WorldWideScience

Sample records for platyfish xiphophorus variatus

  1. Sperm cryopreservation in live-bearing Xiphophorus fishes: offspring production from Xiphophorus variatus and strategies for establishment of sperm repositories.

    Science.gov (United States)

    Yang, Huiping; Cuevas-Uribe, Rafael; Savage, Markita G; Walter, Ronald B; Tiersch, Terrence R

    2012-09-01

    Cryopreservation of sperm from Xiphophorus fishes has produced live young in three species: X. hellerii, X. couchianus, and X. maculatus. In this study, the goal was to establish protocols for sperm cryopreservation and artificial insemination to produce live young in X. variatus, and to identify needs for repository development. The objectives were to: 1) collect basic biological characteristics of males; 2) cryopreserve sperm from X. variatus, 3) harvest live young from cryopreserved sperm, and 4) discuss the requirements for establishment of sperm repositories. The 35 males used in this study had a body weight of 0.298±0.096 g (mean±SD), body length of 2.5±0.2 cm, and testis weight of 6.4±3.4 mg. The sperm production per gram of testis was 2.33±1.32×10(9) cells. After freezing, the post-thaw motility decreased significantly to 37%±17% (ranging from 5% to 70%) (p=0.000) from 57%±14% (40%-80%) of fresh sperm (N=20). Artificial insemination of post-thaw sperm produced confirmed offspring from females of X. hellerii and X. variatus. This research, taken together with previous studies, provides a foundation for development of strategies for sperm repositories of Xiphophorus fishes. This includes: 1) the need for breeding strategies for regeneration of target populations, 2) identification of minimum fertilization capacity of frozen samples, 3) identification of fish numbers necessary for sampling and their genetic relationships, 4) selection of packaging containers for labeling and biosecurity, 5) assurance of quality control and standardization of procedures, 6) information systems that can manage the data associated with cryopreserved samples, including the genetic data, 7) biological data of sampled fish, 8) inventory data associated with frozen samples, and 9) data linking germplasm samples with other related materials such as body tissues or cells saved for DNA and RNA analyses.

  2. Does fin coloration signal social status in a dominance hierarchy of the livebearing fish Xiphophorus variatus?

    Science.gov (United States)

    Culumber, Zachary W; Monks, Scott

    2014-09-01

    In each population of the livebearing fish Xiphophorus variatus, only a small portion of the adult males develop bright yellow-red (YR) coloration on the dorsal and caudal fins. Here we characterized the dominance hierarchy in X. variatus and tested whether YR coloration is related to a male's position in the hierarchy and can therefore serve as a reliable cue to rival males. Populations varied considerably in the frequency of YR males. Across all populations, males with YR coloration were significantly larger than the rest of the males in the population. Observations of aggressive interactions among males in small groups in the laboratory revealed a sized-based dominance hierarchy with YR males at the top. Aggression was more common among males of a similar size and fighting increased as male body size differences decreased. However, despite the reliability of YR coloration as a signal of dominance status, males at lower social ranks did not avoid aggression with YR males and YR males did not experience fewer aggressive attacks compared to non-YR males. Our findings demonstrate that fin coloration is a reliable cue of a male's social status but rival males appear to not use this information to avoid potentially costly interactions with dominant males, suggesting that YR fin coloration has not evolved as a cue in agonistic interactions. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Negative Assortative Mating Based on Body Coloration in the Freshwater Platyfish (Poecillidae: Xiphophorus maculatus

    Directory of Open Access Journals (Sweden)

    Tyler E. Frankel

    2017-04-01

    Full Text Available The ability of individuals within a population to survive and thrive is highly dependent upon the maintenance of genetic variation and phenotypic diversity, thereby ensuring adaptation to dynamic environments. A fundamental method of maintaining such variation is through a negative assortative mating strategy, in which individuals would be expected to reproductively select members of the opposite sex that exhibit dissimilar phenotypes. Employing three uniform body color morphs, red, yellow and blue, of the platyfish (Xiphophorus maculatus, this study was designed to investigate whether X. maculatus females would preferentially be attracted to males exhibiting an alternative color, thereby enabling an examination of the effect of male body coloration on mate choice by adult females. Mate choice was determined based on the initial preference of each female, as well as the amount of time females spent associating with each male. Initial preferences were analyzed using a binomial distribution test, and overall preference data using Wilcoxon signed rank tests. Red females initially selected for dissimilar colored males, and spent a significantly larger amount of time associating with blue and yellow males, as did yellow females with red and blue males. Blue females initially selected and spent a significantly larger amount of time associating with red males but, interestingly, showed no selective preference between blue and yellow males. In these experimental trials, the overall strong mate selection exhibited by female platyfish for males of dissimilar coloration is suggestive of a negative assortative mating strategy and provides evidence for the maintenance of color polymorphism in nature populations.

  4. Subzero water permeability parameters and optimal freezing rates for sperm cells of the southern platyfish, Xiphophorus maculatus.

    Science.gov (United States)

    Pinisetty, D; Huang, C; Dong, Q; Tiersch, T R; Devireddy, R V

    2005-06-01

    This study reports the subzero water transport characteristics (and empirically determined optimal rates for freezing) of sperm cells of live-bearing fishes of the genus Xiphophorus, specifically those of the southern platyfish Xiphophorus maculatus. These fishes are valuable models for biomedical research and are commercially raised as ornamental fish for use in aquariums. Water transport during freezing of X. maculatus sperm cell suspensions was obtained using a shape-independent differential scanning calorimeter technique in the presence of extracellular ice at a cooling rate of 20 degrees C/min in three different media: (1) Hanks' balanced salt solution (HBSS) without cryoprotective agents (CPAs); (2) HBSS with 14% (v/v) glycerol, and (3) HBSS with 10% (v/v) dimethyl sulfoxide (DMSO). The sperm cell was modeled as a cylinder with a length of 52.35 microm and a diameter of 0.66 microm with an osmotically inactive cell volume (Vb) of 0.6 V0, where V0 is the isotonic or initial cell volume. This translates to a surface area, SA to initial water volume, WV ratio of 15.15 microm(-1). By fitting a model of water transport to the experimentally determined volumetric shrinkage data, the best fit membrane permeability parameters (reference membrane permeability to water at 0 degrees C, Lpg or Lpg [cpa] and the activation energy, E(Lp) or E(Lp) [cpa]) were found to range from: Lpg or Lpg [cpa] = 0.0053-0.0093 microm/minatm; E(Lp) or E(Lp) [cpa] = 9.79-29.00 kcal/mol. By incorporating these membrane permeability parameters in a recently developed generic optimal cooling rate equation (optimal cooling rate, [Formula: see text] where the units of B(opt) are degrees C/min, E(Lp) or E(Lp) [cpa] are kcal/mol, L(pg) or L(pg) [cpa] are microm/minatm and SA/WV are microm(-1)), we determined the optimal rates of freezing X. maculatus sperm cells to be 28 degrees C/min (in HBSS), 47 degrees C/min (in HBSS+14% glycerol) and 36 degrees C/min (in HBSS+10% DMSO). Preliminary empirical

  5. Colorful invasion in permissive Neotropical ecosystems: establishment of ornamental non-native poeciliids of the genera Poecilia/Xiphophorus (Cyprinodontiformes: Poeciliidae and management alternatives

    Directory of Open Access Journals (Sweden)

    André Lincoln Barroso Magalhães

    2017-03-01

    Full Text Available ABSTRACT Headwater creeks are environments susceptible to invasion by non-native fishes. We evaluated the reproduction of 22 populations of the non-native livebearers guppy Poecilia reticulata, black molly Poecilia sphenops, Yucatan molly Poecilia velifera, green swordtail Xiphophorus hellerii, southern platyfish Xiphophorus maculatus, and variable platyfish Xiphophorus variatus during an annual cycle in five headwater creeks located in the largest South American ornamental aquaculture center, Paraíba do Sul River basin, southeastern Brazil. With few exceptions, females of most species were found reproducing (stages 2, 3, 4 all year round in the creeks and gravid females of all species showed small sizes indicating stunting. Juveniles were frequent in all sites. The fecundity of the six poeciliids was always low in all periods. The sex ratio was biased for females in most species, both bimonthly as for the whole period. Water temperature, water level and rainfall were not significantly correlated with reproduction in any species. Therefore, most populations appeared well established. The pertinence of different management actions, such as devices to prevent fish escape, eradication with rotenone and research about negative effects on native species, is discussed in the light of current aquaculture practices in the region.

  6. Genetic alterations as determined by quantitative morphological, viability and social behavioral traits in postirradiation generations of an inbred strain of the platyfish, Xiphophorus maculatus (Guenther)(Pisces: Poecliidae), induced by 1000 R of X-rays to spermatogonia and oogonia

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, J.H.; Heinrich, W. (Gesellschaft fuer Strahlen- und Umweltforschung m.b.H. Muenchen, Neuherberg (Germany, F.R.))

    Spermatogonia and oogonia were X-irradiated with 258 mC/kg in neonatal platyfish. This procedure corresponds to an exposure of immature spermatogonia and oogonia. The postirradiation (PI) F/sub 2/ generation was compared with controls of the same origin regarding viability characters (brood size, postnatal mortality, and sex ratio), quantitative morphological (number of vertebrae, body proportions) and social behavioral traits (cohesiveness of both sexes, male sexual and agonistic behavior patterns). Each of 5 pairs of F/sub 2/ fish were used as the founders for a one-year lasting population experiment in which the fish had been subjected to either mutation pressure through derivation from irradiated spermatogonia and oogonia as mentioned above or to selection pressure through predation by the convict cichlid, Cichlasoma nigrofasciatum, or to a combination of both in order to compare the outcome of this experiment with that of a control population. The PI F/sub 2/ exhibited a higher mortality rate than the controls. A unidirectional shift of the mean values of the quantitative morphological characters towards a more compact fish was observed in the postirradiation generations. The social cohesiveness of PI F/sub 2/ was higher than that of the controls. Male sexual activity was enhanced in PI F/sub 2/, and there was a similar trend to higher intraspecific aggressiveness among PI F/sub 2/ males. The single effects of mutation and selection pressures were beneficial in so far as the number of individuals and the biomass were enhanced, while a combination of both was deleterious endangering the population to extinction. Contrary to expectation, the coefficient of variation for the quantitative morphological traits was higher in the controls than in the Pi F/sub 2/.

  7. Sexually dimorphic development and binding characteristics of NMDA receptors in the brain of the platyfish

    Science.gov (United States)

    Flynn, K. M.; Schreibman, M. P.; Yablonsky-Alter, E.; Banerjee, S. P.

    1999-01-01

    This study investigated age- and gender-specific variations in properties of the glutamate N-methyl-d-aspartate receptor (NMDAR) in a freshwater teleost, the platyfish (Xiphophorus maculatus). Prior localization of the immunoreactive (ir)-R1 subunit of the NMDAR protein (R1) in cells of the nucleus olfactoretinalis (NOR), a primary gonadotropin-releasing hormone (GnRH)-containing brain nucleus in the platyfish, suggests that NMDAR, as in mammals, is involved in modulation of the platyfish brain-pituitary-gonad (BPG) axis. The current study shows that the number of cells in the NOR displaying ir-R1 is significantly increased in pubescent and mature female platyfish when compared to immature and senescent animals. In males, there is no significant change in ir-R1 expression in the NOR at any time in their lifespan. The affinity of the noncompetitive antagonist ((3)H)MK-801 for the NMDAR is significantly increased in pubescent females while maximum binding of ((3)H)MK-801 to the receptor reaches a significant maximum in mature females. In males, both MK-801 affinity and maximum binding remain unchanged throughout development. This is the first report of gender differences in the association of NMDA receptors with neuroendocrine brain areas during development. It is also the first report to suggest NMDA receptor involvement in the development of the BPG axis in a nonmammalian vertebrate. Copyright 1999 Academic Press.

  8. Ecological divergence and conservatism: spatiotemporal patterns of niche evolution in a genus of livebearing fishes (Poeciliidae: Xiphophorus).

    Science.gov (United States)

    Culumber, Zachary W; Tobler, Michael

    2016-02-19

    Ecological factors often have a strong impact on spatiotemporal patterns of biodiversity. The integration of spatial ecology and phylogenetics allows for rigorous tests of whether speciation is associated with niche conservatism (constraints on ecological divergence) or niche divergence. We address this question in a genus of livebearing fishes for which the role of sexual selection in speciation has long been studied, but in which the potential role of ecological divergence during speciation has not been tested. By combining reconstruction of ancestral climate tolerances and disparity indices, we show that the earliest evolutionary split in Xiphophorus was associated with significant divergence for temperature variables. Niche evolution and present day niches were most closely associated with each species' geographic distribution relative to a biogeographic barrier, the Trans-Mexican Volcanic Belt. Tests for similarity of the environmental backgrounds of closely related species suggested that the relative importance of niche conservatism and divergence during speciation varied among the primary clades of Xiphophorus. Closely related species in the two swordtail clades exhibited higher levels of niche overlap than expected given environmental background similarity indicative of niche conservatism. In contrast, almost all species of platyfish had significantly divergent niches compared to environmental backgrounds, which is indicative of niche divergence. The results suggest that the relative importance of niche conservatism and divergence differed among the clades of Xiphophorus and that traits associated with niche evolution may be more evolutionarily labile in the platyfishes. Our results ultimately suggest that the taxonomic scale of tests for conservatism and divergence could greatly influence inferences of their relative importance in the speciation process.

  9. 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.

    Science.gov (United States)

    Kang, Ji Hyoun; Schartl, Manfred; Walter, Ronald B; Meyer, Axel

    2013-01-29

    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. 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 selected sword trait is shown to be the most likely

  10. 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

  11. Activity of the thyroid and the pituitary gland in the viviparous Cyprinodonts Lebistes reticulatus (Peters), Xiphophorus helleri Heckel and Xiphophorus maculatus Günther during the development of the gonopodium

    NARCIS (Netherlands)

    Stolk, A.

    1959-01-01

    A description is given of the activity of the thyroid and of the pituitary gland during the development of the gonopodium in the viviparous Cyprinodonts Lebistes reticulatus (Peters), Xiphophorus helleri (Heckel) and Xiphophorus maculatus (Günther). During this process the thyroid gland and the

  12. Strong reproductive skew among males in the multiply mated swordtail Xiphophorus multilineatus (Teleostei).

    Science.gov (United States)

    Luo, J; Sanetra, M; Schartl, M; Meyer, A

    2005-01-01

    Male swordtails in the genus Xiphophorus display a conspicuous ventral elongation of the caudal fin, the sword, which arose through sexual selection due to female preference. Females mate regularly and are able to store sperm for at least 6 months. If multiple mating is frequent, this would raise the intriguing question about the role of female choice and male-male competition in shaping the mating system of these fishes. Size-dependent alternate mating strategies occur in Xiphophorus; one such strategy is courtship with a sigmoid display by large dominant males, while the other is gonopodial thrusting, in which small subordinate males sneak copulations. Using microsatellite markers, we observed a frequency of multiple paternity in wild-caught Xiphophorus multilineatus in 28% of families analyzed, but the actual frequency of multiple mating suggested by the correction factor PrDM was 33%. The number of fathers contributing genetically to the brood ranged from one to three. Compared to other species in the family Poeciliidae, both frequency and degree of multiple paternity were low. Paternity was found to be highly skewed, with one male on average contributing more than 70% to the offspring. Hence in this Xiphophorus mating system, typically one male dominates and sneaker males do not appear to be particularly effective. Postcopulatory mechanisms, however, such as sperm competition, are also indicated by our data, using sex-linked phenotypes among the offspring.

  13. UVB-induced gene expression in the skin of Xiphophorus maculatus Jp 163 B☆

    Science.gov (United States)

    Yang, Kuan; Boswell, Mikki; Walter, Dylan J.; Downs, Kevin P.; Gaston-Pravia, Kimberly; Garcia, Tzintzuni; Shen, Yingjia; Mitchell, David L.; Walter, Ronald B.

