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Sample records for cichlid fish genus

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

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    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.

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

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    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

  3. 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.

  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. Social regulation of reproduction in male cichlid fishes.

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    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.

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

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    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

  7. 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.

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

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    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.

  9. Ancient hybridization fuels rapid cichlid fish adaptive radiations

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    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. 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.

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    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.

  11. Social familiarity modulates personality trait in a cichlid fish

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    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

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

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    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.

  13. 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.

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

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    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

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

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    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.

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

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    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.

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

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    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

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

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    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

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

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    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

  20. 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.

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

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    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...

  2. 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.

  3. 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.

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

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    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

  5. 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

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

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    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

  7. 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.

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

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    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.

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

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    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

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

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    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.

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

    Science.gov (United States)

    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.

  12. 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.

  13. 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.

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

    Science.gov (United States)

    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

  15. Development and characterization of polymorphic microsatellite markers in neotropical fish of the genus Apistogramma (Perciformes : Labroidei : Cichlidae)

    OpenAIRE

    2015-01-01

    The South American genus of Cichlid fish Apistogramma comprises over 100 species, most of which are difficult to identify. There is a need to clarify species limits and evolutionary relationships, conduct fine-scale phylogeographic revision of some species complexes, and collect information on population conservation status. In addition, recent studies suggest that female mate choice may lead to reproductive isolation and potentially to sympatric speciation in some species. Highly variable bi...

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

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    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.

  17. 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.

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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.

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

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    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.

  4. 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

  5. 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

  6. 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.

  7. 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

  8. 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.

  9. 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...

  10. 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.

  11. 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).

  12. 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.

  13. 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

  14. 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.

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

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    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].

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

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

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    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

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

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    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

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

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    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

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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

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

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    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.

  13. 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

  14. 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.

  15. 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.

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

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    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.

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

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    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.

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

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    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.

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

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    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.

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

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    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.

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

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    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.

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

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    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.

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

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    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.

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

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    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.

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

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    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.

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

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    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.

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

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    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.

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

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    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.

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

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    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.

  10. 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.

  11. Sensory drive in cichlid speciation

    NARCIS (Netherlands)

    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

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

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    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.

  13. 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

  14. 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.

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

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    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.

  16. 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.

  17. Neotropical Monogenoidea. 23. Two new species of Gyrodactylus (Gyrodactylidae from a Cichlid and an Erythrinid fish of Southeastern Brazil

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    Walter A. Boeger

    1995-12-01

    Full Text Available Two new species of Gyrodactylus Nordmann, 1832 (Platyhelminthes, Monogenoidea are described from fishes collected from southeastern Brazil. Gyrodactylus geophagensis n. sp. was collected from the body surface of the "cará", Geophagus brasiliensis (Quoy and Gaimard, 1824 (Cichlidae, from the Rio da Guarda, state of Rio de Janeiro; its major diagnostic features are the morphology of the anchor with a short, truncate superficial root and the shape of the hooks - with a long, delicate shaft. Gyrodactylus trairae n. sp. parasitizes the body surface of the "traíra", Hoplias aff. malabaricus (Bloch, 1794 (Erythrinidae, from the rio Guandu, state of Rio de Janeiro and can be easily differentiated from other species of the genus by having a thin, dorsal bridge, connecting the superficial bar with the spathulated shield. These are the first species of Gyrodactylus formally reported from Brazil. Presently, 26 species of Gyrodactylidae are known from freshwater fishes in the neotropical region; a list of these species is provided.

  18. 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.

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

    Science.gov (United States)

    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.

  1. 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

    of Australoheros within CAM heroines. The new phylogeny of the tribe Heroini provides robust framework to stabilize the taxonomy of the group and for future comparative studies on these morphologically and ecologically diverse freshwater fishes. Morphology was mostly informative at the genus level and aid in determining the monophyly and composition of heroine genera. Upon acceptance of all putative genera, as recovered in this study, the Heroini would be with 35 genera the most genus-rich clade of Neotropical cichlids.

  2. Effects of a non-native cichlid fish (African jewelfish, Hemichromis letourneuxi Sauvage 1880) on a simulated Everglades aquatic community

    Science.gov (United States)

    Schofield, Pamela J.; Slone, Daniel H.; Gregoire, Denise R.; Loftus, William F.

    2014-01-01

    In an 8-month mesocosm experiment, we examined how a simulated Everglades aquatic community of small native fishes, snails, and shrimp changed with the addition of either a native predator (dollar sunfish Lepomis marginatus) or a non-native predator (African jewelfish Hemichromis letourneuxi) compared to a no-predator control. Two snail species (Planorbella duryi, Physella cubensis) and the shrimp (Palaemonetes paludosus) displayed the strongest predator-treatment effects, with significantly lower biomasses in tanks with Hemichromis. One small native fish (Heterandria formosa) was significantly less abundant in Hemichromis tanks, but there were no significant treatment effects for Gambusia holbrooki, Jordanella floridae, or Pomacea paludosa (applesnail). Overall, there were few treatment differences between native predator and no-predator control tanks. The results suggest that the potential of Hemichromis to affect basal food-web species that link primary producers with higher-level consumers in the aquatic food web, with unknown consequences for Florida waters.

  3. Effect of lead nitrate on the liver of the cichlid fish (Oreochromis niloticus): a light microscope study.

    Science.gov (United States)

    Khidr, Bothaina M; Mekkawy, Imam A A; Harabawy, Ahmed S A; Ohaida, Abdel Salam M I

    2012-09-15

    The adverse impacts of heavy metals on fish liver were evident with great variability among organs and species. The present study deals with the histological changes of the hepatocytes of the Nile tilapia, Oreochromis niloticus, following exposure to 2.5, 5, 10 ppm of lead nitrate for 1, 2, 3, 4 weeks. The present results revealed that lead nitrate exerts some histological effects on the hepatic tissue after exposure to the first concentration in the form of dilatation and congestion of the blood vessels, vacuolation of hepatic cells, proliferation of connective tissue and hepatic necrosis. Leucocyte aggregation-mostly lymphatic in nature-was seen infiltrating hepatic tissue. These alterations became more pronounced in liver of fishes exposed to second concentrations indicating more progressive signs of necrosis. The presence of eosinophilic oedematous areas surrounding some blood vessels was also observed. Finally, at the third concentration, in addition to the above alterations, melanomacrophages, which store lipofuscin at the site of necrosis, were observed. These histological results imply that the fish liver may serve as a target organ for the toxicity of sublethal concentrations of lead nitrate.

  4. 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.

  5. 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].

  6. Phylogenetic analysis of parasitic trematodes of the genus Euclinostomum found in Trichopsis and Betta fish.

    Science.gov (United States)

    Senapin, S; Phiwsaiya, K; Laosinchai, P; Kowasupat, C; Ruenwongsa, P; Panijpan, B

    2014-06-01

    Many species of fish in the world are infected with digenean trematodes belonging to the genera Clinostomum and Euclinostomum. In this study, metacercariae, identified as Euclinostomum sp. on the basis of morphological characteristics and molecular data, were taken from 3 osphronemid fish- Trichopsis vittata , Trichopsis schalleri, and Betta imbellis, in Thailand. Phylogenetic analysis based on a mitochondrial gene (cytochrome c oxidase subunit I) and 2 nuclear genes (18S rDNA and ITS-internal transcribed spacer) of these Euclinostomum parasites indicated a clear distinction from those belonging to the Clinostomum genus. These are the first records of partial mitochondrial and nuclear DNA sequences of an Euclinostomum sp.

  7. The reasons for successful spreading of the fishes from the genus Carassius

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    Lukáš Kalous

    2015-11-01

    Full Text Available Freshwater fishes of the genus Carassius are widespread throughout home Eurasia but also other continents (Kottelat and Feryhof, 2007. They represent important aquaculture fishes and include the world's most important pet fish, the goldfish (Rylková et al., 2010. On the other hand they are also the most successful invasive pests with a considerable ecological impact at many places (Ribeiro et al., 2015; Copp et al., 2005. High similarities in morphological taxa definitions and occurrence of species complexes have brought lot of confusion in their taxonomy, biogeography and introduction history (Kalous et al., 2012. We present a historical overview and outline past and present reasons that have led to their successful spreading. Our findings are based on phylogenetic, historical and social-economic data. Europe is inhabited by at least five mtDNA lineages of the genus Carassius, which correspond to four taxa and one undescribed species. In Europe there occur: Carassius carassius, feral populations of Carassius auratus, Carassius gibelio, Carassius langsdorfii and Carassius sp.. C. auratus and C. langsdorfii are not native to Europe C. carassius is native to Eastern, Central and Northern Europe (Kalous et al., 2012. The populations of C. gibelio in Eastern and Central Europe should be considered a result of natural postglacial range expansion but the whole Europe was also colonized by introduced Carassius biotypes of various genome combinations from East Asia in the 20th century (Rylková et al., 2013. The spreading of non-native fishes of the genus Carassius has been caused mainly by human activities comprising pet trade, aquaculture and recreational fisheries (Kalous et al., 2013; Kalous et al., 2015.

  8. 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.

  9. Common descent of B chromosomes in two species of the fish genus Prochilodus (Characiformes, Prochilodontidae).

    Science.gov (United States)

    Voltolin, T A; Pansonato Alves, J C; Senhorini, J A; Foresti, F; Camacho, J P M; Porto-Foresti, F

    2013-01-01

    To ascertain the origin of B chromosomes in 2 fish species of the genus Prochilodus, i.e. P. lineatus and P. nigricans, we microdissected them and generated B-specific DNA probes. These probes were used to perform chromosome painting in both species and in 3 further ones belonging to the same genus (P. argenteus, P. brevis and P. costatus). Both probes hybridized with the B chromosomes in P. lineatus and P. nigricans, but with none of the chromosomes in the 5 species. This indicates that the B chromosomes have low similarity with DNAs located in the A chromosomes and suggests the possibility that the B chromosomes in the 2 species have a common origin. The most parsimonious explanation would imply intergeneric hybridization in an ancestor of P. lineatus and P. nigricans yielding the B chromosome as a byproduct, which remained in these 2 species after their phylogenetic origin, but was perhaps lost in other Prochilodus species. This hypothesis predicts that B chromosomes are old genomic elements in this genus, and this could be tested once a species from a relative genus would be found showing homology of its A chromosomes with the B-probes employed here, through a comparison of B chromosome DNA sequences with those in the A chromosomes of this other species.

  10. 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.

  11. Evolution of mouthbrooding and life-history correlates in the fighting fish genus Betta.

    Science.gov (United States)

    Rüber, Lukas; Britz, Ralf; Tan, Heok Hui; Ng, Peter K L; Zardoya, Rafael

    2004-04-01

    The origin of and evolutionary transitions among the extraordinary diverse forms of parental care in teleost fish remain largely unknown. The "safe harbor" hypothesis predicts that the evolution from a "guarding" to a "brooding" form of care in teleost fish is associated with shifts in reproductive and life-history features such as reduced fecundity, and increased egg volume with higher parental investment. Robust phylogenetic hypotheses may help to identify evolutionary changes in key traits associated with differences in the form of parental care. Here, we used reconstruction of ancestral character states to study the evolution of the two forms of parental care, bubble nesting and mouthbrooding in the fighting fish genus Betta. We also applied a comparative analysis using the phylogenetic generalized least-squares method to test the "safe harbor" hypothesis by evaluating differences between the two forms of parental care in standard length, life-history traits, and three habitat variables. Evolutionary hypotheses were derived from the first molecular phylogeny (nuclear and mitochondrial DNA sequence data; 4448 bp) of this speciose group. Ancestral character state reconstructions of the evolution of the form of parental care in the genus Betta, using the methods of unweighted parsimony and maximum likelihood, are uncertain and further indicate a high rate of evolutionary transitions. Applying different weights for the suspected directionality of changes, based on the consistent phenotypic and behavioral differences found between bubble nesters and mouthbrooders, recurrent origin of mouthbrooding in the genus Betta is favored using parsimony. Our comparative analyses further demonstrate that bubble nesters and mouthbrooders do not have a consistent set of life-history correlates. The form of parental care in Betta is correlated only with offspring size, with mouthbrooders having significantly bigger offspring than bubble nesters, but is not correlated with egg

  12. Occurrence of Nematodes of the Genus Anisakis in Mediterranean and Atlantic Fish Marketed in Sardinia

    Science.gov (United States)

    Casti, Daniele; Scarano, Christian; Piras, Maria Cristina; Merella, Paolo; Muglia, Sonia; Piras, Francesca; Garippa, Giovanni; Spanu, Carlo; De Santis, Enrico Pietro Luigi

    2017-01-01

    Anisakiasis is a gastrointestinal fish-borne zoonosis caused by the ingestion of third stage larvae of the genus Anisakis. Between January and December 2013, 1112 specimens of four commercial fish species (Engraulis encrasicolus, Merluccius merluccius, Scomber colias and Trachurus mediterraneus) marketed in Sardinia (Italy) were examined for Anisakis sp. The overall prevalence of Anisakis spp larvae was 39.9%, all morphologically identified as Type I. Scomber colias showed the highest prevalence (100%), followed by M. merluccius (Atlantic 91.0%, Mediterranean 71.2%), T. mediterraneus (32.7%) and E. encrasicolus (25.9%). All the larvae found in Mediterranean hosts were genetically identified as Anisakis pegreffii, whereas 90.0% of the larvae found in the Atlantic M. merluccius belonged to Anisakis simplex sensu stricto and 10.0% to A. pegreffii. The mean abundance of Anisakis sp. larvae was positively correlated with fish size in E. encrasicolus, Atlantic M. merluccius and local M. merluccius. The prevalence of infection was greater in the body cavity (37.9%) than in the edible muscle (9.4%). However, 1.8% of the examined fish were infected exclusively in the muscle. Therefore, the risk associated to the consumption of raw or undercooked fishery products poses the need of measures such as visual inspection and preventive treatments to guarantee consumers’ health. PMID:28299289

  13. A revision of the fish genus Oxyurichthys (Gobioidei: Gobiidae) with descriptions of four new species.

    Science.gov (United States)

    Pezold, Frank L; Larson, Helen K

    2015-07-22

    The widespread tropical gobionelline fish genus Oxyurichthys is monophyletic due to its species sharing two characters considered derived within the Stenogobius Group of the Gobionellinae (Gobioidei: Gobiidae), a transversely broadened (spatulate) third neural spine that is usually bifid, and no preopercular cephalic lateralis canal. It is most closely related to Oligolepis, also of the Indo-west Pacific, and Ctenogobius, an Atlantic-eastern Pacific genus. Sixteen valid species of Oxyurichthys are redescribed and illustrated and four new species are described, O. limophilus from the western Indian Ocean, O. rapa from French Polynesia, and O. chinensis and O. zeta from the western Pacific. Nineteen species share two additional synapomorphies, a rounded fleshy tongue and a palatine lacking an elongate posterior strut, and form the sister group to the plesiomorphous Oxyurichthys keiensis, known from South Africa and Madagascar. One species, O. stigmalophius, occurs in the western Atlantic. There are no records of this genus from the continental eastern Pacific or the eastern Atlantic. Previous accounts from the Gulf of Guinea region of West Africa are references to Gobionellus occidentalis. Many Oxyurichthys species are limited to shallow estuarine and coastal waters with bottom substrates of silt or other fine sediments, but several are known from depths exceeding 10 m and are often collected by trawling.

  14. Molecular Phylogeny and Biogeography of the Amphidromous Fish Genus Dormitator Gill 1861 (Teleostei: Eleotridae).

    Science.gov (United States)

    Galván-Quesada, Sesángari; Doadrio, Ignacio; Alda, Fernando; Perdices, Anabel; Reina, Ruth Gisela; García Varela, Martín; Hernández, Natividad; Campos Mendoza, Antonio; Bermingham, Eldredge; Domínguez-Domínguez, Omar

    2016-01-01

    Species of the genus Dormitator, also known as sleepers, are representatives of the amphidromous freshwater fish fauna that inhabit the tropical and subtropical coastal environments of the Americas and Western Africa. Because of the distribution of this genus, it could be hypothesized that the evolutionary patterns in this genus, including a pair of geminate species across the Central American Isthmus, could be explained by vicariance following the break-up of Gondwana. However, the evolutionary history of this group has not been evaluated. We constructed a time-scaled molecular phylogeny of Dormitator using mitochondrial (Cytochrome b) and nuclear (Rhodopsin and β-actin) DNA sequence data to infer and date the cladogenetic events that drove the diversification of the genus and to relate them to the biogeographical history of Central America. Two divergent lineages of Dormitator were recovered: one that included all of the Pacific samples and another that included all of the eastern and western Atlantic samples. In contrast to the Pacific lineage, which showed no phylogeographic structure, the Atlantic lineage was geographically structured into four clades: Cameroon, Gulf of Mexico, West Cuba and Caribbean, showing evidence of potential cryptic species. The separation of the Pacific and Atlantic lineages was estimated to have occurred ~1 million years ago (Mya), whereas the four Atlantic clades showed mean times of divergence between 0.2 and 0.4 Mya. The splitting times of Dormitator between ocean basins are similar to those estimated for other geminate species pairs with shoreline estuarine preferences, which may indicate that the common evolutionary histories of the different clades are the result of isolation events associated with the closure of the Central American Isthmus and the subsequent climatic and oceanographic changes.

  15. Occurrence of nematodes of the genus Anisakis in Mediterranean and Atlantic fish marketed in Sardinia

    Directory of Open Access Journals (Sweden)

    Daniele Casti

    2017-01-01

    Full Text Available Anisakiasis is a gastrointestinal fishborne zoonosis caused by the ingestion of third stage larvae of the genus Anisakis. Between January and December 2013, 1112 specimens of four commercial fish species (Engraulis encrasicolus, Merluccius merluccius, Scomber colias and Trachurus mediterraneus marketed in Sardinia (Italy were examined for Anisakis sp. The overall prevalence of Anisakis spp larvae was 39.9%, all morphologically identified as Type I. Scomber colias showed the highest prevalence (100%, followed by M. merluccius (Atlantic 91.0%, Mediterranean 71.2%, T. mediterraneus (32.7% and E. encrasicolus (25.9%. All the larvae found in Mediterranean hosts were genetically identified as Anisakis pegreffii, whereas 90.0% of the larvae found in the Atlantic M. merluccius belonged to Anisakis simplex sensu stricto and 10.0% to A. pegreffii. The mean abundance of Anisakis sp. larvae was positively correlated with fish size in E. encrasicolus, Atlantic M. merluccius and local M. merluccius. The prevalence of infection was greater in the body cavity (37.9% than in the edible muscle (9.4%. However, 1.8% of the examined fish were infected exclusively in the muscle. Therefore, the risk associated to the consumption of raw or undercooked fishery products poses the need of measures such as visual inspection and preventive treatments to guarantee consumers’ health.

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

    Science.gov (United States)

    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.

  17. Integrated Taxonomy Reveals Hidden Diversity in Northern Australian Fishes: A New Species of Seamoth (Genus Pegasus.

    Directory of Open Access Journals (Sweden)

    Deborah Osterhage

    Full Text Available Fishes are one of the most intensively studied marine taxonomic groups yet cryptic species are still being discovered. An integrated taxonomic approach is used herein to delineate and describe a new cryptic seamoth (genus Pegasus from what was previously a wide-ranging species. Preliminary mitochondrial DNA barcoding indicated possible speciation in Pegasus volitans specimens collected in surveys of the Torres Strait and Great Barrier Reef off Queensland in Australia. Morphological and meristic investigations found key differences in a number of characters between P. volitans and the new species, P. tetrabelos. Further mt DNA barcoding of both the COI and the slower mutating 16S genes of additional specimens provided strong support for two separate species. Pegasus tetrabelos and P. volitans are sympatric in northern Australia and were frequently caught together in trawls at the same depths.

  18. 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].

  19. 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.

  20. Introgressive hybridization in a trophically polymorphic cichlid.

    Science.gov (United States)

    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.

  1. Evolution of cichlid vision via trans-regulatory divergence

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    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

  2. 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.

  3. Not All Inner Ears are the Same: Otolith Matrix Proteins in the Inner Ear of Sub-Adult Cichlid Fish, Oreochromis Mossambicus, Reveal Insights Into the Biomineralization Process.

    Science.gov (United States)

    Weigele, Jochen; Franz-Odendaal, Tamara A; Hilbig, Reinhard

    2016-02-01

    The fish ear stones (otoliths) consist mainly of calcium carbonate and have lower amounts of a proteinous matrix. This matrix consists of macromolecules, which directly control the biomineralization process. We analyzed the composition of this proteinous matrix by mass spectrometry in a shotgun approach. For this purpose, an enhanced protein purification technique was developed that excludes any potential contamination of proteins from body fluids. Using this method we identified eight proteins in the inner ear of Oreochromis mossambicus. These include the common otolith matrix proteins (OMP-1, otolin-1, neuroserpin, SPARC and otoconin), and three proteins (alpha tectorin, otogelin and transferrin) not previously localized to the otoliths. Moreover, we were able to exclude the occurrence of two matrix proteins (starmaker and pre-cerebellin-like protein) known from other fish species. In further analyses, we show that the absence of the OMP starmaker corresponds to calcitic otoliths and that pre-cerebellin-like protein is not present at any stage during the development of the otoliths of the inner ear. This study shows O. mossambicus does not have all of the known otolith proteins indicating that the matrix proteins in the inner ear of fish are not the same across species. Further functional studies of the novel proteins we identified during otolith development are required.

  4. 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.

  5. Searching for speciation genes: molecular evidence for selection associated with colour morphotypes in the Caribbean reef fish genus Hypoplectrus.

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    Ben G Holt

    Full Text Available Closely related species that show clear phenotypic divergence, but without obvious geographic barriers, can provide opportunities to study how diversification can occur when opportunities for allopatric speciation are limited. We examined genetic divergence in the coral reef fish genus Hypoplectrus (family: Serranidae, which comprises of 10-14 morphotypes that are distinguished solely by their distinct colour patterns, but which show little genetic differentiation. Our goal was to detect loci that show clear disequilibrium between morphotypes and across geographical locations. We conducted Amplified Fragment Length Polymorphism molecular analysis to quantify genetic differentiation among, and selection between, morphotypes. Three loci were consistently divergent beyond neutral expectations in repeated pair-wise morphotype comparisons using two different methods. These loci provide the first evidence for genes that may be associated with colour morphotype in the genus Hypoplectrus.

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

    Science.gov (United States)

    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.

  7. Using Cichlids for Illustrating Mendel's Laws

    Science.gov (United States)

    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)

  8. The first complete mitochondrial genome from Bostrychus genus (Bostrychus sinensis) and partitioned Bayesian analysis of Eleotridae fish phylogeny

    Indian Academy of Sciences (India)

    Tao Wei; Xiao Xiao Jin; Tian Jun Xu

    2013-08-01

    To understand the phylogenetic position of Bostrychus sinensis in Eleotridae and the phylogenetic relationships of the family, we determined the nucleotide sequence of the mitochondrial (mt) genome of Bostrychus sinensis. It is the first complete mitochondrial genome sequence of Bostrychus genus. The entire mtDNA sequence was 16508 bp in length with a standard set of 13 protein-coding genes, 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs) and a noncoding control region. The mitochondrial genome of B. sinensis had common features with those of other bony fishes with respect to gene arrangement, base composition, and tRNA structures. Phylogenetic hypotheses within Eleotridae fish have been controversial at the genus level. We used the mitochondrial cytochrome b (cytb) gene sequence to examine phylogenetic relationships of Eleotridae by using partitioned Bayesian method. When the specific models and parameter estimates were presumed for partitioning the total data, the harmonic mean –lnL was improved. The phylogenetic analysis supported the monophyly of Hypseleotris and Gobiomorphs. In addition, the Bostrychus were most closely related to Ophiocara, and the Philypnodon is also the sister to Microphlypnus, based on the current datasets. Further, extensive taxonomic sampling and more molecular information are needed to confirm the phylogenetic relationships in Eleotridae.

  9. 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].

  10. 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.

  11. Action spectrum for melanoma induction in hybrid fish of the genus Xiphophorus

    Energy Technology Data Exchange (ETDEWEB)

    Setlow, R.B.

    1997-03-01

    Cutaneous malignant melanoma (CMM) is a complicated disease that is dependent on a number of factors that influence its incidence in ways that are quantitatively uncertain. The incidence of CMM increases with proximity to the Equator -- an observation in line with the conclusion that sun exposure is the most important etiologic agent. However, the latitude effect does not implicate UVB because the intensities of all spectral regions increase toward the Equator. An understanding of the useful public health measures to lower the incidence of CMM would benefit greatly if the spectral region of sunlight implicated in melanoma incidence were known. Such knowledge requires animal models to evaluate the incidence as a function of wavelength. There are marsupial models, a transgenic mouse model, and a fish model. To date, only the fish model has been employed to obtain an action spectrum. The paper describes a fish model, implications of the fish spectrum, and epidemiological data.

  12. 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.

  13. 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.

  14. Molecular phylogeny and phylogeography of the Cuban cave-fishes of the genus Lucifuga: evidence for cryptic allopatric diversity.

    Science.gov (United States)

    García-Machado, Erik; Hernández, Damir; García-Debrás, Alfredo; Chevalier-Monteagudo, Pedro; Metcalfe, Cushla; Bernatchez, Louis; Casane, Didier

    2011-11-01

    Underground environments are increasingly recognized as reservoirs of faunal diversity. Extreme environmental conditions and limited dispersal ability of underground organisms have been acknowledged as important factors promoting divergence between species and conspecific populations. However, in many instances, there is no correlation between genetic divergence and morphological differentiation. Lucifuga Poey is a stygobiotic fish genus that lives in Cuban and Bahamian caves. In Cuba, it offers a unique opportunity to study the influence of habitat fragmentation on the genetic divergence of stygobiotic species and populations. The genus includes four species and one morphological variant that have contrasting geographical distributions. In this study, we first performed a molecular phylogenetic analysis of the Lucifuga Cuban species using mitochondrial and nuclear markers. The mitochondrial phylogeny revealed three deeply divergent clades that were supported by nuclear and morphological characters. Within two of these main clades, we identified five lineages that are candidate cryptic species and a taxonomical synonymy between Lucifuga subterranea and Lucifuga teresinarum. Secondly, phylogeographic analysis using a fragment of the cytochrome b gene was performed for Lucifuga dentata, the most widely distributed species. We found strong geographical organization of the haplotype clades at different geographic scales that can be explained by episodes of dispersal and population expansion followed by population fragmentation and restricted gene flow. At a larger temporal scale, these processes could also explain the diversification and the distribution of the different species.

  15. Phylogenetic Systematics, Biogeography, and Ecology of the Electric Fish Genus Brachyhypopomus (Ostariophysi: Gymnotiformes)

    Science.gov (United States)

    de Santana, Carlos David; Waddell, Joseph C.; Lovejoy, Nathan R.

    2016-01-01

    A species-level phylogenetic reconstruction of the Neotropical bluntnose knifefish genus Brachyhypopomus (Gymnotiformes, Hypopomidae) is presented, based on 60 morphological characters, approximately 1100 base pairs of the mitochondrial cytb gene, and approximately 1000 base pairs of the nuclear rag2 gene. The phylogeny includes 28 species of Brachyhypopomus and nine outgroup species from nine other gymnotiform genera, including seven in the superfamily Rhamphichthyoidea (Hypopomidae and Rhamphichthyidae). Parsimony and Bayesian total evidence phylogenetic analyses confirm the monophyly of the genus, and identify nine robust species groups. Homoplastic osteological characters associated with diminutive body size and occurrence in small stream habitats, including loss of squamation and simplifications of the skeleton, appear to mislead a phylogenetic analysis based on morphological characters alone–resulting in the incorrect placing of Microsternarchus + Racenisia in a position deeply nested within Brachyhypopomus. Consideration of geographical distribution in light of the total evidence phylogeny indicates an origin for Brachyhypopomus in Greater Amazonia (the superbasin comprising the Amazon, Orinoco and major Guiana drainages), with subsequent dispersal and vicariance in peripheral basins, including the La Plata, the São Francisco, and trans-Andean basins of northwest South America and Central America. The ancestral habitat of Brachyhypopomus likely resembled the normoxic, low-conductivity terra firme stream system occupied by many extant species, and the genus has subsequently occupied a wide range of terra firme and floodplain habitats including low- and high-conductivity systems, and normoxic and hypoxic systems. Adaptations for impedance matching to high conductivity, and/or for air breathing in hypoxic systems have attended these habitat transitions. Several species of Brachyhypopomus are eurytopic with respect to habitat occupancy and these generally

  16. Evolutionary history of the fish genus Astyanax Baird & Girard (1854 (Actinopterygii, Characidae in Mesoamerica reveals multiple morphological homoplasies

    Directory of Open Access Journals (Sweden)

    Doadrio Ignacio

    2008-12-01

    Full Text Available Abstract Background Mesoamerica is one of the world's most complex biogeographical regions, mostly due to its complex geological history. This complexity has led to interesting biogeographical processes that have resulted in the current diversity and distribution of fauna in the region. The fish genus Astyanax represents a useful model to assess biogeographical hypotheses due to it being one of the most diverse and widely distributed freshwater fish species in the New World. We used mitochondrial and nuclear DNA to evaluate phylogenetic relationships within the genus in Mesoamerica, and to develop historical biogeographical hypotheses to explain its current distribution. Results Analysis of the entire mitochondrial cytochrome b (Cytb gene in 208 individuals from 147 localities and of a subset of individuals for three mitochondrial genes (Cytb, 16 S, and COI and a single nuclear gene (RAG1 yielded similar topologies, recovering six major groups with significant phylogeographic structure. Populations from North America and Upper Central America formed a monophyletic group, while Middle Central America showed evidence of rapid radiation with incompletely resolved relationships. Lower Central America lineages showed a fragmented structure, with geographically restricted taxa showing high levels of molecular divergence. All Bramocharax samples grouped with their sympatric Astyanax lineages (in some cases even with allopatric Astyanax populations, with less than 1% divergence between them. These results suggest a homoplasic nature to the trophic specializations associated with Bramocharax ecomorphs, which seem to have arisen independently in different Astyanax lineages. We observed higher taxonomic diversity compared to previous phylogenetic studies of the Astyanax genus. Colonization of Mesoamerica by Astyanax before the final closure of the Isthmus of Panama (3.3 Mya explains the deep level of divergence detected in Lower Central America. The

  17. Molecular phylogeny of the Neotropical fish genus Tetragonopterus (Teleostei: Characiformes: Characidae).

    Science.gov (United States)

    Melo, Bruno F; Benine, Ricardo C; Silva, Gabriel S C; Avelino, Gleisy S; Oliveira, Claudio

    2016-01-01

    Tetragonopterinae encompasses characid species of the genus Tetragonopterus, which are widely distributed throughout east of the Andes in South America. While taxonomy has recently clarified the species diversity and molecular evidence strongly supports the monophyly of Tetragonopterus, no interspecific relationship studies are currently available. Here we used a large molecular dataset composed of two mitochondrial and three nuclear loci containing an extensive taxon sampling within the family Characidae and included eleven species of Tetragonopterus to generate the first time-calibrated phylogeny for Tetragonopterinae. Our results support monophyly of the subfamily represented solely by Tetragonopterus and corroborate previous molecular hypothesis of close relationship with Exodon plus Roeboexodon and the subfamily Characinae. Internally, we found Moenkhausia georgiae as sister species to all remaining species followed by T. rarus, being both species endemic to the Guiana Shield drainages. Species-level relationships are first hypothesized and putative morphological apomorphies are discussed as support to monophyletic clades. Our time-calibrated phylogeny suggested an origin of the genus during the Late Oligocene-Early Miocene. We hypothesized that the Andean geological activity followed by transformations in the Amazonian hydrographic scenario during the Miocene may have promoted most of the lineage diversification within the Tetragonopterus.

  18. Lactobacillus genus identification isolated from gastrointestinal tract of chickens after bee products application using FISH and RTQ PCR methods

    Directory of Open Access Journals (Sweden)

    Miroslava Kačániová

    2013-05-01

    Full Text Available The general objective of this study was to examine the effect of bee products on the lactobacilli colonization of chickens. Bee products were administered to both feed mixtures in various amounts in addition to the control group. First experimental group was with propolis in feed mixture with the addition of 400 mg propolis per 1 kg of compound and second group was with pollen in feed mixture with the addition of 450 mg pollen per 1 kg of compound. In this experiment, quantitative counts of lactobacilli in ceca of 49-day-old chicken (Ross 308 using classical and FISH method were investigated. Counts of lactobacilli on MRS agar were monitored. To check the reliability of traditional methods of cultivation samples were evaluated by fluorescence in situ hybridization (FISH. Lactobacillus cells, isolated from gastrointestinal tract, were detected after hybridization of fluorescently labeled probe with bacterial cells. Counts of CFU of lactobacilli were compared in experimental and control treatments, respectively. The lowest count was detected in the control experimental group. The highest count was detected in the third experimental group where was 450 mg of pollen added to 1 kg of feed mixture. Using Real-time PCR method, we identified the species range of the genera Lactobacillus in the intestinal tract of broiler. Detected species from the genus Lactobacillus were L. crispatus, L. salivarius and L. acidophilus.

  19. G. J. Billberg's (1833) 'On the ichthyology, and description of some new fish species of the pipefish genus Syngnathus'.

    Science.gov (United States)

    Kullander, Sven O

    2016-01-14

    Gustaf Johan Billberg's review of ichthyology, published in Swedish in 1833 in the Linnéska samfundets handlingar, mentions 92 fish taxa at genus and species level, 41 of which represent new taxa, unnecessary replacement names, or unjustified emendations. Billberg presents his own classification of fishes, in which five new family names are introduced: Ballistidae, Diodontidae, Ooididae, Chironectidae, and Macrorhyncidae. Diodontidae has priority over Diodontidae Bonaparte, 1835. Macrorhyncidae was published earlier than Gempylidae Gill, 1862, but the latter has priority by prevailing usage.        Billberg mentions 61 genera of fishes, 41 of them listed only by name. Six generic names proposed by Billberg are available as unjustified emendations: Myxinus, Petromyzus, Scylia, Mustellus, Zyganna, and Ballistes. Brachionus is an unnecessary replacement name. Aphrus, Capriscus, Exormizus, Enneophthalmus, and Oedaus are nomina nuda. Eight new genera of fishes are proposed: Anodon, Posthias, Orbis, Sphaeroides, and Ooides are junior synonyms; Cotilla is a nomen oblitum in relation to Sufflamen Jordan, 1916; Tropigaster a nomen oblitum in relation to Aracana Gray, 1835; and Tetragonizus a nomen oblitum in relation to Lactoria Jordan & Fowler, 1902.        Billberg lists 31 species of fishes. Three represent new combinations; two are nomina nuda. The following 14 new species are described based on literature: Raja forskohlii, Cephaloptera dumerillii, Myliobatis lacepedei, Scylia russelii, Anodon macropterus, Cotilla frenata, Monacanthus blochii, M. sebae, M. cuvieri, M. marcgravii, Tetraodon striatus, Orbis psittacinus, Orbis punctulatus, and Orbis guttatus. All of those are invalid, except Scylia russelii, which is a species inquirenda. The following nine species group names are unnecessary replacement names and consequently invalid: Raja arabica, Myliobatis rissoi, Scylia isabellina, Anodon cirrhosus, Anodon cornutus, Zyganna voracissima, Centrina

  20. 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.

  1. Current and historical hybridization with differential introgression among three species of cyprinid fishes (genus Cyprinella).

    Science.gov (United States)

    Broughton, Richard E; Vedala, Krishna C; Crowl, Tessa M; Ritterhouse, Lauren L

    2011-05-01

    Hybridization is common among freshwater fishes, particular among the Cyprinidae. We used two mitochondrial genes and one nuclear gene to characterize hybridization among two species pairs of Cyprinella in southwestern North America. Genalogical patterns revealed that C. lutrensis and C. venusta are currently hybridizing in several localities producing apparent F(1), F(2) and backcross generations, yet there was no evidence for introgression outside of local hybrid zones. Alternatively, mitochondrial haplotypes from C. lutrensis appear to have introgressed into a C. lepida population in the Nueces River completely replacing the native C. lepida haplotype. There was no evidence of introgression of nuclear DNA and there does not appear to be ongoing hybridization. The population of C. lepida from the nearby Frio River exhibits no evidence of hybridization with C. lutrensis. Thus, contact between C. lutrensis and C. venusta results in the formation of localized hybrid swarms, while contact between C. lutrensis and C. lepida has resulted in complete mitochondrial introgression in the Nueces River or no apparent hybridization in the Frio River. The three different outcomes of contact between these species illustrate the variable nature of interspecific reproductive interactions and provide an excellent system in which to better understand the factors influencing hybridization among freshwater fishes.

  2. 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].

  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. 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.

  8. 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.

  9. An identification in fish of the genus Puntius Hamilton 1822 (Cypriniformes: Cyprinidae) of some wetlands in northeast Thailand with the use of random amplified polymorphic DNA technique.

    Science.gov (United States)

    Champasri, T; Rapley, R; Duangjinda, M; Suksri, A

    2008-02-15

    The experiment was carried out during the 2003 to 2006 at the Department of Fisheries, Khon Kaen University, Khon Kaen, Thailand in collaboration with the Department of Biosciences, the University of Hertfordshire, College Land, Hatfield, Herts, UK. Molecular RAPD technique was used for the determinations of DNA patterns of the fish genus Puntius Hamilton 1822. The fish samples of 1,500 individual fish were collected from fifteen wetlands in Northeast Thailand and they were used for DNA extraction. Before the experiment was carried out the fish samples were morphologically identified and it was found that the collected fish consisted of 9 species i.e., Puntius altus, P. aurotaeniatus, P. binotatus, P. gonionotus, (e) P. leiacanthus, P. orphoides, P. partipentazona, P. schwanenfeldi and P. wetmorei. Genomic DNAs were extracted from 5 mg of muscle tissues (skeleton muscles) with the use of PUREGENE DNA Isolation Kit for Laboratory Use, Gentra Systems, USA. Eighty decamer primers from four kits were subjected to a preliminary test. It was found that only 10 decamer primers were most suited for this PCR amplification. The results showed that genetic distant values being established among and between pairs of the fishes of the 9 fish species ranged from 0.191 to 0.456 for a pair between Puntius gonionotus and Puntius altus and a pair between Puntius schwanenfeldi and Puntius leiacanthus, respectively. Similarity coefficient values within the 9 fish species ranged from 0.109 to 0.231. The results on a Dendrogram of clusters showed that there were 5 minor groups of the 9 fish species but the 9 species could not be split or shifted into other genera of the fish due to small differences found within the values of similarity coefficients.

