Hybrid speciation may contribute significantly to generating biodiversity, but only a few well-documented examples for it exist so far that do not involve polyploidization as a mechanism. The swordtail fish, Xiphophorus clemenciae, shows common hallmarks of a hybrid origin and still overlaps in its current geographic distribution with its putative ancestral species (Xiphophorus hellerii and Xip...

more than 32 alien (exotic) fish species belonging to 10 orders and 12 families (cyprinidae, gobiidae, salmonidae, anguilidae, mugilidae, centrarchidae, heteropneustidae, gasterosteidae, cichlidae, poecilidae, adrianichthyidae and pleuronectidae) were reported from iran of which 25 species are confirmed by specimens. some of the alien fishes (e.g., cyprinus carpio , carassius auratus , pesudora...

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...

Ornamental fish ponds requires continuous control of water quality such as salt content (salinity), hardness (Ca, Mg), and ionic contents particularly nitrate and ammonium. Conductivity is considered as a parameter correlates with these parameters and sensitive to environmental conditions such as temperature. Therefore, a conductivity detector can be employed for control of water quality in aqu...

compensatory growth response and body composition of male sailfin molly, poecilia latipinna subjected to short-term starvation and subsequent feeding were studied for 54 days. four feeding schedules were used in this study: c, control (were fed to apparent satiation throughout the experiment); t1, treatment 1 (3 days starvation and 6 days refeeding); t2, treatment 2 (6 days starvation and 12 da...

this paper used the results of a research project entitled biodiversity of inland water fishes of iran which was carried out from 2005 to 2010. some 3500 fish specimens were obtained from different basins of iran by using electrofishing method, cast net, gill net and hook. using criteria such as size, shape and color, some of them are considered suitable to keep in aquarium. due to the results ...