problems related to resources like milking system or grazing and to management practices like herd size or pasture management. Farmers’ practice varies depending on their values or attitudes, farm size and breed, but no previous study has mapped their values underlying choice of breeding goals...... these traits is longevity. Even so, dairy cows in Sweden are culled on average after only 2.4 lactations (about 4.5 years of age) i.e. before the housing and management of the heifer has paid off. Reasons for culling given in the literature include infertility, mastitis, disease or leg and claw problems...... cows. Leaving genetic concerns (b) aside we will now map factors leading to farmers culling a healthy cow even before the investment has been secured. Results show that although culling is emotionally difficult, curiosity in breeding and hope for even better heifers keep up recruitment levels and hence...

  20. Evidence for frequent incest in a cooperatively breeding mammal.

    Science.gov (United States)

    Nichols, H J; Cant, M A; Hoffman, J I; Sanderson, J L

    2014-12-01

    As breeding between relatives often results in inbreeding depression, inbreeding avoidance is widespread in the animal kingdom. However, inbreeding avoidance may entail fitness costs. For example, dispersal away from relatives may reduce survival. How these conflicting selection pressures are resolved is challenging to investigate, but theoretical models predict that inbreeding should occur frequently in some systems. Despite this, few studies have found evidence of regular incest in mammals, even in social species where relatives are spatio-temporally clustered and opportunities for inbreeding frequently arise. We used genetic parentage assignments together with relatedness data to quantify inbreeding rates in a wild population of banded mongooses, a cooperatively breeding carnivore. We show that females regularly conceive to close relatives, including fathers and brothers. We suggest that the costs of inbreeding avoidance may sometimes outweigh the benefits, even in cooperatively breeding species where strong within-group incest avoidance is considered to be the norm.

  1. Opportunities for Products of New Plant Breeding Techniques.

    Science.gov (United States)

    Schaart, Jan G; van de Wiel, Clemens C M; Lotz, Lambertus A P; Smulders, Marinus J M

    2016-05-01

    Various new plant breeding techniques (NPBT) have a similar aim, namely to produce improved crop varieties that are difficult to obtain through traditional breeding methods. Here, we review the opportunities for products created using NPBTs. We categorize products of these NPBTs into three product classes with a different degree of genetic modification. For each product class, recent examples are described to illustrate the potential for breeding new crops with improved traits. Finally, we touch upon the future applications of these methods, such as cisgenic potato genotypes in which specific combinations of Phytophthora infestans resistance genes have been stacked for use in durable cultivation, or the creation of new disease resistances by knocking out or removing S-genes using genome-editing techniques.

  2. Plant breeding with marker-assisted selection in Brazil

    Directory of Open Access Journals (Sweden)

    Ney Sussumu Sakiyama

    2014-03-01

    Full Text Available Over the past three decades, molecular marker studies reached extraordinary advances, especially for sequencing and bioinformatics techniques. Marker-assisted selection became part of the breeding program routines of important seed companies, in order to accelerate and optimize the cultivar developing processes. Private seed companies increasingly use marker-assisted selection, especially for the species of great importance to the seed market, e.g. corn, soybean, cotton, and sunflower. In the Brazilian public institutions few breeding programs use it efficiently. The possible reasons are: lack of know-how, lack of appropriate laboratories, few validated markers, high cost, and lack of urgency in obtaining cultivars. In this article we analyze the use and the constraints of marker-assisted selection in plant breeding programs of Brazilian public institutes

  3. Effect of Bacillus subtilis microecological probiotics on livestock breeding

    Directory of Open Access Journals (Sweden)

    Xiaohui ZHOU

    2016-10-01

    Full Text Available As a kind of green and healthy microecologics, Bacillus subtilis could balance the intestinal flora, promote the nutrient absorption and enhance immunity. Microecologics is one of the ideal antibiotics alternative, which are effective in preventing and treating animal disease and promoting the growth and development of the animal. Because of its advantages, such as no toxin side effect and no residual or drug-resistant, microecologics has been used in livestock breeding widely. Here, we concluded the characteristics and mechanism of Bacillus subtilis,elaborated application of microecologics on livestock breeding, discussed its problems and suggested its solved methods. In the end, the future of microecologics was expected in order to provide a reference for subsequent livestock breeding.

