Kin Recognition in Guppies Uses Self-Referencing Based on Olfactory Cues.

AbstractKin recognition plays an important role in social behavior and evolution, but the proximate mechanisms by which individuals recognize kin remain poorly understood. In many species, individuals form a "kin template" that they compare with conspecifics' phenotypes to assess phenotypic similarity-and, by association, relatedness. Individuals may form a kin template through self-inspection (i.

Experimentally altered male mating behaviour affects offspring exploratory behaviour via nongenetic paternal effects.

Evidence is emerging that fathers can have nongenetic effects on the phenotypes of their offspring. Most studies have focused on the role that nongenetic modifications to sperm can have on offspring phenotype; however, fathers can also have nongenetic effects on offspring through their interactions with females, called female-mediated paternal effects. These effects can occur in situations where male phenotype, e.

The problem of estimating recent genetic connectivity in a changing world.

Accurate understanding of population connectivity is important to conservation because dispersal can play an important role in population dynamics, microevolution, and assessments of extirpation risk and population rescue. Genetic methods are increasingly used to infer population connectivity because advances in technology have made them more advantageous (e.g.

Effects of methylphenidate on responses to novelty in a teleost fish (Poecilia reticulata).

Novelty seeking, the willingness to explore novel stimuli, can have important fitness consequences. The neurotransmitter dopamine has been linked to this behavior in studies on lab animals including rodents and fish; however, few studies have investigated this association in individuals from natural populations. Trinidadian guppies (Poecilia reticulata) show variation in willingness to explore novel objects and environments, and females tend to show a preference for novel males.

Tracking the startle response of guppies Poecilia reticulata in three dimensions.

A three-dimensional analysis of startle behaviours of guppies Poecilia reticulata, in dyads or alone, from two populations that show distinct differences in shoaling behaviour was performed. During the first few seconds after a startling stimulus, changes in behaviour, which could be critical if an individual is to survive a predatory attack, and the interactions between pairs of P. reticulata were examined.

An examination of the variation in maternal placentae across the genus Poeciliopsis (Poeciliidae).

Placentae show considerable diversity in a number of nonmammalian, viviparous organisms, including amphibians, reptilian sauropsids, teleost fish, and chondrichthyes. However, the evolutionary processes driving the evolution of placenta are still debated. In teleost fishes, the genus Poeciliopsis (Poeciliidae) offers a rare opportunity for studying placental evolution: extensive placentation has evolved three independent times within the last 750,000 years and there is substantial interspecific variation in the degree of embryonic, maternal nutrient provisioning and development of the placenta.

Casting a wider fish net on animal models in neuropsychiatric research.

Neuropsychiatric disorders, such as schizophrenia, are associated with abnormal brain development. In this review, we discuss how studying dimensional components of these disorders, or endophenotypes, in a wider range of animal models will deepen our understanding of how interactions between biological and environmental factors alter the trajectory of neurodevelopment leading to aberrant behavior. In particular, we discuss some of the advantages of incorporating studies of brain and behavior using a range of teleost fish species into current neuropsychiatric research.

The role of learning by a predator, Rivulus hartii, in the rare-morph survival advantage in guppies.

Negative frequency-dependent selection (NFDS), where rare types are favoured by selection, can maintain diversity. However, the ecological processes that mediate NFDS are often not known. Male guppies (Poecilia reticulata) exhibit extreme diversity of colour patterning and, in a previous field experiment, rare morphs had a survival advantage.

Sexual conflict and the function of genitalic claws in guppies (Poecilia reticulata).

Poeciliid fish, freshwater fish with internal fertilization, are known for the diversity of structures on the male intromittent organ, the gonopodium. Prominent among these, in some species, is a pair of claws at its tip. We conducted a manipulative study of these claws in the guppy, Poecilia reticulata, to determine if these aid in transferring sperm to resistant females.

Evolution in population parameters: density-dependent selection or density-dependent fitness?

Density-dependent selection is one of earliest topics of joint interest to both ecologists and evolutionary biologists and thus occupies an important position in the histories of these disciplines. This joint interest is driven by the fact that density-dependent selection is the simplest form of feedback between an ecological effect of an organism's own making (crowding due to sustained population growth) and the selective response to the resulting conditions. This makes density-dependent selection perhaps the simplest process through which we see the full reciprocity between ecology and evolution.

Seeing orange: prawns tap into a pre-existing sensory bias of the Trinidadian guppy.

Sensory bias, a predisposition towards certain signals, has been implicated in the origin of mate preferences in some species. A risk associated with these biases is that they can be co-opted by predators as sensory lures. Here we propose that the orange spots on the brown pincers of a diurnal, predatory species of prawn function as lures for Trinidadian guppies, which have a sensory bias for orange.

Sequencing and characterization of the guppy (Poecilia reticulata) transcriptome.

