La produccion de peces ornamentales es una actividad importante dentro la acuicultura peruana generando impactos socioeconomicos positivos en toda cadena valor. El pez ornamental Platy (Xiphophorus maculatus) uno los mas coloridos utilizados ampliamente como un sistema modelo animal para comprender base genetica del polimorfismo patron color. coloracion X. maculatus esta relacionada con sintesi...

The fish non–long-terminal-repeat (non-LTR) retrotransposon Rex3 has recently been isolated from the platyfish Xiphophorus maculatus (Volff et al. 1999). Complete versions of Rex3 encode a reverse transcriptase (RT) and an apurinic/apyrimidinic endonuclease (fig. 1). Rex3 belongs to the RTE family of non-LTR retrotransposons (Malik and Eickbush 1998; Volff et al. 1999). From all autonomous fish...

Genetic studies of hybrids between the Mexican killifishes, Platypoecilus maculatus and Xiphophorus hellerii, have shown that when the black-spotted varieties of Platypoecilus are crossed with Xiphophorus, melanosis appears in some of the hybrid offspring. The distinguishing feature of these black-spotted varieties of Platypoecilus is the presence in the skin of a large type of black chromatoph...

About 20% of xiphophorin fish (Xiphophorus maculatus) dermal melanophores which were cultured in monolayer for 5 to 10 days responded to light directly, exhibiting reversible melanosome aggregation within a few minutes. In order to determine the spectral sensitivity for the light-response, absorbance changes due to the light-induced melanosome aggregation were measured on single melanophores in...

sex-determining mechanism in Poeciliid fishes of the genus Xiphophorus ' F : been studied for more than forty years (BELLAMY 1928; GORDON 1927), yet many problems remain unsolved. In the southern platyfish, Xiphophorus maculatus, native to Mexico and adjacent parts of Central America, there are three types of females (XX, WX, WY) and two types of males (XY and YY) (GORDON 1947, 1954; KALLMAN 19...

A fish melanoma cell line, PSM-1, was established from a hereditary melanoma in an interspecific hybrid of Xiphophorus for cytogenetic studies of this melanoma system. An amelanotic melanoma was obtained from the tail fin of a melanotic F1 hybrid between a spotted platyfish (Xiphophorus maculatus) and an albino swordtail (Xiphophorus helleri). The tumor tissue was dissociated and cultured in Ea...

The products of 49 protein-coding loci were examined by starch gel electrophoresis for populational variation in six species of Xiphophorus fishes and/or segregation in intra-and interspecific backcross and intercross hybrids. Electrophoretic variation was observed for 29 of the 35 locus products in a survey of 42 population samples. The highest frequency of polymorphic loci observed in noninbr...

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...

Fluence response relationships for the induction of DNA damage in the skin of UV-irradiated Xiphophorus fish were obtained by quantitative gel electrophoresis of unlabeled DNA following extraction and treatment with an enzyme preparation that makes single strand breaks next to cyclobutane pyrimidine dimers. A buffer containing 7 M urea minimized the degradation of DNA during extraction and gave...