  10. Molecular phylogeny and phylogeography of the Australian freshwater fish genus Galaxiella, with an emphasis on dwarf galaxias (G. pusilla.

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    Peter J Unmack

    Full Text Available The freshwater fauna of Southern Australia is primarily restricted to the southwestern and southeastern corners of the continent, and is separated by a large, arid region that is inhospitable to this biota. This geographic phenomenon has attracted considerable interest from biogeographers looking to explain evolutionary diversification in this region. Here, we employed phylogenetic and phylogeographic approaches to evaluate the effect of this barrier on a group of four galaxiid fish species (Galaxiella endemic to temperate Southern Australia. We also tested if continental shelf width has influenced connectivity among populations during low sea levels when rivers, now isolated, could have been connected. We addressed these questions by sampling each species across its range using multiple molecular markers (mitochondrial cytochrome b sequences, nuclear S7 intron sequences, and 49 allozyme loci. These data also allowed us to assess species boundaries, to refine phylogenetic affinities, and to estimate species ages. Interestingly, we found compelling evidence for cryptic species in G. pusilla, manifesting as allopatric eastern and western taxa. Our combined phylogeny and dating analysis point to an origin for the genus dating to the early Cenozoic, with three of the four species originating during the Oligocene-Miocene. Each Galaxiella species showed high levels of genetic divergences between all but the most proximate populations. Despite extensive drainage connections during recent low sea levels in southeastern Australia, populations of both species within G. pusilla maintained high levels of genetic structure. All populations experienced Late Pleistocene-Holocene population growth, possibly in response to the relaxation of arid conditions after the last glacial maximum. High levels of genetic divergence and the discovery of new cryptic species have important implications for the conservation of this already threatened group of freshwater

  11. Molecular phylogeny and phylogeography of the Australian freshwater fish genus Galaxiella, with an emphasis on dwarf galaxias (G. pusilla).

    Science.gov (United States)

    Unmack, Peter J; Bagley, Justin C; Adams, Mark; Hammer, Michael P; Johnson, Jerald B

    2012-01-01

    The freshwater fauna of Southern Australia is primarily restricted to the southwestern and southeastern corners of the continent, and is separated by a large, arid region that is inhospitable to this biota. This geographic phenomenon has attracted considerable interest from biogeographers looking to explain evolutionary diversification in this region. Here, we employed phylogenetic and phylogeographic approaches to evaluate the effect of this barrier on a group of four galaxiid fish species (Galaxiella) endemic to temperate Southern Australia. We also tested if continental shelf width has influenced connectivity among populations during low sea levels when rivers, now isolated, could have been connected. We addressed these questions by sampling each species across its range using multiple molecular markers (mitochondrial cytochrome b sequences, nuclear S7 intron sequences, and 49 allozyme loci). These data also allowed us to assess species boundaries, to refine phylogenetic affinities, and to estimate species ages. Interestingly, we found compelling evidence for cryptic species in G. pusilla, manifesting as allopatric eastern and western taxa. Our combined phylogeny and dating analysis point to an origin for the genus dating to the early Cenozoic, with three of the four species originating during the Oligocene-Miocene. Each Galaxiella species showed high levels of genetic divergences between all but the most proximate populations. Despite extensive drainage connections during recent low sea levels in southeastern Australia, populations of both species within G. pusilla maintained high levels of genetic structure. All populations experienced Late Pleistocene-Holocene population growth, possibly in response to the relaxation of arid conditions after the last glacial maximum. High levels of genetic divergence and the discovery of new cryptic species have important implications for the conservation of this already threatened group of freshwater species.

  12. 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

  13. Haematozoans from deep water fishes trawled off the Cape Verde Islands and over the Porcupine Seabight, with a revision of species within the genus Desseria (Adeleorina: Haemogregarinidae).

    Science.gov (United States)

    Davies, Angela J; Hosein, Shazia; Merrett, Nigel R

    2012-02-01

    Archived blood smears from 32 of 113 fishes in 18 families and 12 orders, trawled from deep North Atlantic waters off the Cape Verde Islands in 1999 and over the Porcupine Seabight in 2001 were found to harbour haematozoans. These included four species of haemogregarines (Adeleorina, Haemogregarinidae) and a species of trypanosome (Trypanosomatina, Trypanosomatidae) located in Porcupine Seabight fishes. Also present were Haemohormidium-like structures of uncertain status found in samples from this location and from the Cape Verde Islands. Although material was limited, two of the haemogregarines were provisionally named Desseria harriottae sp. n. from Harriotta raleighana Goode et Bean (Chimaeriformes, Rhinochimaeridae), and Haemogregarina bathysauri sp. n. from Bathysaurus ferox Günther (Aulopiformes, Bathysauridae). The two remaining haemogregarines were identified as Desseria marshalllairdi (Khan, Threlfall et Whitty, 1992) from Halosauropsis macrochir (Günther) (Notacanthiformes, Halosauridae), and Haemogregarina michaeljohnstoni (Davies et Merrett, 2000) from Cataetyx laticeps Koefoed (Ophidiformes, Bythitidae). The name H. michaeljohnstoni was proposed to replace Haemogregarinajohnstoni Davies et Merrett, 2000 from C. laticeps and to avoid confusion with Hepatozoon johnstoni (Mackerras, 1961) Smith, 1996 from varanid lizards, originally named Haemogregarina johnstoni Mackerras, 1961. The trypanosome formed a mixed parasitaemia with D. harriottae in H. raleighana and was provisionally named Trypanosoma harriottae sp. n. No blood parasites had been described previously from cartilaginous fishes of the Holocephali, making the finds in H. raleighana unique. Haemohormidium-like structures were located in erythrocytes in one fish, Coryphaenoides armatus (Hector), among the Cape Verde Islands samples and in 12 species of fishes from the Porcupine Seabight; all these hosts were bony fishes. Finally, the haemogregarine species listed in the genus Desseria Siddall

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

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    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.

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

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    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.

  16. Multilocus sequence analysis of the marine bacterial genus Tenacibaculum suggests parallel evolution of fish pathogenicity and endemic colonization of aquaculture systems.

    Science.gov (United States)

    Habib, Christophe; Houel, Armel; Lunazzi, Aurélie; Bernardet, Jean-François; Olsen, Anne Berit; Nilsen, Hanne; Toranzo, Alicia E; Castro, Nuria; Nicolas, Pierre; Duchaud, Eric

    2014-09-01

    The genus Tenacibaculum, a member of the family Flavobacteriaceae, is an abundant component of marine bacterial ecosystems that also hosts several fish pathogens, some of which are of serious concern for marine aquaculture. Here, we applied multilocus sequence analysis (MLSA) to 114 representatives of most known species in the genus and of the worldwide diversity of the major fish pathogen Tenacibaculum maritimum. Recombination hampers precise phylogenetic reconstruction, but the data indicate intertwined environmental and pathogenic lineages, which suggests that pathogenicity evolved independently in several species. At lower phylogenetic levels recombination is also important, and the species T. maritimum constitutes a cohesive group of isolates. Importantly, the data reveal no trace of long-distance dissemination that could be linked to international fish movements. Instead, the high number of distinct genotypes suggests an endemic distribution of strains. The MLSA scheme and the data described in this study will help in monitoring Tenacibaculum infections in marine aquaculture; we show, for instance, that isolates from tenacibaculosis outbreaks in Norwegian salmon farms are related to T. dicentrarchi, a recently described species.

  17. 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.

  18. 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.

  19. 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

  20. 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.

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

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    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.

  2. Preservation Obscures Pelagic Deep-Sea Fish Diversity: Doubling the Number of Sole-Bearing Opisthoproctids and Resurrection of the Genus Monacoa (Opisthoproctidae, Argentiniformes).

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    Poulsen, Jan Yde; Sado, Tetsuya; Hahn, Christoph; Byrkjedal, Ingvar; Moku, Masatoshi; Miya, Masaki

    2016-01-01

    The family Opisthoproctidae (barreleyes) constitutes one of the most peculiar looking and unknown deep-sea fish groups in terms of taxonomy and specialized adaptations. All the species in the family are united by the possession of tubular eyes, with one distinct lineage exhibiting also drastic shortening of the body. Two new species of the mesopelagic opisthoproctid mirrorbelly genus Monacoa are described based on pigmentation patterns of the "sole"-a unique vertebrate structure used in the reflection and control of bioluminescence in most short-bodied forms. Different pigmentation patterns of the soles, previously noted as intraspecific variations based on preserved specimens, are here shown species-specific and likely used for communication in addition to counter-illumination of down-welling sunlight. The genus Monacoa is resurrected from Opisthoproctus based on extensive morphological synaphomorphies pertaining to the anal fin and snout. Doubling the species diversity within sole-bearing opisthoproctids, including recognition of two genera, is unambiguously supported by mitogenomic DNA sequence data. Regular fixation with formalin and alcohol preservation is shown problematic concerning the retention of species-specific pigmentation patterns. Examination or photos of fresh material before formalin fixation is shown paramount for correct species recognition of sole-bearing opisthoproctids-a relatively unknown issue concerning species diversity in the deep-sea pelagic realm.

  3. Species composition of the genus Saprolegnia in fin fish aquaculture environments, as determined by nucleotide sequence analysis of the nuclear rDNA ITS regions.

    Science.gov (United States)

    de la Bastide, Paul Y; Leung, Wai Lam; Hintz, William E

    2015-01-01

    The ITS region of the rDNA gene was compared for Saprolegnia spp. in order to improve our understanding of nucleotide sequence variability within and between species of this genus, determine species composition in Canadian fin fish aquaculture facilities, and to assess the utility of ITS sequence variability in genetic marker development. From a collection of more than 400 field isolates, ITS region nucleotide sequences were studied and it was determined that there was sufficient consistent inter-specific variation to support the designation of species identity based on ITS sequence data. This non-subjective approach to species identification does not rely upon transient morphological features. Phylogenetic analyses comparing our ITS sequences and species designations with data from previous studies generally supported the clade scheme of Diéguez-Uribeondo et al. (2007) and found agreement with the molecular taxonomic cluster system of Sandoval-Sierra et al. (2014). Our Canadian ITS sequence collection will thus contribute to the public database and assist the clarification of Saprolegnia spp. taxonomy. The analysis of ITS region sequence variability facilitated genus- and species-level identification of unknown samples from aquaculture facilities and provided useful information on species composition. A unique ITS-RFLP for the identification of S. parasitica was also described.

  4. Occurrence of parasites of the genus Eustrongylides spp. (Nematoda: Dioctophymatidae in fish caught in Trasimeno lake, Italy

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    Raffaella Branciari

    2016-11-01

    Full Text Available Eustrongylides spp. is considered a freshwater fish zoonotic nematode. In the present study, the prevalence of Eustrongylides spp. in six edible fish (European perch - Perca fluviatilis, goldfish - Carassius auratus, largemouth black bass - Micropterus salmoides, tench- Tinca tinca, carp - Cyprinus carpio and sand smelt - Atherina boyeri of Trasimeno lake was surveyed. The investigations were conducted from October 2014 to September 2015 and 384 specimens per species for each season were caught in Trasimeno lake and examined for the presence of larvae in the abdominal cavity and muscle. The presence of nematodes in the abdominal cavity and musculature was revealed in three fish species. The prevalence of Eustrongylides spp. infection was 6.84, 1.89 and 0.13% in perch, largemouth black bass and sand smelt, respectively. The number of parasites per fish was only one in largemouth black bass and sand smelt and ranged from one up to three in perch. This study states that the European perch, largemouth black bass and sand smelt of Trasimeno lake are infected with zoonotic parasites; therefore, food business operators have to take appropriate measures to guarantee the health of consumers.

  5. Occurrence of Parasites of the Genus Eustrongylides spp. (Nematoda: Dioctophymatidae) in Fish Caught in Trasimeno Lake, Italy

    Science.gov (United States)

    Branciari, Raffaella; Ranucci, David; Miraglia, Dino; Valiani, Andrea; Veronesi, Fabrizia; Urbani, Eleonora; Lo Vaglio, Giovanni; Pascucci, Luisa; Franceschini, Raffaella

    2016-01-01

    Eustrongylides spp. is considered a freshwater fish zoonotic nematode. In the present study, the prevalence of Eustrongylides spp. in six edible fish (European perch - Perca fluviatilis, goldfish - Carassius auratus, largemouth black bass - Micropterus salmoides, tench- Tinca tinca, carp - Cyprinus carpio and sand smelt - Atherina boyeri) of Trasimeno lake was surveyed. The investigations were conducted from October 2014 to September 2015 and 384 specimens per species for each season were caught in Trasimeno lake and examined for the presence of larvae in the abdominal cavity and muscle. The presence of nematodes in the abdominal cavity and musculature was revealed in three fish species. The prevalence of Eustrongylides spp. infection was 6.84, 1.89 and 0.13% in perch, largemouth black bass and sand smelt, respectively. The number of parasites per fish was only one in largemouth black bass and sand smelt and ranged from one up to three in perch. This study states that the European perch, largemouth black bass and sand smelt of Trasimeno lake are infected with zoonotic parasites; therefore, food business operators have to take appropriate measures to guarantee the health of consumers. PMID:28058245

  6. Comparative Cytotaxonomy of Two Species of Fish from the Genus Satanoperca Reveals the Presence of a B Chromosome.

    Science.gov (United States)

    Silva, Francijara Araújo da; Carvalho, Natália Dayane Moura; Schneider, Carlos Henrique; Terencio, Maria Leandra; Feldberg, Eliana; Gross, Maria Claudia

    2016-08-01

    The taxonomy of Satanoperca spp. is still unresolved, especially because coloring, one of the main diagnostic characters, is variable among species of this genus. Thus, the aim of this study was to elucidate the relationship between the genome and the organization of the chromosome in two Satanoperca species. Our main goal was to develop a method to better differentiate taxa and understand the evolution of Satanoperca jurupari and Satanoperca lilith karyotypes, which we analyzed with classical and molecular cytogenetics. Both species have the same diploid number (2n) of 48 and location of 5S rDNA sites on pair 5. Nonetheless, the distribution of heterochromatin and 18S rDNA sites followed a species-specific pattern. The interstitial telomeric sites were not highlighted in either species. Regardless, a single B chromosome was identified in some metaphases of S. lilith. These data show that Satanoperca species harbor chromosomal features that can be used to identify the two species of Satanoperca studied here, allowing for the use of cytogenetic markers to make taxonomic inferences within the genus.

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

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    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

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

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

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    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.

  11. A survey of nematodes of the genus Cucullanus Müller, 1777 (Nematoda, Seuratoidea) parasitic in marine fishes off Brazil, including description of three new species.

    Science.gov (United States)

    Vieira, Fabiano M; Pereira, Felipe B; Pantoja, Camila; Soares, Iris A; Pereira, Aldenice N; Timi, Juan T; Scholz, Tomáš; Luque, José L

    2015-11-05

    A taxonomic survey of six nematode species (including three new taxa) from the genus Cucullanus Müller, 1777, parasites of marine fishes off the Brazilian coast, is provided. Nematodes were studied using light and scanning electron microscopy (SEM). Cucullanus gastrophysi n. sp. parasitic in Lophius gastrophysus Miranda Ribeiro differs from its congeners by the combination of the following features: shape and number of sclerotized structures in the oesophastome (a pair of lateral elongate structures and a single small reniform one), position of deirids and excretory pore (both anterior to oesophagus base), spicule length and spicule/body length ratio (0.97-1.29 mm and 6.5-10.5%, respectively), morphology and length of gubernaculum (V-shaped, 107-135 µm long). Cucullanus protrudens n. sp. from Pagrus pagrus (Linnaeus) has the cloacal lips broadly protruded, which differentiates it from several species of Cucullanus; other features, e.g., the length of spicules and gubernaculum (400-415 µm and 91-103 µm, respectively), arrangement of caudal papillae and position of excretory pore (slightly posterior to oesophagus-intestine junction) also characterize this species. Cucullanus pseudopercis n. sp. from Pseudopercis semifasciata (Cuvier) has deirids and excretory pore posterior to the oesophagus-intestine junction, which distinguishes the species from most of the congeners; furthermore, the arrangement of caudal papillae in combination with the length of spicules and gubernaculum (1.0-1.5 mm and 178-196 µm, respectively) separate this species from other taxa. Newly collected specimens of C. cirratus Müller, 1777 (type species of the genus) from Urophycis brasiliensis (Kaup), C. pedroi from Conger orbignianus Valenciennes (type host of the species) and C. genypteri Sardella, Navone & Timi, 1997 from Genypterus brasiliensis Regan, were studied as well. Comparisons between newly collected samples and the taxonomic data available for each respective species revealed

  12. Histopathological, immunohistochemical and ultraestructural evaluation of inflammatory response in Arius genus fish under experimental inoculation of BCG

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    Ricardo Yuji Sado

    2008-10-01

    Full Text Available The aim of this study was to evaluate the inflammatory response kinetics after experimental inoculation with BCG in the primitive Arius sp. fish. The BCG was applied through the intramuscular injection in the caudal peduncular region, and the samples were collected for the analyses at days 1, 3, 7, 14, 21, and 33 post-injection. Acute phase inflammatory infiltrate was characterized by the predominant mononuclear cells, intersticial edema, and muscular tissue necrosis. As the inflammatory response evolved, a large number of multinuclear giant cells were formed containing the BCG. These giant cells were positive for the S100 protein at the histochemical analysis, which demonstrate the macrofage activity, confirmed by the ultra-structural analysis showing the lack of the cytoplasmic membrane enveloping the many nuclei within the giant cell. These results led to the conclusion that Arius sp. fish injected with the BCG showed a difuse inflammatory response characterized by a large number of mononuclear cells, absence of granuloma formation, and predominant giant cells.Avaliou-se a cinética da resposta inflamatória induzida experimentalmente com BCG em peixes primitivos pertencentes ao gênero Arius. Os animais foram inoculados com BCG por via intramuscular na região do pedúnculo caudal, sendo realizada a coleta do material nos tempos experimentais de 1, 3, 7, 14, 21 e 33 dias pós-inoculação. A fase aguda da resposta inflamatória se mostrou na forma de infiltrado inflamatório composto predominantemente por células mononucleares, edema intersticial e necrose de tecido muscular. À medida que o processo se desenvolveu, houve formação e aumento no número de células gigantes multinucleadas envolvendo o inóculo. Essas células gigantes, ao exame imunohistoquímico, apresentaram positividade à proteína S100 indicando ação de células macrofágicas, além da ultraestrutura apontar a ausência de membrana citoplasmática entre os in

  13. Learned aggression biases in males of Lake Victoria cichlid fish

    NARCIS (Netherlands)

    Dijkstra, Peter D.; Seehausen, O.; Fraterman, R. E.; Groothuis, Ton G. G.

    2008-01-01

    Male-male competition for mating territories can exert negative frequency- dependent selection on a male secondary sexual trait, such as nuptial coloration. This can occur when males bias aggression towards owncoloured competitors, resulting in a fitness advantage for rare phenotypes, thereby promot

  14. Behavioural isolation may facilitate homoploid hybrid speciation in cichlid fish

    NARCIS (Netherlands)

    Selz, O. M.; Thommen, R.; Maan, M. E.; Seehausen, O.

    2014-01-01

    Hybrid speciation is constrained by the homogenizing effects of gene flow from the parental species. In the absence of post-mating isolation due to structural changes in the genome, or temporal or spatial premating isolation, another form of reproductive isolation would be needed for homoploid hybri

  15. 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

  16. A taxonomic revision of the Neotropical electric fish genus Brachyhypopomus (Ostariophysi: Gymnotiformes: Hypopomidae, with descriptions of 15 new species

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    William G. R. Crampton

    Full Text Available ABSTRACT The bluntnose knifefish genus BrachyhypopomusMago-Leccia, 1994, is diagnosed from other Rhamphichthyoidea (Rhamphichthyidae + Hypopomidae by the presence of a disk-like ossification in the anterior portion of the palatoquadrate, and by the following external characters: short snout, 18.7-32.6% of head length (vs. 33.3-68.6% in Hypopomus, Gymnorhamphichthys, Iracema, and Rhamphichthys, absence of a paired accessory electric organ in the mental or humeral region (vs. presence in Hypopygus and Steatogenys, presence of 3-4 pectoral proximal radials (vs. 5 in Akawaio, presence of the antorbital + infraorbital, and the preopercular cephalic lateral line canal bones (vs. absence in Racenisia. Brachyhypopomus cannot be diagnosed unambiguously from Microsternarchus or from Procerusternarchus on the basis of external characters alone. Brachyhypopomus comprises 28 species. Here we describe 15 new species, and provide redescriptions of all 13 previously described species, based on meristic, morphometric, and other morphological characters. We include notes on ecology and natural history for each species, and provide regional dichotomous keys and distribution maps, based on the examination of 12,279 specimens from 2,787 museum lots. A lectotype is designated for Brachyhypopomus pinnicaudatus (Hopkins, Comfort, Bastian & Bass, 1990. Brachyhypopomus species are abundant in shallow lentic and slow-flowing freshwater habitats from southern Costa Rica and northern Venezuela to Uruguay and northern Argentina. Species diversity is highest in Greater Amazonia, where 20 species occur: B. alberti, new species, B. arrayae, new species, and B. cunia, new species, in the upper rio Madeira drainage; B. batesi, new species, in the central Amazon and rio Negro; B. beebei, B. brevirostris, B. regani, new species, B. sullivani, new species, and B. walteri, widespread through the Amazon and Orinoco basins and the Guianas; B. belindae, new species, in the central

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

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    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.

  18. Fishing

    Institute of Scientific and Technical Information of China (English)

    姜群山

    2002-01-01

    @@ Last Saturday my cousin (表兄) came to my home. We were very happy to see each other. We decided that the next day we went to fish. We got up very early that day. When we left home,the moon could still be seen in the sky.

  19. 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.

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

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    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].

  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. 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.

  3. Comprehensive phylogenetic analysis of all species of swordtails and platies (Pisces: Genus Xiphophorus uncovers a hybrid origin of a swordtail fish, Xiphophorus monticolus, and demonstrates that the sexually selected sword originated in the ancestral lineage of the genus, but was lost again secondarily

    Directory of Open Access Journals (Sweden)

    Kang Ji Hyoun

    2013-01-01

    Full Text Available Abstract Background Males in some species of the genus Xiphophorus, small freshwater fishes from Meso-America, have an extended caudal fin, or sword – hence their common name “swordtails”. Longer swords are preferred by females from both sworded and – surprisingly also, non-sworded (platyfish species that belong to the same genus. Swordtails have been studied widely as models in research on sexual selection. Specifically, the pre-existing bias hypothesis was interpreted to best explain the observed bias of females in presumed ancestral lineages of swordless species that show a preference for assumed derived males with swords over their conspecific swordless males. However, many of the phylogenetic relationships within this genus still remained unresolved. Here we construct a comprehensive molecular phylogeny of all 26 known Xiphophorus species, including the four recently described species (X. kallmani, X. mayae, X. mixei and X. monticolus. We use two mitochondrial and six new nuclear markers in an effort to increase the understanding of the evolutionary relationships among the species in this genus. Based on the phylogeny, the evolutionary history and character state evolution of the sword was reconstructed and found to have originated in the common ancestral lineage of the genus Xiphophorus and that it was lost again secondarily. Results We estimated the evolutionary relationships among all known species of the genus Xiphophorus based on the largest set of DNA markers so far. The phylogeny indicates that one of the newly described swordtail species, Xiphophorus monticolus, is likely to have arisen through hybridization since it is placed with the southern platyfish in the mitochondrial phylogeny, but with the southern swordtails in the nuclear phylogeny. Such discordance between these two types of markers is a strong indication for a hybrid origin. Additionally, by using a maximum likelihood approach the possession of the sexually

  4. 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.

  5. Molecular systematics of the enigmatic Middle American genus Vieja (Teleostei: Cichlidae).

    Science.gov (United States)

    McMahan, Caleb D; Geheber, Aaron D; Piller, Kyle R

    2010-12-01

    The genus Vieja represents a group of heroine cichlids (Teleostei: Cichlidae) distributed on the Atlantic and Pacific slopes of North and Central America from southern Mexico to Panama. Sixteen species of Vieja are presently recognized; however, based on long-standing taxonomic problems, the genus itself appears to be weakly defined. A number of different generic designations have been proposed for members of Vieja, and recent systematic studies of heroine cichlids have not specifically addressed the validity of the grouping and have not included all species in the genus. Therefore, the purpose of this study was to assess the monophyly of the genus Vieja by including all nominal species in the genus using the mitochondrial encoded cytochrome b gene and nuclear S7-1 intron. Results of Maximum Parsimony, Bayesian inference, and topology tests (constraint tree searches and post-burn-in Bayesian filtering) indicate that the genus is not monophyletic as it is currently recognized. The genus Herichthys was recovered as sister to a clade consisting of a number of Vieja species (V. fenestrata, V. guttulata, V. zonata, V. hartwegi, V. bifasciata, V. breidohri, V. argentea, V. regani, V. melanura, V. synspila, and V. maculicauda, as well as Paraneetroplusbulleri). A clade consisting of V. intermedia, V. godmanni, and V. microphthalma was recovered sister to Theraps. Additionally, V. heterospila and V. tuyrensis were recovered outside of Vieja and Herichthys clades. Based on the results of this comprehensive study, we suggest a revised classification of Vieja species.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

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

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    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.

  11. Chromosome mapping of repetitive DNAs in sergeant major fishes (Abudefdufinae, Pomacentridae): a general view on the chromosomal conservatism of the genus.

    Science.gov (United States)

    Getlekha, Nuntaporn; Cioffi, Marcelo de Bello; Yano, Cassia Fernanda; Maneechot, Nuntiya; Bertollo, Luiz Antonio Carlos; Supiwong, Weerayuth; Tanomtong, Alongklod; Molina, Wagner Franco

    2016-10-01

    Species of the Abudefduf genus (sergeant-majors) are widely distributed in the Indian, Pacific and Atlantic oceans, with large schools inhabiting rocky coastal regions and coral reefs. This genus consists of twenty recognized species are of generalist habit, showing typical characteristics of colonizers. Some populations maintain gene flow between large oceanic areas, a condition that may influence their cytogenetic features. A number of species have been shown to be invaders and able to hybridize with local species. However, cytogenetic data in this genus are restricted to few species. In this way, the present study includes the chromosomal investigation, using conventional (Giemsa staining, Ag-NOR and C-banding) and molecular (in situ mapping of six different repetitive DNA classes) approaches in four Abudefduf species from different oceanic regions (A. bengalensis and A. sexfasciatus from the Indo-Pacific, A. vaigiensis from the Indian and A. saxatilis from the Atlantic oceans, respectively), to investigate the evolutionary events associated with the chromosomal diversification in this group. All species share a similar karyotype (2n = 48; NF = 52), except A. sexfasciatus (2n = 48; NF = 50), which possesses a characteristic pericentric inversion in the NOR-bearing chromosomal pair. Mapping of repetitive sequences suggests a chromosomal conservatism in this genus. The high karyotypic similarity between allopatric species of Abudefduf may be related to the success of natural viable hybrids among species with recent secondary contact.

  12. Lophiobrycon weitzmani, a new genus and species of glandulocaudine fish (Characiformes: Characidae from the rio Grande drainage, upper rio Paraná system, southeastern Brazil

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    Ricardo M. C. Castro

    Full Text Available A new genus and species of glandulocaudine, Lophiobrycon weitzmani, is described based on specimens collected in headwater tributary streams of the rio Grande, upper rio Paraná system, State of Minas Gerais, southeastern Brazil. The inclusion of the new species in the phylogeny of the subfamily Glandulocaudinae proposed by Weitzman & Menezes (1998, reveals a sister group relationship between the new genus and the monophyletic group composed of Glandulocauda and Mimagoniates that currently form the tribe Glandulocaudini. The new species can be readily distinguished from all other species of the tribe by the autapomorphic presence in adult male individuals (with more than 23.9 mm standard length of an adipose-fin whose base extends for almost the entire distance between the posterior terminus of the base of the dorsal fin and the base of the upper lobe of the caudal fin and averages approximately 25% standard length, along with the presence of globular expansions formed by the lepidotrichia and hypertrophied soft tissue in the middle portions of the first and second pectoral-fin rays. The diagnosis of the tribe Glandulocaudini is modified to accommodate the new genus.

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

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    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

  14. Putative relationships among inseminating and externally fertilizing characids, with a description of a new genus and species of Brazilian inseminating fish bearing an anal-fin gland in males (Characiformes: Characidae

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    Stanley H. Weitzman

    2005-09-01

    Full Text Available A new inseminating fish species of the family Characidae, Bryconadenos tanaothoros, from tributaries of the upper rio Xingu and upper rio Tapajós basins, Mato Grosso, Brazil is described as the type species of a new genus. This new species and the genus are characterized by a glandular organ on the anterior region of the anal fin of sexually mature males, curved lower jaw teeth, and an inseminating reproductive mode. This new genus is hypothesized as most closely related to Attonitus, a genus with three inseminating species from Peru. Bryconadenos and Attonitus are suggested as related to certain inseminating, but undescribed characid species of uncertain relationships that are similar in certain respects to species of the glandulocaudine Planaltina and to the inseminating species of Knodus. These and a few other inseminating characids are included in a previous tentative characid subgroup designated as Clade A. No species among a relatively small sample of the many species of the Clade A genus Bryconamericus were found inseminating, except Bryconamericus pectinatus. However, newly collected specimens of B. pectinatus were found to have caudal-fin squamation like that of the species of Knodus and this species is here tentatively referred to Knodus. Our investigations indicate that at least several species of Knodus, including the type species, Knodus meridae, are not inseminating, but we found two inseminating apparently new characid species that currently would be referred to Knodus. These species lack the derived anal-fin rays present in the males of K. pectinatus. Other Clade A taxa known to be inseminating, such as two species of the large genus Creagrutus, three species of Monotocheirodon (two undescribed, and the species and genera of the characid subfamily Glandulocaudinae are briefly discussed regarding possible relationships to Attonitus and Bryconadenos. The anatomical aspects of the primary and secondary sexual characteristics of

  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. 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.

  17. 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.

  18. 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].

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

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    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.

  20. Threatened fishes of the world: Coptodon walteri (Thys van den Audenaerde 1968 (Perciformes: Cichlidae

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    Konan Felix Koffi

    2016-06-01

    Full Text Available Coptodon walteri Thys van den Audenaerde 1968, an endemic cichlid of Ivory Coast and Liberia, is assessed as Near Threatened due to fishing pressure and loss of habitats, and aquatic pollution as a result of extensive clandestine gold mining in the bed of the Cavally River. There is an immediate need for developing conservation and management plans for this species.

  1. 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

  2. Marine and inland fishes of St. Croix, U. S. Virgin Islands: an annotated checklist

    Science.gov (United States)

    Smith-Vaniz, William F.; Jelks, Howard L.

    2014-01-01

    An historical account is given for the ichthyological research at St. Croix, U. S. Virgin Islands, followed by an annotated list of 544 species of mostly marine shore fishes known or reported from the island to depths of 200 m. Color photographs are included for 103 of these species. Collections made at Buck Island Reef National Monument with the ichthyocide rotenone in 2001 and 2005 increased the known ichthyofauna by about 80 species. The rational for inclusion of each species in the checklist is given, with remarks for those species for which additional documentation or voucher specimens are needed. Reports of species known or presumed to have been based on misidentifications are discussed. Of the total marine fish fauna of the island, 404 species (75%) are restricted to the western Atlantic Ocean, (223 of these species are essentially Caribbean endemics that do not occur south of the Amazon River outflow), and no St. Croix endemic species are known. An additional 17 species (3.2%) also occur at mid-Atlantic islands, 57 species (10.6 %) are limited to both sides of the Atlantic Ocean, and 40 species (7.4%) have circumtropical distributions. The four most species-rich families are the Gobiidae (47 species), Serranidae (groupers and sea basses, 41), Labridae (wrasses and parrotfishes, 31), and Labrisomidae (scaly blennies, 27). Literature reports of Mosquitofish, Gambusia sp., from St. Croix apparently were based on misidentifications of a different introduced poeciliid genus. Four species of the amphidromus goby genus Sicydium occur in St. Croix inland waters, together with three established introduced species (one cichlid and two poeciliids). Also included are one catfish (Ictaluridae) and three sunfishes (Centrarchidae) known only from ponds. The Lionfish, Pterois volitans, the only introduced marine species, was first reported from St. Croix in 2008 and is now common despite control efforts.

  3. Six new species of Lepidapedon Stafford, 1904 (Digenea: Lepocreadiidae) from deep-sea macrourid fishes from the Gulf of Mexico and Caribbean Sea, with revised keys to the species of the genus.

    Science.gov (United States)

    Blend, C K; Dronen, N O; Armstrong, H W

    2000-01-01

    Species of the genus Lepidapecon are divided into various groups and subgroups based on vitelline distribution relative to the acetabulum and anterior extent of the excretory vesicle. Members of this genus predominantly parasitise gadiform fishes and are commonly collected from relatively deep waters. A recent study of deep-sea helminths from macrourids of the Gulf of Mexico and Caribbean Sea revealed six new species of this genus. L. mexicanensis n. sp., of the elongatum group, elongatum subgroup, differs from other species in this subgroup in proportions (as % of body length), lacking confluent vitelline fields between both the ovary and anterior testis and the testes, and in having a smaller egg and body size. L. nezumiatis n. sp., of the elongatum group, desclersae oesophagus than prepharynx. L. caribbaei n. sp. and L. longivesicula n. sp., of the garrardi group, congeri sub-subgroup, differs from both L. filiformis and L. desclersae in having intermediate egg and body sizes, and a longer group, differ from L. congeri in having a sucker-ratio of 1: sucker, a similar-sized oesophagus and prepharynx, and a caecal bifurcation which is closer to the acetabulum than oral sucker, while L. longivesicula n. sp. has shorter, serrate or plate-like, lightly imbedded, widely to sporadically spaced spines, a more elongate body, a spherical to subspherical oral sucker, a longer oesophagus than prepharynx, and a caecal bifurcation which is closer to the oral sucker than acetabulum. L. desotoensis n. sp., of the rachion group, rachion subgroup, is distinct from both L. luteum and L. abyssensis in having a smaller size, lacking cervical glands or pharyngeal gland cells, and possessing dark-staining particles in the mesenchyme, while it differs from L. abyssensis specifically in having a much longer oesophagus than prepharynx, lateral vitelline fields that are not confluent intertesticularly, and wider eggs. L. zaniophori n. sp., also of the rachion subgroup, differs from both L

  4. Ultrastructural characters of the spermatozoa in Digeneans of the genus Lecithochirium Lühe, 1901 (Digenea, Hemiuridae, parasites of fishes: comparative study of L. microstomum and L. musculus

    Directory of Open Access Journals (Sweden)

    Ndiaye Papa Ibnou

    2014-01-01

    Full Text Available This study provides the first ultrastructural data of spermatozoa in the genus Lecithochirium. The spermatozoa of L. microstomum (from Trichiurus lepturus in Senegal and L. musculus (from Anguilla anguilla in Corsica exhibit the general pattern described in the great majority of the Digenea, namely two axonemes with the 9 + “1” pattern typical of the Trepaxonemata, one mitochondrion, a nucleus, parallel cortical microtubules and external ornamentation of the plasma membrane. Spermatozoa of L. microstomum and L. musculus have some specific features such as the presence of a reduced number of cortical microtubules arranged on only one side of the spermatozoon, the lack of spine-like bodies and expansion of the plasma membrane. The external ornamentation of the plasma membrane entirely covers the anterior extremity of the spermatozoa. The ultrastructure of the posterior extremity of the spermatozoa corresponds to the pattern previously described in the Hemiuridae, characterized by only singlets of the second axoneme. A particularity of these spermatozoa is the organization of the microtubule doublets of the second axoneme around the nucleus in the posterior part of the spermatozoon.

  5. X1X1X2X2/X1X2Y sex chromosome systems in the Neotropical Gymnotiformes electric fish of the genus Brachyhypopomus

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    Adauto Lima Cardoso

    2015-06-01

    Full Text Available Several types of sex chromosome systems have been recorded among Gymnotiformes, including male and female heterogamety, simple and multiple sex chromosomes, and different mechanisms of origin and evolution. The X1X1X2X2/X1X2Y systems identified in three species of this order are considered homoplasic for the group. In the genus Brachyhypopomus, only B. gauderio presented this type of system. Herein we describe the karyotypes of Brachyhypopomus pinnicaudatus and B. n. sp. FLAV, which have an X1X1X2X2/X1X2Y sex chromosome system that evolved via fusion between an autosome and the Y chromosome. The morphology of the chromosomes and the meiotic pairing suggest that the sex chromosomes of B. gauderio and B. pinnicaudatus have a common origin, whereas in B . n. sp. FLAV the sex chromosome system evolved independently. However, we cannot discard the possibility of common origin followed by distinct processes of differentiation. The identification of two new karyotypes with an X1X1X2X2/X1X2Y sex chromosome system in Gymnotiformes makes it the most common among the karyotyped species of the group. Comparisons of these karyotypes and the evolutionary history of the taxa indicate independent origins for their sex chromosomes systems. The recurrent emergence of the X1X1X2X2/X1X2Y system may represent sex chromosomes turnover events in Gymnotiformes.

