Poeciliidae

Studying the mechanisms by which immature males learn courtship behaviour is essential to our understanding of the evolution of different mating strategies, yet generally this has been neglected. Here I demonstrate an effect of early social experience on the sexual behaviour of male guppies, Poecilia reticulata. I tested whether the social rearing environment (visual access to females only, males only or both males and females) affects males' sexual performance, including the time and frequency of courtship displays and forced copulation attempt frequency. I conducted trials in which focal male guppies were allowed to interact with a female. Males that experienced early social interactions with mature males performed significantly longer courtship displays than males that grew up without observing other males. This result suggests that young males learn to court efficiently by observing other males courting. Males raised with females performed more forced copulation attempts, possibly because males might need to physically interact with females in order to learn to strategically alternate courtship displays and forced copulation attempts. Early social interactions may play a stronger role in the structure of the mating system in guppies than previously recognized, and might contribute to the differences in sexual behaviour observed between different populations of guppies.

A bibliometric analysis was conducted in order to investigate the research trends and needs of the 111 species of Mexican Poeciliidae, Goodeidae and Cyprinidae at risk listed in the Mexican Red List (NOM-­059-­SEMARNAT-­2010) and the IUCN Red List. We search for abstracts from the ISI Web of Knowledge database using comprehensive and accurate terms regarding our targeted species. We obtained temporal variation of publication frequency by species and, classified and analyzed bibliographic records by the main topics following a modified criterion used by the Sociedad Ictiologica Mexicana. Further, we analyzed conservation related topics by states and years to be able to identify spatio-­‐temporal trends of conservation research in Mexico. We found that the scientific production regarding these species was low (Np= 642) and it was mainly focused on cyprinids and basic science topics such as Development and Morphophysiology, Ecology and Genetics and Evolution. Scientific production has increased since the late 80's in all topics excepting Taxonomic studies. Twenty-­six fish species endemic to Mexico did not register any publication, whereas seven species accounted for nearly 50% of the records, being Ameca splendens and Xenotoca eiseni two of the most studied. Other commonly studied species were Poecilia velifera and Girardinichthys multiradiatus. Conservation related research began in 1985 and is practically inexistent in Mexico (Np= 37); it has been conducted almost entirely with goodeids in the Mesa Central region (Jalisco and Michoacan). This study highlights the needing of conduct research with the less studied species (e.g. Allotoca maculata and Xiphophorus gordoni) and encourage their publication due that lack of knowledge about imperiled species limits their conservation. More studies in applied science such as recovering programs, stock enhancement, captive breeding, translocation, habitat restoration, and invasive species control are needed to enhance the current conservation efforts.

Specialization is fundamentally important in biology because specialized traits allow species to expand into new environments, in turn promoting population differentiation and speciation. Specialization often results in trade-offs between traits that maximize fitness in one environment but not others. Despite the ubiquity of trade-offs, we know relatively little about how consistently trade-offs evolve between populations when multiple sets of populations experience similarly divergent selective regimes. In the present study, we report a case study on Brachyrhaphis fishes from different predation environments. We evaluate apparent within/between population trade-offs in burst-speed and endurance at two levels of evolutionary diversification: high-and low-predation populations of Brachyrhaphis rhabdophora, and sister species Brachyrhaphis roseni and Brachyrhaphis terrabensis, which occur in high-and low-predation environments, respectively. Populations of Brachyrhaphis experiencing different predation regimes consistently evolved swimming specializations indicative of a trade-off between two swimming forms that are likely highly adaptive in the environment in which they occur. We show that populations have become similarly locally adapted at both levels of diversification, suggesting that swimming specialization has evolved rather rapidly and persisted post-speciation. Our findings provide valuable insight into how local adaptation evolves at different stages of evolutionary divergence.

