Pseudochondrostoma duriense and Achondrostoma oligolepis are two Iberian endemic cyprinid fish species that occur in sympatry over most of their distribution range and that are suspected to hybridize in nature. Here, we employed a combination of mitochondrial and microsatellite markers to explore the extent of introgressive hybridization between these fishes. Two natural hybrid zones were ident...

 The scanning electron microscope was used to investigate the ultrastructures of the egg membrane surface (unfertilized egg) of an endemic cyprinid fish, Cyprinion tenuiradius Heckel, 1849. The eggs of this species were almost circular in shape, had a smooth surface and one type II micropyle consisting of the flat pit and a long canal in the animal polar region. The micropyle region was not fla...

Variation of hydrochemical conditions, with special reference to adequacy of waters as fish habitats, was traced based on selected hydrochemical parameters obtained during the studies conducted from February 2013 till February 2014 year. The results were compared with earlier studies. The sources of organic pollution were identified, and the effect of biogenic substances on the biomass, as well...

the normal and lateral line cycloid scales of the native species garra rossica (nikol’skii, 1900), one of the most common and poorly known cyprinid fish in south-eastern iran have been subjected to the scanning electron microscopy technique in order to study their detailed structure. normal scale below the dorsal fin showed a clearcut demonstration between the anterior and posterior region with...

 The scanning electron microscope was used to investigate the ultrastructures of the egg membrane surface (unfertilized egg) of an endemic cyprinid fish, Cyprinion tenuiradius Heckel, 1849. The eggs of this species were almost circular in shape, had a smooth surface and one type II micropyle consisting of the flat pit and a long canal in the animal polar region. The micropyle region w...

Lead concentration in muscle, liver, kidney, brain and gonad tissues of two cyprinid fishes, Cyprinus carpio and Copoeta spp., from three sections of the upper, middle and lower parts of the Kor River was evaluated in 2006. Totally 225 specimens were caught for this purpose (75 specimens from each zone). Tissue samples were digested in acid and their lead concentrations were assayed by ICP meth...

The oxygen consumption rates of two cyprinid fishes, carp (Cyprinus carpio L.) and roach (Rutilus rutilus (L.)), were analysed for a wide range of body mass and swimming speed by computerized intermittent-flow respirometry. Bioenergetic models were derived, based on fish mass (M) and swimming speed (U), to predict the minimal speed and mass-specific active metabolic rate (AMR) in these fishes (...

Pethia longicauda, a new cyprinid fish, is described from Hiranyakeshi River, Krishna drainage, Maharashtra, India. It can be distinguished from congeners based on a combination of characters including: a long caudal peduncle, incomplete lateral line, absence of barbels, upper lip thick and fleshy, distinct lateral fold on snout, 22-24 scales in lateral series, 5-6 lateral-line pored scales, ni...

The cyprinid fish Gila atraria Girard (Utah chub) is generally considered a sexually monomorphic species. However, prior observations revealed variation in pelvic fin length within populations that appears sexually dimorphic. We measured the relative pelvic fin length of 419 sexually mature Utah chub from 8 different locations to determine the magnitude and generality of this apparent dimorphis...

Fish parasites constitute widely diversified groups of unicellular and multicellular organisms. Recently, less known parasite groups have emerged as serious pathogens. Firstly, infection with dinoflagellates of the genus Ichthyodinium has been found during seed production of leopard coral grouper, Plectoropomus leopardus, in Japan and yellowfin tuna, Thunnus albacares, in Indonesia. Schizonts m...