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Christine Dreyer - One of the best experts on this subject based on the ideXlab platform.

  • the genome of the trinidadian guppy Poecilia reticulata and variation in the guanapo population
    PLOS ONE, 2016
    Co-Authors: Axel Kunstner, Verena A. Kottler, Detlef Weigel, Margarete Hoffmann, Eshita Sharma, Bonnie A Fraser, Christine Dreyer
    Abstract:

    For over a century, the live bearing guppy, Poecilia reticulata, has been used to study sexual selection as well as local adaptation. Natural guppy populations differ in many traits that are of intuitively adaptive significance such as ornamentation, age at maturity, brood size and body shape. Water depth, light supply, food resources and predation regime shape these traits, and barrier waterfalls often separate contrasting environments in the same river. We have assembled and annotated the genome of an inbred single female from a high-predation site in the Guanapo drainage. The final assembly comprises 731.6 Mb with a scaffold N50 of 5.3 MB. Scaffolds were mapped to linkage groups, placing 95% of the genome assembly on the 22 autosomes and the X-chromosome. To investigate genetic variation in the population used for the genome assembly, we sequenced 10 wild caught male individuals. The identified 5 million SNPs correspond to an average nucleotide diversity (π) of 0.0025. The genome assembly and SNP map provide a rich resource for investigating adaptation to different predation regimes. In addition, comparisons with the genomes of other Poeciliid species, which differ greatly in mechanisms of sex determination and maternal resource allocation, as well as comparisons to other teleost genera can begin to reveal how live bearing evolved in teleost fish.

  • adenylate cyclase 5 is required for melanophore and male pattern development in the guppy Poecilia reticulata
    Pigment Cell & Melanoma Research, 2015
    Co-Authors: Verena A. Kottler, Iris Koch, Matthias Flötenmeyer, Detlef Weigel, Margarete Hoffmann, Axel Kunstner, Tobias Langenecker, Eshita Sharma, Christine Dreyer
    Abstract:

    Summary Guppies (Poecilia reticulata) are colorful fish that have attracted the attention of pigmentation researchers for almost a century. Here, we report that the blond phenotype of the guppy is caused by a spontaneous mutation in the guppy ortholog of adenylate cyclase 5 (adcy5). Using double digest restriction site-associated DNA sequencing (ddRADseq) and quantitative trait locus (QTL) mapping, we linked the blond phenotype to a candidate region of 118 kb, in which we subsequently identified a 2-bp deletion in adcy5 that alters splicing and leads to a premature stop codon. We show that adcy5, which affects life span and melanoma growth in mouse, is required for melanophore development and formation of male orange pigmentation traits in the guppy. We find that some components of the male orange pattern are particularly sensitive to loss of Adcy5 function. Our work thus reveals a function for Adcy5 in patterning of fish color ornaments.

  • Multiple pigment cell types contribute to the black, blue, and orange ornaments of male guppies (Poecilia reticulata)
    PLoS ONE, 2014
    Co-Authors: Verena A. Kottler, Iris Koch, Matthias Flötenmeyer, Hisashi Hashimoto, Detlef Weigel, Christine Dreyer
    Abstract:

    The fitness of male guppies (Poecilia reticulata) highly depends on the size and number of their black, blue, and orange ornaments. Recently, progress has been made regarding the genetic mechanisms underlying male guppy pigment pattern formation, but we still know little about the pigment cell organization within these ornaments. Here, we investigate the pigment cell distribution within the black, blue, and orange trunk spots and selected fin color patterns of guppy males from three genetically divergent strains using transmission electron microscopy. We identified three types of pigment cells and found that at least two of these contribute to each color trait. Further, two pigment cell layers, one in the dermis and the other in the hypodermis, contribute to each trunk spot. The pigment cell organization within the black and orange trunk spots was similar between strains. The presence of iridophores in each of the investigated color traits is consistent with a key role for this pigment cell type in guppy color pattern formation.;

  • natural variation of male ornamental traits of the guppy Poecilia reticulata
    Zebrafish, 2008
    Co-Authors: Namita Tripathi, Margarete Hoffmann, Christine Dreyer
    Abstract:

    Abstract Male ornamental traits of the guppy, Poecilia reticulata, provide an outstanding example of natural variation in sex-linked male-advantageous traits that are shaped by both sexual and environmental selection. A substantial fraction of the underlying genes is known to be genetically linked to the sex-determining region on the differentiating Y-chromosome. Intercrosses between parental populations originating from geographically distant locations in East Trinidad and Cumana (Venezuela) were used to study segregation of ornamental traits in male progeny. In addition, we performed backcrosses to compare segregation of ornaments in presence or absence of prominent traits linked to the Y-chromosome. Another backcross strategy involving XY females from the laboratory strain zebrinus maculatus allowed studying additive and dominant effects of alleles on two different Y-chromosomes on pattern formation. For genetic mapping, we have previously developed nuclear SNP markers linked to expressed genes, includ...