    2014-01-01

    Xiphophorus fish and interspecies hybrids represent long-standing models to study the genetics underlying spontaneous and induced tumorigenesis. The recent release of the Xiphophorus maculatus genome sequence will allow global genetic regulation studies of genes involved in the inherited susceptibility to UVB-induced melanoma within select backcross hybrids. As a first step toward this goal, we report results of an RNA-Seq approach to identify genes and pathways showing modulated transcription within the skin of X. maculatus Jp 163 B upon UVB exposure. X. maculatus Jp 163 B were exposed to various doses of UVB followed by RNA-Seq analysis at each dose to investigate overall gene expression in each sample. A total of 357 genes with a minimum expression change of 4-fold (p-adj fish skin to UVB exposure. PMID:24556253

  14. Allele-specific marker generation and linkage mapping on the Xiphophorus sex chromosomes.

    Science.gov (United States)

    Woolcock, B; Kazianis, S; Lucito, R; Walter, R B; Kallman, K D; Morizot, D C; Vielkind, J R

    2006-01-01

    There is great interest in the sex chromosomes of Xiphophorus fishes because both WY/YY and XX/XY sex-determining mechanisms function in these species, with at least one taxon possessing all three types of sex chromosomes, and because in certain interspecific hybrids melanoma arises as a consequence of inheritance of the sex-linked macromelanophore determining locus (MDL). Representational difference analysis (RDA) has been used to clone two sequences from the sex-determining region of X. maculatus, including a cholinergic receptor, nicotinic, delta polypeptide (CHRND) orthologue. Allele-specific assays for these sequences, as well as for the sex-linked XMRK1 and XMRK2 genes, were developed to distinguish W, X, and Y chromosomes derived from a X. maculatus (XX/XY) strain and a X. helleri (WY/YY) strain. Linkage mapping localized these markers to linkage group (LG) 24. No recombinants were observed between XMRK2 and MDL, confirming a role for XMRK2 in macromelanophore development. Although the master sex-determining (SD) locus certainly resides on Xiphophorus LG 24, autosomal loci are probably involved in sex determination as well, as indicated by the abnormal sex ratios in the backcross hybrids that contrast theoretical predictions based on LG 24 genotyping. Marker development and allelic discrimination on the Xiphophorus sex chromosomes should prove highly useful for studies that utilize this genus as an animal model.

  15. Production of F1 interspecies hybrid offspring with cryopreserved sperm from a live-bearing fish, the swordtail Xiphophorus helleri.

    Science.gov (United States)

    Yang, Huiping; Hazlewood, Leona; Heater, Sheila J; Guerrero, Paula A; Walter, Ronald B; Tiersch, Terrence R

    2007-03-01

    Despite study of sperm cryopreservation in more than 200 fish species, production of broods from cryopreserved sperm in live-bearing fish has not been demonstrated. This has not been due to a lack of effort, but instead is a result of the unique morphology, biology, and biochemistry of reproduction in viviparous fishes. For example, sperm of Xiphophorus helleri have a cylindrical nucleus, can swim for days after being activated, have glycolytic capabilities, and can reside in the female reproduction tract for months before fertilization. These traits are not found in fishes with external fertilization. The long-standing research use of the genus Xiphophorus has led to development of over 60 pedigreed lines among the 26 species maintained around the world. These species and lines serve as contemporary models in medical research, although they must be maintained as live populations. Previous attempts at establishing sperm cryopreservation protocols for Xiphophorus have not produced live young. To address this we have been studying the parameters surrounding cryobiology of Xiphophorus sperm and applying this information to an improved understanding of internal fertilization and reproduction. Here we report the first successful fertilization and offspring production by cryopreserved sperm in any live-bearing fish. This claim is supported by our use of artificial insemination between two species that yield distinct hybrid offspring to verify paternity via cryopreserved sperm. We provide a practical approach for preservation of valuable genetic resources from live-bearing fish species, a group that is rapidly being lost due to destruction of native habitats.

  16. Exposure to 4100K fluorescent light elicits sex specific transcriptional responses in Xiphophorus maculatus skin.

    Science.gov (United States)

    Boswell, William T; Boswell, Mikki; Walter, Dylan J; Navarro, Kaela L; Chang, Jordan; Lu, Yuan; Savage, Markita G; Shen, Jianjun; Walter, Ronald B

    2018-06-01

    It has been reported that exposure to artificial light may affect oxygen intake, heart rate, absorption of vitamins and minerals, and behavioral responses in humans. We have reported specific gene expression responses in the skin of Xiphophorus fish after exposure to ultraviolet light (UV), as well as, both broad spectrum and narrow waveband visible light. In regard to fluorescent light (FL), we have shown that male X. maculatus exposed to 4100K FL (i.e. "cool white") rapidly suppress transcription of many genes involved with DNA replication and repair, chromosomal segregation, and cell cycle progression in skin. We have also detailed sex specific transcriptional responses of Xiphophorus skin after exposure to UVB. However, investigation of gender differences in global gene expression response after exposure to 4100K FL has not been reported, despite common use of this FL source for residential, commercial, and animal facility illumination. Here, we compare RNA-Seq results analyzed to assess changes in the global transcription profiles of female and male X. maculatus skin in response to 4100K FL exposure. Our results suggest 4100K FL exposure incites a sex-biased genetic response including up-modulation of inflammation in females and down modulation of DNA repair/replication in males. In addition, we identify clusters of genes that become oppositely modulated in males and females after FL exposure that are principally involved in cell death and cell proliferation. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Characterization of basal gene expression trends over a diurnal cycle in Xiphophorus maculatus skin, brain and liver.

    Science.gov (United States)

    Lu, Yuan; Reyes, Jose; Walter, Sean; Gonzalez, Trevor; Medrano, Geraldo; Boswell, Mikki; Boswell, William; Savage, Markita; Walter, Ronald

    2018-06-01

    Evolutionarily conserved diurnal circadian mechanisms maintain oscillating patterns of gene expression based on the day-night cycle. Xiphophorus fish have been used to evaluate transcriptional responses after exposure to various light sources and it was determined that each source incites distinct genetic responses in skin tissue. However, basal expression levels of genes that show oscillating expression patterns in day-night cycle, may affect the outcomes of such experiments, since basal gene expression levels at each point in the circadian path may influence the profile of identified light responsive genes. Lack of knowledge regarding diurnal fluctuations in basal gene expression patterns may confound the understanding of genetic responses to external stimuli (e.g., light) since the dynamic nature of gene expression implies animals subjected to stimuli at different times may be at very different stages within the continuum of genetic homeostasis. We assessed basal gene expression changes over a 24-hour period in 200 select Xiphophorus gene targets known to transcriptionally respond to various types of light exposure. We identified 22 genes in skin, 36 genes in brain and 28 genes in liver that exhibit basal oscillation of expression patterns. These genes, including known circadian regulators, produced the expected expression patterns over a 24-hour cycle when compared to circadian regulatory genes identified in other species, especially human and other vertebrate animal models. Our results suggest the regulatory network governing diurnal oscillating gene expression is similar between Xiphophorus and other vertebrates for the three Xiphophorus organs tested. In addition, we were able to categorize light responsive gene sets in Xiphophorus that do, and do not, exhibit circadian based oscillating expression patterns. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Evolution of sperm quality but not quantity in the internally fertilized fish Xiphophorus nigrensis.

    Science.gov (United States)

    Smith, C C; Ryan, M J

    2010-08-01

    Species with alternative reproductive strategies are characterized by discrete differences among males in suites of traits related to competition for fertilizations. Models predict sneaker males should allocate more resources to their ejaculates because they experience sperm competition more frequently and often occupy a disfavoured 'role' owing to subordinance in intramale competition and female preferences for larger males. We examined whether sperm number and quality differed between male strategies in the internally fertilized fish Xiphophorus nigrensis and explored the relationship between sperm morphology and performance. We found sneaker males had similar testes sizes compared to courting males but ejaculates with both more viable and longer lived sperm. Sneaker sperm also had longer midpieces, which was positively correlated with both velocity and longevity. Our study suggests that the evolution of sperm quantity and quality can be decoupled and that the sperm morphology is likely to play an important role in mediating sperm competition through its effects on sperm performance.

  19. Elevated expression of the cellular src gene in tumors of differing etiologies in Xiphophorus

    Energy Technology Data Exchange (ETDEWEB)

    Schartl, M.; Schmidt, C.R.; Anders, A.; Barnekow, A.

    1985-08-15

    In the fish Xiphophorus the authors have detected elevated levels of pp60c-src kinase activity in a variety of tumors (n = 34) of neurogenic, epithelial, and mesenchymal origin either of hereditary etiology or induced by carcinogens. This elevation ranged from 2-fold up to 50-fold compared to the corresponding non-tumorous tissue and up to 6-fold compared to the highest activities found in any of the normal organs. The level of elevation parallels the degree of malignancy in melanoma and in tumors of mesenchymal origin. In fish bearing tumors of hereditary etiology kinase activity was also elevated in the non-tumorous brain, while in fish bearing induced tumors, kinase activity was elevated only in the cells of the neoplasia.

  20. Acute toxicity of trichlorofon on four viviparous fish: Poecilia latipinna, Poecilia reticulata, Gambusia holbrooki and Xiphophorus helleri (Cyprinodontiformes: Poecilidae

    Directory of Open Access Journals (Sweden)

    Mohammad Forouhar Vajargah

    2014-07-01

    Full Text Available Objective: To determine toxicity and safety margins of trichlorofon in different species as trichlorofon toxicity has a large variation in the susceptibility of different species. Methods: In this research, four viviparous aquarium fish were exposed to trichlorofon for 96 h. LC50 of 24 h, 48 h, 72 h and 96 h were attained by probit analysis software SPSS Version 16. Fish samples were exposed to different concentrations of trichlorofon (5, 10, 20 and 40 mg/L for 96 h and mortality were recorded, separately. Results: The 96 h LC50 of Poecilia latipinna, Poecilia reticulata, Gambusia holbrooki and Xiphophorus helleri were 9.80, 9.80, 9.95 and 7.99 mg/L, respectively. Conclusions: According to the results of this research, LC50 values indicated Xiphophorus helleri was the most resistant and Gambusia holbrooki, with a few differences, was the most sensitive species compared with the fishes examined.

  1. Sexual ornaments, body morphology, and swimming performance in naturally hybridizing swordtails (teleostei: xiphophorus.

    Directory of Open Access Journals (Sweden)

    James B Johnson

    Full Text Available Determining the costs of sexual ornaments is complicated by the fact that ornaments are often integrated with other, non-sexual traits, making it difficult to dissect the effect of ornaments independent of other aspects of the phenotype. Hybridization can produce reduced phenotypic integration, allowing one to evaluate performance across a broad range of multivariate trait values. Here we assess the relationship between morphology and performance in the swordtails Xiphophorus malinche and X. birchmanni, two naturally-hybridizing fish species that differ extensively in non-sexual as well as sexual traits. We took advantage of novel trait variation in hybrids to determine if sexual ornaments incur a cost in terms of locomotor ability. For both fast-start and endurance swimming, hybrids performed at least as well as the two parental species. The sexually-dimorphic sword did not impair swimming performance per se. Rather, the sword negatively affected performance only when paired with a sub-optimal body shape. Studies seeking to quantify the costs of ornaments should consider that covariance with non-sexual traits may create the spurious appearance of costs.

  2. Effects of dietary antioxidant of tomato extract and lycopene on Carassius auratus and Xiphophorus maculatus

    Directory of Open Access Journals (Sweden)

    Cynthia Montoya M.

    2014-06-01

    Full Text Available Objective. Evaluate the effect on tegument pigmentation, survival, growth and antioxidant capacity in diets supplemented with tomato extract and lycopene as additives in experimental feed for Carassius auratus and Xiphophorus maculatus. Materials and methods. The additives were added in different concentrations to a basic diet. We performed beginning and an ending biometrics for 100% of the population in each bioassay. The growth and survival of organisms were evaluated. The antioxidant capacity was analyzed by ABTS assay, both in the tomato extract sample as well as in foods used in different bioassays. The concentration of lycopene was determined in food and liver and muscle samples of fish fed with it. Acquired pigmentation of fish was assessed through photographs analyzed with Adobe Photoshop®. The results were evaluated by analysis of variance, and when differences were found (p0.05 on pigmentation and growth of the organisms under the established experimental conditions was obtained. Significant differences in antioxidant capacity (p<0.05 were obtained in foods with added lycopene. Conclusions. The inclusion of lycopene or tomato extract in food for the organisms used is not recommended to improve pigmentation, but further studies are needed to demonstrate antioxidant effect.

  3. Sperm swimming velocity predicts competitive fertilization success in the green swordtail Xiphophorus helleri.

    Directory of Open Access Journals (Sweden)

    Clelia Gasparini

    Full Text Available Sperm competition is expected to favour the evolution of traits that influence the performance of sperm when they compete to fertilize a female's eggs. While there is considerable evidence that selection favours increases in sperm numbers, much less is known about how sperm quality contributes towards competitive fertilization success. Here, we determine whether variation in sperm quality influences competitive fertilization success in the green swordtail Xiphophorus helleri, a highly promiscuous livebearing fish. We use artificial insemination as a method of controlled sperm delivery and show that sperm swimming velocity is the primary determinant of fertilization success when ejaculates from two males compete to fertilize a female's eggs. By contrast, we found no evidence that sperm length had any effect on siring success. We also found no evidence that pre- and postcopulatory sexual traits were phenotypically integrated in this species, suggesting that the previous observation that reproductive skew favours males with high mating rates is unlikely to be due to any direct association between sperm quality and male sexual ornamentation.

  4. UV causation of melanoma in Xiphophorus is dominated by melanin photosensitized oxidant production

    Science.gov (United States)

    Wood, Simon R.; Berwick, Marianne; Ley, Ronald D.; Walter, Ronald B.; Setlow, Richard B.; Timmins, Graham S.

    2006-01-01

    Controversy continues both as to which wavelengths of sunlight cause melanoma and the mechanisms by which these different wavelengths act. Direct absorption of UVB by DNA is central in albino animal models, but melanin-pigmented models have shown major contributions by wavelengths longer than UVB that are thought to be mediated by photosensitized oxidant production. The only model for which the action spectrum of melanoma causation is known is a genetically melanoma-susceptible specific cross of Xiphophorus fish. We used electron paramagnetic resonance to quantitatively detect the UV induction of reactive melanin radicals in situ in the melanin-containing cells in the skin of this model and derived the action spectrum for melanin-photosensitized oxidant production (Φox). This action spectrum was identical to that for melanoma induction (Φmel). These results confirm the hypothesis that melanin-photosensitized radical production is the major causative step of melanoma in this model and demonstrate that the wavelengths and mechanisms of melanoma causation in different models are dependent on the presence of melanin. This approach should be applicable to humans, thus providing an accurate surrogate for Φmel for prevention studies. PMID:16537493

  5. Protozoan parasites of Xiphophorus spp. (Poeciliidae and their relation with water characteristics Parasitos protozoários de Xiphophorus sp. (Poeciliidae e a relação deles com as características da água

    Directory of Open Access Journals (Sweden)

    F. Garcia

    2009-02-01

    Full Text Available This work investigated the relationship between water characteristics and infestation of protozoan parasites, Icthyophthirius multifiliis and Trichodina sp., in swordtails (Xiphophorus helleri and platy (Xiphophorus maculates collected in an ornamental fish farm in São Paulo, Brazil. Fish were monthly collected from ponds and tanks for one year. The prevalence rates in fish from tanks and ponds were, respectively, 34.2% and 22.5% for I. multifiliis, and 13% and 54.2% for Trichodina sp. Increased electric conductivity and pH provoked reduction of I. multifiliis infestation. Low oxygen concentration increased Trichodina sp. infestation. The use of salt to increase the electric conductivity of water was a method to control I. multifiliis. Low dissolved oxygen and the addition of organic fertilizer favored the reproduction of Trichodina sp.Investigou-se a relação entre as características da água e a infestação de protozoários parasitos, Icthyophthirius multifiliis e Trichodina sp., em peixe espada, Xiphophorus helleri e em plati, Xiphophorus maculatus, coletados em uma piscicultura de peixes ornamentais no Estado de São Paulo, Brasil. Os peixes foram coletados mensalmente, durante um ano, dos viveiros e das caixas de estocagem. A prevalência da infestação nos peixes das caixas e dos viveiros foram, respectivamente, 34,2% e 22,5% para I. multifiliis e 13% e 54% para Trichodina sp. A elevada condutividade elétrica e o pH da água reduziram a infestação por I. multifiliis. A baixa concentração de oxigênio resultou em aumento na infestação por Trichodina sp. O uso do sal, para aumentar a condutividade elétrica da água, consistiu em um método de controle de I. multifiliis. A redução do oxigênio dissolvido e a adição de fertilizante orgânico favoreceram a reprodução de Trichodina sp.

