Classic theories for the evolution of senescence predict that rates of aging should be highest in populations in which extrinsic mortality is high. This predication is called into question in new work by David Reznick and co-workers, who found that guppies Poecilia reticulata derived from natural populations with high levels of predation live the longest in the laboratory. This study illustrate...

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 ...

Populations experiencing consistent differences in predation risk and resource availability are expected to follow divergent evolutionary trajectories. For example, live-history theory makes specific predictions for how predation should drive life-history evolution, and according to the Trexler-DeAngelis model for the evolution of matrotrophy, postfertilization maternal provisioning is most lik...

Pleurolophocercous cercariae emerged from naturally infected Melanoides tuberculata from Minas Gerais State, Brazil, were used to perform experimental infection of laboratory-reared Poecilia reticulata. Mature metacercariae were obtained from the gills of fishes and force-fed to Mus musculus. The adult parasites which recovered from small intestines of mice were identified as Centrocestus formo...

We describe the development and validation of a qPCR assay to detect Poecilia reticulata, highly invasive species freshwater fish Caribbean islands, through environmental DNA (eDNA) sampling. Originating from Trinidad, this is detrimental countless native tropical communities. A assay, consisting set primers fluorescent probe, amplifying 214 base pair target region mitochondrial Cytochrome B ge...

We investigated the ability to recognize the color of surfaces in fish (Poecilia reticulata), bred from birth in conditions of artificial light with constant spectral content. The capacity for color constancy significantly deteriorated when compared that to the control group. Further alteration of lighting conditions and transfer into natural daylight conditions restored the suppressed function...

Two freshwater fishes, Rasbora sumatrana (Cyprinidae) and Poecilia reticulata (guppy) (Poeciliidae) were exposed for a four-day period in the laboratory condition to a range of copper (Cu) and cadmium (Cd) concentrations. Mortality was assessed and median lethal concentrations (LC50) were calculated. LC50 increased with decrease in mean exposure times for both metals. For R. sumatrana, LC50s fo...

In many guppy Poecilia reticulata farms in the vicinity of Bangkok, diseases have caused longlasting fish death and consequently large cumulative mortality. Diseased guppies were collected and subjected to histopathological analysis. The analysis revealed systemic granulomatosis as a remarkable histological sign. Rod-shaped bacterial cells with strong acid-fastness were found in the granulomas....