  6. Ancient Mitochondrial Capture as Factor Promoting Mitonuclear Discordance in Freshwater Fishes: A Case Study in the Genus Squalius (Actinopterygii, Cyprinidae) in Greece

    Science.gov (United States)

    Vukić, Jasna; Šanda, Radek; Doadrio, Ignacio

    2016-01-01

    Hybridization and incomplete lineage sorting are common confounding factors in phylogeny and speciation resulting in mitonuclear disparity. Mitochondrial introgression, a particular case of hybridization, may, in extreme cases, lead to replacement of the mitochondrial genome of one species with that of another (mitochondrial capture). We investigated mitochondrial introgression involving two species of the cyprinid genus Squalius in the western Peloponnese region of Greece using molecular and morphological data. We found evidence of complete mitochondrial introgression of Squalius keadicus into two populations recognized as Squalius peloponensis from the Miras and Pamissos River basins and a divergence of mitochondrial genomes of S. keadicus from the Evrotas basin from that of the introgressed populations dating from the Pleistocene. Secondary contact among basins is a possible factor in connection of the species and the introgression event. Morphological analyses support the hypothesis of mitochondrial introgression, as S. keadicus was different from the other three populations recognized as S. peloponensis, although significant differences were found among the four populations. Isolation by geographical barriers arose during Pleistocene in the western Peloponnese were the source of the evolution of the two reciprocally monophyletic subclades found in the S. keadicus mitochondrial clade, and the morphological differences found among the four populations. Along with the lack of structure in the nuclear genome in the three populations ascribed to S. peloponensis, this suggests an incipient speciation process occurring in these Squalius species in the western Peloponnese. PMID:27906993

  7. Lower biodiversity of native fish but only marginally altered plankton biomass in tropical lakes hosting introduced piscivorous Cichla cf. ocellaris

    NARCIS (Netherlands)

    Menezes, R.F.; Attayde, J.L.; Lacerot, G.; Kosten, S.; Costa, L.S.; Coimbra e Sousa, L.; Nes, van E.H.; Jeppesen, E.

    2012-01-01

    We compared the species richness and abundance of fish, zooplankton and phytoplankton in nine mesotrophic coastal shallow lakes (Northeastern Brazil) with and without the exotic predator cichlid tucunaré or ‘peacock bass’ (Cichla cf. ocellaris). We hypothesized that the introduction of tucunaré woul

  8. Putative relationships among inseminating and externally fertilizing characids, with a description of a new genus and species of Brazilian inseminating fish bearing an anal-fin gland in males (Characiformes: Characidae

    Directory of Open Access Journals (Sweden)

    Stanley H. Weitzman

    Full Text Available A new inseminating fish species of the family Characidae, Bryconadenos tanaothoros, from tributaries of the upper rio Xingu and upper rio Tapajós basins, Mato Grosso, Brazil is described as the type species of a new genus. This new species and the genus are characterized by a glandular organ on the anterior region of the anal fin of sexually mature males, curved lower jaw teeth, and an inseminating reproductive mode. This new genus is hypothesized as most closely related to Attonitus, a genus with three inseminating species from Peru. Bryconadenos and Attonitus are suggested as related to certain inseminating, but undescribed characid species of uncertain relationships that are similar in certain respects to species of the glandulocaudine Planaltina and to the inseminating species of Knodus. These and a few other inseminating characids are included in a previous tentative characid subgroup designated as Clade A. No species among a relatively small sample of the many species of the Clade A genus Bryconamericus were found inseminating, except Bryconamericus pectinatus. However, newly collected specimens of B. pectinatus were found to have caudal-fin squamation like that of the species of Knodus and this species is here tentatively referred to Knodus. Our investigations indicate that at least several species of Knodus, including the type species, Knodus meridae, are not inseminating, but we found two inseminating apparently new characid species that currently would be referred to Knodus. These species lack the derived anal-fin rays present in the males of K. pectinatus. Other Clade A taxa known to be inseminating, such as two species of the large genus Creagrutus, three species of Monotocheirodon (two undescribed, and the species and genera of the characid subfamily Glandulocaudinae are briefly discussed regarding possible relationships to Attonitus and Bryconadenos. The anatomical aspects of the primary and secondary sexual characteristics of

  9. 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

  10. 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.

  11. 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.

  12. Preliminary fish survey of Lac Tseny in northwestern Madagascar

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    Noromalala Raminosoa

    2011-12-01

    Full Text Available We surveyed the fish fauna of Lac Tseny, in the Sofia Region of northwestern Madagascar, during October 2010 by observing commercial catches and targeted netting of areas used by endemic species. We recorded seven native fish species at the lake, including three endemic cichlids, a herring and a catfish. We confirmed the continued survival of the Critically Endangered Paretroplus menarambo, as well as the presence of a Paretroplus taxon that may be new to science. The commercial fishery in the lake is sustained by introduced tilapiines and the native Savagella robusta. The three endemic cichlids (Paretroplus spp. were not targeted by commercial fishermen, but when caught in small numbers were retained for domestic consumption. Submerged trees in the west of the lake restrict fishing with nets and probably provide important habitat for P. menarambo. Priority next steps at the lake include (i additional surveys and biological studies of the endemic fish species and the Critically Endangered Madagascar big-headed turtle, Erymnochelys madagascariensis, (ii clarification of the taxonomic status of Paretroplus cf. kieneri and, should it prove a new taxon, its formal scientific description, and (iii continued engagement with fishing communities and authorities to promote practices that benefit livelihoods and the survival of threatened fish species.

  13. A note on the genus Liocranium Ogilby (Pisces, Scorpaenidae)

    NARCIS (Netherlands)

    Mees, G.F.

    1964-01-01

    The genus Liocranium was established by Ogilby (1903) to contain a new species of scorpion-fish from the east coast of Queensland: L. praepositum. The genus remained monotypic until McCulloch (1921) placed Paracentropogan scorpio Ogilby in it, a species also described from the Queensland coast. Whit

  14. Note on the Genus Microsicydium Bleeker

    NARCIS (Netherlands)

    Koumans, F.P.

    1929-01-01

    This genus was established by Dr. P. BLEEKER in 1874 1) for fishes belonging to the phalanx Sicydiini having the caracteristics: „Dentes intermaxillares stipitati apice clavati obtusi, inframaxillares serie interna parvi aequales, serie externa aciculares. Maxilla inferior cirris nullis. Squamae cap

  15. 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

  16. The genus Bipolaris

    NARCIS (Netherlands)

    Manamgoda, D.S.; Rossman, A.Y.; Castlebury, L.A.; Crous, P.W.; Madrid, H.; Chukeatirote, E.; Hyde, K.D.

    2014-01-01

    The genus Bipolaris includes important plant pathogens with worldwide distribution. Species recognition in the genus has been uncertain due to the lack of molecular data from ex-type cultures as well as overlapping morphological characteristics. In this study, we revise the genus Bipolaris based on

  17. Variation in assemblages of small fishes and microcrustaceans after inundation of rarely flooded wetlands of the lower Okavango Delta, Botswana.

    Science.gov (United States)

    Siziba, Nqobizitha; Chimbari, Moses J; Masundire, Hillary; Mosepele, Ketlhatlogile; Ramberg, Lars

    2013-12-01

    Water extraction from floodplain river systems may alter patterns of inundation of adjacent wetlands and lead to loss of aquatic biodiversity. Water reaching the Okavango Delta (Delta), Botswana, may decrease due to excessive water extraction and climate change. However, due to poor understanding of the link between inundation of wetlands and biological responses, it is difficult to assess the impacts of these future water developments on aquatic biota. Large floods from 2009 to 2011 inundated both rarely and frequently flooded wetlands in the Delta, creating an opportunity to examine the ecological significance of flooding of wetlands with widely differing hydrological characteristics. We studied the assemblages of small fishes and microcrustaceans, together with their trophic relationships, in temporary wetlands of the lower Delta. Densities of microcrustaceans in temporary wetlands were generally lower than previously recorded in these habitats. Microcrustacean density varied with wetland types and hydrological phase of inundation. High densities of microcrustaceans were recorded in the 2009 to 2010 flooding season after inundation of rarely flooded sites. Large numbers of small fishes were observed during this study. Community structure of small fishes differed significantly across the studied wetlands, with poeciliids predominant in frequently flooded wetlands and juvenile cichlids most abundant in rarely flooded wetlands (analysis of similarity, P fishes of fishes (fishes may also be an important regulatory mechanism of microcrustacean assemblages during large floods when inundated terrestrial patches of wetlands are highly accessible by fish. We predict that a decline in the amount of water reaching the Delta will negatively affect fish recruitment, particularly the cichlids that heavily exploited the rarely flooded wetlands. Cichlids are an important human food source, and their decline in fish catches will negatively affect livelihoods. Hence, priority in

  18. 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.

  19. Why do winners keep winning? Androgen mediation of winner but not loser effects in cichlid fish

    Science.gov (United States)

    Oliveira, Rui F.; Silva, Ana; Canário, Adelino V.M.

    2009-01-01

    Animal conflicts are influenced by social experience such that a previous winning experience increases the probability of winning the next agonistic interaction, whereas a previous losing experience has the opposite effect. Since androgens respond to social interactions, increasing in winners and decreasing in losers, we hypothesized that socially induced transient changes in androgen levels could be a causal mediator of winner/loser effects. To test this hypothesis, we staged fights between dyads of size-matched males of the Mozambique tilapia (Oreochromis mossambicus). After the first contest, winners were treated with the anti-androgen cyproterone acetate and losers were supplemented with 11-ketotestosterone. Two hours after the end of the first fight, two contests were staged simultaneously between the winner of the first fight and a naive male and between the loser of first fight and another naive male. The majority (88%) of control winners also won the second interaction, whereas the majority of control losers (87%) lost their second fight, thus confirming the presence of winner/loser effects in this species. As predicted, the success of anti-androgen-treated winners in the second fight decreased significantly to chance levels (44%), but the success of androgenized losers (19%) did not show a significant increase. In summary, the treatment with anti-androgen blocks the winner effect, whereas androgen administration fails to reverse the loser effect, suggesting an involvement of androgens on the winner but not on the loser effect. PMID:19324741

  20. 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,

  1. Sex-specific conditional mating preferences in a cichlid fish : implications for sexual conflict

    NARCIS (Netherlands)

    Baldauf, Sebastian A.; Engqvist, Leif; Ottenheym, Tobias; Bakker, Theo C. M.; Thuenken, Timo

    2013-01-01

    Conditional mating strategies enable individuals to modulate their mating behaviour depending on 'individual status' to maximise fitness. Theory predicts that variation in individual quality can lead to differences in mating preferences. However, empirical evidence is scarce particular in terms of v

  2. Sex-specific effects of postnatal testosterone on lateralization in cichlid fish

    NARCIS (Netherlands)

    Schaafsma, Sara M.; Groothuis, Ton G. G.

    2011-01-01

    Lateralization is a fundamental principle in the organization of brain and behaviour in humans and nonhuman animals. To what extent lateralization is, in addition to genetic factors, under the influence of testosterone, which would also explain sex differences in laterality, is the topic of a long-s

  3. Sex-specific effects of maternal testosterone on lateralization in a cichlid fish

    NARCIS (Netherlands)

    Schaafsma, Sara M.; Groothuis, Ton G. G.

    2012-01-01

    Lateralization of cerebral functions is a fundamental aspect of the organization of brain and behaviour in vertebrates. Sex differences in human lateralization have inspired researchers to postulate several hypotheses concerning the effect of prenatal testosterone on lateralization, but few experime

  4. The fishes of Genome 10K

    KAUST Repository

    Bernardi, Giacomo

    2012-09-01

    The Genome 10K project aims to sequence the genomes of 10,000 vertebrates, representing approximately one genome for each vertebrate genus. Since fishes (cartilaginous fishes, ray-finned fishes and lobe-finned fishes) represent more than 50% of extant vertebrates, it is planned to target 4,000 fish genomes. At present, nearly 60 fish genomes are being sequenced at various public funded labs, and under a Genome 10K and BGI pilot project. An additional 100 fishes have been identified for sequencing in the next phase of Genome 10K project. © 2012 Elsevier B.V.

  5. The genus Idertia (Ochnaceae)

    NARCIS (Netherlands)

    Sosef, M.S.M.

    2013-01-01

    Background and aims - The genus Idertia belongs to the subfamily Ochnoideae, tribe Ochneae, subtribe Ouratinae. This paper aims at a full taxonomic revision and a critical evaluation of the taxonomic position of the genus along with its diagnostic characters. Methods - All characters are studied usi

  6. [Citogenetic characterization of the tropical freshwater fish Parachromis managuensis (Pisces: Cichlidae)].

    Science.gov (United States)

    Arias-Rodríguez, Lenin; Páramo-Delgadillo, Salomón; Durán-González, Alicia de la Luz

    2006-03-01

    To describe the cytogenetics of the jaguar cichlid fish Parachromis managuensis, we collected eight males and 13 females in Villahermosa, Tabasco, México. The specimens were processed with standard cytogenetic techniques (slightly modified), and high quality fields of chromosomes in mitosis and meiosis were obtained; 14 of these fields were analyzed by meristics and statistics methods. The specimens presented a diploid modal number of 2n = 48 chromosomes, which is similar to the number reported for others Central American cichlids; five pairs were submetacentric-metacentrics (biarmed) and 19 were subtelocentric-telocentric (uni-armed), giving a fundamental number (NF) of 58. The haploid number was confirmed by counting meiotic fields in metaphase I. There was not evidence of heteromorphism: sexual chromosomes were not identifiable.

  7. 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...

  8. Complete mitochondrial genome of the Siamese fighting fish (Betta splendens).

    Science.gov (United States)

    Song, Ying-Nan; Xiao, Gui-Bao; Li, Jiong-Tang

    2016-11-01

    The Siamese fighting fish (Betta splendens) is one of the popular aquarium fish. Serious attentions have been paid to the biodiversity of the fish. The mitochondrial genome of the Siamese fighting fish is reported to be 17 099 bp and includes 37 genes. The gene organization is similar to other fish mitogenomes. The control region is AT-rich and includes three tandem repeats. Phylogenetic analysis reveals that the fish is close to fish in the Macropodus genus. This mitogenome will assist in studying the mitochondrial variations and population structure in this fish and examine the evolutionary relationship among fish in the Osphronemidae family.

  9. A Redescription of Riggia paranensis Szidat, 1948 (Isopoda, Cymothoidae Based on Thirty-two Specimens from Curimatid Fish of Rio de Janeiro, Brazil, with an Emendation of the Genus

    Directory of Open Access Journals (Sweden)

    Bastos Paula B

    1997-01-01

    Full Text Available Riggia paranensis Szidat, 1948 is redescribed on the basis of 30 female and 2 male specimens collected from the pericardial cavities of the curimatid fish Cyphocarax (= Curimata gilberti (Quoy & Gaimard. The fishes were caught in the Itabapoana River, State of Rio de Janeiro, southeastern Brazil. The presence of" dwarf" males, as reported by Szidat, was verified. The fusion of the pleonites and pleotelson in adult females was also confirmed. The generic diagnosis was emended to include details of the mouthparts and pleopods

  10. 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.

  11. Fish Allergy

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old Fish Allergy KidsHealth > For Parents > Fish Allergy Print A ... From Home en español Alergia al pescado About Fish Allergy A fish allergy is not exactly the ...

  12. Functional coupling constrains craniofacial diversification in Lake Tanganyika cichlids

    Science.gov (United States)

    Tsuboi, Masahito; Gonzalez-Voyer, Alejandro; Kolm, Niclas

    2015-01-01

    Functional coupling, where a single morphological trait performs multiple functions, is a universal feature of organismal design. Theory suggests that functional coupling may constrain the rate of phenotypic evolution, yet empirical tests of this hypothesis are rare. In fish, the evolutionary transition from guarding the eggs on a sandy/rocky substrate (i.e. substrate guarding) to mouthbrooding introduces a novel function to the craniofacial system and offers an ideal opportunity to test the functional coupling hypothesis. Using a combination of geometric morphometrics and a recently developed phylogenetic comparative method, we found that head morphology evolution was 43% faster in substrate guarding species than in mouthbrooding species. Furthermore, for species in which females were solely responsible for mouthbrooding the males had a higher rate of head morphology evolution than in those with bi-parental mouthbrooding. Our results support the hypothesis that adaptations resulting in functional coupling constrain phenotypic evolution. PMID:25948565

  13. Monogenea of Chinese Marine Fishes XXII.A New Chinese Record Genus and Species Nasicola klawei ( Stunkard, 1962) Yamaguti, 1968 (Capsalidae)%中国海洋鱼类单殖吸虫研究XXⅡ.分室科一新记录属

    Institute of Scientific and Technical Information of China (English)

    杨长平; 胡盼; 丁雪娟

    2012-01-01

    This paper reports a capsalid species of monogenean in China. Nasicola klawei (Stunkard, 1962) Yamaguti, 1968 (Monogenea: Capsalidae) was found in the nasal capsule of longtail tuna, Thunnus tonggol (Bleeker, 1851) , from Shanwei city, Guangdong Province. The specimens are basically consistent with the original description of Stunkard (1962) and the redescription of Yamaguti (1968) and Kohn et al. (2004) except for some differences in the structure of uterus, number of testes and the length of marginal hooks. This is the first time the genus Nasicola and species N. klawei are recorded in China, and the fish Thunnus tonggol is a new host. The specimens are deposited in the Lab of Fish Parasitology, College of life Science, South China Normal University.%记述采自广东汕尾青干金枪鱼Thunnus tonggol鼻腔中的1种单殖吸虫——卡氏嗜鼻虫Nasicola klawei(Stunkard,1962)Yamaguti,1968.所获标本的形态结构及大小与原始描述及Yamaguti( 1968)、Kohn等(2004)的描述基本一致,但在子宫结构、睾丸数目及后吸器边缘小钩的长度上略有差别.嗜鼻虫属及卡氏嗜鼻虫均为我国新记录,青干金枪鱼为宿主新记录.

  14. Environmental change enhances cognitive abilities in fish.

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    Alexander Kotrschal

    Full Text Available Flexible or innovative behavior is advantageous, especially when animals are exposed to frequent and unpredictable environmental perturbations. Improved cognitive abilities can help animals to respond quickly and adequately to environmental dynamics, and therefore changing environments may select for higher cognitive abilities. Increased cognitive abilities can be attained, for instance, if environmental change during ontogeny triggers plastic adaptive responses improving the learning capacity of exposed individuals. We tested the learning abilities of fishes in response to experimental variation of environmental quality during ontogeny. Individuals of the cichlid fish Simochromis pleurospilus that experienced a change in food ration early in life outperformed fish kept on constant rations in a learning task later in life--irrespective of the direction of the implemented change and the mean rations received. This difference in learning abilities between individuals remained constant between juvenile and adult stages of the same fish tested 1 y apart. Neither environmental enrichment nor training through repeated neural stimulation can explain our findings, as the sensory environment was kept constant and resource availability was changed only once. Instead, our results indicate a pathway by which a single change in resource availability early in life permanently enhances the learning abilities of animals. Early perturbations of environmental quality may signal the developing individual that it lives in a changing world, requiring increased cognitive abilities to construct adequate behavioral responses.

  15. Evidence of a specialized feeding niche in a Late Triassic ray-finned fish: evolution of multidenticulate teeth and benthic scraping in †Hemicalypterus.

    Science.gov (United States)

    Gibson, Sarah Z

    2015-04-01

    Fishes have evolved to exploit multiple ecological niches. Extant fishes in both marine (e.g., rabbitfishes, surgeonfishes) and freshwater systems (e.g., haplochromine cichlids, characiforms) have evolved specialized, scoop-like, multidenticulate teeth for benthic scraping, feeding primarily on algae. Here, I report evidence of the oldest example of specialized multidenticulate dentition in a ray-finned fish, †Hemicalypterus weiri, from the Upper Triassic Chinle Formation of southeastern Utah (∼210-205 Ma), USA. †H. weiri is a lower actinopterygian species that is phylogenetically remote from modern fishes, and has evolved specialized teeth that converge with those of several living teleost fishes (e.g., characiforms, cichlids, acanthurids, siganids), with a likely function of these teeth being to scrape algae off a rock substrate. This finding contradicts previously held notions that fishes with multicuspid, scoop-like dentition were restricted to teleosts, and indicates that ray-finned fishes were diversifying into different trophic niches and exploring different modes of feeding earlier in their history than previously thought, fundamentally altering our perceptions of the ecological roles of fishes during the Mesozoic.

  16. The genus Lagenophora (Compositae)

    NARCIS (Netherlands)

    Cabrera, Angel L.

    1966-01-01

    The genus Lagenophora was first described by Cassini under the name Lagenifera (in Bull. Soc. Philomat. 12, 1816, 199) with the following diagnosis: ‘Ce genre, de la tribus des astérées, comprend le calendula magellanicá, Willd. et le bellis stipitata, Labill. Son principal caractère reside dans la

  17. The genus Faradaya (Labiatae)

    NARCIS (Netherlands)

    Kok, de R.P.J.; Mabberley, D.J.

    1999-01-01

    A revision of the genus Faradaya F. Muell. (Labiatae) is presented with taxonomic history, keys, full descriptions, distribution maps and ecological and ethnobotanical notes. Only three species are recognised: F. amicorum (Seem.) Seem., F. lehuntei (Home ex Baker) A.C. Sm. and F. splendida F. Muell.

  18. The genus Cladosporium

    NARCIS (Netherlands)

    Bench, K.; Braun, U.; Groenewald, J.Z.; Crous, P.W.

    2012-01-01

    A monographic revision of the hyphomycete genus Cladosporium s. lat. (Cladosporiaceae, Capnodiales) is presented. It includes a detailed historic overview of Cladosporium and allied genera, with notes on their phylogeny, systematics and ecology. True species of Cladosporium s. str. (anamorphs of Dav

  19. A Fish Assemblage from the Middle Eocene from Libya (Dur At-Talah) and the Earliest Record of Modern African Fish Genera.

    Science.gov (United States)

    Otero, Olga; Pinton, Aurélie; Cappetta, Henri; Adnet, Sylvain; Valentin, Xavier; Salem, Mustapha; Jaeger, Jean-Jacques

    2015-01-01

    In the early nineteen sixties, Arambourg and Magnier found some freshwater fish (i.e., Polypterus sp., Siluriformes indet. and Lates sp.) mixed with marine members in an Eocene vertebrate assemblage at Gebel Coquin, in the southern Libyan Desert. This locality, aged ca 37-39Ma and now known under the name of Dur At-Talah, has been recently excavated. A new fish assemblage, mostly composed of teeth, was collected by the Mission Paléontologique Franco-Libyenne. In this paper, we describe freshwater fish members including a dipnoan (Protopterus sp.), and several actinopterygians: bichir (Polypterus sp.), aba fish (Gymnarchus sp.), several catfishes (Chrysichthys sp. and a mochokid indet.), several characiforms (including the tiger fish Hydrocynus sp., and one or two alestin-like fish), and perciforms (including the snake-head fish Parachanna sp. and at least one cichlid). Together with the fossiliferous outcrops at Birket Qarun in Egypt, the Libyan site at Dur At-Talah reduces a 10-Ma chronological gap in the fossil record of African freshwater fish. Their fish assemblages overlap in their composition and thus constitute a rather homogenous, original and significant amount of new elements regarding the Paleogene African ichthyofauna. This supports the establishment of the modern African freshwater fish fauna during this time period because these sites mostly contain the earliest members known in modern genera.

  20. 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

  1. Studying fish social behavior and cognition: implications for fish welfare and conservation

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    Rui F Oliveira

    2015-12-01

    Full Text Available Within vertebrates teleost fish are the most diverse and plastic taxa in terms of social behavior. With over 29,000 species described so far, one can find all different types of social organization, mating systems and parental care types. Moreover, it is relatively common to find variation of these characters within closely related species, which makes them suitable for comparative studies on the evolution of social behavior (e.g. variation in mating systems and parental care type in African cichlids. Fish are also champions of social plasticity, as can be illustrated by the flexible patterns of sexual expression, as in the case of protrandrous and protogynous sex-change, simultaneous hermaphroditism and intra-sexual variation in the form of discrete alternative male phenotypes. Complex cognitive abilities used in social interactions have also evolved in fish, such as individual recognition, transitive inference and social learning. Therefore, teleosts offer unique opportunities to study both the evolution and the function of social behavior and cognition. In this talk I will summarize the work that our lab has been doing to establish zebrafish as a model organism for the study of social behavior and cognition and I will illustrate how knowledge on this are can be applied to fish welfare and to conservation issues.

  2. Temporal Dynamics of Reproduction of the Neotropical Fish, Crenicichla menezesi (Perciformes: Cichlidae

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    Andréa Soares de Araújo

    2012-01-01

    Full Text Available The reproductive biology and the gonadal development cycle of the Neotropical cichlid fish, Crenicichla menezesi, is described. This species exhibits sexual dimorphism only during the spawning season. First sexual maturity of females is attained earlier than the males. Both macroscopic and histological investigations of ovaries and testes revealed four stages of gonadal maturation. Mean batch fecundity of females was 372 (±10,41 of mature oocytes. This species is a partial spawner, with an extended spawning period. Monthly values of GSI and the condition factor are negatively correlated during the gonadal development cycle of this species.

  3. What is the genus?

    CERN Document Server

    Popescu-Pampu, Patrick

    2016-01-01

    Exploring several of the evolutionary branches of the mathematical notion of genus, this book traces the idea from its prehistory in problems of integration, through algebraic curves and their associated Riemann surfaces, into algebraic surfaces, and finally into higher dimensions. Its importance in analysis, algebraic geometry, number theory and topology is emphasized through many theorems. Almost every chapter is organized around excerpts from a research paper in which a new perspective was brought on the genus or on one of the objects to which this notion applies. The author was motivated by the belief that a subject may best be understood and communicated by studying its broad lines of development, feeling the way one arrives at the definitions of its fundamental notions, and appreciating the amount of effort spent in order to explore its phenomena.

  4. 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.

  5. Fish Allergy

    Science.gov (United States)

    ... in a clear and consistent manner, so that consumers with food allergies and their caregivers can be informed as ... the menu, cross-contact with fish is possible. Ethnic ... fish. Avoid foods like fish sticks and anchovies. Some individuals with ...

  6. Fish Hearing.

    Science.gov (United States)

    Blaxter, J. H. S.

    1980-01-01

    Provides related information about hearing in fish, including the sensory stimulus of sound in the underwater environment, mechanoreceptors in fish, pressure perception and the swimbladder, specializations in sound conduction peculiar to certain fish families. Includes numerous figures. (CS)

  7. Biodegradation of chlorpyrifos by bacterial genus Pseudomonas.

    Science.gov (United States)

    Gilani, Razia Alam; Rafique, Mazhar; Rehman, Abdul; Munis, Muhammad Farooq Hussain; Rehman, Shafiq Ur; Chaudhary, Hassan Javed

    2016-02-01

    Chlorpyrifos is an organophosphorus pesticide commonly used in agriculture. It is noxious to a variety of organisms that include living soil biota along with beneficial arthropods, fish, birds, humans, animals, and plants. Exposure to chlorpyrifos may cause detrimental effects as delayed seedling emergence, fruit deformities, and abnormal cell division. Contamination of chlorpyrifos has been found about 24 km from the site of its application. There are many physico-chemical and biological approaches to remove organophosphorus pesticides from the ecosystem, among them most promising is biodegradation. The 3,5,6-trichloro-2-pyridinol (TCP) and diethylthiophosphate (DETP) as primary products are made when chlorpyrifos is degraded by soil microorganisms which further break into nontoxic metabolites as CO(2), H(2)O, and NH(3). Pseudomonas is a diversified genus possessing a series of catabolic pathways and enzymes involved in pesticide degradation. Pseudomonas putida MAS-1 is reported to be more efficient in chlorpyrifos degradation by a rate of 90% in 24 h among Pseudomonas genus. The current review analyzed the comparative potential of bacterial species in Pseudomonas genus for degradation of chlorpyrifos thus, expressing an ecofriendly approach for the treatment of environmental contaminants like pesticides.

  8. Revision of genus Steindachneridion (Siluriformes: Pimelodidae

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    Julio Cesar Garavello

    Full Text Available After several years collecting in the type-localities and studying representative samples of genus Steindachneridion Eigenmann & Eigenmann, 1919 from Brazilian and foreign museums, a taxonomic revision of the Recent species of the genus is presented, including the description of a new species from the rio Iguaçu, above the great falls. Steindachneridion species are large sized fishes, reaching 1000 mm total length or more, and sharing some anatomical characters that, at least tentatively, support the monophyly of the genus. In addition to the general features found in the Pimelodidae, the species S. amblyurum (Eigenmann & Eigenmann, 1888, S. parahybae (Steindachner, 1877, S. doceanum (Eigenmann & Eigenmann, 1889, S. scriptum (Miranda Ribeiro, 1918, S. punctatum (Miranda Ribeiro, 1918, and S. melanodermatum, new species, share the shape of the vomer tooth plates, six to eight branched rays in the dorsal-fin, and a low number of gill-rakers. All species, except fossil ones, are redescribed and a key for their identification is provided.

  9. First record of Contracaecum spp. (Nematoda : Anisakidae in fish-eating birds from Zimbabwe

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    M. Barson

    2004-06-01

    Full Text Available Endoparasites of fish-eating birds, Phalacrocorax africanus, P. carbo, Anhinga melanogaster and Ardea cinerea collected from Lake Chivero near Harare, Zimbabwe, were investigated. Adult Contracaecum spp. were found in the gastrointestinal tract (prevalence 100% in P. africanus, P. carbo and A. melanogaster; 25 % in A. cinerea. Parasite intensity was 11-24 (mean 19 in P. africanus, 4-10 (mean 7 in P. carbo, 4-56 (mean 30 in A. melanogaster and 2 (mean 0.5 in A. cinerea. The cormorants fed mainly on cichlid fishes and carp; the darters and the grey herons on cichlids. All these fishes are intermediate hosts of Contracaecum spp. Scanning electron microscopy revealed that Contracaecum rudolphii infected both cormorant species and darters; C. carlislei infected only the cormorants while C. tricuspis and C. microcephalum infected only the darters. Parasites from the grey heron were not identified to species because they were still developing larvae. These parasites are recorded in Zimbabwe for the first time.

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

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    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

  11. 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

  12. Breaking the host range: mandarin fish is susceptible to a vesiculovirus derived from snakehead fish.

    Science.gov (United States)

    Liu, Xiaodan; Wen, Yi; Hu, Xianqin; Wang, Wenwen; Liang, Xufang; Li, Jun; Vakharia, Vikram; Lin, Li

    2015-04-01

    Members of the genus Vesiculovirus, which belongs to the family Rhabdoviridae, can cause great economic loss in fish culture. In the present report, a vesiculovirus [named snakehead fish vesiculovirus (SHVV)] was isolated from diseased hybrid snakehead fish. SHVV shared 94 % nucleotide sequence identity at the genomic level with Siniperca chuatsi rhabdovirus (SCRV), which infects mandarin fish (S. chuatsi). We showed that SHVV was able to replicate and proliferate well in SSN-1 cells, which originate from striped snakehead fish (Channa striatus). Furthermore, mandarin fish was susceptible to SHVV by bath exposure, as well as by intraperitoneal injection. The infected fish showed typical clinical signs of rhabdovirus infection, including haemorrhage and oedema. Histopathological analysis revealed that extensive inflammation and necrosis were observed in the spleen, kidney, liver, heart and brain of the moribund mandarin fish. These results will shed new light on the epidemic of vesiculovirus infections among fish.

  13. Diversity in Fish Auditory Systems: One of the Riddles of Sensory Biology

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    Friedrich eLadich

    2016-03-01

    Full Text Available An astonishing diversity of inner ears and accessory hearing structures (AHS that can enhance hearing has evolved in fishes. Inner ears mainly differ in the size of the otolith end organs, the shape and orientation of the sensory epithelia, and the orientation patterns of ciliary bundles of sensory hair cells. Despite our profound morphological knowledge of inner ear variation, two main questions remain widely unanswered. (i What selective forces and/or constraints led to the evolution of this inner ear diversity? (ii How is the morphological variability linked to hearing abilities? Improved hearing is mainly based on the ability of many fish species to transmit oscillations of swim bladder walls or other gas-filled bladders to the inner ears. Swim bladders may be linked to the inner ears via a chain of ossicles (in otophysans, anterior extensions (e.g. some cichlids, squirrelfishes, or the gas bladders may touch the inner ears directly (labyrinth fishes. Studies on catfishes and cichlids demonstrate that larger swim bladders and more pronounced linkages to the inner ears positively affect both auditory sensitivities and the detectable frequency range, but lack of a connection does not exclude hearing enhancement. This diversity of auditory structures and hearing abilities is one of the main riddles in fish bioacoustics research. Hearing enhancement might have evolved to facilitate intraspecific acoustic communication. A comparison of sound-producing species, however, indicates that acoustic communication is widespread in taxa lacking AHS. Eco-acoustical constraints are a more likely explanation for the diversity in fish hearing sensitivities. Low ambient noise levels may have facilitated the evolution of AHS, enabling fish to detect low-level abiotic noise and sounds from con- and heterospecifics, including predators and prey. Aquatic habitats differ in ambient noise regimes, and preliminary data indicate that hearing sensitivities of fishes

  14. 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.

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

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    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.

  16. Boldness, aggression and exploration: evidence for a behavioural syndrome in male pentamorphic livebearing fish, Poecilia parae

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    Godfrey R. Bourne

    2008-09-01

    Full Text Available A body of evidence is being accumulated on consistent individual differences in behaviour for several animal taxa. Individuals of these species exhibit different levels of risk during competition over limited resources, and the resultant behavioural types perform better under different social and physical environmental conditions. We used approach distance to a model of a piscivore predator the pike cichlid (Crenicichla saxatilis to categorize male pentamorphic livebearing fish or pentas (Poecilia parae as bold, intermediate, and shy, and then tested the hypothesis that when behaviours are correlated, individuals express different behaviour types under different contexts. Our results for the most part corroborated the six predictions generated by the aforementioned hypothesis: (1 bold pentas explored a T-maze in the shortest time, and initially approached the chamber with a living pike cichlid instead of the one with the conspecific male; (2 intermediate pentas spent more time exploring the maze and exhibited no initial interest in the predator chamber nor the conspecific one; (3 shy individuals spent the most time exploring the maze, and initially approached the predator chamber, providing only partial support for this prediction because shy males did not initially approach the conspecific chamber; (4 approach distance from the pike cichlid predator model and time to explore the maze was positively correlated; (5 bold pentas exhibit highest levels of aggression toward conspecifics; and (6 bold individuals ingested the most conspecific fry. Our results lead to the conclusion that pentas exhibited a behavioural syndrome with bold fish being more aggressive, faster explorers of novel situations, and more cannibalistic than intermediate and shy individuals of the same population. Thus, penta males fall into a behavioural syndrome formally known as the proactive-reactive axis.

  17. FISH PRODUCTION ESTIMATES FOR GBEDIKERE LAKE, BASSA, KOGI STATE, NIGERIA

    Directory of Open Access Journals (Sweden)

    Samuel Olusegun Adeyemi

    2013-10-01

    Full Text Available Annual estimates of the fish caught by local fishermen in randomly selected fishing villages adjacent to Gbedikere Lake were determined using Catch Assessment (CAS. The studies were carried out within two seasons of low water (February and high water (September periods between 2006 to 2008. Annual fish catch varied from 537.4 mts to 576.9 mts at high water. Mean catch per boat ranged from 7.40 kg to 10.60 kg among the landing sites. A total of 12 fish species were identified belonging to ten families. The catches were dominated by the cichlids with Orechromis niloticus dominating the overall catch compositions. Production estimate was compared with the catches obtained through experimental gill-net sampling and potential fish yield estimates using Ryder’s Morpho - Edaphic Index (MEI as modified by Henderson and Welcomme (1974. Contributions of the gears in use were also done with cast nets ranking above others (29%, followed by the set net (25%, hook and lines (16.6%, traps (16.6%, clap net (8.3%. Management measures were suggested.

  18. Fish allergy and fish allergens

    DEFF Research Database (Denmark)

    Kuehn, A; Hilger, Christiane; Ollert, Markus

    2016-01-01

    Fish is one of the main elicitors for food allergies. For a long time, the clinical picture of fish allergy was reduced to the following features. First, fish-allergic patients suffer from a high IgE cross-reactivity among fishes so that they have to avoid all species. Second, clinically relevant...... review gives an overview on the clinical characteristics of fish allergy and the molecular properties of relevant fish allergens. The advancement of the IgE-based diagnosis using a panel of well-defined fish allergens from different species is in the focus of the discussion. © 2016 Dustri-Verlag Dr. Karl...

  19. Biodiversity of the genus Cladophialophora

    NARCIS (Netherlands)

    Badali, H.; Gueidan, C.; Najafzadeh, M.J.; Bonifaz, A.; Gerrits van den Ende, A.H.G.; de Hoog, G.S.

    2008-01-01

    Cladophialophora is a genus of black yeast-like fungi comprising a number of clinically highly significant species in addition to environmental taxa. The genus has previously been characterized by branched chains of ellipsoidal to fusiform conidia. However, this character was shown to have evolved s

  20. Genus Distributions of Moebius Ladders

    Institute of Scientific and Technical Information of China (English)

    李德明

    2005-01-01

    The genus distribution of a graph is a polynomial whose coefficients are the partition of the number of embeddings with respect to the genera. In this paper,the genus distribution of Moebius ladders is provided which is an infinite class of 3-connected simple graphs.

  1. Social isolation and aggressiveness in the Amazonian juvenile fish Astronotus ocellatus

    Directory of Open Access Journals (Sweden)

    E. Gonçalves-de-Freitas

    Full Text Available We tested the effect of social isolation on the aggressiveness of an Amazonian fish: Astronotus ocellatus. Ten juvenile fishes were transferred from a group aquarium (60 x 60 x 40 cm containing 15 individuals (without distinguishing sex to an isolation aquarium (50 x 40 x 40 cm. Aggressiveness was tested by means of attacks on and displays toward the mirror image. The behavior was video-recorded for 10 min at a time on 4 occasions: at 30 min, 1 day, 5 days and 15 days after isolation. The aggressive drive was analyzed in three ways: latency to display agonistic behavior, frequency of attacks and specific attacks toward the mirror image. The latency to attack decreased during isolation, but the frequency of mouth fighting (a high aggressive attack tended to increase, indicating an augmented aggressive drive. Our findings are congruent with the behavior of the juvenile cichlid, Haplochromis burtoni but differ from the behavior observed in another cichlid, Pterophylum scalare. Increased aggressiveness in A. ocellatus may be mediated by means of the primer effect, the effect of prior residence or processes involving recognition of a conspecific.