  6. Maternal investment in the swordtail fish Xiphophorus multilineatus: support for the differential allocation hypothesis.

    Science.gov (United States)

    Rios-Cardenas, Oscar; Brewer, Jason; Morris, Molly R

    2013-01-01

    The differential allocation hypothesis predicts that reproductive investment will be influenced by mate attractiveness, given a cost to reproduction and a tradeoff between current and future reproduction. We tested the differential allocation hypothesis in the swordtail fish Xiphophorus multilineatus, where males have genetically influenced (patroclinous inheritance) alternative mating tactics (ARTs) maintained by a tradeoff between being more attractive to females (mature later as larger courting males) and a higher probability of reaching sexual maturity (mature earlier as smaller sneaker males). Males in X. multilineatus do not provide parental care or other resources to the offspring. Allelic variation and copy number of the Mc4R gene on the Y-chromosome influences the size differences between males, however there is no variation in this gene on the X-chromosome. Therefore, to determine if mothers invested more in offspring of the larger courter males, we examined age to sexual maturity for daughters. We confirmed a tradeoff between number of offspring and female offspring's age to sexual maturity, corroborating that there is a cost to reproduction. In addition, the ART of their fathers significantly influenced the age at which daughters reached sexual maturity, suggesting increased maternal investment to daughters of courter males. The differential allocation we detected was influenced by how long the wild-caught mother had been in the laboratory, as there was a brood order by father genotype (ART) interaction. These results suggest that females can adjust their reproductive investment strategy, and that differential allocation is context specific. We hypothesize that one of two aspects of laboratory conditions produced this shift: increased female condition due to higher quality diet, and/or assessment of future mating opportunities due to isolation from males.

  7. Maternal investment in the swordtail fish Xiphophorus multilineatus: support for the differential allocation hypothesis.

    Directory of Open Access Journals (Sweden)

    Oscar Rios-Cardenas

    Full Text Available The differential allocation hypothesis predicts that reproductive investment will be influenced by mate attractiveness, given a cost to reproduction and a tradeoff between current and future reproduction. We tested the differential allocation hypothesis in the swordtail fish Xiphophorus multilineatus, where males have genetically influenced (patroclinous inheritance alternative mating tactics (ARTs maintained by a tradeoff between being more attractive to females (mature later as larger courting males and a higher probability of reaching sexual maturity (mature earlier as smaller sneaker males. Males in X. multilineatus do not provide parental care or other resources to the offspring. Allelic variation and copy number of the Mc4R gene on the Y-chromosome influences the size differences between males, however there is no variation in this gene on the X-chromosome. Therefore, to determine if mothers invested more in offspring of the larger courter males, we examined age to sexual maturity for daughters. We confirmed a tradeoff between number of offspring and female offspring's age to sexual maturity, corroborating that there is a cost to reproduction. In addition, the ART of their fathers significantly influenced the age at which daughters reached sexual maturity, suggesting increased maternal investment to daughters of courter males. The differential allocation we detected was influenced by how long the wild-caught mother had been in the laboratory, as there was a brood order by father genotype (ART interaction. These results suggest that females can adjust their reproductive investment strategy, and that differential allocation is context specific. We hypothesize that one of two aspects of laboratory conditions produced this shift: increased female condition due to higher quality diet, and/or assessment of future mating opportunities due to isolation from males.

  8. Waveband specific transcriptional control of select genetic pathways in vertebrate skin (Xiphophorus maculatus).

    Science.gov (United States)

    Walter, Ronald B; Boswell, Mikki; Chang, Jordan; Boswell, William T; Lu, Yuan; Navarro, Kaela; Walter, Sean M; Walter, Dylan J; Salinas, Raquel; Savage, Markita

    2018-05-10

    Evolution occurred exclusively under the full spectrum of sunlight. Conscription of narrow regions of the solar spectrum by specific photoreceptors suggests a common strategy for regulation of genetic pathways. Fluorescent light (FL) does not possess the complexity of the solar spectrum and has only been in service for about 60 years. If vertebrates evolved specific genetic responses regulated by light wavelengths representing the entire solar spectrum, there may be genetic consequences to reducing the spectral complexity of light. We utilized RNA-Seq to assess changes in the transcriptional profiles of Xiphophorus maculatus skin after exposure to FL ("cool white"), or narrow wavelength regions of light between 350 and 600 nm (i.e., 50 nm or 10 nm regions, herein termed "wavebands"). Exposure to each 50 nm waveband identified sets of genes representing discrete pathways that showed waveband specific transcriptional modulation. For example, 350-400 or 450-500 nm waveband exposures resulted in opposite regulation of gene sets marking necrosis and apoptosis (i.e., 350-400 nm; necrosis suppression, apoptosis activation, while 450-500 nm; apoptosis suppression, necrosis activation). Further investigation of specific transcriptional modulation employing successive 10 nm waveband exposures between 500 and 550 nm showed; (a) greater numbers of genes may be transcriptionally modulated after 10 nm exposures, than observed for 50 nm or FL exposures, (b) the 10 nm wavebands induced gene sets showing greater functional specificity than 50 nm or FL exposures, and (c) the genetic effects of FL are primarily due to 30 nm between 500 and 530 nm. Interestingly, many genetic pathways exhibited completely opposite transcriptional effects after different waveband exposures. For example, the epidermal growth factor (EGF) pathway exhibits transcriptional suppression after FL exposure, becomes highly active after 450-500 nm waveband exposure, and again, exhibits strong

  9. Alternative life histories in Xiphophorus multilineatus: evidence for different ages at sexual maturity and growth responses in the wild.

    Science.gov (United States)

    Bono, L M; Rios-Cardenas, O; Morris, M R

    2011-05-01

    In order to examine potential trade-offs in alternative life histories of the high-backed pygmy swordtail Xiphophorus multilineatus, otoliths were used from wild-caught males to determine if sneaker males had the advantage of maturing earlier in natural environments. The sneakers matured significantly earlier than courters, but there was no difference among the three courter variants. In addition, analyses suggested that the effect of the pituitary locus on size at sexual maturity and growth rates was a consequence of age at sexual maturity. Finally, one of the courter variants had a significantly different relationship between age and size at sexual maturity than the other variants, suggesting that in this variant, age at sexual maturity may be more closely related to size and therefore may be less plastic in its growth responses. © 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.

  10. Molecular cloning and expression of a heat-shock cognate 70 (hsc70) gene from swordtail fish ( Xiphophorus helleri)

    Science.gov (United States)

    Li, Ningqiu; Fu, Xiaozhe; Han, Jingang; Shi, Cunbin; Huang, Zhibin; Wu, Shuqin

    2013-07-01

    Heat shock proteins are a family of molecular chaperones that are involved in many aspects of protein homeostasis. In the present study, a full-length cDNA, encoding the constitutively expressed 70-kDa heat shock cognate protein (Hsc70), was isolated from swordtail fish ( Xiphophorus helleri) and designated as XheHsc70. The Xhehsc70 cDNA was 2 104 bp long with an open reading frame of 1 941 bp, and it encoded a protein of 646 amino acids with a theoretical molecular weight of 70.77 kDa and an isoelectric point of 5.04. The deduced amino acid sequence shared 94.1%-98.6% identities with the Hsc70s from a number of other fish species. Tissue distribution results show that the Xhehsc70 mRNA was expressed in brain, heart, head kidney, kidney, spleen, liver, muscle, gill, and peripheral blood. After immunization with formalin-killed Vibrio alginolyticus cells there was a significant increase in the Xhehsc70 mRNA transcriptional level in the head kidney of the vaccinated fish compared with in the control at 6, 12, 24, and 48 h as shown by quantitative real time RT-PCR. Based on an analysis of the amino acid sequence of XheHsc70, its phylogeny, and Xhehsc70 mRNA expression, XheHsc70 was identified as a member of the cytoplasmic Hsc70 (constitutive) subfamily of the Hsp70 family of heat shock proteins, suggesting that it may play a role in the immune response. The Xhehsc70 cDNA sequence reported in this study was submitted to GenBank under the accession number JF739182.

  11. Differential regulation of msx genes in the development of the gonopodium, an intromittent organ, and of the "sword," a sexually selected trait of swordtail fishes (Xiphophorus).

    Science.gov (United States)

    Zauner, Hans; Begemann, Gerrit; Marí-Beffa, Manuel; Meyer, Axel

    2003-01-01

    The possession of a conspicuous extension of colored ventral rays of the caudal fin in male fish of swordtails (genus Xiphophorus) is a prominent example for a trait that evolved by sexual selection. To understand the evolutionary history of this so-called sword molecularly, it is of interest to unravel the developmental pathways responsible for extended growth of sword rays during development of swordtail males. We isolated two msx genes and showed that they are differentially regulated during sword outgrowth. During sword growth in juvenile males, as well as during testosterone-induced sword development and fin ray regeneration in the sword after amputation, expression of msxC is markedly up-regulated in the sword forming fin rays. In contrast, msxE/1 is not differentially expressed in ventral and dorsal male fin rays, suggesting a link between the development of male secondary sexual characters in fins and up-regulation of msxC expression. In addition, we showed that msx gene expression patterns differ significantly between Xiphophorus and zebrafish. We also included in our study the gonopodium, a testosterone-dependent anal fin modification that serves as a fertilization organ in males of live-bearing fishes. Our finding that increased levels of msxC expression are associated with the testosterone-induced outgrowth of the gonopodium might suggest either that at least parts of the signaling pathways that pattern the evolutionary older gonopodium have been coopted to evolve a sexually selected innovation such as the sword or that increased msxC expression may be inherent to the growth process of long fin rays in general.

  12. Camallanus maculatus n. sp. (Nematoda: Camallanidae in an ornamental fish Xiphophorus maculatus (Osteichthyes: Poeciliidae cultivated in São Paulo State, Brazil Camallanus maculatus n. sp. (Nematoda: Camallanidae em peixe ornamental Xiphophorus maculatus (Osteichthyes: Poeciliidae cultivado no estado de São Paulo, Brasil

    Directory of Open Access Journals (Sweden)

    M.L. Martins

    2007-10-01

    Full Text Available The present study describes Camallanus maculatus n. sp. (Nematoda: Camallanidae from Xiphophorus maculatus (Osteichthyes: Poecilidae collected in an ornamental fish farm in São Paulo State, Brazil. Thirty-three out of 40 examined fish were parasitized (82% prevalence with mean intensity of 2.8 (1-20. Male specimens were 3,500µm total length and females 7,100µm total length, provided with orange-brown buccal capsule and two developed tridents. Males showed two unequal spicules, gubernaculum absent and females with vulva situated in the middle of the body. The main characteristics were the sleekly longitudinal ridges in the buccal capsule in both sexes, enlargement at the anterior end of the smaller spicule, the number of genital papillae, longer muscular and glandular portion of esophagus and round tail in female.Descreve-se Camallanus maculatus n. sp. (Nematoda: Camallanidae em Xiphophorus maculatus (Osteichthyes: Poecilidae capturado em uma piscicultura ornamental no estado de São Paulo. De 40 peixes examinados, 33 estavam parasitados (prevalência de 82% cuja intensidade média foi de 2,8 (1-20. Os machos apresentaram 3.500µm e as fêmeas com 7,100µm de comprimento total, providos de uma cápsula bucal laranja-castanho e dois tridentes. Observaram-se machos com espículos desiguais, gubernáculo ausente e fêmeas com vulva situada na metade do corpo. As principais características foram as estrias longitudinais lisas em cada valva da cápsula bucal em ambos os sexos, o espículo menor com alargamento na extremidade anterior, o número de papilas genitais, as porções muscular e glandular do esôfago longas e a cauda longa e arredondada na fêmea.

  13. Distribution and status of five non-native fish species in the Tampa Bay drainage (USA), a hot spot for fish introductions

    Science.gov (United States)

    Lawson, Katelyn M.; Tuckett, Quenton M.; Ritch, Jared L.; Nico, Leo; Fuller, Pam; Matheson, Richard E.; Hill, Jeffrey E.

    2017-01-01

    The Tampa Bay region of Florida (USA) is a hot spot for non-native freshwater fishes. However, published information on most non-native fishes in the basin is not current. Systematic sampling efforts targeting non-native fishes in the region were conducted from 2013–2015 by the University of Florida Tropical Aquaculture Laboratory. Data from these recent surveys were analyzed, along with historic and new data from published and unpublished sources, to assess current fish distributions and determine status. We focus on five of the non-native species sampled: pike killifish Belonesox belizanus Kner, 1860, green swordtail Xiphophorus hellerii Heckel, 1848, southern platyfish Xiphophorus maculatus (Günther, 1866), Mayan cichlid Mayaheros urophthalmus (Günther, 1862), and Jack Dempsey Rocio octofasciata (Regan, 1903). All five were found to have reproducing populations in the basin, each showing broader distributions than previously indicated. Non-native populations of four of the species have persisted in the Tampa Bay region since at least the 1990s. In contrast, the presence of Mayan cichlid in the basin was not confirmed until 2004. Based on numbers, distributions, and years of persistence, these five species all maintain established populations. Pike killifish and Mayan cichlid are established and spreading throughout multiple habitat types, while green swordtail, southern platyfish, and Jack Dempsey are localized and found primarily in more marginal habitats (e.g., small ditches and first order tributary streams). Factors affecting continued existence and distributions likely include aquaculture, biotic resistance, and thermal and salinity tolerances. We also clarify non-native species status determination using a multi-agency collaborative approach, and reconcile differences in terminology usage and interpretation.

  14. Environmental heterogeneity generates opposite gene-by-environment interactions for two fitness-related traits within a population.

    Science.gov (United States)

    Culumber, Zachary W; Schumer, Molly; Monks, Scott; Tobler, Michael

    2015-02-01

    Theory predicts that environmental heterogeneity offers a potential solution to the maintenance of genetic variation within populations, but empirical evidence remains sparse. The live-bearing fish Xiphophorus variatus exhibits polymorphism at a single locus, with different alleles resulting in up to five distinct melanistic "tailspot" patterns within populations. We investigated the effects of heterogeneity in two ubiquitous environmental variables (temperature and food availability) on two fitness-related traits (upper thermal limits and body condition) in two different tailspot types (wild-type and upper cut crescent). We found gene-by-environment (G × E) interactions between tailspot type and food level affecting upper thermal limits (UTL), as well as between tailspot type and thermal environment affecting body condition. Exploring mechanistic bases underlying these G × E patterns, we found no differences between tailspot types in hsp70 gene expression despite significant overall increases in expression under both thermal and food stress. Similarly, there was no difference in routine metabolic rates between the tailspot types. The reversal of relative performance of the two tailspot types under different environmental conditions revealed a mechanism by which environmental heterogeneity can balance polymorphism within populations through selection on different fitness-related traits. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  15. UV causation of melanoma in Xiphophorus is dominated by melanin photosensitized oxidant production

    OpenAIRE

    Wood, Simon R.; Berwick, Marianne; Ley, Ronald D.; Walter, Ronald B.; Setlow, Richard B.; Timmins, Graham S.