  4. Analysis of Tritium Breeding in the Test Module

    Energy Technology Data Exchange (ETDEWEB)

    Hong, SeongHee; Park, YunSeo; Kim, Myung Hyun [Kyung Hee University, Yongin (Korea, Republic of)

    2015-10-15

    In this paper, neutronic analyses are conducted on redesign of TMs which have high tritium breeding performance based on results of previous study. Calculation model is simplified, there is no effect to cover very complex geometry of fusion reactor for this study. As spent fuel disposal problem is issued in nuclear industry, FFHR is one of the most fascinating candidates for solving this problem through waste transmutation. Our research team also was designed a full core FFHR for waste transmutation. However, in this study, Test Module (TM) as test bed of FFHR for various purposes are analyzed. Analysis of tritium breeding on the TM was conducted as a first phase among TMs having various purposes. Because there are no fissionable materials in the TM for tritium breeding, geometry and neutronic reactions of its simpler compared to TM for waste transmutation and power production. Additionally, it is important database for tritium self-sufficiency as basic design condition of TM. In the previous study, neutronic analyses are conducted on these various TMs: Helium cooled solid breeder (HCSB), water cooled solid breeder (WCSB), Helium cooled dual breeder (HCDB) and molten-salt cooled liquid breeder (MSLB) in order to understand design characteristics. Neutronics calculations are performed with MCNPX 2.6.0 with ENDF/B-VII.0 neutron cross section library and activity and time-dependent tritium production calculations are performed with CINDER'90. In this paper, analysis of tritium breeding on WCHESL and WCHELL as TM is conducted. WCHESL is designed for effective tritium breeding performance and it satisfies design conditions. On the other hand WCHELL is designed for tritium breeding as much as possible and it also satisfies design conditions. However, neutron multiplication performance with these TM is not outstanding. WCHESL consist ceramic Li breeder, its period is 4.15E+08 sec.

  5. Genetic diversity and bottleneck studies in the Marwari horse breed

    Indian Academy of Sciences (India)

    A. K. Gupta; M. Chauhan; S. N. Tandon; Sonia

    2005-12-01

    Genetic diversity within the Marwari breed of horses was evaluated using 26 different microsatellite pairs with 48 DNA samples from unrelated horses. This molecular characterisation was undertaken to evaluate the problem of genetic bottlenecks also, if any, in this breed. The estimated mean (± s.e.) allelic diversity was 5.9 (± 2.24), with a total of 133 alleles. A high level of genetic variability within this breed was observed in terms of high values of mean (± s.e.) effective number of alleles (3.3 ± 1.27), observed heterozygosity (0.5306 ± 0.22), expected Levene’s heterozygosity (0.6612 ± 0.15), expected Nei’s heterozygosity (0.6535 ± 0.14), and polymorphism information content (0.6120 ± 0.03). Low values of Wright’s fixation index, $F_{\\text{IS}}$ (0.2433 ± 0.05) indicated low levels of inbreeding. This basic study indicated the existence of substantial genetic diversity in the Marwari horse population. No significant genotypic linkage disequilibrium was detected across the population, suggesting no evidence of linkage between loci. A normal ‘L’ shaped distribution of mode–shift test, non-significant heterozygote excess on the basis of different models, as revealed from Sign, Standardized differences and Wilcoxon sign rank tests as well as non-significant ratio value suggested that there was no recent bottleneck in the existing Marwari breed population, which is important information for equine breeders. This study also revealed that the Marwari breed can be differentiated from some other exotic breeds of horses on the basis of three microsatellite primers.

  6. Mitochondrial haplotypes reveal a strong genetic structure for three Indian sheep breeds.

    Science.gov (United States)

    Pardeshi, V C; Kadoo, N Y; Sainani, M N; Meadows, J R S; Kijas, J W; Gupta, V S

    2007-10-01

    This survey represents the first characterization of mitochondrial DNA diversity within three breeds of Indian sheep (two strains of the Deccani breed, as well as the Bannur and Garole breeds) from different geographic regions and with divergent phenotypic characteristics. A 1061-bp fragment of the mitochondrial genome spanning the control region, a portion of the 12S rRNA gene and the complete phenyl tRNA gene, was sequenced from 73 animals and compared with the corresponding published sequence from European and Asian breeds and the European Mouflon (Ovis musimon). Analysis of all 156 sequences revealed 73 haplotypes, 52 of which belonged to the Indian breeds. The three Indian breeds had no haplotypes in common, but one Indian haplotype was shared with European and other Asian breeds. The highest nucleotide and haplotype diversity was observed in the Bannur breed (0.00355 and 0.981 respectively), while the minimum was in the Sangamneri strain of the Deccani breed (0.00167 and 0.882 respectively). All 52 Indian haplotypes belonged to mitochondrial lineage A. Therefore, these Indian sheep are distinct from other Asian and European breeds studied so far. The relationships among the haplotypes showed strong breed structure and almost no introgression among these Indian breeds, consistent with Indian sheep husbandry, which discourages genetic exchange between breeds. These results have implications for the conservation of India's ovine biodiversity and suggest a common origin for the breeds investigated.

