The potential causes of adult sex ratio variation in guppies Poecilia reticulata were tested in laboratory experiments that evaluated the mortality rates of male and female P. reticulata exposed to potential predators (Hart's rivulus Rivulus hartii and freshwater prawns Macrobrachium crenulatum) and to different resource levels. Poecilia reticulata mortality increased in the presence of R. hart...

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" Poec...

--This study examined habituation of the predator inspection behavior in the guppy (Poecilia reticulata) and its relationship with boldness (open field locomotion). Two different strategies were discovered: (1) initial inspection of a predatorlike fish, correlated with boldness; (2) subsequent surveillance, governed by a random underlying process and unrelated with boldness. The surveillance in...

This study evaluated the sensitivity of male and female guppies (Poecilia reticulata) to ammonia. LC50-96h for males, females combined sexes P. reticulata was 37.33, 48.34, 42.45 mg/L total ammonia or 1.03, 1.34, 1.17 un-ionized The mortality at concentration 40 differed between with higher in males. These results have implications production systems, since recommendations toxicity reference va...

Introduced fishes comprise a substantial fraction of the fish fauna in 2 Bexar County waters: 35% in upper San Antonio River and 43% in Braunig Reservoir. Four species (Astyanax mexicanus, Poecilia latipinna, P. formosa, and Cichlasoma cyanoguttatum) are south Texas fishes displaced northward. Two species (Cyprinodon variegatus and Menidia beryllina) are recent introductions from estuarine wate...

Acute toxicity tests were performed over a period of 120 hours using different concentrations of effluent of treated rubber wood processing wastewater on freshwater fish, Poecilia reticulata. The LC50 values of the effluent exposed to P. reticulata for 24, 48, 72, 96 and 120 hours were 19.77, 19.55, 19.25, 18.99 and 18.75 ml/dl respectively. Mortality was observed in a dose dependant manner. Th...

Studies on fish parasites in Pampulha dam, Belo Horizonte, Minas Gerais, Brazil, found specimens of Poecilia reticulata Peters, 1859 harboring natural infection by larval stages of tapeworms. A total of 250 specimens of P. reticulata were collected and analyzed between February and August 2010, of which 23 were found infected (prevalence 9.2%) with one metacestode each (mean intensity 1, mean a...