    2006-01-01

    Controversy continues both as to which wavelengths of sunlight cause melanoma and the mechanisms by which these different wavelengths act. Direct absorption of UVB by DNA is central in albino animal models, but melanin-pigmented models have shown major contributions by wavelengths longer than UVB that are thought to be mediated by photosensitized oxidant production. The only model for which the action spectrum of melanoma causation is known is a genetically melanoma-susceptible specific cross...

  16. Home ranges and satellite tactics of male green swordtails (Xiphophorus helleri) in nature.

    Science.gov (United States)

    Franck, D; Klamroth, B; Taebel-Hellwig, A; Schartl, M

    1998-05-01

    Dominance relationships were studied between marked or otherwise individually recognizable male green swordtails in a creek at Lake Catemaco and in a tributary of the Rio Atoyac (Veracruz, Mexico). The Atoyac population is unique because of a high degree of polymorphism, including both macromelanophore spotting and a micromelanophore tailspot pattern. During the dry season males living in the same area maintained a linear social hierarchy for periods of many days. The subordinate males settled down either in the same home ranges or in home ranges largely overlapping with that of dominant males. Although dominant males untiringly chased the subordinate males away, they returned persistently and achieved the status of non-tolerated satellites. Females were less stationary and presumably passed through many male home ranges during their feeding activities. The data clearly demonstrate that green swordtails live in complex social systems in which male-male competition and probably also female mate choice are likely to be essential factors for individual reproductive success.

  17. A transcriptome derived female-specific marker from the invasive Western mosquitofish (Gambusia affinis.

    Directory of Open Access Journals (Sweden)

    Dunja K Lamatsch

    Full Text Available Sex-specific markers are a prerequisite for understanding reproductive biology, genetic factors involved in sex differences, mechanisms of sex determination, and ultimately the evolution of sex chromosomes. The Western mosquitofish, Gambusia affinis, may be considered a model species for sex-chromosome evolution, as it displays female heterogamety (ZW/ZZ, and is also ecologically interesting as a worldwide invasive species. Here, de novo RNA-sequencing on the gonads of sexually mature G. affinis was used to identify contigs that were highly transcribed in females but not in males (i.e., transcripts with ovary-specific expression. Subsequently, 129 primer pairs spanning 79 contigs were tested by PCR to identify sex-specific transcripts. Of those primer pairs, one female-specific DNA marker was identified, Sanger sequenced and subsequently validated in 115 fish. Sequence analyses revealed a high similarity between the identified sex-specific marker and the 3´ UTR of the aminomethyl transferase (amt gene of the closely related platyfish (Xiphophorus maculatus. This is the first time that RNA-seq has been used to successfully characterize a sex-specific marker in a fish species in the absence of a genome map. Additionally, the identified sex-specific marker represents one of only a handful of such markers in fishes.

  18. Phylogenetic diversity and biodiversity indices on phylogenetic networks.

    Science.gov (United States)

    Wicke, Kristina; Fischer, Mareike

    2018-04-01

    In biodiversity conservation it is often necessary to prioritize the species to conserve. Existing approaches to prioritization, e.g. the Fair Proportion Index and the Shapley Value, are based on phylogenetic trees and rank species according to their contribution to overall phylogenetic diversity. However, in many cases evolution is not treelike and thus, phylogenetic networks have been developed as a generalization of phylogenetic trees, allowing for the representation of non-treelike evolutionary events, such as hybridization. Here, we extend the concepts of phylogenetic diversity and phylogenetic diversity indices from phylogenetic trees to phylogenetic networks. On the one hand, we consider the treelike content of a phylogenetic network, e.g. the (multi)set of phylogenetic trees displayed by a network and the so-called lowest stable ancestor tree associated with it. On the other hand, we derive the phylogenetic diversity of subsets of taxa and biodiversity indices directly from the internal structure of the network. We consider both approaches that are independent of so-called inheritance probabilities as well as approaches that explicitly incorporate these probabilities. Furthermore, we introduce our software package NetDiversity, which is implemented in Perl and allows for the calculation of all generalized measures of phylogenetic diversity and generalized phylogenetic diversity indices established in this note that are independent of inheritance probabilities. We apply our methods to a phylogenetic network representing the evolutionary relationships among swordtails and platyfishes (Xiphophorus: Poeciliidae), a group of species characterized by widespread hybridization. Copyright © 2018 Elsevier Inc. All rights reserved.

  19. Recombinant expression and purification of the RNA-binding LARP6 proteins from fish genetic model organisms.

    Science.gov (United States)

    Castro, José M; Horn, Daniel A; Pu, Xinzhu; Lewis, Karen A

    2017-06-01

    The RNA-binding proteins that comprise the La-related protein (LARP) superfamily have been implicated in a wide range of cellular functions, from tRNA maturation to regulation of protein synthesis. To more expansively characterize the biological function of the LARP6 subfamily, we have recombinantly expressed the full-length LARP6 proteins from two teleost fish, platyfish (Xiphophorus maculatus) and zebrafish (Danio rerio). The yields of the recombinant proteins were enhanced to >2 mg/L using a tandem approach of an N-terminal His 6 -SUMO tag and an iterative solubility screening assay to identify structurally stabilizing buffer components. The domain topologies of the purified fish proteins were probed with limited proteolysis. The fish proteins contain an internal, protease-resistant 40 kDa domain, which is considerably more stable than the comparable domain from the human LARP6 protein. The fish proteins are therefore a lucrative model system in which to study both the evolutionary divergence of this family of La-related proteins and the structure and conformational dynamics of the domains that comprise the LARP6 protein. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Effects of radiations on ornamental fish

    International Nuclear Information System (INIS)

    Anita; Kalyankar, Amol D.; Ohlyan, Sunita; Gupta, R.K.

    2012-01-01

    Radiation is a process in which energetic particles or energetic waves travel through a medium or space. There are two distinct types of radiations: ionizing and non-ionizing. Ultraviolet, X-rays, and gamma rays are some examples of radiation. 'Ornamental fish' is designed for aquatic hobbyists and the aquatic industry for several purposes. UV light has two primary uses in fish culture: Controlling green water and disinfecting the water supply. Many proponents of UV disinfection sometimes overlook the additional benefits relating to ornamental fish; those being that cleaner water reduces the stress on the fish by not having to fight off diseases, thus enhancing its immune system and leading to faster growth and more brilliant colors. Ultraviolet sterilizers are often used in aquaria to help control unwanted microorganisms in the water. UV radiation also ensures that exposed pathogens cannot reproduce, thus decreasing the likelihood of a disease outbreak in an aquarium. Despite of these benefits, the ill-effects of radiations cannot be ruled out. Ultraviolet Radiation-induced DNA Damage is seen in the skin of the Platyfish Xiphophorus. Higher radiation doses may cause the gastrointestinal syndrome that leads to defects of the intestinal mucosa barrier with successive contamination of musculature. Exposure to UV radiation can kill the fish and induce sublethal effects in embryos, larvae and adults. The change in skin includes irregularity of skin surface, epidermal oedema, necrosis etc. Irradiation may badly influence the textural attributes of fish muscle. (author)

  1. Trichodina nobilis Chen, 1963 and Trichodina reticulata Hirschmann et Partsch, 1955 from ornamental freshwater fishes in Brazil

    Directory of Open Access Journals (Sweden)

    ML Martins

    Full Text Available In the present work Trichodina reticulata and T. nobilis (Ciliophora: Trichodinidae are morphologically characterised from ornamental freshwater fish culture in the State of Santa Catarina, Brazil. The prevalence of infection and a list of comparative measurements are discussed. We examined "southern platyfish" Xiphophorus maculatus (n = 35, "goldfish" Carassius auratus (n = 31, "guppy" Poecilia reticulata (n = 20, "sailfin molly" Poecilia latipinna (n = 6, "beta" Betta splendens (n = 2 and "spotted headstander" Chilodus punctatus (n = 1. After being anesthetised in a benzocaine solution, fishes were examined for parasitological evaluation. A total of 51.57% fishes were parasitised by Trichodina spp. Carassius auratus was the most parasitised species, followed by X. maculatus and P. reticulata. Beta splendens, C. punctatus and P. latipinna were not parasitised by any trichodinid species. Two species of Trichodina were collected from the skin of fish: T. nobilis was found in C. auratus, P. reticulata and X. maculatus and T. reticulata was only observed in C. auratus. The importance of adequate handling in ornamental fish culture are also discussed.

  2. Import of exotic and zoonotic trematodes (Heterophyidae: Centrocestus sp.) in Xiphophorus maculatus

    DEFF Research Database (Denmark)

    Mehrdana, Foojan; Jensen, Hannah M.; Kania, Per Walter

    2014-01-01

    metacercaria with an X-shaped excretory bladder. PCR amplification of a rDNA region (5.8S rRNA gene, ITS-2, 28S rRNA gene) and subsequent sequencing confirmed the diagnosis. Metacercariae were found in gill filaments adjacent to the cartilage associated with cartilage hypertrophy, epithelial and mucous cell...... hyperplasia, clubbing and lamellar fusion. Host cell encapsulation of cysts comprised several layers of leucocytes, chondroblast-like and fibroblast like cells. The observations raise concerns with regard to veterinary inspection and quarantine procedures. The zoonotic potential of these trematodes...

  3. Post-embryonic development of Camallanus cotti (Nematoda: Camallanidae), with emphasis on growth of some taxonomically important somatic characters.

    Science.gov (United States)

    Levsen, Arne; Berland, Bjørn

    2002-01-01

    In this paper, the quantitative post-embryonic development of the Asian freshwater fish nematode Camallanus cotti Fujita, 1927, is described. Larval and adult morphometrics were obtained by following the parasite's life cycle experimentally using copepods Macrocyclops albidus (Jurine) as intermediate host and guppies Poecilia reticulata (Peters), southern platyfish Xiphophorus maculatus (Günther) and paradise fish Macropodus opercularis (L.) as definitive host. Additionally, adult worms were obtained from heavily infected paradise fish imported from Singapore. It is suggested that the gradual change in proportions of the worm's somatic body parts reflects the specific ecological role of each developmental stage. The free-living infective first-stage larva seems to be adapted for transmission, as indicated by its relatively long tail, designed to generate host-attracting movements, and its non-functional intestine. The second- and third-stage larvae from the copepod intermediate host seem mainly to invest in trophic functionality, i.e., the development of the buccal capsule and the oesophagus, which are crucial structures for the worm's successful establishment in the definitive fish host. Once in the fish intestine, the larvae enter a period of considerable growth. After the fourth (i.e., last) moult, a 72% increase in average female body length occurs. This is accompanied by doubling the average vulva-tail tip distance and the average tail length. The length of the female hind body expands in an accelerating allometric fashion, and seems to be closely linked to the posterior-wards expansion of the uterus. In the males however, growth seems to cease after the final moult. We conclude that female post-maturational body size, but especially the length of the hind body and the tail, are closely related to reproductive state, i.e., the developmental stage of the offspring in the uterus, and, probably, the worms' age. Any future taxonomical studies of camallanids in

  4. Using cytogenetic analysis RAPD in determination of genetic variations among four species of ornamental fishes of family: Poecilidae (Order: Cyprinodontiform

    Directory of Open Access Journals (Sweden)

    Abu-Almaaty A.H.

    2015-01-01

    Full Text Available The karyological and molecular analysis of four fresh water fish species of Family: Poecilidae and their genetic relationships have been studied. Xiphophorus maculates and Xiphophorus hellerii have the same diploid chromosome number 2n=48, but they were different in their karyotypes. Poecilia sphenops and Poecilia reticulata have the same diploid chromosome number 2n=46 and the same fundamental number FN=46, also the same karyotype one group of acrocentric chromosomes. Nine RAPD primers, showed monomorphic bands, were used for the construction of the dendrogram and a similarity matrix. A total of 65 bands were obtained; 39 of them were monomorphic bands. Similarity values among the studied samples ranged from 21% to 38%. High similarity value was obtained between Xiphophorus maculates and Xiphophorus hellerii. (38% and the low similarity values were obtained between Xiphophorus hellerii and Poecilia reticulata (21%. The cluster analysis clearly differentiated Xiphophorus maculates and Xiphophorus hellerii from Poecilia sphenops and Poecilia reticulata. RAPD analysis confirmed that the four species under study are genetically different from each other. These cytogenetic data obtained can be applied for further studies in cytotaxonomy and evolutionary relationships of fishes.

  5. Caracterização dos ovarios e do desenvolvimento ovocitario, e da recuperação ovariana pos-parto do platy (Xiphophorus maculatus) (Teleostei, Poeciliidae) em condições laboratoriais controladas e sob ação do hormonio de crescimento

    OpenAIRE

    Laercio dos Anjos Benjamin

    2004-01-01

    Resumo: Os poecilídeos são peixes ovovivíparos de ampla utilização na piscicultura ornamental. Apesar disso, pouco se conhece sobre aspectos reprodutivos dessas espécies. O estudo das características histológicas e ultra-estruturais dos ovócitos constitui etapa básica e primordial para se estabelecer a biologia reprodutiva das diferentes espécies de peixes, essencial para a compreensão da fertilização, desenvolvimento inicial do embrião e crescimento das larvas. Como o sucesso da criação de p...

  6. A private ultraviolet channel in visual communication.

    Science.gov (United States)

    Cummings, Molly E; Rosenthal, Gil G; Ryan, Michael J

    2003-01-01

    Although private communication is considered an important diversifying force in evolution, there is little direct behavioural evidence to support this notion. Here, we show that ultraviolet (UV) signalling in northern swordtails (Xiphophorus) affords a channel for communication that is not accessible to their major predator, Astyanax mexicanus, the Mexican tetra. Laboratory and field behavioural experiments with swordtails (X. nigrensis) and predators (A. mexicanus) demonstrate that male UV ornamentation significantly increases their attractiveness to females but not to this predator, which is less sensitive to UV. UV reflectance among swordtail species correlates positively with tetra densities across habitats, and visual contrast estimates suggest that UV signals are highly conspicuous to swordtails in their natural environment. Cross-species comparisons also support the hypothesis that natural selection drives the use of UV communication. We compared two species, one with high (X. nigrensis) and one with low (X. malinche) Mexican tetra densities. Xiphophorus nigrensis males reflect significantly more UV than X. malinche, exhibit significant UV sexual dimorphism, and UV is a salient component of the sexual communication system. In X. malinche, however, males reflect minimally in the UV, there is no UV sexual dimorphism, and UV does not play a part in its communication system. PMID:12803903

  7. Female social response to male sexual harassment in poeciliid fish: a comparison of six species

    Science.gov (United States)

    Dadda, Marco

    2015-01-01

    Sexual harassment is common among poeciliid fish. In some fishes, males show a high frequency of sneak copulation; such sexual activity is costly to the females in terms of foraging efficiency. In mosquitofish (Gambusia holbrooki), when males are present, the distance between females tends to decrease, and this behavior has been interpreted as an adaptive strategy to dilute the costs of male sexual activity. In this study, the tendency to reduce distance in the presence of a male has been investigated in females of six poeciliid species (Girardinus metallicus, Girardinus falcatus, G. holbrooki, Poecilia reticulata, Xiphophorus hellerii, and Xiphophorus mayae) that exhibit different male mating strategies and different levels of sexual activity. Results revealed large interspecific differences in the pattern of female aggregation. Females of species with a high frequency of sneak copulations tended to reduce their social distance in the presence of a male. By contrast, species that rely mainly on courtship showed little or no variation in social distance. The proportion of sneak copulations predicts the degree of variation in female social response, but the amount of total sexual activity does not, suggesting that the change in females' social distance when a male is present may indeed serve to reduce the costs of male sexual harassment. PMID:26483719

  8. A private ultraviolet channel in visual communication.

    Science.gov (United States)

    Cummings, Molly E; Rosenthal, Gil G; Ryan, Michael J

    2003-05-07

    Although private communication is considered an important diversifying force in evolution, there is little direct behavioural evidence to support this notion. Here, we show that ultraviolet (UV) signalling in northern swordtails (Xiphophorus) affords a channel for communication that is not accessible to their major predator, Astyanax mexicanus, the Mexican tetra. Laboratory and field behavioural experiments with swordtails (X. nigrensis) and predators (A. mexicanus) demonstrate that male UV ornamentation significantly increases their attractiveness to females but not to this predator, which is less sensitive to UV. UV reflectance among swordtail species correlates positively with tetra densities across habitats, and visual contrast estimates suggest that UV signals are highly conspicuous to swordtails in their natural environment. Cross-species comparisons also support the hypothesis that natural selection drives the use of UV communication. We compared two species, one with high (X. nigrensis) and one with low (X. malinche) Mexican tetra densities. Xiphophorus nigrensis males reflect significantly more UV than X. malinche, exhibit significant UV sexual dimorphism, and UV is a salient component of the sexual communication system. In X. malinche, however, males reflect minimally in the UV, there is no UV sexual dimorphism, and UV does not play a part in its communication system.