  7. Seasonal organic pig production with a local breed

    DEFF Research Database (Denmark)

    Kongsted, Anne Grete; Claudi-Magnussen, C.; Horsted, Klaus;

    2009-01-01

    is believed to bea feasible strategy for producing organic pork with high credibility and superior eating quality. The studyincluded a comparison between a modern genotype and the Danish Black-Spotted pig which does almostnot exist in the modern pig production of today. 17 gilts farrowed outdoors in April...... to the modern genotype and thefat of the Black-Spotted pig was characterised as having a special nutty taste. In conclusion, preliminaryresults indicate that the local breed differs markedly with respect to several meat quality aspects comparedto the modern breed but also shows clear disadvantages regarding...... growth performance and lean content...

  8. Genetic characterisation of CSN2 gene in Girgentana goat breed

    OpenAIRE

    2014-01-01

    Among calcium sensitive caseins, β-casein is the most abundant in goat milk, representing up to 50% of total casein content. The goat β-casein locus has been widely investigated and at least ten alleles have been identified in different goat breeds. The aim of this work was to investigate the polymorphisms of β-casein gene in Girgentana dairy goat breed in order to assess the genotype distribution and evaluate how frequencies have changed during the last 10 years, as genotype is known to infl...

  9. Population dynamics of mallards breeding in eastern Washington

    Science.gov (United States)

    Dugger, Bruce D.; Coluccy, John M.; Dugger, Katie M.; Fox, Trevor T.; Kraege, Donald K.; Petrie, Mark J.

    2016-01-01

    Variation in regional population trends for mallards breeding in the western United States indicates that additional research into factors that influence demographics could contribute to management and understanding the population demographics of mallards across North America. We estimated breeding incidence and adult female, nest, and brood survival in eastern Washington in 2006 and 2007 by monitoring female mallards with radio telemetry and tested how those parameters were influenced by study year (2006 vs. 2007), landscape type (agricultural vs. natural), and age (second year [SY] vs. after second year [ASY]). We also investigated the effects of female body condition and capture date on breeding incidence, and nest initiation date and hatch date on nest and brood survival, respectively. We included population parameters in a stage-based demographic model and conducted a perturbation analysis to identify which vital rates were most influential on population growth rate (λ). Adult female survival was best modeled with a constant weekly survival rate (0.994, SE = 0.003). Breeding incidence differed between years and was higher for birds in better body condition. Nest survival was higher for ASY females (0.276, SE = 0.118) than SY females (0.066, SE = 0.052), and higher on publicly managed lands (0.383, SE = 0.212) than agricultural (0.114, SE = 0.058) landscapes. Brood survival was best modeled with a constant rate for the 7-week monitoring period (0.50, SE = 0.155). The single variable having the greatest influence on λ was non-breeding season survival, but the combination of parameters from the breeding grounds explained a greater percent of the variance in λ. Mallard population growth rate was most sensitive to changes in non-breeding survival, nest success, brood survival, and breeding incidence. Future management decisions should focus on activities that improve these vital rates if managers want to increase the production of

  10. Capital versus income breeding in a seasonal environment

    DEFF Research Database (Denmark)

    Sainmont, Julie; Andersen, Ken Haste; Varpe, Oystein;

    2014-01-01

    The allocation of resources between growth, storage, and reproduction is a key trade-off in the life-history strategies of organisms. A central dichotomy is between capital breeders and income breeders. Capital breeders build reserves that allow them to spawn at a later time independently of food...... availability, while income breeders allocate ingested food directly to reproduction. Motivated by copepod studies, we use an analytical model to compare the fitness of income with capital breeding in a deterministic seasonal environment. We analyze how the fitness of breeding strategies depend on feeding...

  11. Growth Curves Analysis of Five Meat Rabbit Breeds

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The growth curves of five meat rabbit breeds are fitted in form of Gompertz model. The results are shown as follows :the goodness of fit is higher than 99.50% ;considering the body weight at one hundred day.the maximum weight (A)、the instantaneous relative growth rate (K)、the turning weight (W*)、 the turning age (t*)、the early average daily gain (KW*) selection,the Checkered Giant (GG) and the New Zealand White (NN) are better than other meat breeds,the slauthter age should be at the age of 90 day.