  2. SCARDINIUS GENUS IN MOLECULAR STUDIES – A REVIEW

    Directory of Open Access Journals (Sweden)

    Ovidiu Popescul

    2015-12-01

    Full Text Available Scardinius is a genus of ray-finned fish in the Cyprinidae family commonly called rudds. The common rudd(Scardinius erithrophthalmus is a bentho-pelagic freshwater fish that occurs mainly in nutrient-rich, well vegetatedlowland rivers, backwaters, oxbows, ponds and lakes and it is widespread in Europe and middle Asia. It has a mediumlength of 20-30 cm, but it can reach 50 cm. The classification of cyprinids has always been controversial the morphologicaltraits have an unclear homology this led to the idea that the recognized monophyletic groups are surely misinterpreted. Thispaper aims to assess the current level of molecular data regarding Scardinius genera. Some of the molecular data obtainedfor Scardinius genus is from DNA barcoding studies on fresh water fishes, but studies regarding this genus and Cyprinidaefamily used mitochondrial genes like cytochrome b (cyt b and cytochrome oxidase (CO, but nuclear genes or nuclearmicrosatellites were also used. We found that molecular data exists for both nuclear and mitochondrial genes, but this genuswasn’t studied separately and as many of the researchers suggest more taxonomic studies are required in order to solve theuncertainties within it.

  3. Antarctic Fishes.

    Science.gov (United States)

    Eastman, Joseph T.; DeVries, Arthur L.

    1986-01-01

    Explains the adaptations to Antarctic waters that Notothenioidei, a group of advanced bony fishes, have exhibited. Discusses the fishes' mechanisms of production of antifreeze properties and their capacities for neutral buoyancy in water. (ML)

  4. Fish Dishes.

    Science.gov (United States)

    Derby, Marie

    2003-01-01

    Describes an art project that was inspired by Greek pottery, specifically dishes shaped as fish. Explains that fourth-grade students drew a fish shape that was later used to create their clay version of the fish. Discusses how the students examined the pottery to make decisions about color and design. (CMK)

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

    Science.gov (United States)

    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.

  6. 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.

  7. 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.

  8. Cooling water of power plant creates "hot spots" for tropical fishes and parasites.

    Science.gov (United States)

    Emde, Sebastian; Kochmann, Judith; Kuhn, Thomas; Dörge, Dorian D; Plath, Martin; Miesen, Friedrich W; Klimpel, Sven

    2016-01-01

    Thermally altered water bodies can function as "hot spots" where non-native species are establishing self-sustaining populations beyond their tropical and subtropical native regions. Whereas many tropical fish species have been found in these habitats, the introduction of non-native parasites often remains undetected. Here, n = 77 convict cichlids (Amatitlania nigrofasciata) were sampled by electro-fishing at two sites from a thermally altered stream in Germany and examined for parasite fauna and feeding ecology. Stomach content analysis suggests an opportunistic feeding strategy of A. nigrofasciata: while plant material dominated the diet at the warm water inlet (∼30 °C), relative contributions of insects, plants, and crustaceans were balanced 3 km downstream (∼27 °C). The most abundant non-native parasite species was the tropical nematode Camallanus cotti with P = 11.90 % and P = 80.00 % at the inlet and further downstream, respectively. Additionally, nematode larvae of Anguillicoloides crassus and one specimen of the subtropical species Bothriocephalus acheilognathi were isolated. A. nigrofasciata was also highly infected with the native parasite Acanthocephalus anguillae, which could be linked to high numbers of the parasite's intermediate host Asellus aquaticus. The aim of this study was to highlight the risk and consequences of the release and establishment of ornamental fish species for the introduction and spread of non-indigenous metazoan parasites using the convict cichlid as a model species. Furthermore, the spread of non-native parasites into adjacent fish communities needs to be addressed in the future as first evidence of Camallanus cotti in native fish species was also found.

  9. Immune activation is inversely related to, but does not cause variation in androgen levels in a cichlid fish species

    NARCIS (Netherlands)

    Ros, Albert F. H.; Oliveira, Rui F.; Dijkstra, Peter D.; Groothuis, Ton G. G.

    2012-01-01

    Studies on birds and mammals indicate that sexual traits may signal superior health because active immunity, like inflammatory responses to infections, is suppressive to the production of androgens that facilitate the expression of these traits. Here we test this possible pathway for honest signalin

  10. Apistogramma ortegai (Teleostei: Cichlidae), a new species of cichlid fish from the Ampyiacu River in the Peruvian Amazon basin

    OpenAIRE

    2014-01-01

    Apistogramma ortegai, new species, is described from small streams tributaries of the Ampiyacu River near Pebas, in eastern Peru. It belongs to the Apistogramma regani species group and is distinguished from all other species of Apistogramma by the combination of contiguous caudal spot to bar 7, presence of abdominal stripes, short dorsal-fin lappets in both sexes, absence of vertical stripes on the caudal fin, and reduced number of predorsal and prepelvic scales.

  11. Apistogramma ortegai (Teleostei: Cichlidae), a new species of cichlid fish from the Ampyiacu River in the Peruvian Amazon basin.

    Science.gov (United States)

    Britzke, Ricardo; Oliveira, Claudio; Kullander, Sven O

    2014-10-02

    Apistogramma ortegai, new species, is described from small streams tributaries of the Ampiyacu River near Pebas, in eastern Peru. It belongs to the Apistogramma regani species group and is distinguished from all other species of Apistogramma by the combination of contiguous caudal spot to bar 7, presence of abdominal stripes, short dorsal-fin lappets in both sexes, absence of vertical stripes on the caudal fin, and reduced number of predorsal and prepelvic scales.

  12. Crenicichla gillmorlisi, a new species of cichlid fish (Teleostei: Cichlidae) from the Paraná river drainage in Paraguay.

    Science.gov (United States)

    Kullander, Sven O; De Lucena, Carlos A Santos

    2013-01-01

    Crenicichla gillmorlisi, new species, is described from the río Acaray, a right bank tributary to the río Paraná. It is most similar to C. mandelburgeri in proportional measurements and meristics, but differs in colour pattern, adults having the body covered with small spots.

  13. 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

  14. Relative abundance and distribution of fishes and crayfish at Ash Meadows National Wildlife Refuge, Nye County, Nevada, 2007-08

    Science.gov (United States)

    Scoppettone, G. Gary; Rissler, Peter; Johnson, Danielle; Hereford, Mark

    2011-01-01

    This study provides baseline data of native and non-native fish populations in Ash Meadows National Wildlife Refuge (NWR), Nye County, Nevada, that can serve as a gauge in native fish enhancement efforts. In support of Carson Slough restoration, comprehensive surveys of Ash Meadows NWR fishes were conducted seasonally from fall 2007 through summer 2008. A total of 853 sampling stations were created using Geographic Information Systems and National Agricultural Imagery Program. In four seasons of sampling, Amargosa pupfish (genus Cyprinodon) was captured at 388 of 659 stations. The number of captured Amargosa pupfish ranged from 5,815 (winter 2008) to 8,346 (summer 2008). The greatest success in capturing Amargosa pupfish was in warm water spring-pools with temperature greater than 25 degrees C, headwaters of warm water spring systems, and shallow (depths less than 10 centimeters) grassy marshes. In four seasons of sampling, Ash Meadows speckled dace (Rhinichthys osculus nevadesis) was captured at 96 of 659 stations. The number of captured Ash Meadows speckled dace ranged from 1,009 (summer 2008) to 1,552 (winter 2008). The greatest success in capturing Ash Meadows speckled dace was in cool water spring-pools with temperature less than 20 degrees C and in the high flowing water outflows. Among 659 sampling stations within the range of Amargosa pupfish, red swamp crayfish (Procambarus clarkii) was collected at 458 stations, western mosquitofish (Gambusia affinis) at 374 stations, and sailfin molly (Poecilia latipinna) at 128 stations. School Springs was restored during the course of this study. Prior to restoration of School Springs, maximum Warm Springs Amargosa pupfish (Cyprinodon nevadensis pectoralis) captured from the six springs of the Warm Springs Complex was 765 (fall 2007). In four seasons of sampling, Warm Springs Amargosa pupfish were captured at 85 of 177 stations. The greatest success in capturing Warm Springs Amargosa pupfish when co-occurring with red

  15. Composite Genus One Belyi Maps

    CERN Document Server

    Vidunas, Raimundas

    2016-01-01

    Motivated by a demand for explicit genus 1 Belyi maps from physics, we give an efficient method of explicitly computing genus one Belyi maps by (1) composing covering maps from elliptic curves to the Riemann surface with the simpler, univariate, genus zero Belyi maps as well as by (2) composing further with isogenies of the elliptic curve. This gives many new explicit dessins on the doubly periodic plane, including several which have been realized in the physics literature as so-called brane-tilings in the context of quiver gauge theories.

  16. Comunidad de parásitos metazoarios de la charra Cichlasoma trimaculatum en la laguna de Tres Palos, Guerrero, México Metazoan parasite community in the three-spot cichlid Cichlasoma trimaculatum from Tres Palos Lagoon, Guerrero, Mexico

    Directory of Open Access Journals (Sweden)

    Juan Violante-González

    2008-12-01

    Ergasilus sp. The community was generally poor in number of parasite species, and characterized by a high number of generalist parasites and fewer cichlid specialists. Four of the 5 common parasite species exhibited seasonally variable infection dynamics associated with environmental differences between the dry and rainy seasons. This variation in the dynamics of infection in the common parasite species generated changes in community structure over time. Clear patterns were not observed, however, indicating that this community has low predictability, as has been suggested for other parasite communities from freshwater fish.

  17. The genus Vitex: A review

    Directory of Open Access Journals (Sweden)

    Anita Rani

    2013-01-01

    Full Text Available The review includes 161 references on the genus Vitex, and comprises ethnopharmacology, morphology and microscopy, phytoconstituents, pharmacological reports, clinical studies, and toxicology of the prominent species of Vitex. Essential oils, flavonoids, iridoid glycosides, diterpenoides and ligans constitute major classes of phytoconstituents of the genus. A few species of this genus have medicinal value, among these, leaves and fruits of V. agnus-castus Linn. (Verbenaceae has been traditionally used in treatment of women complaints. V. agnus-castus has also been included in herbal remedies, which are in clinical use to regulate the menstrual cycle, reduce premenstrual symptom tension and anxiety, treat some menopausal symptoms as well as to treat hormonally induced acne. Despite a long tradition of use of some species, the genus has not been explored properly. In the concluding part, the future scope of Vitex species has been emphasized with a view to establish their multifarious biological activities and mode of action.

  18. 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

  19. Lower biodiversity of native fish but only marginally altered plankton biomass in tropical lakes hosting introduced piscivorous Cichla cf. ocellaris

    DEFF Research Database (Denmark)

    Menezes, Rosemberg; Attayde, José Luiz; Lacerot, Gissell

    2012-01-01

    We compared the species richness and abundance of fish, zooplankton and phytoplankton in nine mesotrophic coastal shallow lakes (Northeastern Brazil) with and without the exotic predator cichlid tucunaré or ‘peacock bass’ (Cichla cf. ocellaris). We hypothesized that the introduction of tucunaré...... and diversity were, in fact, drastically lower in the lakes hosting tucunaré, no significant differences were traced in total fish catch per unit of effort, zooplankton and phytoplankton biomass, plankton diversity or the zooplankton:phytoplankton biomass (TZOO:TPHYTO) ratio. However, zooplankton biomass...... and TZOO:TPHYTO tended to be higher and the phytoplankton biomass lower in lakes with tucunaré. Our analyses therefore suggest that the introduction of tucunaré had marked effect on the fish community structure and diversity in these shallow lakes, but only modest cascading effects on zooplankton...

  20. Fish remains from Miocene beds of Višnja vas near Vojnik, Slovenia

    Directory of Open Access Journals (Sweden)

    Aleš Šoster

    2013-06-01

    Full Text Available This paper discusses fossil teeth of sharks (Elasmobranchii, Neoselachii and porgies (Teleostei, Sparidae fromthe Miocene glauconite sandstones of Vi{nja vas near Vojnik. The remains of fish teeth, mostly tooth crowns, belongto cartilaginous fishes of the genera Notorynchus, Carcharias, Carcharoides, Isurus and Cosmopolitodus and to abony fish genus Pagrus.

  1. Fish health and fish quality

    DEFF Research Database (Denmark)

    Ingerslev, Hans-Christian

    Aquaculture is an expanding worldwide industry producing an increasing amount of fish every year. The quality of the fish meat is dependent upon many biological and non-biological factors. Infectious diseases are known to cause bleedings and damage of the muscle tissue that may lead to scarring...... are poorly described in fish. The present work in this thesis focused on: 1) examination of potential changes in the quality regarding texture of the muscle tissue in rainbow trout (Oncorhynchus mykiss) after previous infection with the bacterial pathogens Yersinia ruckeri and Vibrio anguillarum; 2...... of these studies showed that previous infections by Yersinia ruckeri and Vibrio anguillarum gave rise to subsequent changes regarding textural quality parameters in fresh fish meat, while no differences were seen for cold-smoked meat from the same fish. The texture in previous infected fish was less flaky and less...

  2. Fish parasites

    DEFF Research Database (Denmark)

    This book contains 22 chapters on some of the most important parasitic diseases in wild and farmed fish. International experts give updated reviews and provide solutions to the problems......This book contains 22 chapters on some of the most important parasitic diseases in wild and farmed fish. International experts give updated reviews and provide solutions to the problems...

  3. The genus Cyclidiopsis: an obituary.

    Science.gov (United States)

    Bennett, Matthew S; Triemer, Richard E

    2014-01-01

    Since its creation in 1917 the genus Cyclidiopsis, and its validity, has been a source of debate among euglenid taxonomists. While many authors have supported its legitimacy, various other authors have considered it to be a subgenus of Astasia or even promoted its complete dissolution. In this study, we have sequenced the small subunit and large subunit ribosomal DNA of Cyclidiopsis acus, the type species for the genus. Subsequent phylogenetic analyses showed that C. acus grouped with taxa from the genus Lepocinclis, which necessitated the removal of this taxon from Cyclidiopsis and into Lepocinclis as Lepocinclis cyclidiopsis nom. nov. After an extensive literature search it was determined that only two other previously described Cyclidiopsis taxa were morphologically distinct, and the rest were reassigned as synonyms of L. cyclidiopsis. These findings prompted a re-examination of the initial description of Cyclidiopsis, and it was determined that the morphological characters establishing the genus as a distinct group were no longer valid in light of current phylogenetic analyses and the emended generic description for Lepocinclis. Therefore, the remaining two taxa were formally moved to the genus Lepocinclis as L. crescentia comb. nov. and L. pseudomermis comb. nov.

  4. THE GENUS CULLENIA Wight * (Bombacaceae

    Directory of Open Access Journals (Sweden)

    A. J. G. H. KOSTERMANS

    1956-12-01

    Full Text Available The monotypic genus Cullenia was established by Wight (IconesPI. Ind. or. 5 (1 : pi. 1761—62 & text, 1851, who differentiated it fromDurio Adans. mainly by the lack of a corolla and the position and shapeof the anthers. The only species, originally described as Durio ceylanicusby Gardner, was cited by Wight as Cullenia excelsa Wight. K. Schumanncorrected the specific epithet rather casually and atributed it (wronglyto Wight. Bentham (in Benth. & Hook., Gen. pi. 1: 212. 1867; Baillon(Hist. pi. 4: 159. 1872, Masters (in Hook, f., Fl. Br. Ind. 1: 350. 1874and Beccari (Malesia 3: 219. 1889 accepted the genus.Bakhuizen van den Brink (in Bull. Jard. bot. Buitenzorg III, 6: 228.1924 incorporated the genus in Durio.In my opinion Cullenia represents a "good" genus by its lack ofcorolla. Alston, although accepting Bakhuizen's reduction, informed mepersonally, that he, too, is inclined to consider Cullenia different fromDurio.The pollen were described as being naked and pedicellate by Gardner;this wrong statement was corrected by Wight; the anthers are pedicellateand one-celled.In this paper a new Cullenia species is described, which strengthensthe position of the genus; both species are restricted to the rain forestregion of Ceylon and the Southern Indian Peninsula.

  5. Strong embeddings of minimum genus

    CERN Document Server

    Mohar, Bojan

    2009-01-01

    A "folklore conjecture, probably due to Tutte" (as described in [P.D. Seymour, Sums of circuits, Graph theory and related topics (Proc. Conf., Univ. Waterloo, 1977), pp. 341-355, Academic Press, 1979]) asserts that every bridgeless cubic graph can be embedded on a surface of its own genus in such a way that the face boundaries are cycles of the graph. In this paper we consider closed 2-cell embeddings of graphs and show that certain (cubic) graphs (of any fixed genus) have closed 2-cell embedding only in surfaces whose genus is very large (proportional to the order of these graphs), thus providing plethora of strong counterexamples to the above conjecture. The main result yielding such counterexamples may be of independent interest.

  6. MASS SPECTROMETRIC ANALYSIS FOR THE IDENTIFICATION OF THUNNUS GENUS FOUR SPECIES

    Directory of Open Access Journals (Sweden)

    T. Pepe

    2011-01-01

    Full Text Available An accurate identification of similar fish species is necessary to prevent illegal substitution and is imposed by labeling regulations in UE countries (1. The genus Thunnus comprises many species of different quality and commercial value. The increasing trade of fish preparations of the species included in this genus and the consequent loss of the external anatomical and morphological features enables fraudulent substitutions. This study reports data relating to the proteomic analysis of four tuna species (T. thynnus, T. alalunga, T. albacares, T. obesus. Sarcoplasmic proteins were studied by mono and two dimensional electrophoresis. The most significant proteins for the characterization of the species were analyzed by mass spectrometric techniques. As reported in a previous study (2, an accurate identification of the species seems possible, owing to the polymorphism displayed by the species of the Thunnus genus.

  7. Revision of genus Steindachneridion (Siluriformes: Pimelodidae

    Directory of Open Access Journals (Sweden)

    Julio Cesar Garavello

    2005-12-01

    Full Text Available After several years collecting in the type-localities and studying representative samples of genus Steindachneridion Eigenmann & Eigenmann, 1919 from Brazilian and foreign museums, a taxonomic revision of the Recent species of the genus is presented, including the description of a new species from the rio Iguaçu, above the great falls. Steindachneridion species are large sized fishes, reaching 1000 mm total length or more, and sharing some anatomical characters that, at least tentatively, support the monophyly of the genus. In addition to the general features found in the Pimelodidae, the species S. amblyurum (Eigenmann & Eigenmann, 1888, S. parahybae (Steindachner, 1877, S. doceanum (Eigenmann & Eigenmann, 1889, S. scriptum (Miranda Ribeiro, 1918, S. punctatum (Miranda Ribeiro, 1918, and S. melanodermatum, new species, share the shape of the vomer tooth plates, six to eight branched rays in the dorsal-fin, and a low number of gill-rakers. All species, except fossil ones, are redescribed and a key for their identification is provided.Após vários anos coletando nas localidades tipo e estudando amostras representativas de museus brasileiros e estrangeiros, é apresentada uma revisão taxonômica das espécies Recentes do gênero Steindachneridion Eigenmann & Eigenmann, 1919, incluindo a descrição de uma espécie nova da bacia do rio Iguaçu, acima das Cataratas do Iguaçu. Em comum, os adultos de todas as espécies apresentam grande porte, até 1000 mm ou mais de comprimento padrão e compartilham alguns caracteres anatômicos discutidos neste estudo, que pelo menos preliminarmente suportam o monofiletismo do gênero. Além das características gerais de Pimelodidae, S. amblyurum (Eigenmann & Eigenmann, 1888, S. parahybae (Steindachner, 1877, S. doceanum (Eigenmann & Eigenmann, 1889, S. scriptum (Miranda Ribeiro, 1918, S. punctatum (Miranda Ribeiro, 1918 e S. melanodermatum, espécie nova, têm em comum a forma das placas dentígeras do

  8. One Fish, Two Fish, Redfish, You Fish!

    Science.gov (United States)

    White, Katherine; Timmons, Maryellen; Medders, Paul

    2011-01-01

    The recreational fishing activity presented in this article provides a hands-on, problem-based experience for students; it unites biology, math, economics, environmental policy, and population dynamics concepts. In addition, the activity allows students to shape environmental policy in a realistic setting and evaluate their peers' work. By…

  9. Re-description of Apistogramma payaminonis KULLANDER, 1986, with descriptions of two new cichlid species of the genus Apistogramma (Teleostei, Perciformes, Geophaginae) from northern Peru

    OpenAIRE

    2015-01-01

    Apistogramma payaminonis KULLANDER, 1986 is redescribed based on the only two type specimens available, and two new, closely-related Apistogramma species are described from Peru. Data from the original description of A. payaminonis are supplemented with information on phenotypic appearance, which is important for differentiating the taxon from several other species discovered in the last few years. Apistogramma feconat sp. n. is described from four specimens from the catchment of the Rio Tigr...

  10. 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

  11. The medicinal chemistry of genus Aralia.

    Science.gov (United States)

    Clement, Jason A; Clement, Ella S H

    2015-01-01

    The genus Aralia contains many plants used medicinally in Asia and the Americas. Although many members of this genus are used medicinally, the vast majority of this genus has not been explored chemically. The species of Aralia that have been explored chemically have yielded compounds of several classes, including triterpenoid saponins, sterols, diterpenoids, and acetylenic lipids. Many of the biologically active components found in genus Aralia have been evaluated for their potential as lead compounds for drug discovery. This review will explore the medicinal chemistry of compounds reported from genus Aralia, and future prospects for this genus will be considered.

  12. Fighting fish

    Science.gov (United States)

    Duchi, E.; Guerrini, V.; Rinaldi, S.; Schaeffer, G.

    2017-01-01

    We introduce new combinatorial structures, called fighting fish, that generalize directed convex polyominoes by allowing them to branch out of the plane into independent substructures. On the one hand the combinatorial structure of fighting fish appears to be particularly rich: we show that their generating function with respect to the perimeter and number of tails is algebraic, and we conjecture a mysterious multivariate equidistribution property with the left ternary trees introduced by Del Lungo et al On the other hand, fighting fish provide a simple and natural model of random branching surfaces which displays original features: in particular, we show that the average area of a uniform random fighting fish with perimeter 2n is of order n 5/4: to the best of our knowledge this behaviour is non-standard and suggests that we have identified a new universality class of random structures. Dedicated to Tony Guttmann on the occasion of his 70th birthday.

  13. THE GENUS BURRETIODENDRON* Rehder (Tiliaceae

    Directory of Open Access Journals (Sweden)

    AJGH Kostermans

    2014-01-01

    Full Text Available Seven species of Burretwdendron are recognized, of which B. siamensis and B. yunnanensis are new to science. The distributional area of the genus covers Siam (one species, Yunnan (two species, Kweichow (one species;  Kwangsi (three species  and Tonkin (two species. B. tonkinensis is reduced to the synonymy of B. hsienmu. A key to the species is presented.

  14. Alabama ESI: FISH (Fish Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, and freshwater fish species in Alabama. Vector polygons in this data set represent...

  15. Virginia ESI: FISH (Fish Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, anadromous, and brackishwater fish species in Virginia. Vector polygons in this data...

  16. Maryland ESI: FISH (Fish Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, anadromous, and freshwater fish species in Maryland. Vector polygons in this data...

  17. Hawaii ESI: FISH (Fish Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for reef, marine, estuarine, and native stream fish species in coastal Hawaii. Vector polygons in this data...

  18. Louisiana ESI: FISH (Fish Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for freshwater (inland) fish species in coastal Louisiana. Vector polygons represent water-bodies and other...

  19. Rank and genus of 3-manifolds

    CERN Document Server

    Li, Tao

    2011-01-01

    We construct a counterexample to the Rank versus Genus Conjecture, i.e. a closed orientable hyperbolic 3-manifold with rank of its fundamental group smaller than its Heegaard genus. Moreover, we show that the discrepancy between rank and Heegaard genus can be arbitrarily large for hyperbolic 3-manifolds. We also construct toroidal such examples containing hyperbolic JSJ pieces.

  20. The genus Stixis (Capparaceae). A census

    NARCIS (Netherlands)

    Jacobs, M.

    1963-01-01

    For a long time, the genus Stixis has been known in the Indian Floras under the name Roydsia, until Pierre monographed it in 1887. Several of Pierre’s species have in the present paper been reduced, leaving Stixis a genus comprising 7 species and 1 subspecies. The genus, which is very uniform, exten

  1. 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

  2. Maximum Genus of Strong Embeddings

    Institute of Scientific and Technical Information of China (English)

    Er-ling Wei; Yan-pei Liu; Han Ren

    2003-01-01

    The strong embedding conjecture states that any 2-connected graph has a strong embedding on some surface. It implies the circuit double cover conjecture: Any 2-connected graph has a circuit double cover.Conversely, it is not true. But for a 3-regular graph, the two conjectures are equivalent. In this paper, a characterization of graphs having a strong embedding with exactly 3 faces, which is the strong embedding of maximum genus, is given. In addition, some graphs with the property are provided. More generally, an upper bound of the maximum genus of strong embeddings of a graph is presented too. Lastly, it is shown that the interpolation theorem is true to planar Halin graph.

  3. The genus Phytophthora anno 2012.

    Science.gov (United States)

    Kroon, Laurens P N M; Brouwer, Henk; de Cock, Arthur W A M; Govers, Francine

    2012-04-01

    Plant diseases caused by Phytophthora species will remain an ever increasing threat to agriculture and natural ecosystems. Phytophthora literally means plant destroyer, a name coined in the 19th century by Anton de Bary when he investigated the potato disease that set the stage for the Great Irish Famine. Phytophthora infestans, the causal agent of potato late blight, was the first species in a genus that at present has over 100 recognized members. In the last decade, the number of recognized Phytophthora species has nearly doubled and new species are added almost on a monthly basis. Here we present an overview of the 10 clades that are currently distinguished within the genus Phytophthora with special emphasis on new species that have been described since 1996 when Erwin and Ribeiro published the valuable monograph 'Phytophthora diseases worldwide' (35).

  4. Biodiversity of the genus Cladophialophora.

    Science.gov (United States)

    Badali, H; Gueidan, C; Najafzadeh, M J; Bonifaz, A; van den Ende, A H G Gerrits; de Hoog, G S

    2008-01-01

    Cladophialophora is a genus of black yeast-like fungi comprising a number of clinically highly significant species in addition to environmental taxa. The genus has previously been characterized by branched chains of ellipsoidal to fusiform conidia. However, this character was shown to have evolved several times independently in the order Chaetothyriales. On the basis of a multigene phylogeny (nucLSU, nucSSU, RPB1), most of the species of Cladophialophora (including its generic type C. carrionii) belong to a monophyletic group comprising two main clades (carrionii- and bantiana-clades). The genus includes species causing chromoblastomycosis and other skin infections, as well as disseminated and cerebral infections, often in immunocompetent individuals. In the present study, multilocus phylogenetic analyses were combined to a morphological study to characterize phenetically similar Cladophialophora strains. Sequences of the ITS region, partial Translation Elongation Factor 1-alpha and beta-Tubulin genes were analysed for a set of 48 strains. Four novel species were discovered, originating from soft drinks, alkylbenzene-polluted soil, and infected patients. Membership of the both carrionii and bantiana clades might be indicative of potential virulence to humans.

  5. Fishing Access Areas

    Data.gov (United States)

    Vermont Center for Geographic Information — The Vermont Fish & Wildlife Department maintains developed fishing access areas. These sites provide public access to waters in Vermont for shore fishing...

  6. The fish fauna of Brokopondo Reservoir, Suriname, during 40 years of impoundment

    Directory of Open Access Journals (Sweden)

    Jan H. Mol

    Full Text Available We investigated long-term changes in the fish fauna of Brokopondo Reservoir, Suriname, the first large reservoir (1560 km² that was created in tropical rainforest. Before closure of the dam in 1964, the fish fauna of Suriname River had 172 species, high diversity and high evenness. The riverine fauna was dominated by small-sized species, but no single species was dominant in numbers. Large catfishes were dominant in biomass. Species were evenly distributed over riverine habitats: rapids, tributaries and main channel. Four years after closure of the dam, only 62 fish species were collected from Brokopondo Reservoir, but the composition of the fish fauna was still changing. The reservoir fauna in 1978 was very similar to the reservoir fauna in 2005, indicating that a stable equilibrium had been reached 14 years after closure of the dam. The reservoir fauna had 41 species, low diversity and low evenness. Most species of Suriname River and its tributaries with strict habitat requirements did not survive in Brokopondo Reservoir. Fish community structure was different among four habitats of Brokopondo Reservoir. The open-water habitat (10 species was dominated by the piscivores Serrasalmus rhombeus, Acestrorhynchus microlepis and Cichla ocellaris and their prey Bryconops melanurus and two Hemiodus species. B. melanurus fed on zooplankton, Culicinae pupae and terrestrial invertebrates. Hemiodus fed on fine flocculent detritus, demonstrating that the detritus-based food chain was still important in late stages of reservoir development. Serrasalmus rhombeus also fed on peccaries that drowned when swimming across the large reservoir in rough weather. The shore community (27 species was dominated by seven cichlids, but early stages and juveniles of the open-water species S. rhombeus and B. melanurus also occurred in the shore habitat. Fish biomass in the shore habitat was 66.5±59.9 kg ha-1. The cichlid Geophagus surinamensis and the characid B. melanurus

  7. Chemodiversity in the genus Aspergillus.

    Science.gov (United States)

    Frisvad, Jens C; Larsen, Thomas O

    2015-10-01

    Isolates of Aspergillus species are able to produce a large number of secondary metabolites. The profiles of biosynthetic families of secondary metabolites are species specific, whereas individual secondary metabolite families can occur in other species, even those phylogenetically and ecologically unrelated to Aspergillus. Furthermore, there is a high degree of chemo-consistency from isolate to isolate in a species even though certain metabolite gene clusters are silenced in some isolates. Genome sequencing projects have shown that the diversity of secondary metabolites is much larger in each species than previously thought. The potential of finding even further new bioactive drug candidates in Aspergillus is evident, despite the fact that many secondary metabolites have already been structure elucidated and chemotaxonomic studies have shown that many new secondary metabolites have yet to be characterized. The genus Aspergillus is cladistically holophyletic but phenotypically polythetic and very diverse and is associated to quite different sexual states. Following the one fungus one name system, the genus Aspergillus is restricted to a holophyletic clade that include the morphologically different genera Aspergillus, Dichotomomyces, Phialosimplex, Polypaecilum and Cristaspora. Secondary metabolites common between the subgenera and sections of Aspergillus are surprisingly few, but many metabolites are common to a majority of species within the sections. We call small molecule extrolites in the same biosynthetic family isoextrolites. However, it appears that secondary metabolites from one Aspergillus section have analogous metabolites in other sections (here also called heteroisoextrolites). In this review, we give a genus-wide overview of secondary metabolite production in Aspergillus species. Extrolites appear to have evolved because of ecological challenges rather than being inherited from ancestral species, at least when comparing the species in the different

  8. Mating preferences, sexual selection and patterns of cladogenesis in ray-finned fishes.

    Science.gov (United States)

    Mank, J E

    2007-03-01

    Evolutionary theory predicts that sexual selection may increase taxonomic diversity when emergent mating preferences result in reproductive isolation and therefore speciation. This theory has been invoked to explain patterns of diversity in ray-finned fishes (most notably in the cichlids), but the theory has not been tested comparatively in fish. Additionally, several other unrelated factors have been identified as promoters of cladogenesis, so it is unclear how important sexual selection might be in diversification. Using sister-clade analysis, I tested the relationship between the presence of sexually selected traits and taxonomic diversification in actinopterygiian fishes, a large clade that shows substantial diversity in mating preferences and related sexually selected traits. In all identified sister-families that differed with regard to the proportion of species manifesting sexually selected traits, sexual selection was correlated with increased diversification, and this association was significant across all sister clades (P=0.02). This suggests that sexual selection, when present, is a substantial driver of diversification in the ray-finned fishes, and lends further empirical support to the theoretical link between mating preferences and accelerated cladogenesis.

  9. The Fishing Cat

    Institute of Scientific and Technical Information of China (English)

    孙雅飞; 乐伟国

    2008-01-01

    @@ 一、故事内容 A cat goes fishing every day. He wants to eat fish, but he can't catch any fish. One day, he goes to the river as usual. Suddenly, a fish comes out. He catches the fish and putsthe fish in the basket. He's very happy, but he forgest to put the lid on the basket.

  10. Fish gelatin.

    Science.gov (United States)

    Boran, Gokhan; Regenstein, Joe M

    2010-01-01

    Gelatin is a multifunctional ingredient used in foods, pharmaceuticals, cosmetics, and photographic films as a gelling agent, stabilizer, thickener, emulsifier, and film former. As a thermoreversible hydrocolloid with a narrower gap between its melting and gelling temperatures, both of which are below human body temperature, gelatin provides unique advantages over carbohydrate-based gelling agents. Gelatin is mostly produced from pig skin, and cattle hides and bones. Some alternative raw materials have recently gained attention from both researchers and the industry not just because they overcome religious concerns shared by Jews and Muslims but also because they provide, in some cases, technological advantages over mammalian gelatins. Fish skins from a number of fish species are among the other sources that have been comprehensively studied as sources for gelatin production. Fish skins have a significant potential for the production of high-quality gelatin with different melting and gelling temperatures over a much wider range than mammalian gelatins, yet still have a sufficiently high gel strength and viscosity. Gelatin quality is industrially determined by gel strength, viscosity, melting or gelling temperatures, the water content, and microbiological safety. For gelatin manufacturers, yield from a particular raw material is also important. Recent experimental studies have shown that these quality parameters vary greatly depending on the biochemical characteristics of the raw materials, the manufacturing processes applied, and the experimental settings used for quality control tests. In this review, the gelatin quality achieved from different fish species is reviewed along with the experimental procedures used to determine gelatin quality. In addition, the chemical structure of collagen and gelatin, the collagen-gelatin conversion, the gelation process, and the gelatin market are discussed.

  11. Fish hemoglobins

    Directory of Open Access Journals (Sweden)

    P.C. de Souza

    2007-06-01

    Full Text Available Vertebrate hemoglobin, contained in erythrocytes, is a globular protein with a quaternary structure composed of 4 globin chains (2 alpha and 2 beta and a prosthetic group named heme bound to each one. Having myoglobin as an ancestor, hemoglobin acquired the capacity to respond to chemical stimuli that modulate its function according to tissue requirements for oxygen. Fish are generally submitted to spatial and temporal O2 variations and have developed anatomical, physiological and biochemical strategies to adapt to the changing environmental gas availability. Structurally, most fish hemoglobins are tetrameric; however, those from some species such as lamprey and hagfish dissociate, being monomeric when oxygenated and oligomeric when deoxygenated. Fish blood frequently possesses several hemoglobins; the primary origin of this finding lies in the polymorphism that occurs in the globin loci, an aspect that may occasionally confer advantages to its carriers or even be a harmless evolutionary remnant. On the other hand, the functional properties exhibit different behaviors, ranging from a total absence of responses to allosteric regulation to drastic ones, such as the Root effect.

  12. The genus Lolium; taxonomy and genetic resources.

    OpenAIRE

    Loos, B.P.

    1994-01-01

    Several aspects of variation within the genus Lolium, and more in detail within Lolium perenne (perennial ryegrass) have been highlighted. As the results are extensively discussed in each chapter, the general discussion is focused on two aspects of the research.SpeciationIt is clear that the genus Lolium is a very variable genus. The variation within the species reduces the clarity of separation of the species. Stebbins (1956) found the differences between Lolium and Festuca not sufficient to...

  13. Aspidonepsis (Asclepiadaceae, a new southern African genus

    Directory of Open Access Journals (Sweden)

    A. Nicholas

    1992-12-01

    Full Text Available Aspidonepsis, an endemic southern African genus, is described and compared to the closely allied genus Aspidoglossum. This newly described genus is composed of two subgenera, Aspidonepsis and Unguilobium. consisting of three and two species respectively.  Asclepias diploglossa, A. flava, A. cognata and A. reneensis are transferred to Aspidonepsis. and A. shebae is newly described. All species are discussed, illustrated and a key is given to aid in their identification.

  14. THE GENUS DURIO Adans. (Bombac.

    Directory of Open Access Journals (Sweden)

    A. J. G. H. KOSTERMANS

    2015-11-01

    Full Text Available The genus Durio comprises, as far as known, 27 species. The centre ofdistribution is Borneo with 19 species, followed by Malaya with 11 spe-cies and Sumatra with 7 species. It is likely, when Sumatra will be betterexplored, that this island will prove to have many more species. An exclave of the area of distribution is found in Burma, where one endemic species occurs. The common Durio zibethinus Murr. probably originated in Borneo or in Sumatra. It is now widely cultivated outside of its former area and in many places it has become spontaneous.The genus Durio is subdivided into two subgenera: Durio and BoschiaKosterm. & Soegeng, according to the way of dehiscence of the anthers(with a longitudinal slit in the former, with an apical pore in the latter.A key to the species is proposed. A map is added, to show distribution and endemism. Each species is amply described and provided with a drawing . Economic and ecological data are given.

  15. A new fish of the family Scorpaenidae from New Guinea

    NARCIS (Netherlands)

    Mees, G.F.