  9. Distribution of Fish in the Upper Citarum River: an Adaptive Response to Physico-Chemical Properties

    Directory of Open Access Journals (Sweden)

    SUNARDI

    2012-12-01

    Full Text Available Distribution of fish in river is controlled by physico-chemical properties of the water which is affected by land-use complexity and intensity of human intervention. A study on fish distribution was carried out in the upper Citarum River to map the effects of physio-chemical properties on habitat use. A survey was conducted to collect fish and to measure the water quality both on dry and rainy season. The result showed that distribution of the fish, in general, represented their adaptive response to physico-chemical properties. The river environment could be grouped into two categories: (i clean and relatively unpolluted sites, which associated with high DO and water current, and (ii polluted sites characterized by low DO, high COD, BOD, water temperature, NO3, PO4, H2S, NH3, and surfactant. Fish inhabiting the first sites were Xiphophorus helleri, Punctius binotatus, Xiphophorus maculatus, and Oreochromis mossambicus. Meanwhile, the latter sites were inhabited by Liposarcus pardalis, Trichogaster trichopterus, and Poecilia reticulata. Knowledge about fish distribution in association with the pysico-chemical properties of water is crucial especially for the river management.

  10. Female social response to male sexual harassment in poeciliid fish: A comparison of six species

    Directory of Open Access Journals (Sweden)

    Marco eDadda

    2015-09-01

    Full Text Available Sexual harassment is common among poeciliid fish. In some fishes, males show a high frequency of sneak copulation; such sexual activity is costly to the females in terms of foraging efficiency. In mosquitofish (Gambusia holbrooki, when males are present, the distance between females tends to decrease, and this behavior has been interpreted as an adaptive strategy to dilute the costs of male sexual activity. In this study, the tendency to reduce distance in the presence of a male has been investigated in females of 6 poeciliid species (Girardinus metallicus, Girardinus falcatus, Gambusia holbrooki, Poecilia reticulata, Xiphophorus hellerii and Xiphophorus mayae that exhibit different male mating strategies and different levels of sexual activity. Results revealed large interspecific differences in the pattern of female aggregation. Females of species with a high frequency of sneak copulations tended to reduce their social distance in the presence of a male. By contrast, species that rely mainly on courtship showed little or no variation in social distance. The proportion of sneak copulations predicts the degree of variation in female social response, but the amount of total sexual activity does not, suggesting that the change in females’ social distance when a male is present may indeed serve to reduce the costs of male sexual harassment.

  11. Female social response to male sexual harassment in poeciliid fish: a comparison of six species.

    Science.gov (United States)

    Dadda, Marco

    2015-01-01

    Sexual harassment is common among poeciliid fish. In some fishes, males show a high frequency of sneak copulation; such sexual activity is costly to the females in terms of foraging efficiency. In mosquitofish (Gambusia holbrooki), when males are present, the distance between females tends to decrease, and this behavior has been interpreted as an adaptive strategy to dilute the costs of male sexual activity. In this study, the tendency to reduce distance in the presence of a male has been investigated in females of six poeciliid species (Girardinus metallicus, Girardinus falcatus, G. holbrooki, Poecilia reticulata, Xiphophorus hellerii, and Xiphophorus mayae) that exhibit different male mating strategies and different levels of sexual activity. Results revealed large interspecific differences in the pattern of female aggregation. Females of species with a high frequency of sneak copulations tended to reduce their social distance in the presence of a male. By contrast, species that rely mainly on courtship showed little or no variation in social distance. The proportion of sneak copulations predicts the degree of variation in female social response, but the amount of total sexual activity does not, suggesting that the change in females' social distance when a male is present may indeed serve to reduce the costs of male sexual harassment.

  12. The challenges of implementing pathogen control strategies for fishes used in biomedical research

    Science.gov (United States)

    Lawrence, C.; Ennis, D.G.; Harper, C.; Kent, M.L.; Murray, K.; Sanders, G.E.

    2012-01-01

    Over the past several decades, a number of fish species, including the zebrafish, medaka, and platyfish/swordtail, have become important models for human health and disease. Despite the increasing prevalence of these and other fish species in research, methods for health maintenance and the management of diseases in laboratory populations of these animals are underdeveloped. There is a growing realization that this trend must change, especially as the use of these species expands beyond developmental biology and more towards experimental applications where the presence of underlying disease may affect the physiology animals used in experiments and potentially compromise research results. Therefore, there is a critical need to develop, improve, and implement strategies for managing health and disease in aquatic research facilities. The purpose of this review is to report the proceedings of a workshop entitled "Animal Health and Disease Management in Research Animals" that was recently held at the 5th Aquatic Animal Models for Human Disease in September 2010 at Corvallis, Oregon to discuss the challenges involved with moving the field forward on this front. ?? 2011 Elsevier Inc. All rights reserved.

  13. Is UV-A radiation a cause of malignant melanoma. Er UV-A aarsak til malignt melanom

    Energy Technology Data Exchange (ETDEWEB)

    Moan, J. (Det Norske Radiumhospital, Oslo (Norway))

    1994-03-01

    The first action spectrum for cutaneous malignant melanoma was published recently. This spectrum was obtained using the fish Xiphophorus. If the same action spectrum applies to humans, the following statements are true: Sunbathing products (agents to protect against the sun) that absorb UV-B radiation provide almost no protection against cutaneous malignant melanoma. UV-A-solaria are more dangerous than expected so far. If people are determined to use artificial sources of radiation for tanning, they should choose UV-B solaria rather than UV-A-solaria. Fluorescent tubes and halogen lamps may have weak melanomagenic effects. Ozone depletion has almost no effect on the incidence rates of CMM, since ozone absorbs very little UV-A radiation. Sunbathing products which contain UV-A-absorbing compounds or neutral filter (like titanium oxide) provide real protection against cutaneous malignant melanoma, at least if they are photochemically inert. 34 refs., 2 figs.

  14. Is UV-A radiation a cause of malignant melanoma?

    International Nuclear Information System (INIS)

    Moan, J.

    1994-01-01

    The first action spectrum for cutaneous malignant melanoma was published recently. This spectrum was obtained using the fish Xiphophorus. If the same action spectrum applies to humans, the following statements are true: Sunbathing products (agents to protect against the sun) that absorb UV-B radiation provide almost no protection against cutaneous malignant melanoma. UV-A-solaria are more dangerous than expected so far. If people are determined to use artificial sources of radiation for tanning, they should choose UV-B solaria rather than UV-A-solaria. Fluorescent tubes and halogen lamps may have weak melanomagenic effects. Ozone depletion has almost no effect on the incidence rates of CMM, since ozone absorbs very little UV-A radiation. Sunbathing products which contain UV-A-absorbing compounds or neutral filter (like titanium oxide) provide real protection against cutaneous malignant melanoma, at least if they are photochemically inert. 34 refs., 2 figs

  15. Early social learning triggers neurogenomic expression changes in a swordtail fish.

    Science.gov (United States)

    Cui, Rongfeng; Delclos, Pablo J; Schumer, Molly; Rosenthal, Gil G

    2017-05-17

    Mate choice can play a pivotal role in the nature and extent of reproductive isolation between species. Mating preferences are often dependent on an individual's social experience with adult phenotypes throughout development. We show that olfactory preference in a swordtail fish ( Xiphophorus malinche ) is affected by previous experience with adult olfactory signals. We compare transcriptome-wide gene expression levels of pooled sensory and brain tissues between three treatment groups that differ by social experience: females with no adult exposure, females exposed to conspecifics and females exposed to heterospecifics. We identify potential functionally relevant genes and biological pathways differentially expressed not only between control and exposure groups, but also between groups exposed to conspecifics and heterospecifics. Based on our results, we speculate that vomeronasal receptor type 2 paralogs may detect species-specific pheromone components and thus play an important role in reproductive isolation between species. © 2017 The Author(s).

  16. The cost of the sword: escape performance in male swordtails.

    Directory of Open Access Journals (Sweden)

    Alex Baumgartner

    2011-01-01

    Full Text Available The handicap theory of sexual selection posits that male display traits that are favored in mate choice come at a significant cost to performance. We tested one facet of this hypothesis in the green swordtail (Xiphophorus helleri. In this species, the lower ray of male caudal fin is extended into a 'sword', which serves to attract potential mates. However, bearing a long sword may increase drag and thus compromise a male's ability to swim effectively. We tested escape performance in this species by eliciting C-start escape responses, an instinctive escape behavior, in males with various sword lengths. We then removed males' swords and retested escape performance. We found no relationship between escape performance and sword length and no effect of sword removal on escape performance. While having a large sword may attract a predator's attention, our results suggest that sword size does not compromise a male's escape performance.

  17. Comparative study of infection with Tetrahymena of different ornamental fish species

    DEFF Research Database (Denmark)

    Sharon, G.; Leibowitz, M. Pimenta; Chettri, Jiwan Kumar

    2014-01-01

    different super orders. The species examined were platy (Xiphophorus), molly (Poecilia sphenops) and angelfish (Pterophyllum scalare) of the Acanthopterygii super order (which also includes guppies) and goldfish (Carassius auratus auratus) and koi carp (Cyprinus carpio) of the Ostariophysi super order....... These two super orders are phylogenetically distant from each other. Infection with Tetrahymena resulted in parasite invasion of internal organs, skin and muscle in all fish species. A relatively strong inflammatory response was observed in infected goldfish and koi, with negligible response in fish species...... of the Acanthopterygii super order. Guppies were the most susceptible to Tetrahymena infection, exhibiting a mortality rate of 87% and 100% in two separate experiments. A high mortality rate was also observed in platy (77%), while that of molly and angelfish was significantly lower (23% and 33%, respectively). Goldfish...

  18. New observations on Mexiconema cichlasomae (Nematoda: Dracunculoidea) from fishes in Mexico.

    Science.gov (United States)

    Moravec, F; Jiménez-García, M I; Salgado-Maldonado, G

    1998-09-01

    The dracunculoid nematode Mexiconema cichlasomae Moravec, Vidal et Salgado Maldonado, 1992, originally described from the abdominal cavity and viscera of Cichlasoma spp. from Mexico, was recorded from the abdominal cavity of the poeciliid Xiphophorus helleri Heckel in Lake Catemaco and its small tributary Arroyo Agrio, Veracruz and from the intestine of the nurse shark Ginglystoma cirratum (Bonnaterre) off the southern coast of the Gulf of Mexico in Campeche; both these findings represent new host records. The nematode specimens from these hosts are briefly described and illustrated. Whereas X. helleri evidently served as the true definitive host of this parasite, G. cirratum probably acquired Mexiconema infection accidentally while feeding on fish definitive hosts in the brackish or salt-water environment. The ability of M. cichlasomae to utilize fishes of different orders (Perciformes and Cyprinodontiformes) as definitive hosts is rather exceptional among dracunculoid nematodes.

  19. [Annotation of the mobilomes of nine teleost species].

    Science.gov (United States)

    Gao, Bo; Shen, Dan; Chen, Cai; Wang, Saisai; Yang, Kunlun; Chen, Wei; Wang, Wei; Zhang, Li; Song, Chengyi

    2018-01-25

    In this study, the mobilomes of nine teleost species were annotated by bioinformatics methods. Both of the mobilome size and constitute displayed a significant difference in 9 species of teleost fishes. The species of mobilome content ranking from high to low were zebrafish, medaka, tilapia, coelacanth, platyfish, cod, stickleback, tetradon and fugu. Mobilome content and genome size were positively correlated. The DNA transposons displayed higher diversity and larger variation in teleost (0.50% to 38.37%), was a major determinant of differences in teleost mobilomes, and hAT and Tc/Mariner superfamily were the major DNA transposons in teleost. RNA transposons also exhibited high diversity in teleost, LINE transposons accounted for 0.53% to 5.75% teleost genomic sequences, and 14 superfamilies were detected. L1, L2, RTE and Rex retrotransposons obtained significant amplification. While LTR displayed low amplification in most teleost with less than 2% of genome coverages, except in zebrafish and stickleback, where LTR reachs 5.58% and 2.51% of genome coverages respectively. And 6 LTR superfamilies (Copia, DIRS, ERV, Gypsy, Ngaro and Pao) were detected in the teleost, and Gypsy exhibits obvious amplication among them. While the SINE represents the weakest ampification types in teleost, only within zebrafish and coelacanth, it represents 3.28% and 5.64% of genome coverages, in the other 7 teleost, it occupies less than 1% of genomes, and tRNA, 5S and MIR families of SINE have a certain degree of amplification in some teleosts. This study shows that the teleost display high diversity and large variation of mobilome, there is a strong correlation with the size variations of genomes and mobilome contents in teleost, mobilome is an important factor in determining the teleost genome size.