  • ests and est linked polymorphisms for genetic mapping and phylogenetic reconstruction in the guppy Poecilia reticulata
    BMC Genomics, 2007
    Co-Authors: Christine Dreyer, Margarete Hoffmann, Namita Tripathi, Christa Lanz, Evamaria Willing, Markus Riester, Norman Warthmann, Andrea Sprecher, Stefan R Henz, Detlef Weigel
    Abstract:

    Background The guppy, Poecilia reticulata, is a well-known model organism for studying inheritance and variation of male ornamental traits as well as adaptation to different river habitats. However, genomic resources for studying this important model were not previously widely available.

David N. Reznick - One of the best experts on this subject based on the ideXlab platform.

  • Linking reproduction, locomotion, and habitat use in the Trinidadian guppy (Poecilia reticulata)
    Oecologia, 2016
    Co-Authors: Amanda I. Banet, Jon C. Svendsen, David N. Reznick
    Abstract:

    Pregnancy inhibits locomotion, increases predation risk and may translate into reduced survival. The extent to which animals modify behavior in the wild to compensate for the locomotor costs of pregnancy remains poorly understood. We have investigated how reproductive allocation (RA—the proportion of body mass devoted to reproduction) affects locomotor performance and habitat use in Trinidadian guppy ( Poecilia reticulata ) populations from low- and high-predation regimes. During steady swimming, females with high RA had increased tail beat amplitudes, indicating increased swimming costs. Females with high RA also exhibited slower escape velocities, which may result in an increased risk of predation. In low-predation localities, females with high RA used habitats with a lower water velocity, suggesting that females may be modifying behavior to offset the locomotor costs of pregnancy. Habitat use in high-predation localities was severely restricted to areas without predators, which had a relatively slower water velocity with little or no variation in current. These results provide a link between the performance-related costs of reproduction and behavior in a natural setting and show that animals may compensate for reproductive traits that constrain locomotor performance by modifying habitat use.

  • direct and indirect ecosystem effects of evolutionary adaptation in the trinidadian guppy Poecilia reticulata
    The American Naturalist, 2012
    Co-Authors: Ronald D Bassar, Regis Ferriere, Andres Lopezsepulcre, Michael C Marshall, Joseph Travis, Catherine M Pringle, David N. Reznick
    Abstract:

    Abstract Ecological and evolutionary processes may interact on the same timescale, but we are just beginning to understand how. Several studies have examined the net effects of adaptive evolution on ecosystem properties. However, we do not know whether these effects are confined to direct interactions or whether they propagate further through indirect ecological pathways. Even less well understood is how the combination of direct and indirect ecological effects of the phenotype promotes or inhibits evolutionary change. We coupled mesocosm experiments and ecosystem modeling to evaluate the ecological effects of local adaptation in Trinidadian guppies (Poecilia reticulata). The experiments show that guppies adapted to life with and without predators alter the ecosystem directly through differences in diet. The ecosystem model reveals that the small total indirect effect of the phenotype observed in the experiments is likely a combination of several large indirect effects that act in opposing directions. The...

  • juvenile compensatory growth has negative consequences for reproduction in trinidadian guppies Poecilia reticulata
    Ecology Letters, 2010
    Co-Authors: Sonya K Auer, Jeff Arendt, Radhika Chandramouli, David N. Reznick
    Abstract:

    Compensatory or 'catch-up' growth may be an adaptive mechanism that buffers the growth trajectory of young organisms from deviations caused by reduced food availability. Theory generally assumes that rapid juvenile compensatory growth impacts reproduction only through its positive effects on age and size at maturation, but potential reproductive costs to juvenile compensatory growth remain virtually unexplored. We used a food manipulation experiment to examine the reproductive consequences of compensatory growth in Trinidadian guppies (Poecilia reticulata). Compensatory growth did not affect adult growth rates, litter production rates or investment in offspring size. However, compensatory growth had negative effects on litter size, independent of the effects of female body length, resulting in a 20% decline in offspring production. We discuss potential mechanisms behind this observed cost to reproduction.