    1964-01-01

    The ichthyological collections brought together in various parts of New Guinea by staff members of the Rijksmuseum van Natuurlijke Historie in 1954 and 1955 (cf. Boeseman, 1963), contain a series of scorpion-fishes which are here described as a new species, representing a new genus. Cheroscorpaena g

  16. Global distribution of ciguatera causing dinoflagellates in the genus Gambierdiscus.

    Science.gov (United States)

    Litaker, R Wayne; Vandersea, Mark W; Faust, Maria A; Kibler, Steven R; Nau, Amy W; Holland, William C; Chinain, Mireille; Holmes, Michael J; Tester, Patricia A

    2010-10-01

    Dinoflagellates in the genus Gambierdiscus produce toxins that bioaccumulate in tropical and sub-tropical fishes causing ciguatera fish poisoning (CFP). Little is known about the diversity and distribution of Gambierdiscus species, the degree to which individual species vary in toxicity, and the role each plays in causing CFP. This paper presents the first global distribution of Gambierdiscus species. Phylogenetic analyses of the existing isolates indicate that five species are endemic to the Atlantic (including the Caribbean/West Indies and Gulf of Mexico), five are endemic to the tropical Pacific, and that two species, Gambierdiscus carpenteri and Gambierdiscus caribaeus are globally distributed. The differences in Gambierdiscus species composition in the Atlantic and Pacific correlated with structural differences in the ciguatoxins reported from Atlantic and Pacific fish. This correlation supports the hypothesis that Gambierdiscus species in each region produce different toxin suites. A literature survey indicated a >100-fold variation in toxicity among species compared with a 2 to 9-fold within species variation due to changing growth conditions. These observations suggest that CFP events are driven more by inherent differences in species toxicity than by environmental modulation. How variations in species toxicity may affect the development of an early warning system for CFP is discussed.

  17. Systematics of the Jaguar catfish genus Liosomadoras Fowler, 1940 (Auchenipteridae: Siluriformes

    Directory of Open Access Journals (Sweden)

    José L. O. Birindelli

    Full Text Available Liosomadoras Fowler, 1940 includes two nominal species: L. oncinus, described from the rio Negro in Brazil, and L. morrowi described from the Peruvian Amazon. Both species are known from only few specimens deposited in fish collections, and information on these fishes is scarce. In order to rectify this situation, diagnoses of the genus and its species and an osteological description of L. oncinus are presented based on recently collected specimens. In addition, the taxonomy of the species of Liosomadoras is reviewed, and L. morrowi is confirmed as distinct from L. oncinus, and also distributed in the Brazilian Amazon. Liosomadoras is hypothesized as a relatively basal genus within Auchenipterinae, sister to all other species of the group, except Asterophysus batrachus and Tocantinsia piresi.

  18. Graphical outline of history of the genus Carassius occurrence in the Europe

    Directory of Open Access Journals (Sweden)

    Katerina Rylkova

    2015-11-01

    Full Text Available From the phylogeographical point of view, status of the genus Carassius underwent major transformation within the Europe territory. Apart of two native members (Carassius carassius and diploid biotype of Carassius gibelio, we recognize four non-indigenous taxa (C. auratus, C. langsdorfii, C. sp. and polyploid biotype of C. gibelio. Especially last mentioned one became an icon of invasive fish species. Whether apparent or cryptic invasion, it begun in supposed starting point of lower Danube River, and consequently has spread westwards. This was greatly supported by human intentions. Within last decade, its campaign through Europe was completed by invading of major river systems of Iberian Peninsula. Unclear is origin and pilgrimage of C. langsdorfii which is native to Japanese archipelago. So far, this fish was recorded in various localities of central, south and east Europe. There are molecular clues claiming multiple origin since vast genetic variability of analyzed individuals. Another iconic fish species is C. auratus, one of the oldest fish domesticates and most favorite ornamental fish ever. Its spreading is closely linked to ornamental trade and releasing by breeders or escapes from breeding facilities. Unlike of previous two, C. auratus establishment is dependent on temperate climate. Last taxon occurring in within Europe is C. sp., also marked as Carassius mitochondrial lineage “M”. So far this lineage was recorded from several localities of central Europe. Whether it represents invader form Asia or cryptic native species is not known. Here we tried to resume time schedule of genus Carassius movements through Europe.

  19. Local phylogenetic divergence and global evolutionary convergence of skull function in reef fishes of the family Labridae.

    Science.gov (United States)

    Westneat, Mark W; Alfaro, Michael E; Wainwright, Peter C; Bellwood, David R; Grubich, Justin R; Fessler, Jennifer L; Clements, Kendall D; Smith, Lydia L

    2005-05-22

    The Labridae is one of the most structurally and functionally diversified fish families on coral and rocky reefs around the world, providing a compelling system for examination of evolutionary patterns of functional change. Labrid fishes have evolved a diverse array of skull forms for feeding on prey ranging from molluscs, crustaceans, plankton, detritus, algae, coral and other fishes. The species richness and diversity of feeding ecology in the Labridae make this group a marine analogue to the cichlid fishes. Despite the importance of labrids to coastal reef ecology, we lack evolutionary analysis of feeding biomechanics among labrids. Here, we combine a molecular phylogeny of the Labridae with the biomechanics of skull function to reveal a broad pattern of repeated convergence in labrid feeding systems. Mechanically fast jaw systems have evolved independently at least 14 times from ancestors with forceful jaws. A repeated phylogenetic pattern of functional divergence in local regions of the labrid tree produces an emergent family-wide pattern of global convergence in jaw function. Divergence of close relatives, convergence among higher clades and several unusual 'breakthroughs' in skull function characterize the evolution of functional complexity in one of the most diverse groups of reef fishes.

  20. Development of a real-time PCR method coupled with a selective pre-enrichment step for quantification of Morganella morganii and Morganella psychrotolerans in fish products

    DEFF Research Database (Denmark)

    Podeur, Gaetan; Dalgaard, Paw; Leroi, Francoise;

    2015-01-01

    Histamine fish poisoning is common and due to toxic concentrations of histamine often produced by Gram-negative bacteria in fin-fish products with a high content of the free amino acid histidine. The genus Morganella includes two species previously reported to cause incidents of histamine fish po...

  1. Fish Tales

    Energy Technology Data Exchange (ETDEWEB)

    McLerran, L.

    2010-07-06

    This talk is about fishing and the friendships that have resulted in its pursuit. It is also about theoretical physics, and the relationship of imagination and fantasy to the establishment of ideas about nature. Fishermen, like theoretical physicists, are well known for their inventive imaginations. Perhaps neither are as clever as sailors, who conceived of the mermaid. If one doubts the power of this fantasy, one should remember the ghosts of the many sailors who drowned pursuing these young nymphs. An extraordinary painting by J. Waterhouse is shown as Fig. 1. The enchantment of a mermaid must reflect an extraordinary excess of imagination on the part of the sailor, perhaps together with an impractical turn of mind. A consummated relationship with a mermaid is after all, by its very nature a fantasy incapable of realization. To a theoretical physicist, she is symbolic of many ideas we develop. There are many truths known to fisherman in which one might also find parallels to the goals of scientists: (1) A fish is the only animal that keeps growing after its death; (2) Nothing makes a fish bigger than almost being caught; (3) ''...of all the liars among mankind, the fisherman is the most trustworthy.'' (William Sherwood Fox, in Silken Lines and Silver Hooks); and (4) Men and fish are alike. They both get into trouble when they open their mouths. These quotes may be interpreted as reflecting skepticism regarding the honesty of fisherman, and probably do not reflect adequate admiration for a creative imagination. Is it fair to criticize a person for believing a falsehood that he or she sincerely believes to be true? The fisherman simultaneously invents the lie, and believes in it himself. The parallel with theoretical physics is perhaps only approximate, although we physicists may invent stories that we come to believe, on some rare occasions our ideas actually correspond to a more or less true descriptions of nature. These minor philosophical

  2. Fish Immunoglobulins

    Science.gov (United States)

    Mashoof, Sara; Criscitiello, Michael F.

    2016-01-01

    The B cell receptor and secreted antibody are at the nexus of humoral adaptive immunity. In this review, we summarize what is known of the immunoglobulin genes of jawed cartilaginous and bony fishes. We focus on what has been learned from genomic or cDNA sequence data, but where appropriate draw upon protein, immunization, affinity and structural studies. Work from major aquatic model organisms and less studied comparative species are both included to define what is the rule for an immunoglobulin isotype or taxonomic group and what exemplifies an exception. PMID:27879632

  3. A NEW SPECIES OF THE GENUS NEROCILA (ISOPODA:CYMOTHOIDAE) FROM THE EAST CHINA SEA

    Institute of Scientific and Technical Information of China (English)

    于海燕; 李新正

    2002-01-01

    A new species of cymothoid Isopoda, Nerocila donghaiensis, collected fr om the b ody of a sciaenid fish, Johnius sp., is described in the present paper. The new species can be distinguished from the other species of genus Nerocila by it s en dopod of uropods with deep notch, sharply serrated on the lateral margin and str ongly serrated on the medial margin; antennule with 1st article swollen; dactyli of pereopods I, II, IV, V swollen.

  4. The genus Allium. Part 2.

    Science.gov (United States)

    Fenwick, G R; Hanley, A B

    1985-01-01

    Allium is a genus of some 500 species belonging to the family Liliaceae. However only a few of these are important as food plants, notably onion, garlic, chive, leek, and rakkyo. Such plants have been used for many centuries for the pungency and flavoring value, for their medicinal properties, and, in some parts of the world, their use also has religious connotations. The flavors of members of the genus Alliums, in addition to having certain characteristics, are also complex, being derived enzymically from a number of involatile precursors. In addition to there being variation of flavor between different alliums, there are also considerable changes that occur as a result of cooking and processing. Of course, these are of importance to the consumer and food technologist-processor. The review will introduce the subject by an historical perspective and will set this against data on the present cultivation and usage of commercially cultivated alliums. The chemical composition of these plants will be discussed, emphasis being given to nonvolatile constituents which are, perhaps, less often considered. Discussion of the volatile constituents, which will include mention of the methods currently used for their analysis and for the determination of "flavor strength", will be mainly concerned with literature taken from the last 5 years. In considering the extent and nature of allium cultivation and processing, factors affecting the nutritional value and quality will be highlighted. The medicinal properties of garlic and onion oils have been much studied over the last decade and the review will include critical assessment of this area and also will touch on the more general properties (antimicrobial, antifungal, antibacterial, and insecticidal) of these oils. Finally mention will be made of the antinutritional, toxic, or otherwise undesirable effects of alliums, for example, as inadvertent components of animal diets, tainting of milk and other food products. It is our

  5. Evolution of the Genus Homo

    Science.gov (United States)

    Tattersall, Ian; Schwartz, Jeffrey H.

    2009-05-01

    Definition of the genus Homo is almost as fraught as the definition of Homo sapiens. We look at the evidence for “early Homo,” finding little morphological basis for extending our genus to any of the 2.5-1.6-myr-old fossil forms assigned to “early Homo” or Homo habilis/rudolfensis. We also point to heterogeneity among “early African Homo erectus,” and the lack of apomorphies linking these fossils to the Asian Homo erectus group, a cohesive regional clade that shows some internal variation, including brain size increase over time. The first truly cosmopolitan Homo species is Homo heidelbergensis, known from Africa, Europe, and China following 600 kyr ago. One species sympatric with it included the >500-kyr-old Sima de los Huesos fossils from Spain, clearly distinct from Homo heidelbergensis and the oldest hominids assignable to the clade additionally containing Homo neanderthalensis. This clade also shows evidence of brain size expansion with time; but although Homo neanderthalensis had a large brain, it left no unequivocal evidence of the symbolic consciousness that makes our species unique. Homo sapiens clearly originated in Africa, where it existed as a physical entity before it began (also in that continent) to show the first stirrings of symbolism. Most likely, the biological underpinnings of symbolic consciousness were exaptively acquired in the radical developmental reorganization that gave rise to the highly characteristic osteological structure of Homo sapiens, but lay fallow for tens of thousands of years before being “discovered” by a cultural stimulus, plausibly the invention of language.

  6. Resurrection of the genus Haplanthus (Acanthaceae: Andrographinae)

    NARCIS (Netherlands)

    Gnanasekaran, G.; Murthy, G.V.S.; Deng, Y.F.

    2016-01-01

    A systematic morphological study of Andrographis (Acanthaceae: Andrographinae) in India has revealed that the genus Haplanthus is distinct from Andrographis. We resurrect the genus Haplanthus here with four species, one of which contains three varieties. Five new combinations are proposed: H. laxifl

  7. New Forms in the genus Erebia (Lepidoptera)

    NARCIS (Netherlands)

    Eisner, C.

    1946-01-01

    A revision of the material belonging to the genus Erebia Dalman in the Rijksmuseum van Natuurlijke Historie at Leiden, mainly based on the "Monograph of the genus Erebia" by B. C. S. Warren (London, 1936), induced me to describe a number of new subspecies and aberrations, and to make some remarks on

  8. Cytotaxonomic studies in the genus Campanula

    NARCIS (Netherlands)

    Gadella, Th.W.J.

    1964-01-01

    De Candolle (1830) divided the genus Campanula into two large sections on basis of the presence or absence of calyx-appendages between the calyx-lobes. Boissier (1875) attached great value to the mode of dehiscence of the capsule, and divided the genus into two sections. None of the existing classif

  9. A monograph of the genus Evolvulus

    NARCIS (Netherlands)

    Ooststroom, van S.J.

    1934-01-01

    The great difficulties arising in the identification of a number of plants belonging to the genus Evolvulus, which plants were found in several recent collections of Convolvulaceae and were kindly entrusted to me for study, induced me to submit this genus to a further examination. It soon proved how

  10. A new genus of Lindsaeoid ferns

    NARCIS (Netherlands)

    Kramer, K.U.

    1957-01-01

    In revising the New World representatives of the genus Lindsaea, the author came across a fern specimen from Borneo preserved in the Rijksherbarium, Leiden, that did not seem to fit into any described genus. It had been described as Schizoloma stortii v. A. v. R., but in the author’s opinion the gen

  11. A monograph of the Genus Aristida

    NARCIS (Netherlands)

    Henrard, J.Th.

    1929-01-01

    In a preliminary work: „A critical Revision of the genus Aristida”, I have given a review of all the hitherto described species of this genus with the citation of the literature, the exact copies of the authentic descriptions and the figures of the spikelet-characters, taken from the type specimens

  12. A taxonomic revision of the genus Podocarpus

    NARCIS (Netherlands)

    Laubenfels, de D.J.

    1985-01-01

    In connection with the forthcoming revision of the Coniferae for the Flora Malesiana, the author thought it necessary to revise the genus Podocarpus. Although this genus has a substantial representation in Malesia (30 species), the revision is too involved to be appropriate with the Flora Malesiana

  13. Deep Fish.

    Science.gov (United States)

    Ishaq, Omer; Sadanandan, Sajith Kecheril; Wählby, Carolina

    2017-01-01

    Zebrafish ( Danio rerio) is an important vertebrate model organism in biomedical research, especially suitable for morphological screening due to its transparent body during early development. Deep learning has emerged as a dominant paradigm for data analysis and found a number of applications in computer vision and image analysis. Here we demonstrate the potential of a deep learning approach for accurate high-throughput classification of whole-body zebrafish deformations in multifish microwell plates. Deep learning uses the raw image data as an input, without the need of expert knowledge for feature design or optimization of the segmentation parameters. We trained the deep learning classifier on as few as 84 images (before data augmentation) and achieved a classification accuracy of 92.8% on an unseen test data set that is comparable to the previous state of the art (95%) based on user-specified segmentation and deformation metrics. Ablation studies by digitally removing whole fish or parts of the fish from the images revealed that the classifier learned discriminative features from the image foreground, and we observed that the deformations of the head region, rather than the visually apparent bent tail, were more important for good classification performance.

  14. Are the fish of the upper and lower Mekong interconnected?

    Institute of Scientific and Technical Information of China (English)

    KANG Bin; PERRETT Lisa; LI Yungang; HE Daming

    2009-01-01

    The Mekong supports one of the richest inland fisheries in the world, with many of the fish migrating long distance to spawn. Little is known about the fisheries and migration strategies of the Upper Mekong whilst it is supposed that many fish species move between the Lower and Upper Mekong. Most likely, natural fish migration in the fiver has been altered by dam construction across the mainstream of the Upper Mekong. In this paper, the interconnectivity of fish species between different sections of the Mekong and negative impacts of dams on migratory fish are studied. Of the 162 fish species in the Upper Mekong and the 869 species in the Lower Mekong, 61 species are common. Results show that there is no significant difference at order level between the UM and LM. Similarity coefficients are used to evaluate interconnectivity at species, genus and family levels among four different sections of the Upper Mekong with each other and with the Lower Mekong as a whole. The highest similarity is found between the middle and lower reach of the Upper Mekong at species and genus levels and the middle and upper reach at family level. Of the eight cascade dams, Mengsong Dam in planning is considered as the biggest threat to migratory fish from the Lower Mekong and should be particularly concerned.

  15. Sugawara construction for higher genus Riemann surfaces

    Science.gov (United States)

    Schlichenmaier, Martin

    1999-04-01

    By the classical genus zero Sugawara construction one obtains representations of the Virasoro algebra from admissible representations of affine Lie algebras (Kac-Moody algebras of affine type). In this lecture, the classical construction is recalled first. Then, after giving a review on the global multi-point algebras of Krichever-Novikov type for compact Riemann surfaces of arbitrary genus, the higher genus Sugawara construction is introduced. Finally, the lecture reports on results obtained in a joint work with O. K. Sheinman. We were able to show that also in the higher genus, multi-point situation one obtains (from representations of the global algebras of affine type) representations of a centrally extended algebra of meromorphic vector fields on Riemann surfaces. The latter algebra is a generalization of the Virasoro algebra to higher genus.

  16. Evolution of a genetic incompatibility in the genus Xiphophorus.

    Science.gov (United States)

    Scarpino, Samuel V; Hunt, Patrick J; Garcia-De-Leon, Francisco J; Juenger, Thomas E; Schartl, Manfred; Kirkpatrick, Mark

    2013-10-01

    Genetic incompatibilities are commonly observed between hybridizing species. Although this type of isolating mechanism has received considerable attention, we have few examples describing how genetic incompatibilities evolve. We investigated the evolution of two loci involved in a classic example of a Bateson-Dobzhansky-Muller (BDM) incompatibility in Xiphophorus, a genus of freshwater fishes from northern Central America. Hybrids develop a lethal melanoma due to the interaction of two loci, an oncogene and its repressor. We cloned and sequenced the putative repressor locus in 25 Xiphophorus species and an outgroup species, and determined the status of the oncogene in those species from the literature. Using phylogenetic analyses, we find evidence that a repeat region in the proximal promoter of the repressor is coevolving with the oncogene. The data support a hypothesis that departs from the standard BDM model: it appears the alleles that cause the incompatibilities have coevolved simultaneously within lineages, rather than in allopatric or temporal isolation.

  17. Parasites of freshwater fishes and the Great American Biotic Interchange: a bridge too far?

    Science.gov (United States)

    Choudhury, A; García-Varela, M; Pérez-Ponce de León, G

    2017-03-01

    We examine the extent to which adult helminths of freshwater fishes have been part of the Great American Biotic Interchange (GABI), by integrating information in published studies and new data from Panama with fish biogeography and Earth history of Middle America. The review illustrates the following: (1) the helminth fauna south of the Trans-Mexican Volcanic Belt, and especially south of the Isthmus of Tehuantepec, shows strong Neotropical affinities; (2) host-parasite associations follow principles of the 'biogeographic core fauna' in which host-lineage specificity is pronounced; (3) phylogenetic analysis of the widespread freshwater trematode family Allocreadiidae reveals a complex history of host-shifting and co-diversification involving mainly cyprinodontiforms and characids; (4) allocreadiids, monogeneans and spiruridan nematodes of Middle American cyprinodontiforms may provide clues to the evolutionary history of their hosts; and (5) phylogenetic analyses of cryptogonimid trematodes may reveal whether or how cichlids interacted with marine or brackish-water environments during their colonization history. The review shows that 'interchange' is limited and asymmetrical, but simple narratives of northward isthmian dispersal will likely prove inadequate to explain the historical biogeography of many host-parasite associations in tropical Middle America, particularly those involving poeciliids. Finally, our study highlights the urgent need for targeted survey work across Middle America, focused sampling in river drainages of Colombia and Venezuela, and deeper strategic sampling in other parts of South America, in order to develop and test robust hypotheses about fish-parasite associations in Middle America.

  18. Neuroplastic reactivity of fish induced by altered gravity conditions: a review of recent results

    Science.gov (United States)

    Rahmann, H.; Anken, R. H.

    A review is being presented concerning behavioural, biochemical, histochemical and electronmicroscopical data on the influence of altered gravitational forces on the swimming performance and on the neuronal differentiation of the brain of cichlid fish larvae and adult swordtail fish that had been exposed to hyper-gravity (3g in laboratory centrifuges), hypo-gravity (>10^-2g in a fast-rotating clinostat) and to near weightlessness (10^-4g aboard the spacelab D-2 mission). After long-term alterations of gravity (and parallel light deprivation), initial disturbances in the swimming behaviour followed by a stepwise regain of normal swimming modes are induced. Parallely, neuroplastic reactivities on different levels of investigation were found, such as adaptive alterations of activities of various enzymes in whole brain as well as in specific neuronal integration centers and an intraneuronal reactivity on ultrastructural level in individual brain parts and in the sensory epithelia of the inner ear. Taken together, these data reveal distinct adaptive neuroplastic reactions of fish to altered gravity conditions.

  19. Influence of watershed activities on the water quality and fish assemblages of a tropical African reservoir.

    Science.gov (United States)

    Mustapha, Moshood K

    2009-09-01

    Agricultural and fisheries activities around the watershed of an African tropical reservoir (Oyun reservoir, Offa, Nigeria) were found to contribute significantly to water quality deterioration of the dam axis of the reservoir, leading to eutrophication of that part of the reservoir. This is evident from the high amount of nitrate (6.4 mg/l), phosphate (2.2 mg/l) and sulphate (16.9 mg/l) in the water body which was higher than most other reservoirs in Nigeria. These nutrients originate in fertilizer run-offs from nearby farmlands and were found in higher concentrations in the rainy season which is usually the peak of agricultural activities in the locality. The eutrophication was more pronounced on the dam axis because it is the point of greatest human contact where pressure and run-off of sediments were high. The eutrophication altered the food web cycle which consequently affected the fish species composition and abundance with the dominance of cichlids (planktivorous group) and decline of some species in the fish population. Best management practices (BMP) to control and reduce the eutrophication and improve water quality and fish assemblages should be adopted and adapted to suit the situation in the reservoir.

  20. Fishing amplifies forage fish population collapses.

    Science.gov (United States)

    Essington, Timothy E; Moriarty, Pamela E; Froehlich, Halley E; Hodgson, Emma E; Koehn, Laura E; Oken, Kiva L; Siple, Margaret C; Stawitz, Christine C

    2015-05-26

    Forage fish support the largest fisheries in the world but also play key roles in marine food webs by transferring energy from plankton to upper trophic-level predators, such as large fish, seabirds, and marine mammals. Fishing can, thereby, have far reaching consequences on marine food webs unless safeguards are in place to avoid depleting forage fish to dangerously low levels, where dependent predators are most vulnerable. However, disentangling the contributions of fishing vs. natural processes on population dynamics has been difficult because of the sensitivity of these stocks to environmental conditions. Here, we overcome this difficulty by collating population time series for forage fish populations that account for nearly two-thirds of global catch of forage fish to identify the fingerprint of fisheries on their population dynamics. Forage fish population collapses shared a set of common and unique characteristics: high fishing pressure for several years before collapse, a sharp drop in natural population productivity, and a lagged response to reduce fishing pressure. Lagged response to natural productivity declines can sharply amplify the magnitude of naturally occurring population fluctuations. Finally, we show that the magnitude and frequency of collapses are greater than expected from natural productivity characteristics and therefore, likely attributed to fishing. The durations of collapses, however, were not different from those expected based on natural productivity shifts. A risk-based management scheme that reduces fishing when populations become scarce would protect forage fish and their predators from collapse with little effect on long-term average catches.

  1. Humpback Dolphins: A Brief Introduction to the Genus Sousa.

    Science.gov (United States)

    Jefferson, Thomas A; Curry, Barbara E

    2015-01-01

    The delphinid genus Sousa has recently undergone a major revision, and currently contains four species, the Atlantic humpback (Sousa teuszii), Indian Ocean humpback (Sousa plumbea), Indo-Pacific humpback (Sousa chinensis), and Australian humpback (Sousa sahulensis) dolphins. Recent molecular evidence suggests that humpback dolphins in the Bay of Bengal may comprise a fifth species. These moderate-sized dolphin species are found in shallow (dolphins feed mostly on small fishes, and sometimes shrimps; occur for the most part in small groups (mostly 12 or less); have limited nearshore movements; and in most parts of their range exhibit a fission/fusion type of social organization. Major threats that affect all the species are entanglement in fishing gear, and habitat degradation/destruction from various forms of coastal development. Impacts from vessel traffic (including behavioural disturbance and displacement, as well as mortality and morbidity from collisions with vessels) appear to be significant in most areas. Several other threats are apparently significant only in particular parts of the range of some species (e.g. high levels of organochlorine contaminants affecting Indo-Pacific humpback dolphins in Hong Kong). Direct hunting only occurs in limited areas and primarily on a small scale. Conservation actions so far have been limited, with most populations receiving little study and almost no management attention. Much more work is needed on humpback dolphin population status, threats, and how the major threats can be reduced or eliminated. Extinction risks for the four species and some populations are preliminarily re-assessed using the IUCN Red List criteria in the current volume. The results suggest that all four species in the genus are threatened at some level (suggested Red List status ranges from Vulnerable for S. chinensis and S. sahulensis to Critically Endangered for S. teuszii).

  2. Sport Fishing Regulations

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The regulations for sport fishing on St. Vincent National Wildlife Refuge are outlined in this document. Fishing is only permitted from sunrise to sunset, and only...

  3. Fish Springs pond snail

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Communication scenario between the branch of Listing and Recovery, Fish and Wildlife Enhancement, and Fish Springs National Wildlife Refuge (NWR), in regards to the...

  4. Fish tapeworm infection

    Science.gov (United States)

    Fish tapeworm infection is an intestinal infection with the tapeworm parasite found in fish. ... The fish tapeworm ( Diphyllobothrium latum ) is the largest parasite that infects humans. Humans become infected when they eat raw ...

  5. Got a Sick Fish?

    Science.gov (United States)

    ... Welfare Veterinary Careers Public Health Got a sick fish? Fish with disease can show a variety of signs. If you notice your pet fish having any unusual disease signs, contact your veterinarian ...

  6. Perception and discrimination of movement and biological motion patterns in fish.

    Science.gov (United States)

    Schluessel, V; Kortekamp, N; Cortes, J A Ortiz; Klein, A; Bleckmann, H

    2015-09-01

    Vision is of primary importance for many fish species, as is the recognition of movement. With the exception of one study, assessing the influence of conspecific movement on shoaling behaviour, the perception of biological motion in fish had not been studied in a cognitive context. The aim of the present study was therefore to assess the discrimination abilities of two teleost species in regard to simple and complex movement patterns of dots and objects, including biological motion patterns using point and point-light displays (PDs and PLDs). In two-alternative forced-choice experiments, in which choosing the designated positive stimulus was food-reinforced, fish were first tested in their ability to distinguish the video of a stationary black dot on a light background from the video of a moving black dot presented at different frequencies and amplitudes. While all fish succeeded in learning the task, performance declined with decreases in either or both parameters. In subsequent tests, cichlids and damselfish distinguished successfully between the videos of two dots moving at different speeds and amplitudes, between two moving dot patterns (sinus vs. expiring sinus) and between animated videos of two moving organisms (trout vs. eel). Transfer tests following the training of the latter showed that fish were unable to identify the positive stimulus (trout) by means of its PD alone, thereby indicating that the ability of humans to spontaneously recognize an organism based on its biological motion may not be present in fish. All participating individuals successfully discriminated between two PDs and two PLDs after a short period of training, indicating that biological motions presented in form of PLDs are perceived and can be distinguished. Results were the same for the presentation of dark dots on a light background and light dots on a dark background.

  7. No Fishing Now,More Fish Later

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Fishing ban for ecological purposes starts on the Pearl River Since April1,a two-month ban on fishing has been imposed on the Pearl River valley in south China.It is the first fishing ban in this area with the purpose of preserving biodiversity in China’s third longest

  8. Microbiological spoilage of fish and fish products

    DEFF Research Database (Denmark)

    Gram, Lone; Huss, Hans Henrik

    1996-01-01

    Spoilage of fresh and lightly preserved fish products is caused by microbial action. This paper reviews the current knowledge in terms of the microbiology of fish and fish products with particular emphasis on identification of specific spoilage bacteria and the qualitative and quantitative...

  9. Genus llex L.: Phytochemistry, Ethnopharmacology, and Pharmacology

    Institute of Scientific and Technical Information of China (English)

    Fan Yi; Xiao-ling Zhao; Yong Peng; Pei-gen Xiao

    2016-01-01

    The genus llex L. has been used as remedies in traditional Chinese medicine in Aquifoliaceae and beverages for thousands of years due to abundant pharmaceutical bioactivities. There are 600 species in genus llex L. containing various compounds such as terpenoids, saponins, glycosides, etc. Three species, I. cornuta, I. chinensis, and I. rotunda have been admitted in Chinese Pharmacopoeia 2015 to treat dyspepsia, stomatitis, and hyperactivity cough and protect the liver and kidney. Recent studies showed that several species have been daily drunk to promote human health and prevent cardiovascular diseases in the folk. Here we reviewed the genus llex L. in phytochemistry, ethnopharmacology, and pharmacology.

  10. The genus of a type of graph

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Based on the joint tree model introduced by Liu, the genera of further types of graphs not necessary to have certain symmetry can be obtained. In this paper, we obtain the genus of a new type of graph with weak symmetry. As a corollary, the genus of complete tripartite graph K n,n,l (l≥n≥2) is also derived. The method used here is more direct than those methods, such as current graph, used to calculate the genus of a graph and can be realized in polynomial time.

  11. Keanekaragaman metabolit sekunder Genus Artocarpus (Moraceae

    Directory of Open Access Journals (Sweden)

    ALIEFMAN HAKIM

    2011-11-01

    Full Text Available Hakim A. 2011. Keanekaragaman metabolit sekunder Genus Artocarpus (Moraceae. Bioteknologi 8: 86-98. Beberaapa spesies dari genus Artocarpus (Moraceae telah diteliti kandungan bahan alamnya. Metabolit sekunder yang berhasil diisolasi dari genus Artocarpus terdiri dari terpenoid, flavonoid, stilbenoid, arilbenzofuran, neolignan, dan adduct Diels-Alder. Kelompok flavonoid merupakan senyawa yang paling banyak ditemukan dari tumbuhan Artocarpus. Senyawa flavonoid yang telah berhasil diisolasi dari tumbuhan Artocarpus memiliki kerangka yang beragam seperti calkon, flavanon, flavan-3-ol, flavon sederhana, prenilflavon, oksepinoflavon, piranoflavon, dihidrobenzosanton, furanodi hidrobenzosanton, piranodihidrobenzosanton, kuinonosanton, siklolopentenosanton, santonolid, dihidrosanton.

  12. Current status of parasitic ciliates Chilodonella spp. (Phyllopharyngea: Chilodonellidae) in freshwater fish aquaculture.

    Science.gov (United States)

    Bastos Gomes, G; Jerry, D R; Miller, T L; Hutson, K S

    2016-07-30

    Freshwater fish farming contributes to more than two-thirds of global aquaculture production. Parasitic ciliates are one of the largest causes of production loss in freshwater farmed fishes, with species from the genus Chilodonella being particularly problematic. While Chilodonella spp. include 'free-living' fauna, some species are involved in mortality events of fish, particularly in high-density aquaculture. Indeed, chilodonellosis causes major productivity losses in over 16 species of farmed freshwater fishes in more than 14 countries. Traditionally, Chilodonella species are identified based on morphological features; however, the genus comprises yet uncharacterized cryptic species, which indicates the necessity for molecular diagnostic methods. This review synthesizes current knowledge on the biology, ecology and geographic distribution of harmful Chilodonella spp. and examines pathological signs, diagnostic methods and treatments. Recent advances in molecular diagnostics and the ability to culture Chilodonella spp. in vitro will enable the development of preventative management practices and sustained freshwater fish aquaculture production.

  13. Plastic fish

    CERN Multimedia

    Antonella Del Rosso

    2015-01-01

    In terms of weight, the plastic pollution in the world’s oceans is estimated to be around 300,000 tonnes. This plastic comes from both land-based and ocean-based sources. A lecture at CERN by chemist Wolfgang Trettnak addressed this issue and highlighted the role of art in raising people’s awareness.   Artwork by Wolfgang Trettnak. Packaging materials, consumer goods (shoes, kids’ toys, etc.), leftovers from fishing and aquaculture activities… our oceans and beaches are full of plastic litter. Most of the debris from beaches is plastic bottles. “PET bottles have high durability and stability,” explains Wolfgang Trettnak, a chemist by education and artist from Austria, who gave a lecture on this topic organised by the Staff Association at CERN on 26 May. “PET degrades very slowly and the estimated lifetime of a bottle is 450 years.” In addition to the beach litter accumulated from human use, rivers bring several ki...

  14. Molecular epidemiology and evolution of fish Novirhabdoviruses

    Science.gov (United States)

    Kurath, Gael

    2014-01-01

    The genus Novirhabdoviridae contains several of the important rhabdoviruses that infect fish hosts. There are four established virus species: Infectious hematopoietic necrosis virus (IHNV), Viral hemorrhagic septicemia virus (VHSV), Hirame rhabdovirus(HIRRV), and Snakehead rhabdovirus (SHRV). Viruses of these species vary in host and geographic range, and they have all been studied at the molecular and genomic level. As globally significant pathogens of cultured fish, IHNV and VHSV have been particularly well studied in terms of molecular epidemiology and evolution. Phylogenic analyses of hundreds of field isolates have defined five major genogroups of IHNV and four major genotypes of VHSV worldwide. These phylogenies are informed by the known histories of IHNV and VHSV, each involving a series of viral emergence events that are sometimes associated with host switches, most often into cultured rainbow trout. In general, IHNV has relatively low genetic diversity and a narrow host range, and has been spread from its endemic source in North American to Europe and Asia due to aquaculture activities. In contrast, VHSV has broad host range and high genetic diversity, and the source of emergence events is virus in widespread marine fish reservoirs in the northern Atlantic and Pacific Oceans. Common mechanisms of emergence and host switch events include use of raw feed, proximity to wild fish reservoirs of virus, and geographic translocations of virus or naive fish hosts associated with aquaculture.

  15. Monograph of the genus Phylacium (Leguminosae)

    NARCIS (Netherlands)

    Bresser, Mirjam

    1978-01-01

    In the genus Phylacium 2 species are recognized. Special attention is paid to the morphology of the inflorescence; full descriptions are given with plates and a map, showing the distribution of both species.

  16. Taxonomy of the genus Passerina (Thymelaeaceae

    Directory of Open Access Journals (Sweden)

    C. L. Bredenkamp

    2003-12-01

    Full Text Available Passerina L. is mainly a southern African genus, comprising 20 species and four subspecies. A few species occur along the Great Escarpment, two extend into Zimbabwe and Mozambique, but most are concentrated in the Cape Floristic Region. Palynological. macromorphological and anatomical evidence was used in the delimitation of the genus and its infrageneric taxa. A cladistic study supports Passerina as a monophyletic genus. A genus treatment, key to species and a full species treatment are given. Each species treatment includes a taxonomic diagnosis, description and notes on taxonomy, etymology, economic value and distribution. Illustrations of representative species are provided and distribution maps are included for each species.  P. esterhuyseniae Bredenk. & A.E.van Wyk is newly described. A list of excluded species names highlights the previous cosmopolitan taxonomic interpretation of Passerina. as many names are now in synony my under other genera of the Thymelaeaceae.

  17. Synaptospory in the fern genus Pyrrosia (Polypodiaceae)

    NARCIS (Netherlands)

    Uffelen, van Gerda A.

    1985-01-01

    The correlation between sporoderm sculpture and life form of the sporophyte as postulated by Kramer (1977) is investigated for the fern genus Pyrrosia. This correlation is not found in Pyrrosia but may be present in other fern groups.

  18. Synaptospory in the fern genus Pyrrosia (Polypodiaceae)

    NARCIS (Netherlands)

    Uffelen, van Gerda A.

    1983-01-01

    The correlation between sporoderm sculpture and life form of the sporophyte as postulated by Kramer (1977) is investigated for the fern genus Pyrrosia. This correlation is not found in Pyrrosia but may be present in other fern groups.

  19. Phylogeny and taxonomy of the genus Gliocephalotrichum

    NARCIS (Netherlands)

    Lombard, L.; Serrato-Diaz, L.M.; Cheewangkoon, R.; French-Monar, R.D.; Decock, C.; Crous, P.W.

    2014-01-01

    Species in the genus Gliocephalotrichum (= Leuconectria) (Hypocreales, Nectriaceae) are soilborne fungi, associated with post-harvest fruit spoilage of several important tropical fruit crops. Contemporary taxonomic studies of these fungi have relied on morphology and DNA sequence comparisons of the

  20. Taxonomic novelties in the genus Campylospermum (Ochnaceae)

    OpenAIRE

    Bissiengou, P.; Chatrou, L.W.; Wieringa, J. J.; Sosef, M.S.M.

    2013-01-01

    Four new species, one with two subspecies, of the genus Campylospermum are described, all endemic or sub-endemic to Gabon. These are C. auriculatum, C. gabonensis, C. gabonensis subsp. australis, C. glaucifolium and C. occidentalis. Distribution maps and scans of the holotypes are provided as well as preliminary IUCN Red List assessments. New combinations for nine species formerly assigned to the genus Ouratea and/or Gomphia are proposed: C. andongensis, C. glomeratum, C. longestipulatum, C. ...

  1. Cosmetic crossings of genus one knots

    CERN Document Server

    Balm, Cheryl

    2011-01-01

    We show that for genus one knots the Alexander polynomial and the homology of the double cover branching over the knot provide obstructions to cosmetic crossings. As an application we prove the nugatory crossing conjecture for the negatively twisted, positive Whitehead doubles of all knots. We also verify the conjecture for several families of pretzel knots and all genus one knots with up to 10 crossings.

  2. Histology of the first fish

    Science.gov (United States)

    Smith, M.P.; Sansom, I.J.; Repetski, J.E.