  20. Comparative analysis of transposable elements highlights mobilome diversity and evolution in vertebrates.

    Science.gov (United States)

    Chalopin, Domitille; Naville, Magali; Plard, Floriane; Galiana, Delphine; Volff, Jean-Nicolas

    2015-01-09

    Transposable elements (TEs) are major components of vertebrate genomes, with major roles in genome architecture and evolution. In order to characterize both common patterns and lineage-specific differences in TE content and TE evolution, we have compared the mobilomes of 23 vertebrate genomes, including 10 actinopterygian fish, 11 sarcopterygians, and 2 nonbony vertebrates. We found important variations in TE content (from 6% in the pufferfish tetraodon to 55% in zebrafish), with a more important relative contribution of TEs to genome size in fish than in mammals. Some TE superfamilies were found to be widespread in vertebrates, but most elements showed a more patchy distribution, indicative of multiple events of loss or gain. Interestingly, loss of major TE families was observed during the evolution of the sarcopterygian lineage, with a particularly strong reduction in TE diversity in birds and mammals. Phylogenetic trends in TE composition and activity were detected: Teleost fish genomes are dominated by DNA transposons and contain few ancient TE copies, while mammalian genomes have been predominantly shaped by nonlong terminal repeat retrotransposons, along with the persistence of older sequences. Differences were also found within lineages: The medaka fish genome underwent more recent TE amplification than the related platyfish, as observed for LINE retrotransposons in the mouse compared with the human genome. This study allows the identification of putative cases of horizontal transfer of TEs, and to tentatively infer the composition of the ancestral vertebrate mobilome. Taken together, the results obtained highlight the importance of TEs in the structure and evolution of vertebrate genomes, and demonstrate their major impact on genome diversity both between and within lineages. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  1. Gene expression analysis after receptor tyrosine kinase activation reveals new potential melanoma proteins

    International Nuclear Information System (INIS)

    Teutschbein, Janka; Haydn, Johannes M; Samans, Birgit; Krause, Michael; Eilers, Martin; Schartl, Manfred; Meierjohann, Svenja

    2010-01-01

    Melanoma is an aggressive tumor with increasing incidence. To develop accurate prognostic markers and targeted therapies, changes leading to malignant transformation of melanocytes need to be understood. In the Xiphophorus melanoma model system, a mutated version of the EGF receptor Xmrk (Xiphophorus melanoma receptor kinase) triggers melanomagenesis. Cellular events downstream of Xmrk, such as the activation of Akt, Ras, B-Raf or Stat5, were also shown to play a role in human melanomagenesis. This makes the elucidation of Xmrk downstream targets a useful method for identifying processes involved in melanoma formation. Here, we analyzed Xmrk-induced gene expression using a microarray approach. Several highly expressed genes were confirmed by realtime PCR, and pathways responsible for their induction were revealed using small molecule inhibitors. The expression of these genes was also monitored in human melanoma cell lines, and the target gene FOSL1 was knocked down by siRNA. Proliferation and migration of siRNA-treated melanoma cell lines were then investigated. Genes with the strongest upregulation after receptor activation were FOS-like antigen 1 (Fosl1), early growth response 1 (Egr1), osteopontin (Opn), insulin-like growth factor binding protein 3 (Igfbp3), dual-specificity phosphatase 4 (Dusp4), and tumor-associated antigen L6 (Taal6). Interestingly, most genes were blocked in presence of a SRC kinase inhibitor. Importantly, we found that FOSL1, OPN, IGFBP3, DUSP4, and TAAL6 also exhibited increased expression levels in human melanoma cell lines compared to human melanocytes. Knockdown of FOSL1 in human melanoma cell lines reduced their proliferation and migration. Altogether, the data show that the receptor tyrosine kinase Xmrk is a useful tool in the identification of target genes that are commonly expressed in Xmrk-transgenic melanocytes and melanoma cell lines. The identified molecules constitute new possible molecular players in melanoma development

  2. Gene expression analysis after receptor tyrosine kinase activation reveals new potential melanoma proteins

    Directory of Open Access Journals (Sweden)

    Krause Michael

    2010-07-01

    Full Text Available Abstract Background Melanoma is an aggressive tumor with increasing incidence. To develop accurate prognostic markers and targeted therapies, changes leading to malignant transformation of melanocytes need to be understood. In the Xiphophorus melanoma model system, a mutated version of the EGF receptor Xmrk (Xiphophorus melanoma receptor kinase triggers melanomagenesis. Cellular events downstream of Xmrk, such as the activation of Akt, Ras, B-Raf or Stat5, were also shown to play a role in human melanomagenesis. This makes the elucidation of Xmrk downstream targets a useful method for identifying processes involved in melanoma formation. Methods Here, we analyzed Xmrk-induced gene expression using a microarray approach. Several highly expressed genes were confirmed by realtime PCR, and pathways responsible for their induction were revealed using small molecule inhibitors. The expression of these genes was also monitored in human melanoma cell lines, and the target gene FOSL1 was knocked down by siRNA. Proliferation and migration of siRNA-treated melanoma cell lines were then investigated. Results Genes with the strongest upregulation after receptor activation were FOS-like antigen 1 (Fosl1, early growth response 1 (Egr1, osteopontin (Opn, insulin-like growth factor binding protein 3 (Igfbp3, dual-specificity phosphatase 4 (Dusp4, and tumor-associated antigen L6 (Taal6. Interestingly, most genes were blocked in presence of a SRC kinase inhibitor. Importantly, we found that FOSL1, OPN, IGFBP3, DUSP4, and TAAL6 also exhibited increased expression levels in human melanoma cell lines compared to human melanocytes. Knockdown of FOSL1 in human melanoma cell lines reduced their proliferation and migration. Conclusion Altogether, the data show that the receptor tyrosine kinase Xmrk is a useful tool in the identification of target genes that are commonly expressed in Xmrk-transgenic melanocytes and melanoma cell lines. The identified molecules constitute

  3. Predator avoidance in extremophile fish.

    Science.gov (United States)

    Bierbach, David; Schulte, Matthias; Herrmann, Nina; Zimmer, Claudia; Arias-Rodriguez, Lenin; Indy, Jeane Rimber; Riesch, Rüdiger; Plath, Martin

    2013-02-06

    Extreme habitats are often characterized by reduced predation pressures, thus representing refuges for the inhabiting species. The present study was designed to investigate predator avoidance of extremophile populations of Poecilia mexicana and P. sulphuraria that either live in hydrogen sulfide-rich (sulfidic) springs or cave habitats, both of which are known to have impoverished piscine predator regimes. Focal fishes that inhabited sulfidic springs showed slightly weaker avoidance reactions when presented with several naturally occurring predatory cichlids, but strongest differences to populations from non-sulfidic habitats were found in a decreased shoaling tendency with non-predatory swordtail (Xiphophorus hellerii) females. When comparing avoidance reactions between P. mexicana from a sulfidic cave (Cueva del Azufre) and the adjacent sulfidic surface creek (El Azufre), we found only slight differences in predator avoidance, but surface fish reacted much more strongly to the non-predatory cichlid Vieja bifasciata. Our third experiment was designed to disentangle learned from innate effects of predator recognition. We compared laboratory-reared (i.e., predator-naïve) and wild-caught (i.e., predator-experienced) individuals of P. mexicana from a non-sulfidic river and found no differences in their reaction towards the presented predators. Overall, our results indicate (1) that predator avoidance is still functional in extremophile Poecilia spp. and (2) that predator recognition and avoidance reactions have a strong genetic basis.

  4. Parasites of ornamental fish commercialized in Macapá, Amapá State (Brazil

    Directory of Open Access Journals (Sweden)

    Érico de Melo Hoshino

    2018-02-01

    Full Text Available Abstract This study investigated the parasites fauna of four freshwater ornamental fish species in aquarium shops of Macapá, Amapá State, in addition to survey the commercialized fish species and sanitary conditions of aquarium shops. Different native and non-native ornamental fish species were found in aquarium shops, mainly Poecilidae. We examined 30 specimens of Xiphophorus maculatus, 30 Danio rerio, 30 Paracheirodon axelrodi, and 30 Corydoras ephippifer for parasites. Of the 120 fish examined, 22.5% were parasitized by one or more species and a total of 438 parasites were collected and identified. Parasites such as: Ichthyophthirius multifiliis, Monogenea, undermined Digenea metacercariae, Acanthostomum sp. metacercariae, Camallanus spp., Bothriocephalus acheilognathi and Echinorhynchus sp. infected the hosts examined. Endoparasites in the larval stage showed the greatest diversity and Camallanus spp. was found in all hosts species examined. Paracheirodon axelrodi (43.3% was the most parasitized host, while C. ephippifer (6.7% was the least parasitized. Despite the low ectoparasites level, six species of endoparasites was observed, demonstrating that prophylactic and quarantine procedures were not fully adequate. Therefore, failures in prophylactic procedures on any link in the production industry of ornamental fish may cause parasite transmission to ornamental fish captured in different environments and localities.

  5. 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.

  6. Richness patterns in the parasite communities of exotic poeciliid fishes.

    Science.gov (United States)

    Dove, A D

    2000-06-01

    Three species of poeciliids (Gambusia holbrooki, Xiphophorus helleri and X. maculatus) and 15 species of ecologically similar native freshwater fishes (mainly eleotrids, ambassids, melanotaeniids and retropinnids) were examined for parasite richness to investigate parasite flux, qualitative differences, quantitative differences and the structuring factors in parasite communities in the 2 fish types in Queensland, Australia. Theory suggests that poeciliids would harbour depauperate parasite communities. Results supported this hypothesis; poeciliids harboured more species-poor parasite infracommunities and regional faunas than natives (P analysis of presence/absence data for poeciliids and the 6 most-sampled native fishes revealed that parasite communities of the 2 fish groups are qualitatively distinct; the proportion of parasite species with complex life-cycles was lower in poeciliids than in native species, and Myxosporea, Microspora, Coccidia and parasitic Crustacea were all absent from poeciliids. Limited exchange of parasite species has occurred between natives and poeciliids. Logistic ordinal regression analysis revealed that fish origin (exotic or native), environmental disturbance and host sex were all significant determinants of parasite community richness (P competitive advantage over native fishes because of their lack of parasites.

  7. Aquatic food production modules in bioregenerative life support systems based on higher plants

    Science.gov (United States)

    Bluem, V.; Paris, F.

    Most bioregenerative life support systems (BLSS) are based on gravitropic higher plants which exhibit growth and seed generation disturbances in microgravity. Even when used for a lunar or martian base the reduced gravity may induce a decreased productivity in comparison to Earth. Therefore, the implementation of aquatic biomass production modules in higher plant and/or hybrid BLSS may compensate for this and offer, in addition, the possibility to produce animal protein for human nutrition. It was shown on the SLS-89 and SLS-90 space shuttle missions with the C.E.B.A.S.-MINI MODULE that the edible non gravitropic rootless higher aquatic plant Ceratophyllum demeresum exhibits an undisturbed high biomass production rate in space and that the teleost fish species, Xiphophorus helleri, adapts rapidly to space conditions without loss of its normal reproductive functions. Based on these findings a series of ground-based aquatic food production systems were developed which are disposed for utilization in space. These are plant production bioreactors for the species mentioned above and another suitable candidate, the lemnacean (duckweed) species, Wolffia arrhiza. Moreover, combined intensive aquaculture systems with a closed food loop between herbivorous fishes and aquatic and land plants are being developed which may be suitable for integration into a BLSS of higher complexity.

  8. Ictiofauna de sistemas cárstico-palustres con impacto antrópico: los petenes de Campeche, México

    Directory of Open Access Journals (Sweden)

    Ivette Liliana Torres-Castro

    2009-06-01

    Full Text Available Los petenes son pequeños manantiales y arroyos asociados que drenan a sistemas palustres en áreas cársticas costeras. Se estudió la composición, distribución y abundancia de la ictiofauna en dos petenes del noroeste de Campeche, en el manantial principal, el arroyo asociado, y pequeños ojos de agua secundarios (temporales, en dos épocas del año. Se registraron variables ambientales y tipos de impacto antrópico en cada petén. Se encontraron en total 27 especies de peces, con extensiones de ámbito de ‘Cichlasoma’ salvini, Rivulus tenuis, Phallichthys fairweatheri, Xiphophorus hellerii y X. maculatus. La especie dominante en ambas épocas fue Astyanax (probables híbridos A. aeneus × altior en Hampolol, A. altior en El Remate. Hubo diferencia significativa en diversidad entre ambos petenes. El análisis de conglomerados diferenció dos agrupaciones dentro de cada petén: aguas permanentes y sitios temporales. Las variables ambientales (excepto salinidad presentaron diferencias significativas por sitio y época; un análisis de correspondencia canónica indicó que la distribución de los conjuntos de peces tuvo influencia de las variables ambientales en ambas temporadas. En términos de composición, los factores históricos juegan un papel en las diferencias ictiológicas entre ambos petenes, sobre todo por lo que concierne a la presencia de híbridos de Astyanax, así como Xiphophorus hellerii en el petén del sur (Hampolol y de Poecilia velifera en el petén del norte (El Remate.Ichthyofauna of karstic wetlands under anthropic impact: the "petenes" of Campeche, Mexico. "Petenes" are small springs and associated streams that drain into wetlands near the coast in karstic areas. We studied composition, distribution, and abundance of the ichthyofauna in Los Petenes region (northwest Campeche. Two petenes displaying different degrees and types of anthropic impact were selected, Hampolol and El Remate. Hampolol has a smaller area but

  9. SOLAR RADIATION AND INDUCTION OF DNA DAMAGE, MUTATIONS AND SKIN CANCERS.

    Energy Technology Data Exchange (ETDEWEB)

    SETLOW,R.B.

    2007-05-10

    An understanding of the effects of sunlight on human skin begins with the effects on DNA and extends to cells, animals and humans. The major DNA photoproducts arising from UVB (280-320 nm) exposures are cyclobutane pyrimidine dimers. If unrepaired, they may kill or mutate cells and result in basal and squamous cell carcinomas. Although UVA (320-400 nm) and visible wavelengths are poorly absorbed by DNA, the existing data indicate clearly that exposures to these wavelengths are responsible, in an animal model, for {approx}95 % of the incidence of cutaneous malignant melanoma (CMM). Six lines of evidence, to be discussed in detail, support the photosensitizing role of melanin in the induction of this cancer. They are: (1) Melanomas induced in backcross hybrids of small tropical fish of the genus Xiphophorus, exposed to wavelengths from 302-547 nm, indicate that {approx}95% of the cancers induced by exposure to sunlight would arise from UVA + visible wavelengths; (2) The action spectrum for inducing melanin-photosensitized oxidant production is very similar to the spectrum for inducing melanoma; (3) Albino whites and blacks, although very sensitive to sunburn and the sunlight induction of non-CMM, have very low incidences of CMM; (4) The incidence of CMM as a function of latitude is very similar to that of UVA, but not UVB; (5) Use of UVA-exposing sun-tanning parlors by the young increases the incidence rate of CMM and (6) Major mutations observed in CMM are not UVB-induced.

  10. Automated interactive video playback for studies of animal communication.

    Science.gov (United States)

    Butkowski, Trisha; Yan, Wei; Gray, Aaron M; Cui, Rongfeng; Verzijden, Machteld N; Rosenthal, Gil G

    2011-02-09

    Video playback is a widely-used technique for the controlled manipulation and presentation of visual signals in animal communication. In particular, parameter-based computer animation offers the opportunity to independently manipulate any number of behavioral, morphological, or spectral characteristics in the context of realistic, moving images of animals on screen. A major limitation of conventional playback, however, is that the visual stimulus lacks the ability to interact with the live animal. Borrowing from video-game technology, we have created an automated, interactive system for video playback that controls animations in response to real-time signals from a video tracking system. We demonstrated this method by conducting mate-choice trials on female swordtail fish, Xiphophorus birchmanni. Females were given a simultaneous choice between a courting male conspecific and a courting male heterospecific (X. malinche) on opposite sides of an aquarium. The virtual male stimulus was programmed to track the horizontal position of the female, as courting males do in the wild. Mate-choice trials on wild-caught X. birchmanni females were used to validate the prototype's ability to effectively generate a realistic visual stimulus.