  • predicting the direction of ornament evolution in trinidadian guppies Poecilia reticulata
    Proceedings of The Royal Society B: Biological Sciences, 2009
    Co-Authors: Darrell J Kemp, David N. Reznick, John A Endler, Gregory F Grether
    Abstract:

    Sexual selection is thought to be opposed by natural selection such that ornamental traits express a balance between these two antagonistic influences. Phenotypic variation among populations may indicate local shifts in this balance, or that different stable ‘solutions’ are possible, but testing these alternatives presents a major challenge. In the guppy (Poecilia reticulata), a small freshwater fish with male-limited ornamental coloration, these issues can be addressed by transplanting fish among sites of varying predation pressure, thus effectively manipulating the strength and nature of natural selection. Here, we contrast the evolutionary outcome of two such introductions conducted in the Trinidadian El Cedro and Aripo Rivers. We use sophisticated colour appraisal methods that account for full spectrum colour variation and which incorporate the very latest visual sensitivity data for guppies and their predators. Our data indicate that ornamentation evolved along different trajectories: whereas Aripo males evolved more numerous and/or larger orange, black and iridescent markings, El Cedro males only evolved more extensive and brighter iridescence. Examination of the El Cedro experiment also revealed little or no ornamental evolution at the control site over 29 years, which contrasts markedly with the rapid (approx. 2–3 years) changes reported for introduction populations. Finally, whole colour-pattern analysis suggested that the greatest visual difference between El Cedro introduction and control fish would be perceived by the two most salient viewers: guppies and the putatively dangerous predator Crenicichla alta. We discuss whether and how these evolutionary trajectories may result from founder effects, population-specific mate preferences and/or sensory drive.

  • can commercial fishing cause evolution answers from guppies Poecilia reticulata
    Canadian Journal of Fisheries and Aquatic Sciences, 2005
    Co-Authors: David N. Reznick, Cameron K Ghalambor
    Abstract:

    Life history theory predicts that high adult mortality rates select for earlier maturity and increased reproduc- tion. If such evolution occurs in response to the commercial exploitation of natural fish populations, then the correlated reduction in body size would reduce the yield of the fishery. Earlier maturity and reduced body size are seen in com- mercially exploited populations. Here, we compare the life histories of natural populations of guppies (Poecilia reticulata) from Trinidad that live in either high- or low-predation environments, which serve as surrogates for the presence or absence of commercial fishing. We can quantify mortality rate and life history variables, including age and size at maturity, in the laboratory and in nature. We have manipulated mortality rates in nature and measured the rate of evolution. High mortality selects for earlier maturity at a smaller size, as observed in commercial fisheries and as predicted by theory. Furthermore, the nature and magnitude of predator-induced mortality are comparable to those caused by commercial fishing. The rate of evolution in guppies predicts similar evolution in commercial fisheries on a time scale of decades. These attributes support arguments that humans, like predators, have acted as an agent of selec- tion when exploiting populations of fish. Resume : La theorie demographique predit qu'une forte mortalite des adultes entraine la selection d'une maturite precoce et d'une reproduction accrue. Si une telle selection se produisait en reaction a l'exploitation commerciale des populations naturelles de poissons, la reduction de la taille corporelle, un effet en correlation, reduirait le rendement de la peche. La maturation precoce et la taille reduite s'observent dans les populations exploitees commercialement. Nous comparons ici les cycles biologiques de populations naturelles de guppys (Poecilia reticulata) de Trinidad qui vivent dans des milieux de forte ou de faible predation, ce qui sert ici de phenomene de remplacement pour la presence ou l'absence de peche commerciale. Nous pouvons mesurer le taux de mortalite et les variables demographiques, en parti- culier l'âge et la taille a la maturite, en laboratoire et en nature. Nous avons manipule les taux de mortalite en nature et mesure le taux d'evolution. Une forte mortalite entraine la selection d'une maturite a une taille reduite comme on l'observe dans les peches commerciales, en accord avec la theorie. De plus, la nature et l'importance de la mortalite induite par les predateurs sont comparables a celles causees par la peche commerciale. Le taux d'evolution observe chez les guppys permet de predire une evolution semblable dans les peches commerciales sur une echelle de decennies. Ces caracteristiques appuient les arguments qui veulent que les humains, tout comme les predateurs, aient agi comme agents de selection naturelle en exploitant les populations de poissons. (Traduit par la Redaction) Reznick and Ghalambor 801

Darren P. Croft - One of the best experts on this subject based on the ideXlab platform.