    1996-01-01

    THE first description of Anatolepis Bockelie & Fortey was from early Ordovician sediments of Ny Friesland, Spitsbergen1,2, but the genus is now known from many localities in North America and Greenland, ranging in age from the Late Cambrian period to the Early Ordovician3-6. Although initially interpreted as an agnathan fish2,3 that predated other representatives7, this has been widely disputed because the available histological data were unconvincing6,8-10 and the scales fell outside the known morphological range of other accepted early vertebrates9-11. Further doubt was cast upon the vertebrate affinity of Anatolepis when specimens from East Greenland were interpreted as the cuticular fragments of aglaspid arthropods6, although this interpretation has also been refuted12. Here we report on the morphology and histology of large collections of Anatolepis, and demonstrate the presence of dentine, a tissue unique to vertebrates, confirming that the taxon is both a vertebrate and the oldest known fish.

  3. Three Kinds of Fish

    DEFF Research Database (Denmark)

    Høst, Jeppe Engset

    2012-01-01

    There are three kinds of fish. Fish you were given, fish you bought and fish you lease. This might sound a bit odd, but it is nevertheless the basis for the activities of Danish commercial fishers since the introduction of transferable fishing concessions (TFCs) in 2007. In the current 2012 reform...... of market based systems are wild speculation, concentration and monopolization of fishing access and subsequent leasing with fishing communities and new entrants very likely being worse off (see for example the chapter “From fishing rights to financial derivatives” is this volume or Olson 2011; Sumaila 2010...... will examine five Danish fishing operations and discuss how they have reacted in different ways to the newly introduced system of transferable fishing concessions. By introducing TFCs as a solution to fleet overcapacity, the EU Commission will also be introducing a system where buying, selling and leasing...

  4. Genus distribution of ladder type and cross type graphs

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this paper a method is given to calculate the explicit expressions of embedding genus distribution for ladder type graphs and cross type graphs. As an example, we refind the genus distri- bution of the graph Jn which is the first class of graphs studied for genus distribution where its genus depends on n.

  5. Genus distribution of ladder type and cross type graphs

    Institute of Scientific and Technical Information of China (English)

    WAN LiangXia; FENG KeQin; LIU YanPei; WANG DianJun

    2009-01-01

    In this paper a method is given to calculate the explicit expressions of embedding genus distribution for ladder type graphs and cross type graphs.As an example,we refind the genus distribution of the graph Jn which is the first class of graphs studied for genus distribution where its genus depends on n.

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

    NARCIS (Netherlands)

    Guyon, R.; Rakotomanga, M.; Azzouzi, N.; Coutanceau, J.P.; Bonillo, C.; Cotta, D' H.; Pepey, E.; Soler, L.; Rodier-Goud, M.; Hont, D' A.; Conte, M.A.; Bers, van N.E.M.; Penman, D.J.; Hitte, C.; Crooijmans, R.P.M.A.; Kocher, T.D.; Ozouf-Costaz, C.; Baroiller, J.F.; Galibert, F.

    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 vertebr

  7. Genomic diversity within the haloalkaliphilic genus Thioalkalivibrio

    Science.gov (United States)

    Ahn, Anne-Catherine; Meier-Kolthoff, Jan P.; Overmars, Lex; Richter, Michael; Woyke, Tanja; Sorokin, Dimitry Y.

    2017-01-01

    Thioalkalivibrio is a genus of obligate chemolithoautotrophic haloalkaliphilic sulfur-oxidizing bacteria. Their habitat are soda lakes which are dual extreme environments with a pH range from 9.5 to 11 and salt concentrations up to saturation. More than 100 strains of this genus have been isolated from various soda lakes all over the world, but only ten species have been effectively described yet. Therefore, the assignment of the remaining strains to either existing or novel species is important and will further elucidate their genomic diversity as well as give a better general understanding of this genus. Recently, the genomes of 76 Thioalkalivibrio strains were sequenced. On these, we applied different methods including (i) 16S rRNA gene sequence analysis, (ii) Multilocus Sequence Analysis (MLSA) based on eight housekeeping genes, (iii) Average Nucleotide Identity based on BLAST (ANIb) and MUMmer (ANIm), (iv) Tetranucleotide frequency correlation coefficients (TETRA), (v) digital DNA:DNA hybridization (dDDH) as well as (vi) nucleotide- and amino acid-based Genome BLAST Distance Phylogeny (GBDP) analyses. We detected a high genomic diversity by revealing 15 new “genomic” species and 16 new “genomic” subspecies in addition to the ten already described species. Phylogenetic and phylogenomic analyses showed that the genus is not monophyletic, because four strains were clearly separated from the other Thioalkalivibrio by type strains from other genera. Therefore, it is recommended to classify the latter group as a novel genus. The biogeographic distribution of Thioalkalivibrio suggested that the different “genomic” species can be classified as candidate disjunct or candidate endemic species. This study is a detailed genome-based classification and identification of members within the genus Thioalkalivibrio. However, future phenotypical and chemotaxonomical studies will be needed for a full species description of this genus. PMID:28282461

  8. 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...

  9. The genus Isodon (Schrad. ex Benth. Spach in Africa and a new genus Rabdosiella Codd (Lamiaceae

    Directory of Open Access Journals (Sweden)

    L. E. Codd

    1984-12-01

    Full Text Available The typification of the genus Isodon (Schrad. ex Benth. Spach and its occurrence in Africa are discussed; an allied genus Rabdosiella Codd is described and the combinations R. calycina (Benth. Codd and R. ternifolia (D.Don Codd (the latter an Indian species are effected.

  10. Phylogenetic relationships of the algae scraping cyprinid genus Capoeta (Teleostei: Cyprinidae).

    Science.gov (United States)

    Levin, Boris A; Freyhof, Jörg; Lajbner, Zdeněk; Perea, Silvia; Abdoli, Asghar; Gaffaroğlu, Muhammet; Ozuluğ, Müfit; Rubenyan, Haikaz R; Salnikov, Vladimir B; Doadrio, Ignacio

    2012-01-01

    We reconstructed the matrilineal phylogeny of Asian algae-eating fishes of the genus Capoeta based on complete mitochondrial gene for cytochrome b sequences obtained from 20 species sampled from the majority of the range and 44 species of closely related barbs of the genera Barbus s. str. and Luciobarbus. The results of this study show that Capoeta forms a strongly supported monophyletic subclade nested within the Luciobarbus clade, suggesting that specialized scraping morphology appeared once in the evolutionary history of the genus. We detected three main groups of Capoeta: the Mesopotamian group, which includes three species from the Tigris-Euphrates system and adjacent water bodies, the Anatolian-Iranian group, which has the most diversified structure and encompasses many species distributed throughout Anatolian and Iranian inland waters, and the Aralo-Caspian group, which consists of species distributed in basins of the Caspian and Aral Seas, including many dead-end rivers in Central Asia and Northern Iran. The most probable origination pathway of the genus Capoeta is hypothesized to occur as a result of allopolyploidization. The origin of Capoeta was found around the Langhian-Serravallian boundary according to our molecular clock. The diversification within the genus occurred along Middle Miocene-Late Pliocene periods.

  11. Accumulation of dietary and aqueous cadmium into the epidermal mucus of the discus fish Symphysodon sp

    Energy Technology Data Exchange (ETDEWEB)

    Maunder, Richard J., E-mail: richard.maunder@astrazeneca.com [School of Marine Science and Engineering, University of Plymouth, Drake Circus, Plymouth, PL4 8AA (United Kingdom); Buckley, Jonathan, E-mail: jonathan.buckley@plymouth.ac.uk [School of Marine Science and Engineering, University of Plymouth, Drake Circus, Plymouth, PL4 8AA (United Kingdom); Val, Adalberto L., E-mail: dalval@inpa.gov.br [Department of Ecology, Laboratory of Ecophysiology and Molecular Evolution, INPA, Manaus (Brazil); Sloman, Katherine A., E-mail: katherine.sloman@uws.ac.uk [School of Science, University of the West of Scotland, Paisley, PA1 2BE, Scotland (United Kingdom)

    2011-06-15

    The discus fish Symphysodon sp. is an Amazonian cichlid with a unusual form of parental care where fry obligately feed from parental mucus for the first few weeks of life. Here, we investigated the possible impact of environmental cadmium on this species, particularly with respect to mucus contamination. We exposed groups of fish to cadmium either through their food (400 mg kg{sup -1}) or through the water (3 {mu}g l{sup -1}) for 4 weeks, and measured tissue concentrations and ATPase activities at weekly intervals. Cadmium significantly accumulated in all tissues (except for muscle) after 7 days, and tissue concentrations increased until the end of the experiment. Significant alterations in ATPase activities of intestine and kidney were observed at day 7 and 14, but no alterations in gill ATPase activities occurred. The epidermal mucus showed a high accumulation of cadmium from both exposures, but particularly from the diet, indicating that dietary cadmium can be transferred from gut to mucus. Combining this data with approximations of fry bite volumes and bite frequencies, we constructed daily estimates of the cadmium that could potentially be consumed by newly hatched fry feeding on this mucus. These calculations suggest that feeding fry might consume up to 11 {mu}g g{sup -1} day{sup -1}, and hence indicate that this species' dependency on parental mucus feeding of fry could make them particularly susceptible to cadmium contamination of their native habitat.

  12. Linking adults and immatures of South African marine fishes.

    Science.gov (United States)

    Steinke, Dirk; Connell, Allan D; Hebert, Paul D N

    2016-11-01

    The early life-history stages of fishes are poorly known, impeding acquisition of the identifications needed to monitor larval recruitment and year-class strength. A comprehensive database of COI sequences, linked to authoritatively identified voucher specimens, promises to change this situation, representing a significant advance for fisheries science. Barcode records were obtained from 2526 early larvae and pelagic eggs of fishes collected on the inshore shelf within 5 km of the KwaZulu-Natal coast, about 50 km south of Durban, South Africa. Barcodes were also obtained from 3215 adults, representing 946 South African fish species. Using the COI reference library on BOLD based on adults, 89% of the immature fishes could be identified to a species level; they represented 450 species. Most of the uncertain sequences could be assigned to a genus, family, or order; only 92 specimens (4%) were unassigned. Accumulation curves based on inference of phylogenetic diversity indicate near-completeness of the collecting effort. The entire set of adult and larval fishes included 1006 species, representing 43% of all fish species known from South African waters. However, this total included 189 species not previously recorded from this region. The fact that almost 90% of the immatures gained a species identification demonstrates the power and completeness of the DNA barcode reference library for fishes generated during the 10 years of FishBOL.

  13. [Phylogeny and divergence time estimation of Schizothoracinae fishes in Xinjiang].

    Science.gov (United States)

    Ayelhan, Haysa; Guo, Yan; Meng, Wei; Yang, Tianyan; Ma, Yanwu

    2014-10-01

    Based on combined data of mitochondrial COI, ND4 and 16S RNA genes, molecular phylogeny of 4 genera, 10 species or subspecies of Schizothoracinae fishes distributed in Xinjiang were analyzed. The molecular clock was calibrated by divergence time of Cyprininae and geological segregation event between the upper Yellow River and Qinghai Lake. Divergence time of Schizothoracinae fishes was calculated, and its relationship with the major geological events and the climate changes in surrounding areas of Tarim Basin was discussed. The results showed that genus Aspiorhynchus did not form an independent clade, but clustered with Schizothorax biddulphi and S. irregularis. Kimura 2-parameter model was used to calculate the genetic distance of COI gene, the genetic distance between genus Aspiorhynchus and Schizothorax did not reach genus level, and Aspiorhynchus laticeps might be a specialized species of genus Schizothorax. Cluster analysis showed a different result with morphological classification method, and it did not support the subgenus division of Schizothorax fishes. Divergence of two groups of primitive Schizothoracinae (8.18Ma) and divergence of Gymnodiptychus dybowskii and Diptychus maculates (7.67Ma) occurred in late Miocene, which might be related with the separation of Kunlun Mountain and north Tianshan Mountain River system that was caused by the uplift of Qinghai-Tibet Plateau and Tianshan Mountain, and the aridification of Tarim Basin. The terrain of Tarim Basin that was affected by Quaternary Himalayan movement was high in west but low in east, as a result, Lop Nor became the center of surrounding mountain rivers in Tarim Basin, which shaped the distribution pattern of genus Schizothorax.

  14. A Genus Oblivious Approach to Cross Parameterization

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, J C; Pascucci, V; Joy, K I

    2008-06-16

    In this paper we present a robust approach to construct a map between two triangulated meshes, M and M{prime} of arbitrary and possibly unequal genus. We introduce a novel initial alignment scheme that allows the user to identify 'landmark tunnels' and/or a 'constrained silhouette' in addition to the standard landmark vertices. To describe the evolution of non-landmark tunnels we automatically derive a continuous deformation from M to M{prime} using a variational implicit approach. Overall, we achieve a cross parameterization scheme that is provably robust in the sense that it can map M to M{prime} without constraints on their relative genus. We provide a number of examples to demonstrate the practical effectiveness of our scheme between meshes of different genus and shape.

  15. Revision of monotypic genus Llavea (Cryptogrammoideae: Pteridaceae

    Directory of Open Access Journals (Sweden)

    Mónica Palacios-Rios

    2016-12-01

    Full Text Available Llavea Lag. is a genus of Cryptogrammoideae (Pteridaceae, whose only species is distributed from southern United States and Mexico to Guatemala and Costa Rica, although it lives mainly in Mesoamerica, inhabiting preferably calcicolous habitats associated with forests and mountains. The genus is easily recognized by the presence of fertile leaves hemi-dimorphic, with the fertile apical portion with longer and narrower segments than the sterile ones, with strongly revolute margin, and rhizome scales bicolorous, shiny, and black. This paper presents a revision of the genus, nomenclatural issues are resolved, and and palynological morphological diversity are reviewed, as well as its distribution, phenology, ecology, and applications, based on field and herbarium specimens studies. In addition, two names related to Llavea, Allosorus karwinskii Kunze and Ceratodactylis osmundioides J. Sm., were lectotypified.

  16. A mycosis-like granuloma of fish

    Science.gov (United States)

    Wood, E.M.; Yasutake, W.T.; Lehman, W.L.

    1955-01-01

    Mycoses of systemic distribution are rarely observed in fresh-water fish in this country. In a recent review of atypical cell growths in fishes, Nigrelli cited the only known instance of a mycetoma in a North American fresh-water fish which occurred in the head of fingerling landlocked salmon from an Idaho hatchery. The fungus associated with this granuloma was characterized by a branching septate mycelium. Rucker reported a streptomycete which was pathogenic to blueblack salmon. This organism produced internal nodules containing masses of hyphae but no inflammatory response. A pathogenic fungus has been observed frequently in marine fish, however, and in both marine and fresh-water fish in Europe. This organism was tentatively classified as a Phycomycete in or near the order Chytridiales and was assigned to the genus and species Ichthyophonus hoferi, later reclassified as Ichthyosporidium hoferi. The graduloma described in this report occurs in fresh-water trout and is apparently caused by a budding, yeast-like form with no hyphae which evokes a tremendous inflammatory reaction. Morphologically, the organism does not resemble the previously described Ichthyosporidium. The lesions were first seen accidentally in sections prepared from a diplobacillus infection of brook trout termed “kidney disease.” Subsequently, the granuloma was observed in three widely separated infections involving the diplobacillus in each instance.The histological material was received in a fixed condition; thus, no cultural data was available and the nomenclature and classification of the mycotic organism were not attempted. The present distribution of the disease, however, with its potential threat to domestic fish populations, seemed to warrant a description and discussion of the disease. Efforts are in progress to culture the organism.

  17. Systematics of the genus Daubenya (Hyacinthaceae: Massonieae

    Directory of Open Access Journals (Sweden)

    J. C. Manning

    2002-12-01

    Full Text Available Daubenya Lindl. was until recently thought to comprise the single species D. aurea Lindl. but is now considered to include the monotypic genera Androsiphon Schltr. and Amphisiphon W.F.Barker. as well as the species previously referred to the genus Neobakeria Schltr. Eight species are now recognized in the genus, including the new combinations Daubenya comata (Burch, ex Baker J.C.Manning & A.M.van der Merwe and D. zeyheri (Kunth J.C.Manning & A.M.van der Merwe. Each species is fully described and illustrated in black-and-white and in colour. A key to the species, and distribution maps are provided.

  18. Slope equalities for genus 5 surface fibrations

    CERN Document Server

    Tenni, Elisa

    2010-01-01

    K. Konno proved a slope equality for fibred surfaces with fibres of odd genus and general fibre of maximal gonality. More precisely he found a relation between the invariants of the fibration and certain weights of special fibres (called the Horikawa numbers). We give an alternative and more geometric proof in the case of a genus 5 fibration, under generality assumptions. In our setting we are able to prove that the fibre with positive Horikawa numbers are precisely the trigonal ones, we compute their weights explicitly and thus we exhibit explicit examples of regular surfaces with assigned invariants and Horikawa numbers.

  19. Umatilla - Rough Fish Eradication

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In order to enhance environmental conditions in the McCormack Slough on Umatilla NWR, the population of rough fish, including common carp (Cyprinus carpio) and...

  20. Scorpion fish sting

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002849.htm Scorpion fish sting To use the sharing features on this page, please enable JavaScript. Scorpion fish are members of the family Scorpaenidae, which ...

  1. Pittsburgh Fish Fry Locations

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Lenten Fish Fry records for the Greater Pittsburgh region. Data is collected before and during the Lenten fish fry season each year by Code for Pittsburgh. Data is...

  2. An integrated closed system for fish-plankton aquaculture in Amazonian fresh water.

    Science.gov (United States)

    Gilles, S; Ismiño, R; Sánchez, H; David, F; Núñez, J; Dugué, R; Darias, M J; Römer, U

    2014-08-01

    A prototype of an integrated closed system for fish-plankton aquaculture was developed in Iquitos (Peruvian Amazonia) in order to cultivate the Tiger Catfish, Pseudoplatystoma punctifer (Castelnau, 1855). This freshwater recirculating system consisted of two linked sewage tanks with an intensive rearing unit (a cage) for P. punctifer placed in the first, and with a fish-plankton trophic chain replacing the filters commonly used in clear water closed systems. Detritivorous and zooplanktivorous fishes (Loricariidae and Cichlidae), maintained without external feeding in the sewage volume, mineralized organic matter and permitted the stabilization of the phytoplankton biomass. Water exchange and organic waste discharge were not necessary. In this paper we describe the processes undertaken to equilibrate this ecosystem: first the elimination of an un-adapted spiny alga, Golenkinia sp., whose proliferation was favored by the presence of a small rotifer, Trichocerca sp., and second the control of this rotifer proliferation via the introduction of two cichlid species, Acaronia nassa Heckel, 1840 and Satanoperca jurupari Heckel, 1840, in the sewage part. This favored some development of the green algae Nannochloris sp. and Chlorella sp. At that time we took the opportunity to begin a 3-month rearing test of P. punctifer. The mean specific growth rate and feed conversion ratio (FCR) of P. punctifer were 1.43 and 1.27, respectively, and the global FCR, including fish in the sewage part, was 1.08. This system has proven to be suitable for growing P. punctifer juveniles out to adult, and provides several practical advantages compared with traditional recirculating clear water systems, which use a combination of mechanical and biological filters and require periodic waste removal, leading to water and organic matter losses.

  3. Exponentially many maximum genus embeddings and genus embeddings for complete graphs

    Institute of Scientific and Technical Information of China (English)

    REN Han; BAI Yun

    2008-01-01

    There are many results on the maximum genus,among which most are written for the existence of values of such embeddings,and few attention has been paid to the estimation of such embeddings and their applications.In this paper we study the number of maximum genus embeddings for a graph and find an exponential lower bound for such numbers.Our results show that in general case,a simple connected graph has exponentially many distinct maximum genus embeddings.In particular,a connected cubie graph G of order n always has at least (√2)m+n+α/2 distinct maximum genus embeddings,where α and m denote,respectively,the number of inner vertices and odd compo-nents of an optimal tree T.What surprise us most is that such two extremal embeddings (i.e.,the maximum genus embeddings and the genus embeddings) are sometimes closely related with each other.In fact,as applications,we show that for a sufficient large natural number n,there are at least C2n/4 many genus embeddings for complete graph Kn with n=4,7,10 (mod12),where C is a constance depending on the Value of n of residue 12.These results improve the bounds obtained by Korzhik and Voss and the methods used here are much simpler and straight.

  4. 49 CFR 173.218 - Fish meal or fish scrap.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Fish meal or fish scrap. 173.218 Section 173.218... Fish meal or fish scrap. (a) Except as provided in Column (7) of the HMT in § 172.101 of this subchapter, fish meal or fish scrap, containing at least 6%, but not more than 12% water, is authorized...

  5. Medusivorous fishes, a review

    NARCIS (Netherlands)

    Ates, R.M.L.

    1988-01-01

    A preliminary review is presented of fish species having consumed pelagic Cnidaria (Scyphozoa and Hydrozoa) as well as Ctenophora. Quantitative data are scarce. Knowledge of morphological and physiological adaptations of fishes foraging on gelatinous plankton is almost non-existent. Many fish specie

  6. Medusivorous fishes, a review

    OpenAIRE

    Ates, R.M.L.

    1988-01-01

    A preliminary review is presented of fish species having consumed pelagic Cnidaria (Scyphozoa and Hydrozoa) as well as Ctenophora. Quantitative data are scarce. Knowledge of morphological and physiological adaptations of fishes foraging on gelatinous plankton is almost non-existent. Many fish species consume medusae and some reasons to suspect that there are even more that do so, are discussed.

  7. A New Record of Sea Star Genus Nearchaster (Asteroidea: Notomyotida: Benthopectinidae from East Sea, Korea

    Directory of Open Access Journals (Sweden)

    Shin, Sook

    2015-04-01

    Full Text Available An asteroid specimen was collected in adjacent water of Gisamun, Gangwon-do in the East Sea, Korea at a depth of 170 m by fishing net at May 2013. It was identified as Nearchaster (Nearchaster pedicellaris (Fisher, 1910 belonging to family Benthopectinidae of order Notomyotida, which was new to the Korean fauna. The genus, family, and order of this species were also new to Korean waters. The partial sequence of mitochodrial cytochrome c oxidase subunit 1 (CO1 was determined for the first time and registered at GenBank.

  8. The genus Alocasia (Araceae) in Australasia

    NARCIS (Netherlands)

    Hay, A.; Wise, Rosemary

    1991-01-01

    The genus Alocasia (Araceae) is revised for Australasia. Thirteen species are recognised and keyed; eleven are endemic to and one is thought to be introduced to and escaped in Papuasia; A. brisbanensis (F.M. Bailey) Domin is endemic to Australia, and is redescribed; five are new to science. The genu

  9. The genus Lolium; taxonomy and genetic resources.

    NARCIS (Netherlands)

    Loos, B.P.

    1994-01-01

    Several aspects of variation within the genus Lolium, and more in detail within Lolium perenne (perennial ryegrass) have been highlighted. As the results are extensively discussed in each chapter, the general discussion is focused on two aspects of the research.SpeciationIt is clear that the

  10. The genus Lophopyxis Hook. f. (Lophopyxidaceae)

    NARCIS (Netherlands)

    Sleumer, H.

    1968-01-01

    When revising the Icacinaceae from SE. Asia and Malesia recently, my interest was drawn again to the genus Lophopyxis Hook. f. Designated by its author (1887) tentatively as a member of the Euphorbiaceae, it was rejected from this family by Pax as early as 1890. Engler (1893) transferred Lophopyxis

  11. Sarawakodendron, a new genus of Celastraceae

    NARCIS (Netherlands)

    Hou, Ding

    1967-01-01

    During my trip to Malaysia in 1966, sponsored by the Netherlands Foundation for the Advancement of Tropical Research (WOTRO), for doing field work on Anacardiaceae, a new tree genus was found in Sarawak belonging to the family Celastraceae which I have revised for the Flora Malesiana series I, volum

  12. Interspecific hybridization in the genus Tulipa L.

    NARCIS (Netherlands)

    Creij, van M.G.M.

    1997-01-01

    The genus Tulipa L. comprises about 55 species. The tulip species are classified in two subgenera, Tulipa and Eriostemones, which are subdivided into five and three sections respectively. Commercial tulips are mainly cultivars of T. gesneriana L . and of Darwin hybrids, the latter of which are obtai

  13. Taxonomic novelties in the genus Campylospermum (Ochnaceae)

    NARCIS (Netherlands)

    Bissiengou, P.; Chatrou, L.W.; Wieringa, J.J.; Sosef, M.S.M.

    2013-01-01

    Four new species, one with two subspecies, of the genus Campylospermum are described, all endemic or sub-endemic to Gabon. These are C. auriculatum, C. gabonensis, C. gabonensis subsp. australis, C. glaucifolium and C. occidentalis. Distribution maps and scans of the holotypes are provided as well a

  14. Phylogeny of the plant genus Pachypodium (Apocynaceae

    Directory of Open Access Journals (Sweden)

    Dylan O. Burge

    2013-04-01

    Full Text Available Background. The genus Pachypodium contains 21 species of succulent, generally spinescent shrubs and trees found in southern Africa and Madagascar. Pachypodium has diversified mostly into arid and semi-arid habitats of Madagascar, and has been cited as an example of a plant group that links the highly diverse arid-adapted floras of Africa and Madagascar. However, a lack of knowledge about phylogenetic relationships within the genus has prevented testing of this and other hypotheses about the group. Methodology/Principal Findings. We use DNA sequence data from the nuclear ribosomal ITS and chloroplast trnL-F region for all 21 Pachypodium species to reconstruct evolutionary relationships within the genus. We compare phylogenetic results to previous taxonomic classifications and geography. Results support three infrageneric taxa from the most recent classification of Pachypodium, and suggest that a group of African species (P. namaquanum, P. succulentum and P. bispinosum may deserve taxonomic recognition as an infrageneric taxon. However, our results do not resolve relationships among major African and Malagasy lineages of the genus. Conclusions/Significance. We present the first molecular phylogenetic analysis of Pachypodium. Our work has revealed five distinct lineages, most of which correspond to groups recognized in past taxonomic classifications. Our work also suggests that there is a complex biogeographic relationship between Pachypodium of Africa and Madagascar.

  15. A revision of the genus Podococcus

    NARCIS (Netherlands)

    Valkenburg, van J.L.C.H.; Sunderland, T.

    2008-01-01

    A taxonomic revision of the palm genus Podococcus (Arecaceae) is presented. Two species are recognised: P. barteri, a species relatively widespread in a coastal band from Nigeria to the D. R. Congo and P. acaulis, a species previously considered conspecific to P. barteri, almost exclusively confined

  16. Farrowia, a new genus in the Chaetomiaceae

    NARCIS (Netherlands)

    Hawksworth, D.L.

    1975-01-01

    The new genus Farrowia D. Hawksw. is described to accommodate Chaetomium longicolleum Krzem. & Badura and C. longirostre (Farrow) L. Ames, species formerly incorrectly referred to Chaetoceratostoma Turc. & Maffei. These two species are united under the name F. longicollea (Krzem. & Badura) D. Hawksw

  17. A conspectus of the genus Bhesa (Celastraceae)

    NARCIS (Netherlands)

    Hou, Ding

    1958-01-01

    In his Numerical List Wallich inserted four specific epithets in the genus Kurrimia, viz 4334 K. pulcherrima Wall., 4335 K. calophylla Wall., 4336 K. paniculata Wall., and later 7200 K.? macrophylla Wall. The latter one was provided with a question mark; it was a new combination for Itea macrophylla

  18. Identification and nomenclature of the genus Penicillium

    DEFF Research Database (Denmark)

    Visagie, C.M.; Houbraken, J.; Frisvad, Jens Christian

    2014-01-01

    Penicillium is a diverse genus occurring worldwide and its species play important roles as decomposers of organic materials and cause destructive rots in the food industry where they produce a wide range of mycotoxins. Other species are considered enzyme factories or are common indoor air allergens...

  19. Nomenclatural changes in the genus Bremeria (Rubiaceae)

    NARCIS (Netherlands)

    Davis, A.P.; Razafimandimbison, S.G.; Andriambololonera, S.

    2011-01-01

    Five new combinations are made in the genus Bremeria: B. arachnocarpa, B. eriantha, B. scabrella, B. landia var. holosericea, and B. landia var. stadmanii. Bremeria gerrardii is conspecific with Gaertnera phanerophlebia, and thus excluded from Bremeria. Lectotypes are designated for Mussaenda erecti

  20. The position of the genus Thomandersia Bail

    NARCIS (Netherlands)

    Bremekamp, C.E.B.

    1942-01-01

    Among the most aberrant types of pollen grains found in plants which have been referred to the family Acanthaceae, are those of the genera Meyenia N. ab E. and Thomandersia Baill. Although the pollen grains were described by LINDAU under different names, those of the first genus as cogwheel-shaped a

  1. Polyphasic taxonomy of the genus Talaromyces

    DEFF Research Database (Denmark)

    Yilmaz, N.; Visagie, C.M.; Houbraken, J.;

    2014-01-01

    The genus Talaromyces was described by Benjamin in 1955 as a sexual state of Penicillium that produces soft walled ascomata covered with interwoven hyphae. Phylogenetic information revealed that Penicillium subgenus Biverticillium and Talaromyces form a monophyletic clade distinct from the other ...

  2. The genus Alfonsiella Waterston (Hymenoptera, Chalcidoidea, Agaonidae)

    NARCIS (Netherlands)

    Wiebes, J.T.

    1972-01-01

    This paper is a tribute to Prof. Dr. L. D. Brongersma, in remembrance of the years I served as his deputy in the Rijksmuseum van Natuurlijke Historie. The genus Alfonsiella was described by Waterston (1920) for A. fimbriata, a series of females of which were collected at Dar es Salaam, Tanganyika. I

  3. Paramyristica, a new genus of Myristicaceae

    OpenAIRE

    Wilde, de, J.G.S.

    1994-01-01

    The new genus Paramyristica from New Guinea, based on Myristica sepicana Foreman, is described and discussed, and included in keys to the Asian genera of Myristicaceae. Detailed drawings of the androecia of Paramyristica sepicana and of Myristica hooglandii and M. hollrungii are presented for comparison.

  4. Endocomia, a new genus of Myristicaceae

    NARCIS (Netherlands)

    Wilde, de W.J.J.O.

    1984-01-01

    The new genus Endocomia, ranging from South China to New Guinea, is described, keyed out and discussed among the other four Southeast Asiatic genera of Myristicaceae, viz. Knema, Myristica, Gymnacranthera, and Horsfieldia. Endocomia was formerly included in Horsfieldia under the name H. macrocoma, a

  5. Revision of the genus Gymnacranthera (Myristicaceae)

    NARCIS (Netherlands)

    Schouten, R.T.A.

    1986-01-01

    In Gymnacranthera, a small genus of Southeast Asian Myristicaceae, at present 7 species have been accepted, one (G. forbesii) with 2 and another ( G. farquhariana) with 4 varieties. One species, G. canarica, occurs in S. India, the remainder of the species is distributed in the area from S. Thailand

  6. Paramyristica, a new genus of Myristicaceae

    NARCIS (Netherlands)

    Wilde, de W.J.J.O.

    1994-01-01

    The new genus Paramyristica from New Guinea, based on Myristica sepicana Foreman, is described and discussed, and included in keys to the Asian genera of Myristicaceae. Detailed drawings of the androecia of Paramyristica sepicana and of Myristica hooglandii and M. hollrungii are presented for compar

  7. The composite genus Blumea, a taxonomic revision

    NARCIS (Netherlands)

    Randeria, Aban J.

    1960-01-01

    My first acquaintance with the genus Blumea was made in December of 1949. On one of my taxonomy field trips then, and many more subsequently, I encountered these weedy, yellow-flowered composites. Perhaps what most helped to attract my attention was their relative abundance and their characteristic

  8. Mitogenomic analysis of the genus Panthera.

    Science.gov (United States)

    Wei, Lei; Wu, Xiaobing; Zhu, Lixin; Jiang, Zhigang

    2011-10-01

    The complete sequences of the mitochondrial DNA genomes of Panthera tigris, Panthera pardus, and Panthera uncia were determined using the polymerase chain reaction method. The lengths of the complete mitochondrial DNA sequences of the three species were 16990, 16964, and 16773 bp, respectively. Each of the three mitochondrial DNA genomes included 13 protein-coding genes, 22 tRNA, two rRNA, one O(L)R, and one control region. The structures of the genomes were highly similar to those of Felis catus, Acinonyx jubatus, and Neofelis nebulosa. The phylogenies of the genus Panthera were inferred from two combined mitochondrial sequence data sets and the complete mitochondrial genome sequences, by MP (maximum parsimony), ML (maximum likelihood), and Bayesian analysis. The results showed that Panthera was composed of Panthera leo, P. uncia, P. pardus, Panthera onca, P. tigris, and N. nebulosa, which was included as the most basal member. The phylogeny within Panthera genus was N. nebulosa (P. tigris (P. onca (P. pardus, (P. leo, P. uncia)))). The divergence times for Panthera genus were estimated based on the ML branch lengths and four well-established calibration points. The results showed that at about 11.3 MYA, the Panthera genus separated from other felid species and then evolved into the several species of the genus. In detail, N. nebulosa was estimated to be founded about 8.66 MYA, P. tigris about 6.55 MYA, P. uncia about 4.63 MYA, and P. pardus about 4.35 MYA. All these estimated times were older than those estimated from the fossil records. The divergence event, evolutionary process, speciation, and distribution pattern of P. uncia, a species endemic to the central Asia with core habitats on the Qinghai-Tibetan Plateau and surrounding highlands, mostly correlated with the geological tectonic events and intensive climate shifts that happened at 8, 3.6, 2.5, and 1.7 MYA on the plateau during the late Cenozoic period.

  9. Do Fish Resist?

    Directory of Open Access Journals (Sweden)

    Dinesh Joseph Wadiwel

    2016-03-01

    Full Text Available There have been a number of scientific studies on the question of whether fish feel pain. Some have suggested that some fish indeed do feel pain and that this has significant welfare implications (2003. Others have argued that fish do not have the brain development necessary to feel pain. In terms of number of animals killed, the slaughter of sea animals for human consumption significantly exceeds that of any land animals that we use for food, and sea animal slaughter practices frequently lack any basic welfare protections. If fish can be shown to feel pain—or more importantly, if humans can agree that fish feel pain—then this would place a significant question mark over many contemporary fishing practices.  This article substitutes the question 'Do Fish Feel Pain?' with an alternative: 'Do Fish Resist?' It explores the conceptual problems of understanding fish resistance, and the politics of epistemology that surrounds and seeks to develop a conceptual framework for understanding fish resistance to human capture by exploring the development of fishing technologies - the hook, the net and contemporary aquaculture.

  10. Fish allergy: in review.

    Science.gov (United States)

    Sharp, Michael F; Lopata, Andreas L

    2014-06-01

    Globally, the rising consumption of fish and its derivatives, due to its nutritional value and divergence of international cuisines, has led to an increase in reports of adverse reactions to fish. Reactions to fish are not only mediated by the immune system causing allergies, but are often caused by various toxins and parasites including ciguatera and Anisakis. Allergic reactions to fish can be serious and life threatening and children usually do not outgrow this type of food allergy. The route of exposure is not only restricted to ingestion but include manual handling and inhalation of cooking vapors in the domestic and occupational environment. Prevalence rates of self-reported fish allergy range from 0.2 to 2.29 % in the general population, but can reach up to 8 % among fish processing workers. Fish allergy seems to vary with geographical eating habits, type of fish processing, and fish species exposure. The major fish allergen characterized is parvalbumin in addition to several less well-known allergens. This contemporary review discusses interesting and new findings in the area of fish allergy including demographics, novel allergens identified, immunological mechanisms of sensitization, and innovative approaches in diagnosing and managing this life-long disease.

  11. Fish under exercise.

    Science.gov (United States)

    Palstra, Arjan P; Planas, Josep V

    2011-06-01

    Improved knowledge on the swimming physiology of fish and its application to fisheries science and aquaculture (i.e., farming a fitter fish) is currently needed in the face of global environmental changes, high fishing pressures, increased aquaculture production as well as increased concern on fish well-being. Here, we review existing data on teleost fish that indicate that sustained exercise at optimal speeds enhances muscle growth and has consequences for flesh quality. Potential added benefits of sustained exercise may be delay of ovarian development and stimulation of immune status. Exercise could represent a natural, noninvasive, and economical approach to improve growth, flesh quality as well as welfare of aquacultured fish: a FitFish for a healthy consumer. All these issues are important for setting directions for policy decisions and future studies in this area. For this purpose, the FitFish workshop on the Swimming Physiology of Fish ( http://www.ub.edu/fitfish2010 ) was organized to bring together a multidisciplinary group of scientists using exercise models, industrial partners, and policy makers. Sixteen international experts from Europe, North America, and Japan were invited to present their work and view on migration of fishes in their natural environment, beneficial effects of exercise, and applications for sustainable aquaculture. Eighty-eight participants from 19 different countries contributed through a poster session and round table discussion. Eight papers from invited speakers at the workshop have been contributed to this special issue on The Swimming Physiology of Fish.

  12. Zoonoses associated with fish.

    Science.gov (United States)

    Boylan, Shane

    2011-09-01

    The taxonomic group that composes the fishes is the most diverse group of vertebrates worldwide. The challenges of unique physiologies, a foreign environment, and many unknowns attract a passionate group of biologists and veterinarians. Economically, fishes have become vital as food, bait, and companion animals. Fishermen and fish handlers (processing plants) represent the historical human population exposed to fish zoonoses, but growth in aquaculture and aquarium hobbyists have led to an increase in published fish-borne zoonotic cases starting in the late 1950s that bloomed in the 1980s. Human physicians, particularly dermatologists and infectious disease specialists, are now more aware of fish-borne zoonoses, but they can be assisted with diagnosis when informed patients give more detailed histories with fish/water exposure.

  13. A New Genus of Macropsinae (Hemiptera: Cicadellidae) From Madagascar.

    Science.gov (United States)

    Yang, Liyuan; Dietrich, C H; Zhang, Yalin

    2016-01-01

    Paragalboa acuta GEN & SP N: is described and illustrated from Madagascar. The new genus shows morphological affinities to the Macropsini genus Galboa Distant recorded from Seychelles. A checklist of all known genera of Macropsinae is provided.

  14. An account of the fern genus Belvisia Mirbel (Polypodiaceae)

    NARCIS (Netherlands)

    Hovenkamp, P.H.; Franken, N.A.P.