  11. Predator Avoidance in Extremophile Fish

    Science.gov (United States)

    Bierbach, David; Schulte, Matthias; Herrmann, Nina; Zimmer, Claudia; Arias-Rodriguez, Lenin; Indy, Jeane Rimber; Riesch, Rüdiger; Plath, Martin

    2013-01-01

    Extreme habitats are often characterized by reduced predation pressures, thus representing refuges for the inhabiting species. The present study was designed to investigate predator avoidance of extremophile populations of Poecilia mexicana and P. sulphuraria that either live in hydrogen sulfide-rich (sulfidic) springs or cave habitats, both of which are known to have impoverished piscine predator regimes. Focal fishes that inhabited sulfidic springs showed slightly weaker avoidance reactions when presented with several naturally occurring predatory cichlids, but strongest differences to populations from non-sulfidic habitats were found in a decreased shoaling tendency with non-predatory swordtail (Xiphophorus hellerii) females. When comparing avoidance reactions between P. mexicana from a sulfidic cave (Cueva del Azufre) and the adjacent sulfidic surface creek (El Azufre), we found only slight differences in predator avoidance, but surface fish reacted much more strongly to the non-predatory cichlid Vieja bifasciata. Our third experiment was designed to disentangle learned from innate effects of predator recognition. We compared laboratory-reared (i.e., predator-naïve) and wild-caught (i.e., predator-experienced) individuals of P. mexicana from a non-sulfidic river and found no differences in their reaction towards the presented predators. Overall, our results indicate (1) that predator avoidance is still functional in extremophile Poecilia spp. and (2) that predator recognition and avoidance reactions have a strong genetic basis. PMID:25371337

  12. An annotated distributional checklist of exotic freshwater fishes from the Baja California Peninsula, Mexico Lista comentada sobre la distribución de peces dulceacuícolas exóticos de la península de Baja California, México

    Directory of Open Access Journals (Sweden)

    Gorgonio Ruiz-Campos

    2012-03-01

    Full Text Available We documented the distributional status of 27 exotic fish species in the inland waters of the Baja California Peninsula, Mexico, based on voucher specimens collected from 122 sites between 1977 and 2010, and on published records. The species reported here are representatives of genera from the Atlantic drainages of North America (Ictalurus, Ameiurus, Pylodictis, Morone, Lepomis, Pomoxis, Dorosoma, Cyprinella, and Micropterus, Middle America (Poecilia, Gambusia, and Xiphophorus, Eurasia (Cyprinus and Carassius, and Africa (Tilapia and Oreochromis. The family containing the highest number of species is Centrarchidae (7 species followed by Ictaluridae and Poeciliidae (6 species each. Four species were determined to be invasive due to their wide distribution and fast dispersal through the Peninsula (Gambusia affinis, Poecilia reticulata, Lepomis cyanellus, and Tilapia sp. cf. zillii. We analyze the impacts of exotic species on the native populations of 3 species with problems of conservation: Cyprinodon macularius (endangered, Fundulus lima (endangered, and Gasterosteus aculeatus (vulnerable. Alien fishes have been introduced for a variety of reasons in Mexico: ornament, sport, aquaculture, biological control, and by accident. In some cases fish introductions were carried out for more than one reason.El estatus de la distribución de peces exóticos es documentado para 27 especies en las aguas continentales de la península de Baja California, México, basado en registros de ejemplares recolectados en 122 localidades durante el período de 1977 a 2010, así como registros referidos en la literatura. Las especies aquí reportadas son representativas de géneros que proceden de la vertiente Atlántica de Norteamérica (Ictalurus, Ameiurus, Pylodictis, Morone, Lepomis, Pomoxis, Dorosoma, Cyprinella y Micropterus, Mesoamérica (Poecilia, Gambusia y Xiphophorus, Eurasia (Cyprinus y Carassius y África (Tilapia y Oreochromis. La familia con mayor n

  13. Experimental infection in Notodiaptomus sp. (Crustacea: Calanoida with larvae of Camallanus sp. (Nematoda: Camallanidae Infecção experimental em Notodiaptomus sp. (Crustacea: Calanoida com larvas de Camallanus sp. (Nematoda: Camallanidae

    Directory of Open Access Journals (Sweden)

    M.L. Martins

    2007-04-01

    Full Text Available This trial registered the experimental infection viability with nematode larvae Camallanus sp. in Notodiaptomus sp., a crustacean, which can be an intermediate host. Adult females of nematode were dissected from the intestines of Xiphophorus maculatus (Osteichthyes: Poeciliidae, at a fish farm in the State of São Paulo. Females were slightly compressed for larvae release, collected with Pasteur pipette and separated on Petri dishes with 9ml filtered water at 28.1ºC, from zooplankton culture. Treatments consisted of Petri dishes with 60 and 105 copepods, in which 120, 150 and 210 larvae of nematode were added in four replications. Twenty-four and 36h after exposition to the larvae, the copepods were fixed in 70% alcohol to record the amount of fixed larvae. Twenty four hours after exposition, 60 copepods group with 120 larvae showed significantly higher prevalence (46.5% when compared to 105 copepods and 120 larvae (33.2%. Thus, these answers suggested that 120 larvae were enough for a successful infectivity. Experimental infection was available and so, it was used as a pattern to life cycle studies of camallanid nematodes and hosts susceptibility tests.A viabilidade da infecção experimental com larvas do nematóide Camallanus sp. em Notodiaptomus sp., crustáceo com potencial para hospedeiro intermediário foi avaliada. Fêmeas adultas do nematóide foram extraídas de Xiphophorus maculatus (Osteichthyes: Poeciliidae, provenientes de piscicultura de peixes ornamentais no estado de São Paulo. As fêmeas foram ligeiramente pressionadas para liberar as larvas, coletadas com pipeta Pasteur e separadas em placas de Petri contendo 9ml de água filtrada a 28,1ºC do próprio cultivo de zooplâncton. Os tratamentos consistiram de placas contendo 60 e 105 copépodes onde se adicionou 120, 150 e 210 larvas de nematóides em quatro repetições. Nos tempos de 24 e 36h após a exposição às larvas, os copépodes foram fixados em álcool 70% para

  14. An Index of Biotic Integrity for shallow streams of the Hondo River basin, Yucatan Peninsula

    Energy Technology Data Exchange (ETDEWEB)

    Schmitter-Soto, Juan J., E-mail: jschmitt@ecosur.mx; Ruiz-Cauich, Lissie E.; Herrera, Roberto L.; Gonzalez-Solis, David

    2011-01-15

    An Index of Biotic Integrity (IBI) is proposed, based on the fish communities and populations in streams of the Hondo River basin, Mexico-Belize. Freshwater environments in this area are threatened by exotic fishes, eutrophication, and pesticide pollution, among other problems. This IBI should allow to identify the most vulnerable sites and eventually guide rehabilitation efforts. Data on composition, structure, and function of fish communities were evaluated. Twenty-three sites in the Mexican part of the basin were explored; a stratified sample of 13 sites was used to design the IBI, and the rest were used to test and refine the index. Thirty-four candidate indicator metrics were scanned for their correlation with an index of water and habitat quality (IWHQ), as well as for the possible influence of stream width and altitude or distance to the Hondo River mainstem. Twelve variables were selected to constitute the IBI: relative abundances of Astyanax aeneus, 'Cichlasoma' urophthalmus, Poecilia mexicana, Poecilia sp. (a new species, probably endemic to the upper Hondo River basin), Xiphophorus hellerii, and X. maculatus; relative abundances of bentholimnetic, herbivore, and sensitive species; percentage of native and tolerant species; and Pielou's evenness index. Most of the sites have a low-medium quality and integrity, showing impact due to partial channelization or to suboptimal water quality, reflected in scarcity or absence of sensitive species, frequent excess of tolerant species, occasional presence of exotics, dominance of herbivores (perhaps due to proliferation of filamentous algae), or dominance of the opportunistic species P. mexicana. The streams with better water and habitat quality are those farthest away from the river mainstem, probably because of lower human population and economical production. - Research Highlights: {yields} An Index of Biotic Integrity based on fishes is proposed for streams of the Hondo River basin. {yields

  15. Fish Inner Ear Otolith Growth Under Real Microgravity (Spaceflight) and Clinorotation

    Science.gov (United States)

    Anken, Ralf; Brungs, Sonja; Grimm, Dennis; Knie, Miriam; Hilbig, Reinhard

    2016-06-01

    Using late larval stages of cichlid fish ( Oreochromis mossambicus) we have shown earlier that the biomineralization of otoliths is adjusted towards gravity by means of a neurally guided feedback loop. Centrifuge experiments, e.g., revealed that increased gravity slows down otolith growth. Microgravity thus should yield an opposite effect, i.e., larger than normal otoliths. Consequently, late larval cichlids (stage 14, vestibular system operational) were subjected to real microgravity during the 12 days FOTON-M3 spaceflight mission (OMEGAHAB-hardware). Controls were kept at 1 g on ground within an identical hardware. Animals of another batch were subsequently clinorotated within a submersed fast-rotating clinostat with one axis of rotation (2d-clinostat), a device regarded to simulate microgravity. Temperature and light conditions were provided in analogy to the spaceflight experiment. Controls were maintained at 1 g within the same aquarium. After all experiments, animals had reached late stage 21 (fish can swim freely). Maintenance under real microgravity during spaceflight resulted in significantly larger than normal otoliths (both lapilli and sagittae, involved in sensing gravity and the hearing process, respectively). This result is fully in line with an earlier spaceflight study in the course of which otoliths from late-staged swordtails Xiphophorus helleri were analyzed. Clinorotation resulted in larger than 1 g sagittae. However, no effect on lapilli was obtained. Possibly, an effect was present but too light to be measurable. Overall, spaceflight obviously induces an adaptation of otolith growth, whereas clinorotation does not fully mimic conditions of microgravity regarding late larval cichlids.

  16. An Index of Biotic Integrity for shallow streams of the Hondo River basin, Yucatan Peninsula.

    Science.gov (United States)

    Schmitter-Soto, Juan J; Ruiz-Cauich, Lissie E; Herrera, Roberto L; González-Solís, David

    2011-01-15

    An Index of Biotic Integrity (IBI) is proposed, based on the fish communities and populations in streams of the Hondo River basin, Mexico-Belize. Freshwater environments in this area are threatened by exotic fishes, eutrophication, and pesticide pollution, among other problems. This IBI should allow to identify the most vulnerable sites and eventually guide rehabilitation efforts. Data on composition, structure, and function of fish communities were evaluated. Twenty-three sites in the Mexican part of the basin were explored; a stratified sample of 13 sites was used to design the IBI, and the rest were used to test and refine the index. Thirty-four candidate indicator metrics were scanned for their correlation with an index of water and habitat quality (IWHQ), as well as for the possible influence of stream width and altitude or distance to the Hondo River mainstem. Twelve variables were selected to constitute the IBI: relative abundances of Astyanax aeneus, 'Cichlasoma' urophthalmus, Poecilia mexicana, Poecilia sp. (a new species, probably endemic to the upper Hondo River basin), Xiphophorus hellerii, and X. maculatus; relative abundances of bentholimnetic, herbivore, and sensitive species; percentage of native and tolerant species; and Pielou's evenness index. Most of the sites have a low-medium quality and integrity, showing impact due to partial channelization or to suboptimal water quality, reflected in scarcity or absence of sensitive species, frequent excess of tolerant species, occasional presence of exotics, dominance of herbivores (perhaps due to proliferation of filamentous algae), or dominance of the opportunistic species P. mexicana. The streams with better water and habitat quality are those farthest away from the river mainstem, probably because of lower human population and economical production. Copyright © 2010 Elsevier B.V. All rights reserved.

  17. The thermal regime and species composition of fish and invertebrates in Kelly Warm Spring, Grand Teton National Park, Wyoming

    Science.gov (United States)

    Harper, David; Farag, Aida

    2017-01-01

    We evaluated the thermal regime and relative abundance of native and nonnative fish and invertebrates within Kelly Warm Spring and Savage Ditch, Grand Teton National Park, Wyoming. Water temperatures within the system remained relatively warm year-round with mean temperatures >20 °C near the spring source and >5 °C approximately 2 km downstream of the source. A total of 7 nonnative species were collected: Convict/Zebra Cichlid (Cichlasoma nigrofasciatum), Green Swordtail (Xiphophorus hellerii), Tadpole Madtom (Noturus gyrinus), Guppy (Poecilia reticulata), Goldfish (Carassius auratus), red-rimmed melania snail (Melanoides tuberculata), and American bullfrog tadpoles (Lithobates catesbeianus). Nonnative fish (Zebra Cichlids and Green Swordtails), red-rimmed melania snails, and bullfrog tadpoles dominated the upper 2 km of the system. Abundance estimates of the Zebra Cichlid exceeded 12,000 fish/km immediately downstream of the spring source. Relative abundance of native species increased movingdownstream as water temperatures attenuated with distance from the thermally warmed spring source; however, nonnative species were captured 4 km downstream from the spring. Fish diseases were prevalent in both native and nonnative fish from the Kelly Warm Spring pond. Clinostomum marginatum, a trematode parasite, was found in native species samples, and the tapeworm Diphyllobothrium dendriticum was present in samples from nonnative species. Diphyllobothrium dendriticum is rare in Wyoming. Salmonella spp. were also found in some samples of nonnative species. These bacteria are associated with aquarium fish and aquaculture and are generally not found in the wild.

  18. Omega-3 Fatty Acid Content in Various Tissues of Different Persian Gulf Fish

    Directory of Open Access Journals (Sweden)

    MJ Zibaee Nezhad

    2008-11-01

    Full Text Available Background: The fatty acids of omega-3 family have high nutritional value and can prevent coronary heart disease.These fatty acids are found in various fish and sea foods. To investigate the level of omega-3 fatty acids indifferent kind of fish head, muscle and liver from 30 species of fish collected from Persian Gulf.Material and Methods: In this experimental study, the fish were collected by hunting from Boushehr and Hormozgansea ports. Their head, muscle and liver fatty acids were determined on their methylated fatty acids dissolvedin N-hexin. Quantitative analysis of fatty acids was performed by gas chromatography (GC with methylmyristateused as the reference material in this analysis and the qualitative analysis of fatty acids was done bygas chromatography and mass spectrometer (GC- mass and cod liver oil which contained all of omega-3 fattyacids used as standard.Results: Our study showed that some fish were good sources of omega-3 fatty acids and Trout (Ghezel-ALA,Bartail flathead (Zaminkan-e-domnavari, Malabar blood snapper (Sorkhoo malabari had maximum levels ofomega-3 in all body tissues. Other types of fish were rich in omega 3 fatty acids in separate organs, such as liverin Bartail flathead (Zaminkan-e-domnavari, head in Sillago Sihama (Shoort and muscle in Trout (Ghezel-ALA. In contrast, lesser amount of omega 3 fatty acids is found in tissues of other species of fish such as Silverpomfret (Halva sefid, Longfin trevally (Gish-e-derazbale and Xiphophorus Hellerii (Dom-shamshiri.Conclusion: This research showed that the liver of fish had the highest level of omega-3 fatty acids and fish musclecontained more omega-3 fatty acids than the head. Thus for having maximum levels of omega-3 fatty acids inthe diet, all fish tissues can be served. As liver and head of fish are not usually consumed, it is recommended thatsuch organs be used for preparation of omega 3-containing cardio supportive supplements.

  19. Phylogenetic comparative methods on phylogenetic networks with reticulations.

    Science.gov (United States)

    Bastide, Paul; Solís-Lemus, Claudia; Kriebel, Ricardo; Sparks, K William; Ané, Cécile

    2018-04-25

    The goal of Phylogenetic Comparative Methods (PCMs) is to study the distribution of quantitative traits among related species. The observed traits are often seen as the result of a Brownian Motion (BM) along the branches of a phylogenetic tree. Reticulation events such as hybridization, gene flow or horizontal gene transfer, can substantially affect a species' traits, but are not modeled by a tree. Phylogenetic networks have been designed to represent reticulate evolution. As they become available for downstream analyses, new models of trait evolution are needed, applicable to networks. One natural extension of the BM is to use a weighted average model for the trait of a hybrid, at a reticulation point. We develop here an efficient recursive algorithm to compute the phylogenetic variance matrix of a trait on a network, in only one preorder traversal of the network. We then extend the standard PCM tools to this new framework, including phylogenetic regression with covariates (or phylogenetic ANOVA), ancestral trait reconstruction, and Pagel's λ test of phylogenetic signal. The trait of a hybrid is sometimes outside of the range of its two parents, for instance because of hybrid vigor or hybrid depression. These two phenomena are rather commonly observed in present-day hybrids. Transgressive evolution can be modeled as a shift in the trait value following a reticulation point. We develop a general framework to handle such shifts, and take advantage of the phylogenetic regression view of the problem to design statistical tests for ancestral transgressive evolution in the evolutionary history of a group of species. We study the power of these tests in several scenarios, and show that recent events have indeed the strongest impact on the trait distribution of present-day taxa. We apply those methods to a dataset of Xiphophorus fishes, to confirm and complete previous analysis in this group. All the methods developed here are available in the Julia package PhyloNetworks.