  • intraspecific variation in inhibitory motor control in guppies Poecilia reticulata
    Journal of Fish Biology, 2021
    Co-Authors: Alessandro Macario, Safi K Darden, Frederick Verbruggen, Darren P. Croft
    Abstract:

    Inhibitory control (IC) is the ability to overcome impulsive or prepotent but ineffective responses in favour of more appropriate behaviours. The ability to inhibit internal predispositions or external temptations is vital in coping with a complex and variable world. Traditionally viewed as cognitively demanding and a main component of executive functioning and self-control, IC was historically examined in only a few species of birds and mammals but recently a number of studies has shown that a much wider range of taxa rely on IC. Furthermore, there is growing evidence that inhibitory abilities may vary within species at the population and individual levels owing to genetic and environmental factors. Here we use a detour-reaching task, a standard paradigm to measure motor inhibition in nonhuman animals, to quantify patterns of interindividual variation in IC in wild-descendant female guppies, Poecilia reticulata. We found that female guppies displayed inhibitory performances that were, on average, half as successful as the performances reported previously for other strains of guppies tested in similar experimental conditions. Moreover, we showed consistent individual variation in the ability to inhibit inappropriate behaviours. Our results contribute to the understanding of the evolution of fish cognition and suggest that IC may show considerable variation among populations within a species. Such variation in IC abilities might contribute to individual differences in other cognitive functions such as spatial learning, quantity discrimination or reversal learning.

  • sex matters a social context to boldness in guppies Poecilia reticulata
    Behavioral Ecology, 2010
    Co-Authors: Jens Krause, Chantima Piyapong, Ben B Chapman, Indar W Ramnarine, Vasilis Louca, Darren P. Croft
    Abstract:

    Boldness is a key element of behavioral variation in animals. Many studies have shown variation between individuals in their propensity to take risks across a wide range of taxa, yet surprisingly few studies have investigated the importance of social context in influencing an animal’s boldness. Here, we focus on the role that the sex composition of a social group plays in individual boldness in a sexually dimorphic species, the Trinidadian guppy (Poecilia reticulata). We predict that after exposure to a simulated aerial predator, male guppies should be bolder in the presence of females compared with males to maximize their mating opportunities. Furthermore, we predict that female guppies will adopt riskier behavior when shoaling with males in an effort to avoid sexual harassment. Using a model avian predator, we tested these hypotheses and found evidence to support our second prediction but not our first. Specifically, we found that male guppies returned to movement more rapidly after a fright response when shoaling with males than with females. Female focal fish in contrast returned to movement significantly quicker when shoaling with males than females. Also, we found a significant correlation in boldness across social contexts (a behavioral syndrome) in male but not female fish. This study highlights the importance of social context for individual boldness and suggests that for risk-averse behavior in social, sexually dimorphic species, sex matters. Key words: behavioral syndrome, behavioral type, guppy, personality, Poecilia reticulata, predation. [Behav Ecol]

  • social structure and co operative interactions in a wild population of guppies Poecilia reticulata
    Behavioral Ecology and Sociobiology, 2006
    Co-Authors: Darren P. Croft, Richard James, P O R Thomas, C Hathaway, D Mawdsley, Kevin N Laland, Jens Krause
    Abstract:

    In contrast to the substantial number of theoretical papers that have examined the mechanisms by which cooperation may evolve, very few studies have investigated patterns of co-operation in natural animal populations. In the current study, we use a novel approach, social network analysis, to investigate the structure of co-operative interactions in the context of predator inspection in a wild population of guppies (Poecilia reticulata). Female guppies showed social preferences for stable partners, fulfilling a key assumption made by models of reciprocity. In the laboratory, wild female guppies disproportionately engaged in predator inspection with others with whom they had strong social associations. Furthermore, pairs of fish that frequently engaged in predator inspection did so in a particularly co-operative way, potentially reducing costs associated with predator inspection. Taken together, these results provide evidence for assortative interactions forming the basis of co-operation during predator inspection in a natural fish population. The occurrence of highly interconnected social networks between stable partners suggests the existence of co-operation networks in free-ranging populations of the guppy.