    1993-01-01

    The genus Belvisia is revised. Two species are transferred from Lemmaphyllum to Belvisia, and two species are reduced to varieties. The genus now includes eight species, reaching from tropical Africa to China, Polynesia, and Australia.

  15. Certhiasomus, a new genus of woodcreeper (Aves: Passeriformes: Dendrocolaptidae)

    Science.gov (United States)

    Derryberry, Elizabeth; Claramunt, Santiago; Chesser, R. Terry; Aleixo, Alexandre; Cracraft, Joel; Moyle, Robert G.; Brumfield, Robb T.

    2010-01-01

    Phylogenetic analysis of the family Dendrocolaptidae (Aves: Passeriformes) indicates that the two species traditionally placed in the genus Deconychura are not sister taxa. Certhiasomus, a new genus of woodcreeper, is described for one of these species, C. stictolaemus.

  16. Genus Phyllanthus for chronic hepatitis B virus infection

    DEFF Research Database (Denmark)

    Liu, J; Lin, Haili; McIntosh, H

    2001-01-01

    To evaluate the efficacy and safety of genus Phyllanthus for chronic hepatitis B virus (HBV) infection we performed a systematic review of randomized clinical trials. Randomized trials comparing genus Phyllanthus vs. placebo, no intervention, general nonspecific treatment, other herbal medicine...

  17. Exponentially many maximum genus embeddings and genus embeddings for complete graphs

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    There are many results on the maximum genus, among which most are written for the existence of values of such embeddings, and few attention has been paid to the estimation of such embeddings and their applications. In this paper we study the number of maximum genus embeddings for a graph and find an exponential lower bound for such numbers. Our results show that in gen-eral case, a simple connected graph has exponentially many distinct maximum genus embeddings. In particular, a connected cubic graph G of order n always has at least 2~1/2m+n+ α2 distinct maximum genus embeddings, where α and m denote, respectively, the number of inner vertices and odd compo-nents of an optimal tree T . What surprise us most is that such two extremal embeddings (i.e., the maximum genus embeddings and the genus embeddings) are sometimes closely related with each other. In fact, as applications, we show that for a suffcient large natural number n, there are at least C2 n4 dmeapneyn dgienngu os ne mthbee vdadliuneg soffonrocf ormespidleutee 1g2r.a pThh eKsen rwesiuthlt sn i m≡p r4o,v 7e, 1th0e ( mbooudn1d2)s, owbthaeirnee dC b iys Ka ocroznhsikta anncde Voss and the methods used here are much simpler and straight.

  18. Southeast Alaska ESI: FISH (Fish Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for estuarine, benthic, and pelagic fish in Southeast Alaska. Vector polygons in this data set represent locations of...

  19. Columbia River ESI: FISH (Fish Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, anadromous, and freshwater fish species in Columbia River. Vector polygons in this...

  20. North Slope, Alaska ESI: FISH (Fish Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, anadromous, and freshwater fish species for the North Slope of Alaska. Vector...

  1. American Samoa ESI: FISH (Fish Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for reef, pelagic, benthic, and estuarine fish species in American Samoa. Vector polygons in this data set...

  2. Taxonomy of the genus Passerina (Thymelaeaceae)

    OpenAIRE

    C. L. Bredenkamp; A. E. van Wyk

    2003-01-01

    Passerina L. is mainly a southern African genus, comprising 20 species and four subspecies. A few species occur along the Great Escarpment, two extend into Zimbabwe and Mozambique, but most are concentrated in the Cape Floristic Region. Palynological. macromorphological and anatomical evidence was used in the delimitation of the genus and its infrageneric taxa. A cladistic study supports Passerina as a monophyletic genus. A genus treatment, key to species and a full species treatment are give...

  3. Brasacanthus sphoeroides gen. n., sp. n. (Acanthocephala, Echinorhynchidae from a coastal marine fish of Paraná State, Brazil

    Directory of Open Access Journals (Sweden)

    Vernon E. Thatcher

    2001-12-01

    Full Text Available Brasacanthus sphoeroides gen. n.. sp. n. is described from the marine fish, Sphoeroides greeleyi (Steindachner, taken in Paranaguá Bay, Paraná State, Brazil. The new genus differs from Acanthocephalus Koelreuter, 1771, the nearest genus in the family Echinorhynchidae, by having very flat and variable lemnisci in both sexes and a uterine egg reservoir in the female. The species is characterized by its spherical body form and in having parallel or diagonal testes.

  4. Interspecific chromosomal divergences in the genus Characidium (Teleostei: Characiformes: Crenuchidae

    Directory of Open Access Journals (Sweden)

    José Carlos Pansonato Alves

    Full Text Available Karyotypes of seven fish species of the genus Characidium, three of them studied for the first time, were characterized using conventional cytogenetic techniques (Giemsa staining, Ag-NOR, and C-banding. All species presented a diploid number of 2n=50, with only metacentric and submetacentric chromosomes, as observed in all Characidium species studied. In two species cells with one to three B chromosomes were observed. All species analyzed have a single NOR-bearing chromosome pair with morphological differences among them. Characidium cf. zebra shows heterochromatic blocks restricted to the pericentromeric regions of all chromosomes denoting the absence of a sex chromosome system. On the other hand, the species Characidium lanei, C. pterostictum, C. lauroi, C. oiticicai, C. schubarti, and Characidium sp., besides presenting pericentromeric heterochromatic blocks, exhibited large interstitial and/or terminal heterochromatic blocks, and a ZZ/ZW sex chromosome system. The constitutive heterochromatin seems to play a relevant role in the chromosome differentiation process of the studied species, mainly in relation to the sex chromosomes. The geographical isolation of the rivers in which the species were sampled, associated with their way of life restricted to headwaters environments, may have favored the process of fixation of different karyotypes found in each of the analyzed species.

  5. Comparative Genomic Analysis Reveals Ecological Differentiation in the Genus Carnobacterium

    Science.gov (United States)

    Iskandar, Christelle F.; Borges, Frédéric; Taminiau, Bernard; Daube, Georges; Zagorec, Monique; Remenant, Benoît; Leisner, Jørgen J.; Hansen, Martin A.; Sørensen, Søren J.; Mangavel, Cécile; Cailliez-Grimal, Catherine; Revol-Junelles, Anne-Marie

    2017-01-01

    Lactic acid bacteria (LAB) differ in their ability to colonize food and animal-associated habitats: while some species are specialized and colonize a limited number of habitats, other are generalist and are able to colonize multiple animal-linked habitats. In the current study, Carnobacterium was used as a model genus to elucidate the genetic basis of these colonization differences. Analyses of 16S rRNA gene meta-barcoding data showed that C. maltaromaticum followed by C. divergens are the most prevalent species in foods derived from animals (meat, fish, dairy products), and in the gut. According to phylogenetic analyses, these two animal-adapted species belong to one of two deeply branched lineages. The second lineage contains species isolated from habitats where contact with animal is rare. Genome analyses revealed that members of the animal-adapted lineage harbor a larger secretome than members of the other lineage. The predicted cell-surface proteome is highly diversified in C. maltaromaticum and C. divergens with genes involved in adaptation to the animal milieu such as those encoding biopolymer hydrolytic enzymes, a heme uptake system, and biopolymer-binding adhesins. These species also exhibit genes for gut adaptation and respiration. In contrast, Carnobacterium species belonging to the second lineage encode a poorly diversified cell-surface proteome, lack genes for gut adaptation and are unable to respire. These results shed light on the important genomics traits required for adaptation to animal-linked habitats in generalist Carnobacterium. PMID:28337181

  6. 76 FR 4292 - Certain Frozen Fish Fillets From the Socialist Republic of Vietnam: Preliminary Results of...

    Science.gov (United States)

    2011-01-25

    ... Bocourti, Pangasius Hypophthalmus (also known as Pangasius Pangasius), and Pangasius Micronemus. Frozen... data in the FAO Report specifically identify the whole live fish examined as Pangasianodon Hypopthalmus... subject to the Order. First, we note that Pangasius is a genus name and Pangasianodon Hypopthalmus is...

  7. Record of the species of Tripartiella (Lom, 1959) from fishes of Manipur.

    Science.gov (United States)

    Mohilal, Naorem; Hemananda, Thounaojam

    2012-04-01

    Survey on Trichodinid ciliophorans from the fresh water fishes of Manipur revealed three known species of the genus Tripartiella from the gills of major carps Labeo rohita (Hamilton); Cirrhinus mrigala (Hamilton); Catla catla and Ciprinus carpio. These are redescribed in this communication.

  8. Fish elevator and method of elevating fish

    Science.gov (United States)

    Truebe, Jonathan; Drooker, Michael S.

    1984-01-01

    A means and method for transporting fish from a lower body of water to a higher body of water. The means comprises a tubular lock with a gated entrance below the level of the lower body of water through which fish may enter the lock and a discharge passage above the level of the upper body of water. The fish raising means in the lock is a crowder pulled upward by a surface float as water from the upper body of water gravitationally flows into the closed lock filling it to the level of the upper body. Water is then pumped into the lock to raise the level to the discharge passage. The crowder is then caused to float upward the remaining distance through the water to the level of the discharge passage by the introduction of air into a pocket on the underside of the crowder. The fish are then automatically discharged from the lock into the discharge passage by the out of water position of the crowder. The movement of the fish into the discharge passage is aided by the continuous overflow of water still being pumped into the lock. A pipe may be connected to the discharge passage to deliver the fish to a selected location in the upper body of water.

  9. Modular functors are determined by their genus zero data

    DEFF Research Database (Denmark)

    Andersen, Jørgen Ellegaard; Ueno, Kenji

    2012-01-01

    We prove in this paper that the genus zero data of a modular functor determines the modular functor. We do this by establishing that the S-matrix in genus one with one point labeled arbitrarily can be expressed in terms of the genus zero information and we give an explicit formula. We do not assume...

  10. Notes on the genus Digitaria, with descriptions of new species

    NARCIS (Netherlands)

    Henrard, J.Th.

    1934-01-01

    Some years ago I had the opportunity to study more extensively a very interesting group of grasses, belonging to what is now accepted as a distinct genus, the genus Digitaria, formerly belonging as a subgenus to the genus Panicum. As to living plants of this group I was familiar with two european sp

  11. Pseudasthenes, a new genus of ovenbird (Aves: Passeriformes: Furnariidae)

    Science.gov (United States)

    Derryberry, Elizabeth; Claramunt, Santiago; O'Quin, Kelly E.; Aleixo, Alexandre; Chesser, R. Terry; Remsen, J.V.; Brumfield, Robb T.

    2010-01-01

    Phylogenetic analysis of the family Furnariidae (Aves: Passeriformes) indicates that the genus Asthenes is polyphyletic, consisting of two groups that are not sister taxa. Pseudasthenes, a new genus of ovenbird, is described for one of these groups. The four species included in the new genus, formerly placed in Asthenes, are P. humicola, P. patagonica, P. steinbachi, and P. cactorum.

  12. The strong symmetric genus of the finite Coxeter groups

    OpenAIRE

    2004-01-01

    The strong symmetric genus of a finite group G is the smallest genus of a closed orientable topological surface on which G acts faithfully as a group of orientation preserving automorphisms. In this paper we complete the calculation of the strong symmetric genus for each finite Coxeter group excluding the group E8.

  13. Remarks on the Lower Bounds for the Average Genus

    Institute of Scientific and Technical Information of China (English)

    Yi-chao Chen

    2011-01-01

    Let G be a graph of maximum degree at most four. By using the overlap matrix method which is introduced by B. Mohar, we show that the average genus of G is not less than 1/3 of its maximum genus, and the bound is best possible. Also, a new lower bound of average genus in terms of girth is derived.

  14. Cobalt Chloride Treatment Used to Ablate the Lateral Line System Also Impairs the Olfactory System in Three Freshwater Fishes.

    Directory of Open Access Journals (Sweden)

    Julie M Butler

    Full Text Available Fishes use multimodal signals during both inter- and intra-sexual displays to convey information about their sex, reproductive state, and social status. These complex behavioral displays can include visual, auditory, olfactory, tactile, and hydrodynamic signals, and the relative role of each sensory channel in these complex multi-sensory interactions is a common focus of neuroethology. The mechanosensory lateral line system of fishes detects near-body water movements and is implicated in a variety of behaviors including schooling, rheotaxis, social communication, and prey detection. Cobalt chloride is commonly used to chemically ablate lateral line neuromasts, thereby eliminating water-movement cues to test for mechanosensory-mediated behavioral functions. However, cobalt acts as a nonspecific calcium channel antagonist and could potentially disrupt function of all superficially located sensory receptor cells, including those for chemosensing. Here, we examined whether CoCl2 treatment used to ablate the lateral line system also impairs olfaction in three freshwater fishes, the African cichlid fish Astatotilapia burtoni, goldfish Carassius auratus, and the Mexican blind cavefish Astyanax mexicanus. To examine the impact of CoCl2 on the activity of peripheral receptors, we quantified DASPEI fluorescence intensity of the olfactory epithelium from fish exposed to control and CoCl2 solutions. In addition, we examined brain activation in olfactory processing regions of A. burtoni immersed in either control or cobalt solutions. All three species exposed to CoCl2 had decreased DASPEI staining of the olfactory epithelium, and in A. burtoni, cobalt treatment caused reduced neural activation in olfactory processing regions of the brain. To our knowledge this is the first empirical evidence demonstrating that the same CoCl2 treatment used to ablate the lateral line system also impairs olfactory function. These data have important implications for the use of

  15. Hepeviruses of fish: Chapter 24

    Science.gov (United States)

    Batts, William N.; Kibenge, Frederick S. B.; Godoy, Marcos

    2016-01-01

    Originally reported from California, the cutthroat trout virus (CTV) has now been isolated from eight species of salmonids in North America. Early work focused on the replication and physical characteristics of the small, round virus, but not until 20 years later was it determined to be most closely related to viruses causing hepatitis E in humans or infecting avian and mammalian hosts. The genome of CTV consists of 7269 nucleotides of positive-sense, single-stranded RNA with a genome organization similar to other members of the family Hepeviridae, although the amino acid sequence identity appears low enough to support creation of a novel genus. While CTV has not been associated with acute disease in fish, the virus was able to form persistently infected cell cultures that may aid research in treatment of hepatitis E-like viruses affecting humans or other animals. Interestingly, trout exposed to CTV were protected for about a month against subsequent exposure to Infectious hematopoietic necrosis virus. Replicating agents suspected to be CTV can be confirmed by polymerase chain reaction (PCR) and sequencing.

  16. Phytochemistry of the genus Skimmia (Rutaceae).

    Science.gov (United States)

    Epifano, Francesco; Fiorito, Serena; Genovese, Salvatore; Granica, Sebastian; Vitalini, Sara; Zidorn, Christian

    2015-07-01

    The genus Skimmia is a rich source of interesting secondary metabolites, including 20 alkaloids derived from anthranilic acid, 45 coumarins, 21 limonoids, four cholestane derivatives, six pentacyclic triterpenes, six flavonoids, and two unusual fatty acid derivatives. Skimmia is employed in folk medicine e.g. against fever, inflammations, and rheumatism. Skimmia extracts, Skimmia essential oils and pure compounds isolated from Skimmia extracts have been experimentally shown to have various bioactivities such as antioxidant, anti-inflammatory, antimicrobial, and insecticidal. In this review we discuss the exact structures of compounds isolated from members of the genus Skimmia, bioactivities of Skimmia extracts and pure compounds derived from them, and systematic implications of the patterns of occurrence of these compounds. Moreover, research gaps and interesting avenues for future research are discussed briefly.

  17. Genus Tinospora: Ethnopharmacology, Phytochemistry, and Pharmacology.

    Science.gov (United States)

    Chi, Sensen; She, Gaimei; Han, Dan; Wang, Weihua; Liu, Zhao; Liu, Bin

    2016-01-01

    The genus Tinospora includes 34 species, in which several herbs were used as traditional medicines by indigenous groups throughout the tropical and subtropical parts of Asia, Africa, and Australia. The extensive literature survey revealed Tinospora species to be a group of important medicinal plants used for the ethnomedical treatment of colds, headaches, pharyngitis, fever, diarrhea, oral ulcer, diabetes, digestive disorder, and rheumatoid arthritis. Indian ethnopharmacological data points to the therapeutic potential of the T. cordifolia for the treatment of diabetic conditions. While Tinospora species are confusing in individual ingredients and their mechanisms of action, the ethnopharmacological history of those plants indicated that they exhibit antidiabetic, antioxidation, antitumor, anti-inflammation, antimicrobial, antiosteoporosis, and immunostimulation activities. While the clinical applications in modern medicine are lacking convincing evidence and support, this review is aimed at summarizing the current knowledge of the traditional uses, phytochemistry, biological activities, and toxicities of the genus Tinospora to reveal its therapeutic potentials and gaps, offering opportunities for future researches.

  18. Gene order phylogeny of the genus Prochlorococcus.

    Directory of Open Access Journals (Sweden)

    Haiwei Luo

    Full Text Available BACKGROUND: Using gene order as a phylogenetic character has the potential to resolve previously unresolved species relationships. This character was used to resolve the evolutionary history within the genus Prochlorococcus, a group of marine cyanobacteria. METHODOLOGY/PRINCIPAL FINDINGS: Orthologous gene sets and their genomic positions were identified from 12 species of Prochlorococcus and 1 outgroup species of Synechococcus. From this data, inversion and breakpoint distance-based phylogenetic trees were computed by GRAPPA and FastME. Statistical support of the resulting topology was obtained by application of a 50% jackknife resampling technique. The result was consistent and congruent with nucleotide sequence-based and gene-content based trees. Also, a previously unresolved clade was resolved, that of MIT9211 and SS120. CONCLUSIONS/SIGNIFICANCE: This is the first study to use gene order data to resolve a bacterial phylogeny at the genus level. It suggests that the technique is useful in resolving the Tree of Life.

  19. Vaccination in Fish

    DEFF Research Database (Denmark)

    Chettri, Jiwan Kumar

    vaccines have reduced the need for usage of antibiotics with more than 99 % since the 1980s. Fish can be vaccinated by three different administration routes: injection, immersion and oral vaccination. Injection vaccination (intraperitoneal injection of vaccine) is the most time consuming and labor...... intensive method, which however, provides the best protection of the fish. Immersion vaccination is used for immunization of a high number of small fish is cost-efficient and fast (30 sec immersion into vaccine). Oral vaccination (vaccine in feed) is the least efficient. As in higher vertebrates fish...... respond to vaccination by increasing the specific antibody titer and by activating the cellular responses. My talk will cover vaccination methods in fish, immune responses and some adverse effect of oil-adjuvanted vaccines in fish with reference to our work in rainbow trout, Oncorhynchus mykiss....

  20. Genus Schistochila Dumort. (Schistochilaceae, Marchantiophyta in Thailand

    Directory of Open Access Journals (Sweden)

    Wanwisa Juengprayoon

    2015-08-01

    Full Text Available A review of the genus Schistochila Dumort. in Thailand is presented, based on the study of fresh and herbarium specimens. Five species are recognized, namely S. aligera (Nees & Blume J.B. Jack & Steph., S. blumei (Nees Trevis., S. nuda Horik., S. sciurea (Nees Schiffn., and S. yakushimensis Ohnishi & Deguchi. In addition, a key to species, descriptions and line drawings are provided, and notes on the ecology and geographical distribution of the species.

  1. Operators and higher genus mirror curves

    CERN Document Server

    Codesido, Santiago; Marino, Marcos

    2016-01-01

    We perform further tests of the correspondence between spectral theory and topological strings, focusing on mirror curves of genus greater than one with nontrivial mass parameters. In particular, we analyze the geometry relevant to the SU(3) relativistic Toda lattice, and the resolved C^3/Z_6 orbifold. Furthermore, we give evidence that the correspondence holds for arbitrary values of the mass parameters, where the quantization problem leads to resonant states. We also explore the relation between this correspondence and cluster integrable systems.

  2. The minimal genus problem in rational surfaces

    Institute of Scientific and Technical Information of China (English)

    ZHAO; Xu'an

    2006-01-01

    [1]Kronheimer P B,Mrowka T S.The genus of embedding surfaces in the projective plane.Math Res Lett,1994,1:797-808[2]Lawson T.The minimal genus problem.Expo Math,1997,15:385-431[3]Li B H.Representing nonnegative homology classes of CP2#n-CP2 by minimal genus smooth embedding.Trans Amer Soc,1999,352(9):4155-4169[4]Ruberman D.The minimal genus of an embedding surface of non-negative square in a rational surface.Turkish J Math,1996,20:129-133[5]Wall C T C.On the orthogonal groups of unimodular quadratic forms Ⅱ.Crelle Jour,1963,213:122-136[6]Gao H.Representing homology classes of almost definite 4-manifolds.Topology Appl,1993,52:109-120[7]Kikuchi K.Positive 2-spheres in 4-manifolds of signature (1,n).Pacific Jour Math,1993,160:245-258[8]Li B H,Li T J.Smooth minimal genera for small negative classes in CP2#n-CP2 with n ≤ 9.Topology Appl,2003,132(1):1-15[9]Friedman R,Morgan J.On the diffeomorphism types of certain algebraic surfaces.Journal of Differential Geometry,1988,27(3):371-398[10]Kac V G.Infinite-Dimensional Lie Algebras.3rd ed.Cambridge:Cambridge University Press,1990[11]Li T J,Liu A.Symplectic structure on ruled surfaces and generalized adjunction formula.Math Res Lett,1995,2:453-471

  3. Operators and higher genus mirror curves

    Science.gov (United States)

    Codesido, Santiago; Gu, Jie; Mariño, Marcos

    2017-02-01

    We perform further tests of the correspondence between spectral theory and topological strings, focusing on mirror curves of genus greater than one with nontrivial mass parameters. In particular, we analyze the geometry relevant to the SU(3) relativistic Toda lattice, and the resolved C{^3}/Z_6 orbifold. Furthermore, we give evidence that the correspondence holds for arbitrary values of the mass parameters, where the quantization problem leads to resonant states. We also explore the relation between this correspondence and cluster integrable systems.

  4. Concordance of Bing Doubles and Boundary Genus

    Science.gov (United States)

    Livingston, Charles; van Cott, Cornelia A.

    2011-11-01

    Cha and Kim proved that if a knot K is not algebraically slice, then no iterated Bing double of K is concordant to the unlink. We prove that if K has nontrivial signature $\\sigma$, then the n-iterated Bing double of K is not concordant to any boundary link with boundary surfaces of genus less than $2^{n-1}\\sigma$. The same result holds with $\\sigma$ replaced by $2\\tau$, twice the Ozsvath-Szabo knot concordance invariant.

  5. Phytochemical, ethnomedicinal uses and pharmacological profile of genus Pistacia.

    Science.gov (United States)

    Rauf, Abdur; Patel, Seema; Uddin, Ghias; Siddiqui, Bina S; Ahmad, Bashir; Muhammad, Naveed; Mabkhot, Yahia N; Hadda, Taibi Ben

    2017-02-01

    Pistacia genus belong to family Anacardiaceae and it is versatile in that its member species have food (P. vera), medicinal (P. lentiscus) and ornamental (P. chinensis) values. Various species of this genus have folkloric uses with credible mention in diverse pharmacopeia. As a trove of phenolic compounds, terpenoids, monoterpenes, flavonoids, alkaloids, saponins, fatty acids, and sterols, this genus has garnered pharmaceutical attention in recent times. With adequate clinical studies, this genus might be exploited for therapy of a multitude of inflammatory diseases, as promised by preliminary studies. In this regard, the ethnomedicinal, phytochemistry, biological potencies, risks, and scopes of Pistacia genus have been reviewed here.

  6. Do Fish Sleep?

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    Most fish can’t shut their eyes, so it’s easy to think they don’t sleep. But that’s like assuming humans don’t sleep because we can’t shut our ears to drown out sound. In fact, many species of fish take time out during the day or (more often) at night to enter a sleeplike stage. Some of these fish float in place, others lie on the bottom。

  7. Fish and wildlife surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Poston, T.M.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the monitoring of radioactive contaminants in fish and wildlife species that inhabit the Colombia River and Hanford Site. Wildlife have access to areas of the Site containing radioactive contamination, and fish can be exposed to contamination in spring water entering the river along the shoreline. Therefore, samples are collected at various locations annually, generally during the hunting or fishing season, for selected species.

  8. Ethnopharmacology of the plants of genus Ajuga.

    Science.gov (United States)

    Israili, Zafar H; Lyoussi, Badiâa

    2009-10-01

    The plants of genus Ajuga are evergreen, clump-forming rhizomatous perennial or annual herbaceous flowering species, with Ajuga being one of the 266 genera of the family Lamiaceae. There are at least 301 species of the genus Ajuga with many variations. These plants, growing in Europe, Asia, Africa, Australia and North America, are used in gardens as ground cover or border for their foliage and beautiful flowers. Many of these plants have been used in traditional medicine as a remedy for fever, toothache, dysentery, malaria, high blood pressure, diabetes, gastrointestinal disorders, as anthelmintic, diuretic and antifungal, anti-inflammatory, and antimycobacterial agents. They are also used as insect growth inhibitor s. A large number of compounds have been isolated from the Ajuga plants, including phytoecdysteroids, neo-clerodane-diterpenes and diterpenoids, triterpenes, sterols, anthocyanidin-glucosides and iridoid glycosides, withanolides, flavonoids, triglycerides and essential oils. These compounds possess a broad spectrum of biological, pharmacological and medicinal properties, such as anabolic, analgesic, antibacterial, antiestrogenic, antifungal, anti-inflammatory, antihypertensive, antileukemic, antimalarial, antimycobacterial, antioxidant, antipyretic, cardiotonic, cytotoxic, hypoglycemic, and vasorelaxing activity, as well as antifeedant and insect growth-inhibitory properties. Thus, genus Ajuga has significant medicinal and economic importance.

  9. The Pangenome of the genus Clostridium.

    Science.gov (United States)

    Udaondo, Zulema; Duque, Estrella; Ramos, Juan Luis

    2017-03-21

    We present the pangenome for the genus Clostridium sensu stricto, which was obtained using highly curated and annotated genomes from 16 species, some of these cause disease, while others are used for the production of added-value chemicals. Multilocus sequencing analysis revealed that species of this genus group into at least two clades that include non-pathogenic and pathogenic strains, suggesting that pathogenicity is dispersed across the phylogenetic tree. The core genome of the genus includes 546 protein families, which mainly comprise those involved in protein translation and DNA repair. The GS-GOGAT may represent the central pathway for generating organic nitrogen from inorganic nitrogen sources. Glycerol and glucose metabolism genes are well represented in the core genome together with a set of energy conservation systems. A metabolic network comprising proteins/enzymes, RNAs and metabolites, whose topological structure is a non-random and scale-free network with hierarchically structured modules was built. These modules shed light on the interactions between RNAs, proteins and metabolites, revealing biological features of transcription and translation, cell wall biosynthesis, C1 metabolism and N metabolism. Network analysis identified four nodes that function as hubs and bottlenecks, namely, coenzyme A, HPr kinases, S-adenosylmethionine and the ribonuclease P-protein, suggesting pivotal roles for them in Clostridium. This article is protected by copyright. All rights reserved.

  10. The genus Capsicum (Solanaceae in Africa

    Directory of Open Access Journals (Sweden)

    W. H. Eshbaugh

    1983-12-01

    Full Text Available The genus Capsicum (Solanaceae includes approximately 20 wild species and 4-5 domesticated taxa commonly referred to as ‘chilies’ or ‘peppers’. The pre-Colombian distribution of the genus was New World. The evolutionary history of the genus is now envisaged as including three distinct lines leading to the domesticated taxa. The route of Capsicum to the Old World is thought to have followed three different courses. First, explorers introduced it to Europe with secondary introduction into Africa via further exploratory expeditions; second, botanical gardens played a major role in introduction; and third, introduction followed the slave trade routes. Today, pepper production in Africa is of two types, vegetable and spice. Statistical profiles on production are difficult to interpret, but the data available indicate that Nigeria, Egypt, Tunisia and Ghana are the leading producers. Production is mainly a local phenomenon and large acreage is seldom devoted to the growing of peppers. The primary peppers in Africa are C.  annuum and C.  frutescens.

  11. The genus Crataegus: chemical and pharmacological perspectives

    Directory of Open Access Journals (Sweden)

    Dinesh Kumar

    2012-10-01

    Full Text Available Traditional drugs have become a subject of world importance, with both medicinal and economical implications. A regular and widespread use of herbs throughout the world has increased serious concerns over their quality, safety and efficacy. Thus, a proper scientific evidence or assessment has become the criteria for acceptance of traditional health claims. Plants of the genus Crataegus, Rosaceae, are widely distributed and have long been used in folk medicine for the treatment of various ailments such as heart (cardiovascular disorders, central nervous system, immune system, eyes, reproductive system, liver, kidney etc. It also exhibits wide range of cytotoxic, gastroprotective, anti-inflammatory, anti-HIV and antimicrobial activities. Phytochemicals like oligomeric procyanidins, flavonoids, triterpenes, polysaccharides, catecholamines have been identified in the genus and many of these have been evaluated for biological activities. This review presents comprehensive information on the chemistry and pharmacology of the genus together with the traditional uses of many of its plants. In addition, this review discusses the clinical trials and regulatory status of various Crataegus plants along with the scope for future research in this aspect.

  12. Phylogenetic studies of the genus Cebus (Cebidae-Primates using chromosome painting and G-banding

    Directory of Open Access Journals (Sweden)

    Pissinatti A

    2008-06-01

    Full Text Available Abstract Background Chromosomal painting, using whole chromosome probes from humans and Saguinus oedipus, was used to establish karyotypic divergence among species of the genus Cebus, including C. olivaceus, C. albifrons, C. apella robustus and C. apella paraguayanus. Cytogenetic studies suggested that the species of this genus have conservative karyotypes, with diploid numbers ranging from 2n = 52 to 2n = 54. Results Banding studies revealed morphological divergence among some chromosomes, owing to variations in the size of heterochromatic blocks. This analysis demonstrated that Cebus species have five conserved human associations (i.e., 5/7, 2/16, 10/16, 14/15, 8/18 and 3/21 when compared with the putative ancestral Platyrrhini karyotype. Conclusion The autapomorphies 8/15/8 in C. albifrons and 12/15 in C. olivaceus explain the changes in chromosome number from 54 to 52. The association 5/16/7, which has not previously been reported in Platyrrhini, was also found in C. olivaceus. These data corroborate previous FISH results, suggesting that the genus Cebus has a very similar karyotype to the putative ancestral Platyrrhini.

  13. Intelligent Fish Freshness Assessment

    Directory of Open Access Journals (Sweden)

    Hamid Gholam Hosseini

    2008-01-01

    Full Text Available Fish species identification and automated fish freshness assessment play important roles in fishery industry applications. This paper describes a method based on support vector machines (SVMs to improve the performance of fish identification systems. The result is used for the assessment of fish freshness using artificial neural network (ANN. Identification of the fish species involves processing of the images of fish. The most efficient features were extracted and combined with the down-sampled version of the images to create a 1D input vector. Max-Win algorithm applied to the SVM-based classifiers has enhanced the reliability of sorting to 96.46%. The realisation of Cyranose 320 Electronic nose (E-nose, in order to evaluate the fish freshness in real-time, is experimented. Intelligent processing of the sensor patterns involves the use of a dedicated ANN for each species under study. The best estimation of freshness was provided by the most sensitive sensors. Data was collected from four selected species of fishes over a period of ten days. It was concluded that the performance can be increased using individual trained ANN for each specie. The proposed system has been successful in identifying the number of days after catching the fish with an accuracy of up to 91%.

  14. Anglers' fishing problem

    CERN Document Server

    Karpowicz, Anna

    2011-01-01

    The considered model will be formulated as related to "the fishing problem" even if the other applications of it are much more obvious. The angler goes fishing. He uses various techniques and he has at most two fishing rods. He buys a fishing ticket for a fixed time. The fishes are caught with the use of different methods according to the renewal processes. The fishes' value and the inter arrival times are given by the sequences of independent, identically distributed (i.i.d.) random variables with the known distribution functions. It forms the marked renewal--reward process. The angler's measure of satisfaction is given by the difference between the utility function, depending on the value of the fishes caught, and the cost function connected with the time of fishing. In this way, the angler's relative opinion about the methods of fishing is modelled. The angler's aim is to have as much satisfaction as possible and additionally he has to leave the lake before a fixed moment. Therefore his goal is to find two...

  15. Combating Illegal Fishing

    Directory of Open Access Journals (Sweden)

    Sorin Stanciu

    2010-10-01

    Full Text Available Illegal, unreported and unregulated (IUU fishing is a worldwide phenomenon. Its extent and its environmental,economic and social consequences are such that it has become a priority issue at international level. IUU fishingcontributes to the depletion of fish stocks and jeopardises protection and recovery measures put in place to ensure theviability of resources. It represents unfair competition for those who exploit fish resources legally. The Commissionhave been involved in the fight against IUU fishing for over a decade and in 2002 the Commission adopted an ActionPlan against IUU fishing inspired by the FAOs International Plan of Action to prevent, deter and eliminate IUUfishing of 2001. However, despite regional and international efforts to stop IUU fishing the phenomenon is still agrowing problem and as a result, the European Community intensified its action towards IUU fishing by launching aconsultation process in 2007. A Proposal to prevent, deter and eliminate IUU fishing was adopted in October 2007and a Regulation to prevent, deter and eliminate illegal, unreported and unregulated (IUU fishing was adopted on 29September 2008, after a unanimous political agreement.

  16. Meat, Poultry and Fish

    Science.gov (United States)

    ... types of fish may contain high levels of mercury, PCBs (polychlorinated biphenyls), dioxins and other environmental contaminants. Shark, swordfish, tilefish (golden bass or golden snapper) and ...

  17. Humpback Dolphins (Genus Sousa) in India: An Overview of Status and Conservation Issues.

    Science.gov (United States)

    Sutaria, Dipani; Panicker, Divya; Jog, Ketki; Sule, Mihir; Muralidharan, Rahul; Bopardikar, Isha

    2015-01-01

    This chapter aims to collate recent work done by different research teams along the Indian coast and presents research plans for the conservation and management of the genus Sousa in Indian waters. Humpback dolphins are the most common nearshore cetaceans found along the Indian coast. The taxonomy is confused, but two or more species of humpback dolphins may be present in India. Dedicated research on humpback dolphins and other cetaceans has been initiated only in the past few years and vast gaps in the ecology and conservation of the genus from the region remain. Dedicated and opportunistic research indicates that humpback dolphin presence is continuous along the west coast of India, owing to the contiguous favourable habitat of shallow nearshore waters, while along the east coast humpback dolphins are apparently found in pockets. Humpback dolphins are also the most numerous in incidental catch records from the coast, owing to the large overlap in space use with nearshore fisheries like small gillnets, trawls, shore seines and purse seines. Along many coastal sites, humpback dolphins are known to cause damage and depredation of fish catch of certain fishing gears, making them unpopular. At the same time, many fishers along the west coast have developed local dolphin-watching programmes as an alternate source of livelihood, providing positive impetus for conservation. However, research on the long-term effects of dolphin watching and its management is required. Some recommendations for more effective management of this species are made.

  18. Electronmicroscopic Investigations on the Role of Vesicle-like Bodies in Inner Ear Maculae for Fish Otolith Growth

    Science.gov (United States)

    Ibsch, M.; Vöhringer, P.; Anken, R. H.; Rahmann, H.

    The presence, morphology and possible origin of vesicle-like bodies (VBs) within the inner ear otolithic membrane of developmental stages of cichlid fish Oreochromis mossambicus and adult swordtail fish Xiphophorus helleri was analysed by means of transmission and scanning electron microscopy (TEM and SEM, respectively) employing various fixation procedures. The VBs are believed to be involved in the formation of the otolith (or statolith in birds and mammals) regarding the supply of the otolith's organic material. Increasing the osmolarity of the fixation medium decreased the number of VBs seen. Decalcification ended up in a complete disappearance of the VBs. Whilst a fixation with glutaraldehyde followed by OS04 fixation yielded numerous VBs, only few of them were observed when the tissue was fixed with glutaraldehyde and OSO4 simultaneously. Therefore, the results strongly suggest that the VBs are fixative (i.e., glutaraldehyde) induced artifacts, so-called blisters. With this, the supply of an oto- or statolith's organic material remains obscure. Possibly, it is provided by secretion from the supporting cells as has been hypothesized earlier

  19. Antagonistic activity of antibiotic producing Streptomyces sp. against fish and human pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    Nazmul Hossain

    2014-04-01

    Full Text Available In this study, attempts were made to isolate Streptomyces sp. from soil samples of two different regions of Bangladesh and evaluate their antagonistic activity against fish and human pathogenic bacteria. A total of 10 isolates were identified as Streptomyces sp. based on several morphological, physiological and biochemical tests. Cross streak method was used to observe the antagonistic activity of the Streptomyces sp. isolates against different fish pathogens belonging to the genus Aeromonas, Pseudomonas and Edwardsiella and human clinical isolates belonging to the genus Klebsiella, Salmonella and Streptococcus. Seven Streptomyces sp. isolates showed antagonism against both fish and human pathogenic bacteria. Four isolates viz., N24, N26, N28 and N47 showed broad spectrum of antagonistic activity (80-100% against all genera of fish and human pathogenic bacteria. The isolate N49 exhibited highest spectrum of antagonism against all fish pathogens (90-100% but comparatively lower degree of antagonism against human pathogens (50-60%. Rest of the two isolates (N21 and N23 showed variability in their antagonism. Results showed that broad spectrum antibiotic(s could be developed from the isolates N24, N26, N28 and N47against several human and fish pathogens. The isolate N49 could be a potential source of antibiotic, especially for fish pathogenic bacteria.