We evaluated the establishment of the ornamental non-native guppy Poecilia reticulata bimonthly from November 2006 to October 2007 in an urban reservoir located in the city of Belo Horizonte, Southeastern Brazil. Females were found in reproduction during almost all the sampling period. The fecundity was always low. For the total period, we found more females than males, and the number of juveniles in all periods was higher than adults. There was no correlation between water temperature, rainfall and reproduction. Of the five stages of biological invasion, the species was at least in the stage three: establishment through reproduction and recruitment. Management recommendations, such as prohibition on sales of P. reticulata by local aquarium trade, and awareness campaigns with wholesalers, retailers and hobbyists showing that aquarium dumping is an environmental crime are suggested to avoid introductions of P. reticulata in the region.

The first records of sympatric populations of the poorly studied sister species Brachyrhaphis roseni and Brachyrhaphis terrabensis are presented. Sympatric populations were found in a total of 14 localities in four river drainages throughout the Pacific slopes of western Panama, and they occurred in a wide range of elevations, from 90 to 651 m. These data expand the elevation range of each species, and provide the first case of sympatric sister species within the genus.

Since 1997, Poeciliopsis infans Woolman 1894 has been recognized as a new inhabitant of Lake Patzcuaro, Michoacan in Central Mexico. Between February 1997 and October 1998, nine fish samples were collected at Lake Patzcuaro. Morphometric and meristic counts were conducted on a random selection of 40 organisms of both sexes of Poeciliopsis infans. Males of these viviparous fish posses a modified anal fin called gonopodium. The characteristic hemal spine on the 18th caudal vertebra for this species is described herein and the bony components of the gonopodial structure and suspensoria that together comprise the gonopodial system, which is important for taxonomic studies at various levels of classification were reviewed. Poeciliopsis infans displays a high degree of sexual dimorphism in body shape and anal fin anatomy with the most conspicuous difference observed in anal fin height, which averages 40% of SI in males and 17% in females. Comparisons between male and female anal fins are ...

Members of the genus Poecilia exhibit extensive morphological, behavioral, and life history variation within and between species. This natural variation, coupled with short generation times and the ease with which members of this genus can be cultured in the lab, have made several species model systems for studying the effects of sexual and natural selection on the evolution of natural populations. Given that there is no clear understanding of the phylogenetic relationships within the genus, these studies have not been put into a ...

How selection acts to drive trait evolution at different stages of divergence is of fundamental importance in our understanding of the origins of biodiversity. Yet, most studies have focused on a single point along an evolutionary trajectory. Here, we provide a case study evaluating the strength of divergent selection acting on life-history traits at early-versus-late stages of divergence in Brachyrhaphis fishes. We find that the difference in selection is stronger in the early-diverged population than the late-diverged population, and that trait differences acquired early are maintained over time.

En 2013, la Secretaría de Medio Ambiente y Recursos Naturales inició el proceso de actualización de la lista de especies en riesgo de México (NOM-­059-­SEMARNAT-­2010). Al respecto, la CONABIO inició un trabajo de colaboración con diversos ictiólogos especialistas en poecílidos, goodeidos y ciprínidos para determinar el grado de vulnerabilidad de 92 especies por medio del Método de Evaluación del Riesgo de Extinción (MER). Para recopilar la información necesaria, se diseñó una encuesta en línea y se consultó a 43 especialistas. Nueve de ellos aportaron información para 22 especies, que fue complementada con datos del Sistema de Especies Prioritarias de la CONABIO y de la literatura científica disponible. Se elaboraron mapas de distribución por especie utilizando registros del Sistema Nacional de Información sobre Biodiversidad (SNIB), así como datos inéditos proporcionados por los especialistas. Siete propuestas de ratificación y cambio de categoría de riesgo fueron presentadas. En ellas, se ratifica a los peces microendémicos Allotoca goslinei y Ameca splendens como en  Peligro de Extinción (P), al igual que Girardinichthys viviparus, pez endémico de la cuenca lacustre del Valle de México. Poecilia velifera resultó correctamente evaluada como Amenazada (A). Algansea aphanea (restringida a dos localidades) subió de categoría de A a P, al igual que Algansea popoche, que ha sido severamente afectada por la alteración de su hábitat y la sobrepesca en el Lago de Chapala. El poecílido Priapella bonita, no colectado desde 1950, fue propuesto como una especie Probablemente Extinta en el Medio Silvestre (E). Finalmente, después de la revisión del grupo de trabajo del sector ambiental gubernamental y de un comité de especialistas, las propuestas fueron aprobadas. Este ejercicio es un buen ejemplo de que si bien la información para los peces en riesgo es muy escasa, ésta puede utilizarse para evaluar su estado de riesgo y asegurar su protección legal.