  12. Participatory definition of breeding objectives for sheep breeds under pastoral systems--the case of Red Maasai and Dorper sheep in Kenya.

    Science.gov (United States)

    König, Emelie Zonabend; Mirkena, Tadele; Strandberg, Erling; Audho, James; Ojango, Julie; Malmfors, Birgitta; Okeyo, Ally Mwai; Philipsson, Jan

    2016-01-01

    Crossing local breeds with exotic breeds may be an option for increased livestock productivity. However, there is a risk for endangerment of the local breeds. One such case is in Kenya where the imported Dorper breed is used for crossbreeding with Red Maasai sheep. The aim of this study was to investigate farmers' trait preferences as a basis for determination of breeding objectives for Red Maasai and Dorper sheep at two sites, Amboseli and Isinya, in Kenya. Within their own flock, each farmer identified three ewes representing the best, average and poorest within each breed group: Red Maasai, Dorper and Crosses. Farmers gave reasons for their ranking. Body measurements and weights were also taken. At the harshest site, Amboseli, differences between breed groups in body weight were small and breeds were equally preferred. In Isinya, where environmental conditions are better and farmers are more market oriented, Dorper and Crosses had significantly higher body weights and market prices and were thus preferred by the farmers. Red Maasai were preferred for their maternal and adaptive traits. Breeding objectives should emphasize growth traits and milk production in both breeds at both sites. Body condition needs to be specifically considered in the breeding objectives for sheep in Amboseli, whereas adaptive traits need to be generally emphasized in Dorper.

  13. THE IMPACT OF SEASON OF BIRTH AND BREEDING OF BOARS OF POLISH LANDRACE BREED ON THEIR INSEMINATION EFFICIENCY

    Directory of Open Access Journals (Sweden)

    Kazimierz Pokrywka

    2014-09-01

    Full Text Available The effectiveness of breeding boars in insemination depends mainly on the skill of optimal use of their reproductive potential. Nevertheless, their semen is highly variable in its quality and physical characteristics, which makes it difficult to organise semen production for artificial insemination purposes. The present study contains an analysis of semen collected from Polish Landrace breed boars - the most popular pigs bred in Poland. It demonstrates that there is a statistically significant interaction between season of birth and reproductive season of Polish Landrace boars. What is more, it proves that these significant differences between reproductive performances of boars are closely connected to their breeding season and seasons of their birth and life. The results also illustrate how to improve organisation of insemination centres and make them better financially efficient.

  14. Does timing of breeding matter less where the grass is greener? Seasonal declines in breeding performance differ between regions in an endangered endemic raptor

    Directory of Open Access Journals (Sweden)

    Marie-Sophie Garcia-Heras

    2016-09-01

    Full Text Available The timing of breeding can strongly influence individual breeding performance and fitness. Seasonal declines in breeding parameters have been often documented in birds, particularly in the Northern Hemisphere. Fewer studies have investigated whether seasonal declines in productivity vary in space, which would have implications for a species’ population dynamics across its distributional range. We report here on variation in the timing of breeding in the Black Harrier (Circus maurus, an endangered and endemic raptor to Southern Africa. We investigated how key breeding parameters (clutch size, nesting success and productivity varied with the timing of breeding, weather conditions (rainfall and temperature and between contrasted regions (coastal vs. interior-mountain. Black Harrier onset of breeding extended over an 8-month period, with a peak of laying between mid-August and end of September. We show a marked seasonal decline in all breeding parameters. Importantly, for clutch size and productivity these seasonal declines differed regionally, being more pronounced in interior-mountain than in coastal regions, where the breeding season was overall shorter. Timing of breeding, clutch size and productivity were also partly explained by weather conditions. In coastal regions, where environmental conditions, in particular rainfall, appear to be less variable, the timing of breeding matters less for breeding output than in interior-mountain regions, and breeding attempts thus occurred over a longer period. The former areas may act as population sources and be key in protecting the long-term population viability of this threatened endemic raptor. This study provides unique evidence for a regionally variable seasonal decline in breeding performance with implications for population biology and conservation.