  20. Diplomonad flagellates of some ornamental fish cultured in Thailand

    Directory of Open Access Journals (Sweden)

    Boonkob Viriyapongsutee

    2012-11-01

    Full Text Available The study on diplomonad flagellates infection in some ornamental fishes in the family cichlidae i.e., angelfish(Pterophyllum scalare, oscar (Astronotus ocellatus, blue mbuna (Labeotropheus fuelleborni and the family osphronemidaei.e., Siamese fighting fish (Betta splendens revealed that this parasite infected three out of four ornamental fish species,angelfish, oscar and blue mbuna. The highest infection was recorded in angelfish (90% followed by oscar (75.4% and bluembuna (61%, respectively. Identification of diplomonad flagellates from angelfish by means of morphological studies underlight and electron microscopes indicated that the parasite was Spironucleus vortens. The 14–days LD50 of S. vortens inangelfish was 2.99x103 cells. Histopathological changes of infected angelfish revealed granulomatous liver, numerousnumbers of melanomacrophage in the spleen and inflammation of the intestine. Susceptibility study of S. vortens to goldfish(Carassius auratus, guppy (Poecilia reticulata and platy (Xiphophorus maculatus indicated that they were resistant toartificial infection. In vitro examination of the growth inhibition assay of S. vortens indicated that dimetridazole and metronidazolewere effective in inhibiting parasite growth after 48 hrs exposure at concentrations of >4.0 μg/ml and >6.0 μg/ml,respectively. Magnesium sulfate at a concentration of >60 mg/ml inhibited the parasite growth after 72 hrs exposure. In vivoexamination of the dimetridazole efficiency on S. vortens infection indicated that dimetridazole at 4.0 μg/ml provided thehighest efficiency which could be used for treatment of spironucleosis in angelfish.

  1. Aquatic modules for bioregenerative life support systems: Developmental aspects based on the space flight results of the C.E.B.A.S. mini-module

    Science.gov (United States)

    Blüm, V.

    The Closed Equilibrated Biological Aquatic System (C.E.B.A.S.) is an artificial aquatic ecosystem which contains teleost fishes, water snails, ammonia oxidizing bacteria and edible non-gravitropic water plants. It serves as a model for aquatic food production modules which are not seriously affected by microgravity and other space conditions. Its space flight version, the so-called C.E.B.A.S. MINI-MODULE was already successfidly tested in the STS-89 and STS-90 (NEUROLAB) missions. It will be flown a third time in space with the STS-107 mission in January 2003. All results obtained so far in space indicate that the basic concept of the system is more than suitable to drive forward its development. The C.E.B.A.S. MINI-MODULE is located within a middeck locker with limited space for additional components. These technical limitations allow only some modifications which lead to a maximum experiment time span of 120 days which is not long enough for scientifically essential multi-generation-experiments. The first necessary step is the development of "harvesting devices" for the different organisms. In the limited space of the plant bioreactor a high biomass production leads to self-shadowing effects which results in an uncontrolled degradation and increased oxygen consumption by microorganisms which will endanger the fishes and snails. It was shown already that the latter reproduce excellently in space and that the reproductive functions of the fish species are not affected. Although the parent-offspring-cannibalism of the ovoviviparous fish species ( Xiphophorus helleri) serves as a regulating factor in population dynamics an uncontrolled snail reproduction will also induce an increased oxygen consumption per se and a high ammonia concentration in the water. If harvesting locks can be handled by astronauts in, e. g., 4-week intervals their construction is not very difficult and basic technical solutions are already developed. The second problem is the feeding of the

  2. Aquatic modules for bioregenerative life support systems: Developmental aspects based on the space flight results of the C.E.B.A. Mini Module

    Science.gov (United States)

    Bluem, S. V.

    The Closed Equilibrated Biological Aquatic System (C.E.B.A.S.) is an artificial aquatic ecosystem which contains teleost fishes, water snails, ammonia oxidizing bacteria and edible non-gravitropic water plants. It serves as a model for aquatic food production modules which are not seriously affected by microgravity and other space conditions. Its space flight version, the so-called C.E.B.AS. MINI-MODULE was already successfully tested in the STS-89 and STS 90 (NEUROLAB) missions.- I will be flown a third time in space with the STS 107 mission in July 2002. All- results obtained so far in space indicate that the basic concept of the system is more than suitable to drive forward its development. The C.E.B.A.S. MINI-MODULE is located within a middeck locker whith limited the space for additional components. These technical limitations allow only some modifications which lead to a maximum experiment time span of 120 days which is not long enough for the demanded scientifically essential multi-generation-experiments. This first necessary step is the development of "harvesting devices" for the different organisms. In the limited space of the plant bioreactor a high biomass production leads to self- shadowing effects which results in an uncontrolled degradation and increased oxygen consum ption by microorganisms which will endanger the fishes and snails. It was shown already that the latter reproduce excellently in space and that the reproductive functions of the fishes are not affected. Although the parent - offspring- cannibalism of the used ovoviviparous fish species (Xiphophorus helleri) serves as a regulating factor in population dynamics an uncontrolled snail reproduction will also induce an increased ox gen consumption per se and a high ammonia concentrationy in the water. If harvesting locks can be handled by astronauts in, e. g., 4w e e k- intervals their construction is not very difficult and basic technical solutions are already developed. The second problem is

  3. An Index of Biotic Integrity for shallow streams of the Hondo River basin, Yucatan Peninsula

    International Nuclear Information System (INIS)

    Schmitter-Soto, Juan J.; Ruiz-Cauich, Lissie E.; Herrera, Roberto L.; Gonzalez-Solis, David

    2011-01-01

    An Index of Biotic Integrity (IBI) is proposed, based on the fish communities and populations in streams of the Hondo River basin, Mexico-Belize. Freshwater environments in this area are threatened by exotic fishes, eutrophication, and pesticide pollution, among other problems. This IBI should allow to identify the most vulnerable sites and eventually guide rehabilitation efforts. Data on composition, structure, and function of fish communities were evaluated. Twenty-three sites in the Mexican part of the basin were explored; a stratified sample of 13 sites was used to design the IBI, and the rest were used to test and refine the index. Thirty-four candidate indicator metrics were scanned for their correlation with an index of water and habitat quality (IWHQ), as well as for the possible influence of stream width and altitude or distance to the Hondo River mainstem. Twelve variables were selected to constitute the IBI: relative abundances of Astyanax aeneus, 'Cichlasoma' urophthalmus, Poecilia mexicana, Poecilia sp. (a new species, probably endemic to the upper Hondo River basin), Xiphophorus hellerii, and X. maculatus; relative abundances of bentholimnetic, herbivore, and sensitive species; percentage of native and tolerant species; and Pielou's evenness index. Most of the sites have a low-medium quality and integrity, showing impact due to partial channelization or to suboptimal water quality, reflected in scarcity or absence of sensitive species, frequent excess of tolerant species, occasional presence of exotics, dominance of herbivores (perhaps due to proliferation of filamentous algae), or dominance of the opportunistic species P. mexicana. The streams with better water and habitat quality are those farthest away from the river mainstem, probably because of lower human population and economical production. - Research Highlights: → An Index of Biotic Integrity based on fishes is proposed for streams of the Hondo River basin. → Twelve variables were

  4. Invasion risks posed by ornamental freshwater fish trade to southeastern Brazilian rivers

    Directory of Open Access Journals (Sweden)

    André Lincoln Barroso de Magalhães

    Full Text Available A model was developed to assess the risk of invasion of ornamental non-native fishes to six rivers in the state of Minas Gerais, southeastern Brazil, with focus on species popularity. Thirty-nine aquarium shops, in six cities, were visited monthly from January to December 2007. In each city, fish species were identified, and their biology and invasion history information was obtained from the literature. We calculated the annual frequency of occurrence and average number of specimens monthly available in stores. Quarterly water temperature and dissolved oxygen data from 1997 to 2007 were obtained for the Velhas, Muriaé, Uberabinha, Sapucaí-Mirim, Doce and Todos os Santos Rivers from public databases. The invasion risk of each species was assessed through a model comprising nine parameters grouped in four variables: (i Invasiveness (thermal and dissolved oxygen ranges, diet, parental care or fecundity, (ii History of invasions (establishment, (iii Propagule pressure (commercial success, comprising annual frequency of occurrence and number of specimens available monthly at stores, and (iv Invasibility (water temperature and dissolved oxygen in the target river compatible with the species ranges. Of the 345 ornamental fish species for sale, 332 are non-native to either Minas Gerais (n = 151 or Brazil (n = 194. Based on the proposed cutting values, in particular the compatibility between species and recipient thermal ranges, five ornamental non-native species (Cyprinus rubrofuscus, Carassius auratus, Xiphophorus hellerii, Poecilia reticulata, and P. latipinna can potentially invade the Velhas and Muriaé Rivers, four species (Cyprinus rubrofuscus, Carassius auratus, X. helleri, and P. reticulata the Uberabinha River, four species (Cyprinus rubrofuscus, Carassius auratus, X. maculatus, and P. reticulata the Sapucaí-Mirim River, three species (Carassius auratus, X. hellerii, and P. reticulata the Doce River, and three species (Cyprinus rubrofuscus

  5. A critical period for gravitational effects on otolith formation

    Science.gov (United States)

    Wiederhold, M.; Harrison, J.

    Gravity and linear acceleration are sensed in fish by the saccule, utricle (as in mammals) and lagena, each with a solid otolith. Previous experiments in which eggs or larvae of a marine mollusk ( plysia) or fish larvae were raised on aA centrifuge, demonstrated that the size of the otolith or statoconia (in Aplysia) were reduced, in a graded manner, as the gfield was increased, suggesting that some- control mechanism was acting to normalize the weight of the mass. Pre-mated adult female swordtail fish (Xiphophorus helleri) were flown in the CEBAS aquarium system on space shuttle missions STS 89 and STS-90 (Neurolab). Developing- larvae were removed from the adult ovaries after shuttle landing. Otolith sizes were compared between ground- and flight -reared larvae of similar sizes. For later-stage swordtail larvae, with spine lengths from 3 to 6 mm from STS-90 (16 days), the growth of the otolith with increasing spine length was significantly greater in the flight - reared fish for all three otoliths, from the saccule (saggita), utricle (lapillus) and lagena (astericus). However, juvenile fish, 1 cm long at launch, showed no significant difference in otolith size between flight - and ground-reared animals. In very early stage larvae from STS-89 (9 days), with spine length of 1.5 to 3.5 mm, the utricular and saccular otoliths were actually larger in the ground-reared larvae. Thus, it appears that late-stage fish embryos reared in space do produce larger-than - normal otoliths, apparently in an attempt to c mpensate for the reduced weight ofo the test mass in space. However, the results from very early-stage larvae and juvenile fish suggest that there is a fairly short critical period during which altered gravity can affect the size of the test mass. Recent studies on the development of the inner ear of the zebrafish (Danio raria) may explain the critical period for gravitational effects on otolith growth. By 16 hours after zebrafish fertilization (at 28.5 o

  6. Novel laboratory approaches to multi-purpose aquatic bioregenerative closed-loop food production systems

    Science.gov (United States)

    Blüm, V.; Andriske, M.; Kreuzberg, K.; Paassen, U.; Schreibman, M. P.; Voeste, D.

    Based on the construction principle of the Closed Equilibrated Biological Aquatic System (C.E.B.A.S.) two novel combined animal-plant production systems were developed in laboratory scale the first of which is dedicated to mid-term operation in closed state up to two years. In principle both consist of the "classic" C.E.B.A.S. subcomponents: animal tank (Zoological Component), plant cultivators (Botanical Component), ammonia converting bacteria filter (Microbial Component) and data acquisition/control unit (Electronical Component). The innovative approach in the first system is the utilization of minimally three aquatic plant cultivators for different species. In this one the animal tank has a volume of about 160 liters and is constructed as an "endless-way system" surronding a central unit containing the heat exchanger and the bacteria filter with volumes of about 1.5 liters each. A suspension plant cultivator (1 liter) for the edible duckweed Wolffia arrhiza is externally connected. The second plant cultivator is a meandric microalgal bioreactor for filamentous green algae. The third plant growth facilitiy is a chamber with about 2.5 liters volume for cultivation of the "traditional" C.E.B.A.S. plant species, the rootless buoyant Ceratophyllum demersum. Both latter units are illuminated with 9 W fluorescent lamps. In the current experiment the animal tank contains the live-bearing teleost fish Xiphophorus helleri and the small pulmonate water snail Biomphalaria glabrata because their physiological adaptation to the closed system conditions is well known from many previous C.E.B.A.S. experiments. The water temperature is maintained at 25 °C and the oxygen level is regulated between 4 and 7 mg/1 by switching on and off the plant cultivator illuminations according to a suitable pattern thus utilizing solely the oxygen produced by photosynthesis. The animals and the micoorganisms of filter and bioflim provide the plants with a sufficient amount of carbon dioxide

  7. Aquatic modules for bioregenerative life support systems based on the C.E.B.A.S. biotechnology

    Science.gov (United States)

    Bluem, Volker; Paris, Frank

    2001-03-01

    Most concepts for bioregenerative life support systems are based on edible higher land plants which create some problems with growth and seed generation under space conditions. Animal protein production is mostly neglected because of the tremendous waste management problems with tetrapods under reduced weightlessness. Therefore, the "Closed Equilibrated Biological Aquatic System" (C.E.B.A.S.) was developed which represents an artificial aquatic ecosystem containing aquatic organisms which are adpated at all to "near weightlessness conditions" (fishes Xiphophorus helleri, water snails Biomphalaria glabrata, ammonia oxidizing bacteria and the rootless non-gravitropic edible water plant Ceratophyllum demersum). Basically the C.E.B.A.S. consists of 4 subsystems: a ZOOLOGICASL COMPONENT (animal aquarium), a BOTANICAL COMPONENT (aquatic plant bioreactor), a MICROBIAL COMPONENT (bacteria filter) and an ELECTRONICAL COMPONENT (data acquisition and control unit). Superficially, the function principle appears simple: the plants convert light energy into chemical energy via photosynthesis thus producing biomass and oxygen. The animals and microorganisms use the oxygen for respiration and produce the carbon dioxide which is essential for plant photosynthesis. The ammonia ions excreted by the animals are converted by the bacteria to nitrite and then to nitrate ions which serve as a nitrogen source for the plants. Other essential ions derive from biological degradation of animal waste products and dead organic matter. The C.E.B.A.S. exists in 2 basic versions: the original C.E.B.A.S. with a volume of 150 liters and a self-sustaining standing time of more than 13 month and the so-called C.E.B.A.S. MINI MODULE with a volume of about 8.5 liters. In the latter there is no closed food loop by reasons of available space so that animal food has to be provided via an automated feeder. This device was flown already successfully on the STS-89 and STS-90 spaceshuttle missions and the

  8. The C.E.B.A. Mini Module on the STS-107 Mission: Data of Ground Experiments and Preliminary Results of the third Spaceflight of an Artificial Aquatic Ecosystem

    Science.gov (United States)

    Bluem, V.; Paris, F.; Bungart, S.

    The C.E.B.A.S MINI MODULE is the miniaturized version of an artificial aquatic ecosystem consisting of four subcomponents: a ZOOLOGICAL COMPONENT (aquarium for animals), a BOTANICAL COMPONENT (higher water plant bioreactor), a MICROBIAL COMPONENT (bacteria filter) and an ELECTRONICAL COMPONENT (data acquisition, control unit). It has a total volume of 8.6 liters and contains the ovoviviparous teleost Xiphophorus helleri (swordtail), larvae of the ovuliparous cichlid fish Oreochromis mossambicus, the pulmonate water snail Biomphalaria glabrata, the rootless (non-graivitropic) higher water plant Ceratophyllum demersum (hornweed) and special strains of ammonia oxidizing bacteria. This device was already flown twice successfully in space with the space shuttle missions STS- 89 and STS-90 (NEUROLAB) in 1998. It will fly a third time with the STS-107-mission the launch of which has been repeatedly shifted December 222, April 2001, October 2001) and is now finally scheduled for June 2002. The main focus of scientific interest in the past missions were system performance, reproductive biology (reproductive function of adult females including endocrine system, fertilization, gonadal development in juveniles), vestibular and immunological research in X. helleri, embryology and shell formation in B. glabrata, general morphology and physiology of C. demersum and groth rates of the bacteria. The standard load of the system were 4 adult and 200 neonate X. helleri, 30 adult B. glabrata and 30 g of C. demersum. The evaluation of these experiments showed that all reproductive functions and the immune system of the fishes snails remained undisturbed in space, that the snails developed normally and exhibited no disturbance of shell formation and that the plants showed growth and photosynthesis rates comparable to those on Earth. So, as a logical continuation, the main topics for the STS-107 mission are the remaining important questions in X. helleri biology: puberty, male sexual