  • Social networks in the guppy (Poecilia reticulata).
    Proceedings of The Royal Society B: Biological Sciences, 2004
    Co-Authors: Darren P. Croft, Jens Krause, Richard James
    Abstract:

    Social network theory is used to elicit details of the social structure of a population of free-ranging guppies, Poecilia reticulata. They were found to have a complex and highly structured social network, which exhibited characteristics consistent with the 'small world' phenomenon. Stable partner associations between individuals were observed, a finding that fulfils the basic prerequisite for the evolution of reciprocal altruism. The findings are discussed in relation to the ecology and evolution of the wild population, highlighting the potential application of network theory to social associations in animals.

  • sex biased movement in the guppy Poecilia reticulata
    Oecologia, 2003
    Co-Authors: Darren P. Croft, Brett Albanese, Bethany J Arrowsmith, Marc S Botham, M M Webster, Jens Krause
    Abstract:

    The movement strategies of birds and mammals are often closely linked to their mating system, but few studies have examined the relationship between mating systems and movement in fishes. We examined the movement patterns of the guppy (Poecilia reticulata) in the Arima river of Trinidad and predicted that sexual asymmetry in reproductive investment would result in male-biased movement. Since male guppies maximize their reproductive success by mating with as many different females as possible, there should be strong selection for males to move in search of mates. In agreement with our prediction, the percentage of fish that emigrated from release pools was higher for males than females (27.3% vs. 6.9%, respectively). Sex ratio was highly variable among pools and may influence a male's decision to emigrate or continue moving. We also detected a positive relationship between body length and the probability of emigration for males and a significant bias for upstream movement by males. Among the few females that did emigrate, a positive correlation was observed between body length and distance moved. Sex-biased movement appears to be related to mating systems in fishes, but the evidence is very limited. Given the implications for ecology, evolution, and conservation, future studies should explicitly address the influence of sex and mating systems on movement patterns.

Andrea Pilastro - One of the best experts on this subject based on the ideXlab platform.

  • sperm number and velocity affect sperm competition success in the guppy Poecilia reticulata
    Behavioral Ecology and Sociobiology, 2011
    Co-Authors: Chiara Boschetto, Clelia Gasparini, Andrea Pilastro
    Abstract:

    While both sperm number and quality are now recognized to be important in determining the outcome of sperm competition, very few studies have experimentally assessed the influence of these two parameters simultaneously. We studied the effect of sperm quality and number on competitive fertilization success in an internal-fertilizing fish, the guppy (Poecilia reticulata), which is characterized by high levels of sperm competition. We artificially inseminated virgin females with varying proportion of sperm from two competing males, while holding constant the total number of sperm transferred to the female. Sperm morphology and sperm swimming velocity were also determined prior to insemination. The paternity outcome of sperm competition trials was assessed through molecular analyses of the resulting offspring using polymorphic microsatellite loci. We found that both sperm number and sperm velocity affected the outcome of sperm competition, with males that contributed more and faster sperm achieving a greater paternity share.

  • effect of male age on sperm traits and sperm competition success in the guppy Poecilia reticulata
    Journal of Evolutionary Biology, 2010
    Co-Authors: Clelia Gasparini, Chiara Boschetto, Ilaria A M Marino, Andrea Pilastro
    Abstract:

    Deleterious mutations can accumulate in the germline with age, decreasing the genetic quality of sperm and imposing a cost on female fitness. If these mutations also affect sperm competition ability or sperm production, then females will benefit from polyandry as it incites sperm competition and, consequently, minimizes the mutational load in the offspring. We tested this hypothesis in the guppy (Poecilia reticulata), a species characterized by polyandry and intense sperm competition, by investigating whether age affects post-copulatory male traits and sperm competition success. Females did not discriminate between old and young males in a mate choice experiment. While old males produced longer and slower sperm with larger reserves of strippable sperm, compared to young males, artificial insemination did not reveal any effect of age on sperm competition success. Altogether, these results do not support the hypothesis that polyandry evolved in response to costs associated with mating with old males in the guppy.

  • insemination efficiency of two alternative male mating tactics in the guppy Poecilia reticulata
    Proceedings of The Royal Society B: Biological Sciences, 1999
    Co-Authors: Andrea Pilastro, Angelo Bisazza
    Abstract:

    In this study we compared the insemination efficiency of two alternative mating tactics (courtship and sneak mating) in the guppy Poecilia reticulata by quantifying the number of sperm delivered during a copulation. During a single copulation, guppies delivered between zero and 92% of the sperm available, as determined by mechanically stripping the male's sperm reserve at rest. The absolute number of sperm delivered after courtship was three times larger than that delivered through sneak mating; nonetheless, the variance was large with both tactics and the two distributions largely overlapped. The number of sperm available at rest increased with male size. With both tactics, the number of sperm delivered was positively correlated with the sperm available. Contrary to courtship copulations, in sneak copulations there was no correlation between the number of sperm delivered and male size. However, once the data were standardized for sperm reserve, small males delivered a larger proportion of their available sperm during sneak copulation. The rate of sexual acts (sigmoid and thrust rate) before copulation was not correlated with the number of sperm available. After the occurrence of a copulation in both the courtship and sneak copulation groups, the sexual activity of the male decreased in proportion to the amount of sperm he previously inseminated.