Background: Next-generation sequencing is providing researchers with a relatively fast and affordable option for developing genomic resources for organisms that are not among the traditional genetic models. Here we present a de novo assembly of the guppy (Poecilia reticulata) transcriptome using 454 sequence reads, and we evaluate potential uses of this transcriptome, including detection of sex-specific transcripts and deployment as a reference for gene expression analysis in guppies and a related species. Guppies have been model organisms in ecology, evolutionary biology, and animal behaviour for over 100 years.

The role of predation in variation in body shape in guppies Poecilia reticulata: a comparison of field and common garden phenotypes.

The body shapes of both wild-caught and laboratory-reared male and female Trinidadian guppies Poecilia reticulata from two low-predation and two high-predation populations were studied, but predation regime did not seem to be the most important factor affecting body shape. Instead, complicated patterns of plasticity in body shape among populations and the sexes were found. In particular, populations differed in the depth of the caudal peduncle, which is the muscular region just anterior to the tail fin rays and from which most swimming power is generated.

Temporally variable multivariate sexual selection on sexually dimorphic traits in a wild insect population.

A widely held view is that the strength and form of natural selection varies in time and space in response to varying ecological forces; however, adequate quantitative evaluations of this are relatively scarce. In this study, we measured the strength and form of sexual selection acting on a suite of male morphological traits in a wild ambush bug (Phymata americana) population at 10 sampling dates over 2 years. We tested the prediction that the strength and direction of sexual selection would be associated with one or more important ecological variables.

Adaptive maternal adjustments of offspring size in response to conspecific density in two populations of the least killifish, Heterandria formosa.

Given a trade-off between offspring size and number and an advantage to large size in competition, theory predicts that the offspring size that maximizes maternal fitness will vary with the level of competition that offspring experience. Where the strength of competition varies, selection should favor females that can adjust their offspring size to match the offspring's expected competitive environment. We looked for such phenotypically plastic maternal effects in the least killifish, Heterandria formosa, a livebearing, matrotrophic species.

Pigments, patterns, and fish behavior.

Color patterns in fish are often multicomponent signals, composed of pigment-based and structural color patches that can be used to communicate within species, in both inter- and intrasexual interactions, and between species. In this review, we discuss some of the roles played by pigment-based elements of color pattern. We begin by discussing general forms of coloration, classifying them by appearance (e.

Female choice and the relatedness of mates in the guppy (Poecilia reticulata): mate choice and inbreeding depression.

Several studies suggest that females may offset the costs of genetic incompatibility by exercising pre-copulatory or post-copulatory mate choice to bias paternity toward more compatible males. One source of genetic incompatibility is the degree of relatedness among mates; unrelated males are expected to be genetically more compatible with a female than her relatives. To address this idea, we investigated the potential for inbreeding depression and paternity biasing mechanisms (pre- and post-copulatory) of inbreeding avoidance in the guppy, Poecilia reticulata.

Sexual selection mediated by the thermoregulatory effects of male colour pattern in the ambush bug Phymata americana.

Sexual dimorphism in coloration is a taxonomically widespread phenomenon often attributed to sexual selection on visual signals. However, the ambush bug Phymata americana exhibits sexual dimorphism in coloration that has no apparent signalling function. Here we provide evidence that colour pattern in this species influences male mating success indirectly through its effect on thermoregulation.

Frequency-dependent survival in natural guppy populations.

The maintenance of genetic variation in traits under natural selection is a long-standing paradox in evolutionary biology. Of the processes capable of maintaining variation, negative frequency-dependent selection (where rare types are favoured by selection) is the most powerful, at least in theory; however, few experimental studies have confirmed that this process operates in nature. One of the most extreme, unexplained genetic polymorphisms is seen in the colour patterns of male guppies (Poecilia reticulata).

Carotenoid availability affects the development of a colour-based mate preference and the sensory bias to which it is genetically linked.

Regardless of their origins, mate preferences should, in theory, be shaped by their benefits in a mating context. Here we show that the female preference for carotenoid colouration in guppies (Poecilia reticulata) exhibits a phenotypically plastic response to carotenoid availability, confirming a key prediction of sexual selection theory. Earlier work indicated that this mate preference is genetically linked to, and may be derived from, a sensory bias that occurs in both sexes: attraction to orange objects.

Genetic and environmental effects on secondary sex traits in guppies (Poecilia reticulata).

Male guppies (Poecilia reticulata) exhibit extreme phenotypic and genetic variability for several traits that are important to male fitness, and several lines of evidence suggest that resource level affects phenotypic expression of these traits in nature. We tested the hypothesis that genetic variation for male secondary sex traits could be maintained by genotype-specific effects of variable resource levels (genotype-environment interaction). To do this, we measured genetic variation and covariation under two environmental conditions--relatively low and relatively high food availability.

Multiple mating and sequential mate choice in guppies: females trade up.

The trade-up hypothesis outlines a behavioural strategy that females could use to maximize the genetic benefits to their offspring. The hypothesis proposes that females should be more willing to accept a mate when the new male encountered is a superior genetic source to previous mates. We provide a direct test of the trade-up hypothesis using guppies (Poecilia reticulata), and evaluate both behavioural and paternity data.