The effect of divergent natural selection on the evolution of behavioral traits has long been a focus of behavioral ecologists. Predation, due to its ubiquity in nature and strength as a selective agent, has been considered an important environmental driver of behavior. Predation is often confounded with other environmental factors that could also play a role in behavioral evolution. For example, environments that contain predators are often more ecologically complex and 'risky' (i.e., exposed, dangerous). Previous work shows that individuals from risky environments are often more bold, active, and explorative than those from low-risk environments. To date, most comparative studies of environmentally driven behavioral divergence are limited to comparisons among populations within species that occur in divergent selective environments, but neglect comparisons between species following speciation. This limits our understanding of how behavior evolves post-speciation. The Central American livebearing fish genus Brachyrhaphis provides an ideal system for examining the relationship between selective environments and behavior, within and between species. Here, we test for differences in boldness between sister species B. roseni and B. terrabensis that occur in streams with and without piscivorous predators, respectively. We found that species do differ in boldness, with species that occur with predators being bolder than those that do not. Within each species, we found that sexes differed in boldness, with males being bolder than females. We also tested for a relationship between size (a surrogate for metabolic rate) and boldness, but found no size effects. Therefore, sex, not size, affects boldness. These results are consistent with the hypothesis that complex and risky environments favor individuals with more bold behavioral traits, but they are not consistent with the hypothesis that size (and therefore metabolic rate) drives divergence in boldness. Finally, our results provide evidence that behavioral trait divergence continues even after speciation is complete.

The family Poeciliidae (37 genera and about 304 species) includes live-bearing fishes of small size (<200 mm length) having diverse morphology and coloration, with distribution in the freshwater and brackish environments of the eastern United States, South America, and Africa, including Madagascar (Moyle 2002, Nelson 2006). Males of new world species possess the elongated anterior anal fin rays modified as a gonopodia to place packets of sperm in the vents of females, which subsequently bear live young (Moyle 2002). Twelve poeciliid species are native to the United States (Page and Burr 1991), and about 78 are native to Mexico (Miller et al. 2005). The genus Poecilia, with 27 species (Nelson 2006), is represented in Mexico by 12 nominal species (Miller et al. 2005). A myriad of species of the genus Poecilia have been widely and deliberately introduced worldwide for mosquito control (Fuller et al. 1999) or the aquarium trade (Crossman and Cudmore 1999) due their short generation t...

Vertebrate pigmentation is emerging as a powerful system for studying the evolution of adaptive traits and the maintenance of genetic and phenotypic variation in natural populations. Though melanism has been linked to physiological and behavioral traits in a variety of taxa, the generality of these associations for many taxa such as fishes remains unclear. Here I tested whether variation in melanism in a livebearing fish was correlated with a variety of traits often tested in other taxa: locomotor stress coping style during confinement, boldness in a novel environment, and metabolic rate. There were significant negative associations between an individual's amount of melanistic pigmentation and both activity in confinement and boldness in a novel environment. In contrast with evidence from many prior studies, there was no relationship between melanism and metabolic rate. Overall, the data provide some support for documented relationships between melanism and behavioral traits, but did not support the generally reported relationship between melanism and metabolic rate. Links between melanism and behavioral coping strategies related to environmental stressors may have important implications for the evolution and maintenance of behavioral and morphological variation in natural populations. Nonetheless, these results also suggest variation among taxa in the extent to which pleiotropy has evolved between melanism and diverse organismal traits.