Oner Kocak - One of the best experts on this subject based on the ideXlab platform.

  • investigation of acute toxicity of deltamethrin on guppies Poecilia reticulata
    Ecotoxicology and Environmental Safety, 2003
    Co-Authors: Rukiye Viran, Figen Erkoc, Hilal Polat, Oner Kocak
    Abstract:

    Deltamethrin, a synthetic pyrethroid pesticide contaminating aquatic ecosystems as a potential toxic pollutant, was investigated in the present study for acute toxicity. Guppy fish (Poecilia reticulata) were selected for the bioassay experiments. The 48-h LC50 was determined for the guppies. The experiments were repeated three times and a total of 210 guppies were used. The static test method of acute toxicity test was used. In addition, behavioral changes at each deltamethrin concentration were determined for the individuals. Data obtained from the deltamethrin acute toxicity tests were evaluated using the Probit Analysis Statistical Method. The 48-h LC50 value for guppy was estimated as 5.13 microg/L.

  • investigation of acute toxicity of permethrin on guppies Poecilia reticulata
    Chemosphere, 2003
    Co-Authors: Sibel Baser, Figen Erkoc, Mahmut Selvi, Oner Kocak
    Abstract:

    Permethrin, a synthetic pyrethroid pesticide and potential toxic pollutant contaminating aquatic ecosystems, was investigated in the present study for acute toxicity. Guppy fish (Poecilia reticulata) were selected for the bioassay experiments. The experiments were repeated 3 times and the 48-h LC50 was determined for the guppies. The static test method of acute toxicity test was used. Water temperature was regulated at 20 � 1 C. In addition, behavioral changes at each permethrin concentration were observed for the individual fish. Data obtained from the permethrin acute toxicity tests were evaluated using the probit analysis statistical method. The 48-h LC50 value for guppy was estimated as 245.7 lg/l. Values in the range of 0.05–97.0 lg/l have been reported for various other fish species. 2003 Elsevier Science Ltd. All rights reserved.

  • investigation of acute toxicity of permethrin on guppies Poecilia reticulata
    Chemosphere, 2003
    Co-Authors: Sibel Baser, Figen Erkoc, Mahmut Selvi, Oner Kocak
    Abstract:

    Permethrin, a synthetic pyrethroid pesticide and potential toxic pollutant contaminating aquatic ecosystems, was investigated in the present study for acute toxicity. Guppy fish (Poecilia reticulata) were selected for the bioassay experiments. The experiments were repeated 3 times and the 48-h LC(50) was determined for the guppies. The static test method of acute toxicity test was used. Water temperature was regulated at 20+/-1 degrees C. In addition, behavioral changes at each permethrin concentration were observed for the individual fish. Data obtained from the permethrin acute toxicity tests were evaluated using the probit analysis statistical method. The 48-h LC(50) value for guppy was estimated as 245.7 microg/l. Values in the range of 0.05-97.0 microg/l have been reported for various other fish species.

  • investigation of acute toxicity of beta cypermethrin on guppies Poecilia reticulata
    Chemosphere, 2002
    Co-Authors: Hilal Polat, Rukiye Viran, Figen Erkoc, Oner Kocak
    Abstract:

    Beta-cypermethrin, a synthetic pyrethroid pesticide and potential toxic pollutant, contaminating aquatic ecosystems was investigated in the present study for acute toxicity. Guppy fish (Poecilia reticulata) was selected for the bioassay experiments. The experiments were repeated three times and the 48-h LC50 was determined for the guppies. The static test method of acute toxicity test was used. Water temperature was regulated at 22 +/- 1 degrees C. In addition, behavioral changes at each beta-cypermethrin concentration were observed for the individual fish. Data obtained from the beta-cypermethrin acute toxicity tests were evaluated using the probit analysis statistical method. The 48-h LC50 value for guppy was estimated as 21.4 microg/l.