Arowana (Osteoglossum bicirrhosum) and cat fish (Hypostomus plecostomus) are two species of ornamental fishes which are mostly imported to Iran. Monogenea are plathyhelminthes which can dominantly infest the fish skin and gills with high host specificity. In this research, 35 O. bicirrhosum and 50 H. plecostomus with clinical signs were collected from different ornamental fish markets in Semnan...

Arowana (Osteoglossum bicirrhosum) and cat fish (Hypostomus plecostomus) are two species of ornamental fishes which are mostly imported to Iran. Monogenea are plathyhelminthes which can dominantly infest the fish skin and gills with high host specificity. In this research, 35 O. bicirrhosum and 50 H. plecostomus with clinical signs were collected from different ornamental fish markets in Semnan...

The Southern Pacific Rattlesnake (Crotalus helleri) is found in southwestern California (USA), southward through north Baja California (MX) into the northern part of southern Baja California (MX). In this study, the venoms from two Southern Pacific Rattlesnakes were characterized. The two venoms were different in color, concentration, and enzyme activities. Two commercial antivenoms neutralized...

Xiphophorus cortezi males are polymorphic for the pigment pattern vertical bars. In this study, we determined whether X. cortezi females are polymorphic in their preference for this trait by examining both withinand between-individual variation in female preference. There was significantly more variation in female preference within than between individuals using both video animations and live m...

In the fish Xiphophorus we have detected elevated levels of pp60c-src kinase activity in a variety of tumors (n = 34) of neurogenic, epithelial, and mesenchymal origin either of hereditary etiology or induced by carcinogens. This elevation ranged from 2-fold up to 50-fold compared to the corresponding non-tumorous tissue and up to 6-fold compared to the highest activities found in any of the no...

Internally fertilizing animals show a remarkable diversity in male genital morphology that is associated with sexual selection, and these traits are thought to be evolving particularly rapidly. Male fish in some internally fertilizing species have "gonopodia," highly modified anal fins that are putatively important for sexual selection. However, our understanding of the evolution of genital div...