  15. Out-of-season breeding of milk goats - the effect of light treatment, melatonin and breed : research communication

    OpenAIRE

    E.R. Du Preez; E.F. Donkin; P.A. Boyazoglu; G.H. Rautenbach; D.M. Barry; Schoeman, H S

    2001-01-01

    The purpose of this study was to evaluate the effectivity of melatonin in addition to light treatment (exposure to 2 hours of light during the night = a long-day photoperiod) to modify the breeding season of Saanen and cross-bred milk goats and to compare the difference between the breeds. Twenty-two Saanen and 22 cross-bred does were randomly divided into 3 treatment groups. Group 1 (controls) received no treatment, Group 2 received light treatment for 37 days and Group 3 received light trea...

  16. On-line charge breeding using ECRIS and EBIS

    Science.gov (United States)

    Vondrasek, Richard

    2016-06-01

    The efficient and rapid production of a high-quality, pure beam of highly charged ions is at the heart of any radioactive ion beam facility. Whether an electron cyclotron resonance (ECR) ion source or an electron beam ion source (EBIS) is used to produce these highly charged ions, their operating characteristics will set the boundaries on the range of experiments which can be performed. In addition, time structure and duty cycle have to be considered when defining the operating parameters of the accelerator system as a whole. At Argonne National Laboratory (ANL), an ECR charge breeder was developed as part of the Californium Rare Ion Breeder Upgrade (CARIBU) program. The charge breeding efficiency and high charge state production of the source is at the forefront of ECR charge breeders, but its overall performance as part of the accelerator system is limited by pervasive background and relatively long breeding times. As such, an EBIS charge breeder has been developed and is running in an off-line configuration. It has already demonstrated good breeding efficiencies, shorter residence times, and reduced background and is scheduled to replace the ECR charge breeder in late 2015. The resultant change in duty cycle and time structure necessitates changes to the overall operation of the facility. The experiences with these breeders, as well as from several other facilities which already utilize an ECR or EBIS for charge breeding, help to define the operational characteristics of each technology - their strengths, their weaknesses, and the possible paths to improvement.

  17. Genetic characterisation of CSN2 gene in Girgentana goat breed

    Directory of Open Access Journals (Sweden)

    Lina Tortorici

    2014-12-01

    Full Text Available Among calcium sensitive caseins, β-casein is the most abundant in goat milk, representing up to 50% of total casein content. The goat β-casein locus has been widely investigated and at least ten alleles have been identified in different goat breeds. The aim of this work was to investigate the polymorphisms of β-casein gene in Girgentana dairy goat breed in order to assess the genotype distribution and evaluate how frequencies have changed during the last 10 years, as genotype is known to influence technological and nutritional milk properties. Sequencing analysis and alignment of the obtained sequences of β-casein exon 7, showed the presence of C, C1, and A strong alleles, and 0' null allele, with frequencies of 0.597, 0.326, 0.023, and 0.054, respectively. Seven genotypic classes were found in Girgentana goat breed and the most frequent genotype was CC1 (0.423 followed by CC (0.326, C1C1 (0.110, and C0' (0.096. No AA nor 0'0' homozygous individuals were found. The presence of strong alleles at CSN2 gene in Girgentana goat breed could be useful for the production of milk with high protein content and good cheese-making properties. Moreover, food business operators should consider the possibility of reviving interest in Girgentana goat milk using weak and null genotypes at CSN2 locus to make peculiar food products, such as drinking milk.

  18. On the Breeds of Cattle - Historic and Current Classifications

    DEFF Research Database (Denmark)

    Felius, Marleen; Koolmees, Peter A; Theunissen, Bert

    2011-01-01

    Classification of cattle breeds contributes to our understanding of the history of cattle and is essential for an effective conservation of genetic diversity. Here we review the various classifications over the last two centuries and compare the most recent classifications with genetic data...

  19. The relevance of milk protein polymorphisms for dairy cattle breeding.

    NARCIS (Netherlands)

    Bovenhuis, H.

    1992-01-01

    An isoelectric focusing method is described that is suitable for phenotyping a large number of milk samples due to its short separation time and its high capacity. To estimate milk protein gene frequencies for breeds represented in the crossbred population and to estimate the fraction of animals mis

  20. Breeding of a Tomato Genotype Readily Accessible to Genetic Manipulation

    NARCIS (Netherlands)

    Koornneef, Maarten; Hanhart, Corrie; Jongsma, Maarten; Toma, Ingrid; Weide, Rob; Zabel, Pim; Hille, Jacques

    1986-01-01

    A tomato genotype, superior in regenerating plants from cell cultures, was obtained by transferring regeneration capacity from Lycopersicon peruvianum into L. esculentum by classical breeding. This genotype, MsK93, greatly facilitates genetic manipulation of tomato, as was demonstrated by successful