  20. Phenotypic and genotypic characteristics of Mycobacterium isolates from fighting fish Betta spp. in Malaysia.

    Science.gov (United States)

    Najiah, M; Lee, K L; Noorasikin, H; Nadirah, M; Lee, S W

    2011-12-01

    Mycobacteriosis due to mycobacteria is one of the most common bacterial diseases in ornamental fish. We describe here the phenotypic and genotypic characteristics of Mycobacterium isolates from fighting fish Betta spp. using ATCC Mycobacterium marinum, Mycobacterium fortuitum and Mycobacterium chelonae as references. A total of four isolates (M1, M2, M3, M4) were obtained from four out of 106 fish samples using selective agar, and identified to Mycobacterium genus using acid-fast staining and 16s rRNA gene-based genus specific polymerase chain reaction. DNA sequencing and NCBI-BLAST analysis further identified isolate M1 as M. marinum and isolates M2, M3, M4 as M. fortuitum. Morphological, physiological and biochemical tests were carried out for phenotypic characterizations. Universal M13 and wild-type phage M13 RAPD dendogram was generated to illustrate the genetic relationship of the isolates and reference strains.

  1. Egg size-dependent expression of growth hormone receptor accompanies compensatory growth in fish.

    Science.gov (United States)

    Segers, F H I D; Berishvili, G; Taborsky, B

    2012-02-07

    Large egg size usually boosts offspring survival, but mothers have to trade off egg size against egg number. Therefore, females often produce smaller eggs when environmental conditions for offspring are favourable, which is subsequently compensated for by accelerated juvenile growth. How this rapid growth is modulated on a molecular level is still unclear. As the somatotropic axis is a key regulator of early growth in vertebrates, we investigated the effect of egg size on three key genes belonging to this axis, at different ontogenetic stages in a mouthbrooding cichlid (Simochromis pleurospilus). The expression levels of one of them, the growth hormone receptor (GHR), were significantly higher in large than in small eggs, but remarkably, this pattern was reversed after hatching: young originating from small eggs had significantly higher GHR expression levels as yolk sac larvae and as juveniles. GHR expression in yolk sac larvae was positively correlated with juvenile growth rate and correspondingly fish originating from small eggs grew faster. This enabled them to catch up fully in size within eight weeks with conspecifics from larger eggs. This is the first evidence for a potential link between egg size, an important maternal effect, and offspring gene expression, which mediates an adaptive adjustment in a relevant hormonal axis.

  2. Egg size-dependent expression of growth hormone receptor accompanies compensatory growth in fish

    Science.gov (United States)

    Segers, F. H. I. D.; Berishvili, G.; Taborsky, B.

    2012-01-01

    Large egg size usually boosts offspring survival, but mothers have to trade off egg size against egg number. Therefore, females often produce smaller eggs when environmental conditions for offspring are favourable, which is subsequently compensated for by accelerated juvenile growth. How this rapid growth is modulated on a molecular level is still unclear. As the somatotropic axis is a key regulator of early growth in vertebrates, we investigated the effect of egg size on three key genes belonging to this axis, at different ontogenetic stages in a mouthbrooding cichlid (Simochromis pleurospilus). The expression levels of one of them, the growth hormone receptor (GHR), were significantly higher in large than in small eggs, but remarkably, this pattern was reversed after hatching: young originating from small eggs had significantly higher GHR expression levels as yolk sac larvae and as juveniles. GHR expression in yolk sac larvae was positively correlated with juvenile growth rate and correspondingly fish originating from small eggs grew faster. This enabled them to catch up fully in size within eight weeks with conspecifics from larger eggs. This is the first evidence for a potential link between egg size, an important maternal effect, and offspring gene expression, which mediates an adaptive adjustment in a relevant hormonal axis. PMID:21752823

  3. Juvenile exposure to predator cues induces a larger egg size in fish

    Science.gov (United States)

    Segers, Francisca H. I. D.; Taborsky, Barbara

    2012-01-01

    When females anticipate a hazardous environment for their offspring, they can increase offspring survival by producing larger young. Early environmental experience determines egg size in different animal taxa. We predicted that a higher perceived predation risk by juveniles would cause an increase in the sizes of eggs that they produce as adults. To test this, we exposed juveniles of the mouthbrooding cichlid Eretmodus cyanostictus in a split-brood experiment either to cues of a natural predator or to a control situation. After maturation, females that had been confronted with predators produced heavier eggs, whereas clutch size itself was not affected by the treatment. This effect cannot be explained by a differential female body size because the predator treatment did not influence growth trajectories. The observed increase of egg mass is likely to be adaptive, as heavier eggs gave rise to larger young and in fish, juvenile predation risk drops sharply with increasing body size. This study provides the first evidence that predator cues perceived by females early in life positively affect egg mass, suggesting that these cues allow her to predict the predation risk for her offspring. PMID:21976689

  4. Phylogeny and tempo of diversification in the superradiation of spiny-rayed fishes.

    Science.gov (United States)

    Near, Thomas J; Dornburg, Alex; Eytan, Ron I; Keck, Benjamin P; Smith, W Leo; Kuhn, Kristen L; Moore, Jon A; Price, Samantha A; Burbrink, Frank T; Friedman, Matt; Wainwright, Peter C

    2013-07-30

    Spiny-rayed fishes, or acanthomorphs, comprise nearly one-third of all living vertebrates. Despite their dominant role in aquatic ecosystems, the evolutionary history and tempo of acanthomorph diversification is poorly understood. We investigate the pattern of lineage diversification in acanthomorphs by using a well-resolved time-calibrated phylogeny inferred from a nuclear gene supermatrix that includes 520 acanthomorph species and 37 fossil age constraints. This phylogeny provides resolution for what has been classically referred to as the "bush at the top" of the teleost tree, and indicates acanthomorphs originated in the Early Cretaceous. Paleontological evidence suggests acanthomorphs exhibit a pulse of morphological diversification following the end Cretaceous mass extinction; however, the role of this event on the accumulation of living acanthomorph diversity remains unclear. Lineage diversification rates through time exhibit no shifts associated with the end Cretaceous mass extinction, but there is a global decrease in lineage diversification rates 50 Ma that occurs during a period when morphological disparity among fossil acanthomorphs increases sharply. Analysis of clade-specific shifts in diversification rates reveal that the hyperdiversity of living acanthomorphs is highlighted by several rapidly radiating lineages including tunas, gobies, blennies, snailfishes, and Afro-American cichlids. These lineages with high diversification rates are not associated with a single habitat type, such as coral reefs, indicating there is no single explanation for the success of acanthomorphs, as exceptional bouts of diversification have occurred across a wide array of marine and freshwater habitats.

  5. Essential Fish Habitat (EFH) Areas Protected From Fishing

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Designated Essential Fish Habitat (EFH) areas where fishing or the use of fishing gears has been restricted or modified in order to minimize the adverse effects of...

  6. Fish Springs NWR mammal, fish, amphibian, and reptile list

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The following is a species list for mammals, fishes, amphibians, and reptiles found on or adjacent to Fish Springs National Wildlife Refuge, as of October, 1996.

  7. Redescription of Proctophantastes gillissi (Overstreet et Pritchard, 1977) (Trematoda: Zoogonidae) with discussion on the systematic position of the genus Proctophantastes Odhner, 1911.

    Science.gov (United States)

    Sokolov, Sergey; Gordeev, Ilya; Lebedeva, Daria

    2016-09-01

    The redescription of Proctophantastes gillissi (Overstreet et Pritchard, 1977) (Trematoda: Zoogonidae) was made on specimens collected from Muraenolepis marmorata Günther, 1880 (Gadiformes) caught in the Ross Sea and the Amundsen Sea (Antarctic). The fish is a new host of this parasite. Phylogenetic relations of P. gillissi were inferred by Maximum Likelihood and Bayesian inference analysis of partial sequences from 28S rDNA. The findings from analysis of the molecular data are not consistent with the traditional point of view about the position of the genus Proctophantastes Odhner, 1911 in the subfamily Lepidophyllinae. The taxonomical position of the genus needs further revision.

  8. [Analysis of diet composition and overlap in four species of the genus Diplectrum (Perciformes: Serranidae) in the Mexican Central Pacific].

    Science.gov (United States)

    Aguilar Palomino, Bernabé; González Sansón, Gaspar

    2010-12-01

    Analysis of diet composition and overlap in four species of the genus Diplectrum (Perciformes: Serranidae) in the Mexican Central Pacific. The information of trophic interactions among species is essential to understand ecosystem function. To assess this in four Diplectrum species, we analyzed the stomach contents of 397 individuals caught using shrimp trawling nets off the coasts of Jalisco and Colima, Mexico. Main food component of D. eumelum were fish of the Order Pleuronectiformes, followed by shrimps (Metapenaeopsis spp). D. euryplectrum feeds mainly on crustaceans, with stomatopods (Squilla mantoidea) as main food items followed by shrimps and brachyurans. Fish and polychaetes had a low representation in the diet of this species. D. labarum feeds mainly on crustaceans, mollusks and fish. The stomatopod Eurysquilla veleronis contributed to with a high diet percentage by weight, followed by shrimps (mostly Solenoceraflorae) and brachyurans, as well as the squid Lolliguncula diomedae. Fishes (Ophidion spp.) were also an important component of the diet of this species. The most common preys of D. rostrum were crustaceans, mollusks, polychaetes and fish. The squid Lolliguncula diomedae and fishes of genus Ophidion were also well represented in the diet. Diet breadth index yielded significant differences between species. The number of diet items varied from 16 in D. euryplectrum to 6 in D. eumelum. The average value of overlap (0.247) was not significantly different (p = 0.118) from the expected one for a null model (0.174). The observed variance of the overlap index (0.071) was significantly higher (V = 0.025, p = 0.0004) than the value expected for a null model.

  9. Metabolite variability in Caribbean sponges of the genus Aplysina

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    Monica Puyana

    2015-12-01

    Full Text Available Abstract Sponges of the genus Aplysina are among the most common benthic animals on reefs of the Caribbean, and display a wide diversity of morphologies and colors. Tissues of these sponges lack mineralized skeletal elements, but contain a dense spongin skeleton and an elaborate series of tyrosine-derived brominated alkaloid metabolites that function as chemical defenses against predatory fishes, but do not deter some molluscs. Among the earliest marine natural products to be isolated and identified, these metabolites remain the subject of intense interest for commercial applications because of their activities in various bioassays. In this study, crude organic extracts from 253 sponges from ten morphotypes among the species Aplysina archeri,Aplysina bathyphila,Aplysina cauliformis,Aplysina fistularis,Aplysina fulva,A. insularis, and Aplysina lacunosa were analyzed by liquid chromatography–mass spectrometry (LC–MS to characterize the pattern of intra- and interspecific variabilities of the twelve major secondary metabolites present therein. Patterns across Aplysina species ranged from the presence of mostly a single compound, fistularin-3, in A. cauliformis, to a mixture of metabolites present in the other species. These patterns did not support the biotransformation hypothesis for conversion of large molecular weight molecules to smaller ones for the purpose of enhanced defense. Discriminant analyses of the metabolite data revealed strong taxonomic patterns that support a close relationship between A. fistularis,A. fulva and A. insularis, while two morphotypes of A. cauliformis (lilac creeping vs. brown erect were very distinct. Two morphotypes of A. lacunosa, one with hard tissue consistency, the other soft and thought to belong to a separate genus (Suberea, had very similar chemical profiles. Of the twelve metabolites found among samples, variation in fistularin-3, dideoxyfistularin-3 and hydroxyaerothionin provided the most predictive

  10. Alaskan sport fishing waters

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — As a guide to newcomers and visitors, fishery biologists have compiled a list of some of the well-known fishing waters in Alaska. The list is merely a starting point...

  11. Virus diseases of fish

    Science.gov (United States)

    Watson, Stanley W.

    1954-01-01

    Viruses are probably the cause of a wide spectrum of fish diseases. Although relatively few virus diseases of fish are known today, some of the diseases of unknown etiology, as well as some diseases presently accepted as due to bacteria, protozoa, fungi or nutritional deficiencies, possibly will be recognized eventually as virus diseases.

  12. PARASITES OF FISH

    Science.gov (United States)

    The intent of this chapter is to describe the parasites of importance to fishes maintained and used in laboratory settings. In contrast to the frist edition, the focus will be only on those parasites that pose a serious threat to or are common in fishes held in these confined en...

  13. Folkbiology of Freshwater Fish

    Science.gov (United States)

    Medin, Douglas L.; Ross, Norbert O.; Atran, Scott; Cox, Douglas; Coley, John; Proffitt, Julia B.; Blok, Sergey

    2006-01-01

    Cross-cultural comparisons of categorization often confound cultural factors with expertise. This paper reports four experiments on the conceptual behavior of Native American and majority-culture fish experts. The two groups live in the same general area and engage in essentially the same set of fishing-related behaviors. Nonetheless, cultural…

  14. Biannual Fish Survey, Spring 1993

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The biannual fish survey was initiated in 1989 to monitor population trends of federally endangered fish species at Ash Meadows National Wildlife Refuge. Item 421 of...

  15. Genomic characterization of the Taylorella genus.

    Directory of Open Access Journals (Sweden)

    Laurent Hébert

    Full Text Available The Taylorella genus comprises two species: Taylorella equigenitalis, which causes contagious equine metritis, and Taylorella asinigenitalis, a closely-related species mainly found in donkeys. We herein report on the first genome sequence of T. asinigenitalis, analyzing and comparing it with the recently-sequenced T. equigenitalis genome. The T. asinigenitalis genome contains a single circular chromosome of 1,638,559 bp with a 38.3% GC content and 1,534 coding sequences (CDS. While 212 CDSs were T. asinigenitalis-specific, 1,322 had orthologs in T. equigenitalis. Two hundred and thirty-four T. equigenitalis CDSs had no orthologs in T. asinigenitalis. Analysis of the basic nutrition metabolism of both Taylorella species showed that malate, glutamate and alpha-ketoglutarate may be their main carbon and energy sources. For both species, we identified four different secretion systems and several proteins potentially involved in binding and colonization of host cells, suggesting a strong potential for interaction with their host. T. equigenitalis seems better-equipped than T. asinigenitalis in terms of virulence since we identified numerous proteins potentially involved in pathogenicity, including hemagluttinin-related proteins, a type IV secretion system, TonB-dependent lactoferrin and transferrin receptors, and YadA and Hep_Hag domains containing proteins. This is the first molecular characterization of Taylorella genus members, and the first molecular identification of factors potentially involved in T. asinigenitalis and T. equigenitalis pathogenicity and host colonization. This study facilitates a genetic understanding of growth phenotypes, animal host preference and pathogenic capacity, paving the way for future functional investigations into this largely unknown genus.

  16. Genus paracoccidioides: Species recognition and biogeographic aspects.

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    Raquel Cordeiro Theodoro

    Full Text Available BACKGROUND: Paracoccidioidomycosis is a systemic mycosis caused by Paracoccidioides brasiliensis (species S1, PS2, PS3, and Paracoccidioides lutzii. This work aimed to differentiate species within the genus Paracoccidioides, without applying multilocus sequencing, as well as to obtain knowledge of the possible speciation processes. METHODOLOGY/PRINCIPAL FINDINGS: Single nucleotide polymorphism analysis on GP43, ARF and PRP8 intein genes successfully distinguished isolates into four different species. Morphological evaluation indicated that elongated conidia were observed exclusively in P. lutzii isolates, while all other species (S1, PS2 and PS3 were indistinguishable. To evaluate the biogeographic events that led to the current geographic distribution of Paracoccidioides species and their sister species, Nested Clade and Likelihood Analysis of Geographic Range Evolution (LAGRANGE analyses were applied. The radiation of Paracoccidioides started in northwest South America, around 11-32 million years ago, as calculated on the basis of ARF substitution rate, in the BEAST program. Vicariance was responsible for the divergence among S1, PS2 and P. lutzii and a recent dispersal generated the PS3 species, restricted to Colombia. Taking into account the ancestral areas revealed by the LAGRANGE analysis and the major geographic distribution of L. loboi in the Amazon basin, a region strongly affected by the Andes uplift and marine incursions in the Cenozoic era, we also speculate about the effect of these geological events on the vicariance between Paracoccidioides and L. loboi. CONCLUSIONS/SIGNIFICANCE: The use of at least 3 SNPs, but not morphological criteria, as markers allows us to distinguish among the four cryptic species of the genus Paracoccidioides. The work also presents a biogeographic study speculating on how these species might have diverged in South America, thus contributing to elucidating evolutionary aspects of the genus Paracoccidioides.

  17. A review of the genus Curtisia (Curtisiaceae

    Directory of Open Access Journals (Sweden)

    E. YU Yembaturova

    2009-12-01

    Full Text Available A review of the monotypic southern African endemic genus Curtisia Aiton is presented. Detailed studies of the fruit and seed structure provided new evidence in support of a close relationship between the family Curtisiaceae and Comaceae. Comparisons with several other members of the Comales revealed carpological similarities to certain species of Comus s.I., sometimes treated as segregate genera Dendrobenthamia Hutch, and Benthamidia Spach. We also provide information on the history of the assegai tree, Curtisia dentata (Burm.f. C.A.Sm. and its uses, as well as a formal taxonomic revision, including nomenclature, typification, detailed description and geographical distribution.

  18. Genus Microsporum dermatophytes in Eastern Bohemia.

    Science.gov (United States)

    Dvorák, J; Otcenásek, M

    1976-01-01

    The authors presented a taxonomic survey of dermatophytes of the genus Microsporum. From the 19 species described so far, they isolated ten species in the region of Eastern Bohemia. Only the species Microsporum cookei and M. gypsem are considered to be endemic species. The remaining are regarded as imported dermatophytes which are not able to maintain their existence permanently in the conditions of the mentioned region. Data on the findings of the individual species were completed by the authors' remarks on their primary hosts and/or substrates of heterotrophy, frequency of occurrence and geographical distribution.

  19. Rust fungi on Annonaceae: the genus Sphaerophragmium.

    Science.gov (United States)

    Beenken, Ludwig; Berndt, Reinhard

    2010-01-01

    Seven species of the rust genus Sphaerophragmium occur on members of the tropical plant family Annonaceae. Uropyxis gerstneri is recombined to S. gerstneri. A new species, S. xylopiae, is described from Xylopia acutiflora. The host plant of S. boanense is identified as Mitrella sp. Sphaerophragmium pulchrum is transferred to Dicheirinia. The anatomy of telia with teliospores and parasitizing mycelium is described and illustrated in detail. A new type of M-haustorium, which emanates laterally from intracellular hypha, is detected in S. monodorae. An identification key is given.

  20. 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.

  1. 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.

  2. A Brief Chronicle of the Genus Cordyceps Fr., the Oldest Valid Genus in Cordycipitaceae (Hypocreales, Ascomycota)

    Science.gov (United States)

    Tanaka, Eiji; Han, Jae-Gu; Oh, Junsang; Han, Sang-Kuk; Lee, Kang-Hyo

    2014-01-01

    The earliest pre-Linnaean fungal genera are briefly discussed here with special emphasis on the nomenclatural connection with the genus Cordyceps Fr. Since its valid publication under the basidiomycetous genus Clavaria Vaill. ex L. (Clavaria militaris L. Sp. Pl. 2:1182, 1753), the genus Cordyceps has undergone nomenclatural changes in the post-Linnaean era, but has stood firmly for approximately 200 years. Synonyms of Cordyceps were collected from different literature sources and analyzed based on the species they represent. True synonyms of Cordyceps Fr. were defined as genera that represented species of Cordyceps Fr. emend. G. H. Sung, J. M. Sung, Hywel-Jones & Spatafora. The most common synonyms of Cordyceps observed were Clavaria and Sphaeria Hall, reported in the 18th and in the first half of the 19th century, respectively. Cordyceps, the oldest genus in the Cordyceps s. s. clade of Cordycipitaceae, is the most preferred name under the "One Fungus = One Name" principle on priority bases. PMID:25071376

  3. Otoliths as an integral part in fossil fish taxonomy

    Directory of Open Access Journals (Sweden)

    Christoph Gierl

    2015-11-01

    Full Text Available Otoliths are small structures in the skull of fishes. They are responsible for hearing and orientation in the 3-dimensional space. They also hold valuable information regarding the taxonomy. Their outline, the shape of the sulcus and other features allow the determination of a fish even to the species level. A lot of fossil species are solely based on otoliths because of their good chance of preservation. Gobies are in this case no different. An additional challenge in gobies is their high similarity between species concerning the preservable parts. Fossil skeletons that are 20 Million years old can show only few differences compared to recent gobies. These features are often hardly recognizable due to their preservation. As a consequence many fossil gobies have been assigned to the genus Gobius sensu lato. Examples are two gobies from the Miocene of Southern Germany. They have a unique combination of characters (six branchiostegals, palatine resembling a “T”, no entopterygoid that allows the rectification of a new fossil genus but the two species are hardly distinguishable based only on the skeleton. The key hints in having two species are the otoliths. They show slight but consistent differences in their outline. This shows that otoliths can be a key feature in species identification. They should also be taken into consideration by recent fish species. Not to mention their possible phylogenetic potential that remains to be explored.

  4. STUDY OF Salmo GENUS (PISCES, SALMONIDAE ON THE BALKAN PENINSULA

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    Simo Georgijev

    2011-03-01

    Full Text Available Author disputes the position of the authors K o t t e l a t (1997 and K o t t e l a t & F r e y h o f (2007 about the existence of several species belonging to the Salmo genus in some parts of Balkan Peninsula: Salmo aphelios Kottelat, 1997; Salmo balcanicus (Karaman, 1927; Salmo farioides (Karaman, 1938; Salmo labrax Pallas, 1814; Salmo letnica (Karaman, 1924; Salmo lumi Poljakov, Filipi & Basho, 1958; Salmo macedonicus (Karaman, 1924; Salmo montenigrinus (Karaman, 1933; Salmo pelagonicus Karaman, 1938; Salmo peristericus Karaman, 1938; Salmo taleri (Karaman, 1932. Majority of those species were described by dr. Stanko Karaman, the author who is, regarding the number of described species of European freshwater fishes, on the second place, just behind Carl Linnaeus. It is hardly believable that four trout species were formed in a small and oligotrophic microhabitat like Ohrid Lake, or three species in the Vardar River, knowing that the factor of geographic isolation doesn’t exist in either of the habitats. The author’s position is that all of these species are actually just types of one, highly plastic regarding the micro ecological conditions and phenotypic manifestations, species: Salmo trutta (Linnaeus, 1785. The author supports his opinion by his own results, as well the results of other scientists, obtained through studies of ecology and taxonomy of the brown trout in fluent and still water microhabitats. Also the author suggests that it is unacceptable to apply the terminology immanent to the anthropogenic factor in a sphere of another scientific area where such factor doesn't exist (agronomy-race and biology-natural selection.

  5. Olfactory toxicity in fishes.

    Science.gov (United States)

    Tierney, Keith B; Baldwin, David H; Hara, Toshiaki J; Ross, Peter S; Scholz, Nathaniel L; Kennedy, Christopher J

    2010-01-21

    Olfaction conveys critical environmental information to fishes, enabling activities such as mating, locating food, discriminating kin, avoiding predators and homing. All of these behaviors can be impaired or lost as a result of exposure to toxic contaminants in surface waters. Historically, teleost olfaction studies have focused on behavioral responses to anthropogenic contaminants (e.g., avoidance). More recently, there has been a shift towards understanding the underlying mechanisms and functional significance of contaminant-mediated changes in fish olfaction. This includes a consideration of how contaminants affect the olfactory nervous system and, by extension, the downstream physiological and behavioral processes that together comprise a normal response to naturally occurring stimuli (e.g., reproductive priming or releasing pheromones). Numerous studies spanning several species have shown that ecologically relevant exposures to common pollutants such as metals and pesticides can interfere with fish olfaction and disrupt life history processes that determine individual survival and reproductive success. This represents one of the pathways by which toxic chemicals in aquatic habitats may increasingly contribute to the decline and at-risk status of many commercially and ecologically important fish stocks. Despite our emerging understanding of the threats that pollution poses for chemical communication in aquatic communities, many research challenges remain. These include: (1) the determination of specific mechanisms of toxicity in the fish olfactory sensory epithelium; (2) an understanding of the impacts of complex chemical mixtures; (3) the capacity to assess olfactory toxicity in fish in situ; (4) the impacts of toxins on olfactory-mediated behaviors that are still poorly understood for many fish species; and (5) the connections between sublethal effects on individual fish and the long-term viability of wild populations. This review summarizes and integrates

  6. Why do fish school?

    Institute of Scientific and Technical Information of China (English)

    Matz LARSSON

    2012-01-01

    Synchronized movements (schooling) emit complex and overlapping sound and pressure curves that might confuse the inner ear and lateral line organ (LLO) of a predator.Moreover,prey-fish moving close to each other may blur the electro-sensory perception of predators.The aim of this review is to explore mechanisms associated with synchronous swimming that may have contributed to increased adaptation and as a consequence may have influenced the evolution of schooling.The evolutionary development of the inner ear and the LLO increased the capacity to detect potential prey,possibly leading to an increased potential for cannibalism in the shoal,but also helped small fish to avoid joining larger fish,resulting in size homogeneity and,accordingly,an increased capacity for moving in synchrony.Water-movements and incidental sound produced as by-product of locomotion (ISOL) may provide fish with potentially useful information during swimming,such as neighbour body-size,speed,and location.When many fish move close to one another ISOL will be energetic and complex.Quiet intervals will be few.Fish moving in synchrony will have the capacity to discontinue movements simultaneously,providing relatively quiet intervals to allow the reception of potentially critical environmental signals.Besides,synchronized movements may facilitate auditory grouping of ISOL.Turning preference bias,well-functioning sense organs,good health,and skillful motor performance might be important to achieving an appropriate distance to school neighbors und aid the individual fish in reducing time spent in the comparatively less safe school periphery.Turning preferences in ancestral fish shoals might have helped fish to maintain groups and stay in formarion,reinforcing aforementioned predator confusion mechanisms,which possibly played a role in the lateralization of the vertebrate brain [Current Zoology 58 (1):116-128,2012].

  7. A MONOGRAPH OF THE GENUS DIPLODISCUS* Turcz. (TILIACEAE

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    A. J. G. H. KOSTERMANS

    2014-01-01

    Full Text Available 1. Seven species of the genus Diplodiscus are described, of which three(D. microlepis, D. parviflorus and D. decumbens are new to science, and one (D. hookerianus was formerly described as Pentace (for the description of D. decumbens cf. p. 264.2. The area of distribution of the genus covers the Malay Peninsula,Borneo and the Philippines.3. The affinities of the genus are discussed.4. A key to the species is presented.

  8. The Genus Alpinia: A Review of Its Phytochemistry and Pharmacology

    OpenAIRE

    Wei-Jie Zhang; Jian-Guang Luo; Ling-Yi Kong

    2016-01-01

    Genus Alpinia consists of over 250 species, which are widely distributed in south and southeast Asia. Many plants of genus Alpinia have been used for thousands of years to treat digestive system diseases and as anti-inflammatory drugs. Phytochemical research on this genus has led to the isolation of different kinds of diarylheptanoids, terpenes triterpenoids, phenylbutanoids, lignans, and flavonoids. Experimental evidences revealed that both the crude extracts and pure constituents isolated f...

  9. A new trans-Andean Stick Catfish of the genus Farlowella Eigenmann & Eigenmann, 1889 (Siluriformes: Loricariidae) with the first record of the genus for the río Magdalena Basin in Colombia.

    Science.gov (United States)

    Ballen, Gustavo A; Mojica, José Iván

    2014-02-17

    A new species of Farlowella is described from El Carmen de Chucurí in the Departamento de Santander, western flank of the Cordillera Oriental, río Magdalena Basin, Colombia. Farlowella yarigui n. sp. differs from its congeners in lateral body plate morphology, abdominal cover, cephalic hypertrophied odontodes, and details of coloration. This is the first verifiable record of the genus in the Magdalena drainage. Aspects of natural history and implications of this finding are provided concerning the state of knowledge of the fishes of the río Magdalena Basin. Previous records of Farlowella gracilis in the río Cauca basin are examined and herein considered erroneous, rendering the new species the only representative of the genus in the Magdalena-Cauca system. A key to species of Farlowella from Colombia is provided.

  10. Elliptic Genus of E-strings

    CERN Document Server

    Kim, Joonho; Lee, Kimyeong; Park, Jaemo; Vafa, Cumrun

    2014-01-01

    We study a family of 2d N=(0,4) gauge theories which describes at low energy the dynamics of E-strings, the M2-branes suspended between a pair of M5 and M9 branes. The gauge theory is engineered using a duality with type IIA theory, leading to the D2-branes suspended between an NS5-brane and 8 D8-branes on an O8-plane. We compute the elliptic genus of this family of theories, and find agreement with the known results for single and two E-strings. The partition function can in principle be computed for arbitrary number of E-strings, and we compute them explicitly for low numbers. We test our predictions against the partially known results from topological strings, as well as from the instanton calculus of 5d Sp(1) gauge theory. Given the relation to topological strings, our computation provides the all genus partition function of the refined topological strings on the canonical bundle over 1/2 K3.

  11. Genus Tinospora: Ethnopharmacology, Phytochemistry, and Pharmacology

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    Sensen Chi

    2016-01-01

    Full Text Available The genus Tinospora includes 34 species, in which several herbs were used as traditional medicines by indigenous groups throughout the tropical and subtropical parts of Asia, Africa, and Australia. The extensive literature survey revealed Tinospora species to be a group of important medicinal plants used for the ethnomedical treatment of colds, headaches, pharyngitis, fever, diarrhea, oral ulcer, diabetes, digestive disorder, and rheumatoid arthritis. Indian ethnopharmacological data points to the therapeutic potential of the T. cordifolia for the treatment of diabetic conditions. While Tinospora species are confusing in individual ingredients and their mechanisms of action, the ethnopharmacological history of those plants indicated that they exhibit antidiabetic, antioxidation, antitumor, anti-inflammation, antimicrobial, antiosteoporosis, and immunostimulation activities. While the clinical applications in modern medicine are lacking convincing evidence and support, this review is aimed at summarizing the current knowledge of the traditional uses, phytochemistry, biological activities, and toxicities of the genus Tinospora to reveal its therapeutic potentials and gaps, offering opportunities for future researches.

  12. Aggressive behavior in the genus Gallus sp

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    SA Queiroz

    2006-03-01

    Full Text Available The intensification of the production system in the poultry industry and the vertical integration of the poultry agribusiness have brought profound changes in the physical and social environment of domestic fowls in comparison to their ancestors and have modified the expression of aggression and submission. The present review has covered the studies focusing on the different aspects linked to aggressiveness in the genus Gallus. The evaluated studies have shown that aggressiveness and subordination are complex behavioral expressions that involve genetic differences between breeds, strains and individuals, and differences in the cerebral development during growth, in the hormonal metabolism, in the rearing conditions of individuals, including feed restriction, density, housing type (litter or cage, influence of the opposite sex during the growth period, existence of hostile stimuli (pain and frustration, ability to recognize individuals and social learning. The utilization of fighting birds as experimental material in the study of mechanisms that have influence on the manifestation of aggressiveness in the genus Gallus might comparatively help to elucidate important biological aspects of such behavior.

  13. The genus Geobacillus and their biotechnological potential.

    Science.gov (United States)

    Hussein, Ali H; Lisowska, Beata K; Leak, David J

    2015-01-01

    The genus Geobacillus comprises a group of Gram-positive thermophilic bacteria, including obligate aerobes, denitrifiers, and facultative anaerobes that can grow over a range of 45-75°C. Originally classified as group five Bacillus spp., strains of Bacillus stearothermophilus came to prominence as contaminants of canned food and soon became the organism of choice for comparative studies of metabolism and enzymology between mesophiles and thermophiles. More recently, their catabolic versatility, particularly in the degradation of hemicellulose and starch, and rapid growth rates have raised their profile as organisms with potential for second-generation (lignocellulosic) biorefineries for biofuel or chemical production. The continued development of genetic tools to facilitate both fundamental investigation and metabolic engineering is now helping to realize this potential, for both metabolite production and optimized catabolism. In addition, this catabolic versatility provides a range of useful thermostable enzymes for industrial application. A number of genome-sequencing projects have been completed or are underway allowing comparative studies. These reveal a significant amount of genome rearrangement within the genus, the presence of large genomic islands encompassing all the hemicellulose utilization genes and a genomic island incorporating a set of long chain alkane monooxygenase genes. With G+C contents of 45-55%, thermostability appears to derive in part from the ability to synthesize protamine and spermine, which can condense DNA and raise its Tm.

  14. Genus Tinospora: Ethnopharmacology, Phytochemistry, and Pharmacology

    Science.gov (United States)

    She, Gaimei; Han, Dan; Wang, Weihua; Liu, Zhao

    2016-01-01

    The genus Tinospora includes 34 species, in which several herbs were used as traditional medicines by indigenous groups throughout the tropical and subtropical parts of Asia, Africa, and Australia. The extensive literature survey revealed Tinospora species to be a group of important medicinal plants used for the ethnomedical treatment of colds, headaches, pharyngitis, fever, diarrhea, oral ulcer, diabetes, digestive disorder, and rheumatoid arthritis. Indian ethnopharmacological data points to the therapeutic potential of the T. cordifolia for the treatment of diabetic conditions. While Tinospora species are confusing in individual ingredients and their mechanisms of action, the ethnopharmacological history of those plants indicated that they exhibit antidiabetic, antioxidation, antitumor, anti-inflammation, antimicrobial, antiosteoporosis, and immunostimulation activities. While the clinical applications in modern medicine are lacking convincing evidence and support, this review is aimed at summarizing the current knowledge of the traditional uses, phytochemistry, biological activities, and toxicities of the genus Tinospora to reveal its therapeutic potentials and gaps, offering opportunities for future researches. PMID:27648105

  15. West Lake Fish

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    Sweet & Sour Fish is widely recognized as the best fish recipe found in the city of Hangzhou. The delectable tender sweet & sour dish would please the palate of even the most demanding gourmet. The unique preparation method follows: Method: Place a one kilogram grass carp in clear water for three days to eliminate any offensive odor, and allowing adequate time for defecation. Gut and clean the carp thoroughly. Slice open the belly, Make five equally spaced one centimeter deep incisions on one side of the fish, and another slanting cut through the thick meat on the opposite side. Be certain to ensure the

  16. Influence of long-term hyper-gravity on the reactivity of succinic acid dehydrogenase and NADPH-diaphorase in the central nervous system of fish: a histochemical study

    Science.gov (United States)

    Anken, R. H.; Rahmann, H.

    In the course of a densitometric evaluation, the histochemically demonstrated reactivity of succinic acid dehydrogenase (SDH) and of NADPH-diaphorase (NADPHD) was determined in different brain nuclei of two teleost fish (cichlid fish Oreochromis mossambicus, swordtail fish Xiphophorus helleri), which had been kept under 3g hyper-gravity for 8 days. SDH was chosen since it is a rate limiting enzyme of the Krebs cycle and therefore it is regarded as a marker for metabolic and neuronal activity. NADPHD reactivity reflects the activity of nitric oxide synthase. Nitric oxide (NO) is a gaseous intercellular messenger that has been suggested to play a major role in several different in vivo models of neuronal plasticity including learning. Within particular vestibulum-connected brain centers, significant effects of hyper-gravity were obtained, e.g., in the magnocellular nucleus, a primary vestibular relay ganglion of the brain stem octavolateralis area, in the superior rectus subdivision of the oculomotoric nucleus and within cerebellar eurydendroid cells, which in teleosts possibly resemble the deep cerebellar nucleus of higher vertebrates. Non-vestibulum related nuclei did not respond to hypergravity in a significant way. The effect of hyper-gravity found was much less distinct in adult animals as compared to the circumstances seen in larval fish (Anken et al., Adv. Space Res. 17, 1996), possibly due to a development correlated loss of neuronal plasticity.

  17. Topological classification and enumeration of RNA structures by genus

    DEFF Research Database (Denmark)

    Andersen, Jørgen Ellegaard; Penner, Robert; Reidys, C. M.

    2013-01-01

    To an RNA pseudoknot structure is naturally associated a topological surface, which has its associated genus, and structures can thus be classified by the genus. Based on earlier work of Harer-Zagier, we compute the generating function for the number of those structures of fixed genus and minimum...... stack size with nucleotides so that no two consecutive nucleotides are basepaired and show that is algebraic. In particular, we prove that , where . Thus, for stack size at least two, the genus only enters through the sub-exponential factor, and the slow growth rate compared to the number of RNA...

  18. DNA barcoding of marine ornamental fishes from India.

    Science.gov (United States)

    Bamaniya, Dhaval C; Pavan-Kumar, A; Gireesh-Babu, P; Sharma, Niti; Reang, Dhalongsaih; Krishna, Gopal; Lakra, W S

    2016-09-01

    India has rich marine ornamental fish diversity with 400 fish species distributed in Gulf of Munnar/Palk Bay, Gulf of Kutch, and in reefs around Andaman & Nicobar and Lakshadweep Islands. Marine ornamental fish identification at the field level is very difficult because of their high diversity and profound changes in appearance during their developmental stages and camouflage. To facilitate ornamental fish trading with ease and in compliance with the biodiversity act, DNA barcoding technique could be used to accurately identify species. In this study, DNA barcodes were generated for 31 species of commercially important marine ornamental fishes from India. The average genetic distance (K2P model) within species, genus, and family was 0.446, 13.08, and 20.09%, respectively. Intraspecific variation has increased several folds (15-20 times) after including conspecific sequences from different geographical locations. The presence of allopatric lineages/cryptic species was observed in the Indo-pacific region. The NJ tree constructed based on K2P values showed distinct clusters shared by congeneric species specific to populations.

  19. Fish germ cells

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Fish, like many other animals, have two major cell lineages, namely the germline and soma. The germ-soma separation is one of the earliest events of embryonic development. Germ cells can be specifically labeled and isolated for culture and transplan-tation, providing tools for reproduction of endangered species in close relatives, such as surrogate production of trout in salmon. Haploid cell cultures, such as medaka haploid embryonic stem cells have recently been obtained, which are capable of mimicking sperm to produce fertile offspring, upon nuclear being directly transferred into normal eggs. Such fish originated from a mosaic oocyte that had a haploid meiotic nucleus and a transplanted haploid mitotic cell culture nucleus. The first semi-cloned fish is Holly. Here we review the current status and future directions of understanding and manipulating fish germ cells in basic research and reproductive technology.

  20. Fishing Community Profiles

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — To enable fisheries managers to comply with National Standard 8 (NS8), NMFS social scientists around the nation are preparing fishing community profiles that present...