The biodegradation of organic matter ingressing spawning gravels in rivers exerts an oxygen demand which is believed to contribute to detrimental impacts on aquatic ecology including salmonids. Catchment management strategies therefore require reliable information on the key sources of sediment-bound organic matter. Accordingly, a novel source fingerprinting procedure based on analyses of bulk ...

Processes that influence habitat selection in landscapes involve the interaction of habitat composition and configuration and are particularly important for species with complex life cycles. We assessed the relative influence of landscape spatial processes and local habitat characteristics on patterns in the distribution and abundance of spawning steelhead (Oncorhynchus mykiss), a threatened sa...

Rohu is a leading candidate species for freshwater aquaculture in South-East Asia. Unlike common carp the monsoon breeding habit of rohu restricts its seed production beyond season indicating strong genetic control over spawning. Genetic information is limited in this regard. The problem is exacerbated by the lack of genomic-resources. We identified 182 reproduction-related genes previously by ...

The external appearance of brood fish has long been used to assess the stage of sexual development. In some species, males change in appearance during the spawning season (e.g., vivid breeding colors in cichlids, hooked jaw in salmon, and roughened texture of the pectoral fins or head of cyprinids). These physical changes make it relatively easy to identify sexually mature males. However, secon...

Like many teleosts, male bluegill sunfish (Lepomis macrochirus) provide sole parental care. To understand some of the proximate costs of parental care, we measured body condition and plasma levels of testosterone (T), 11-ketotestosterone (11KT) and cortisol in nesting bluegill males during pre-spawning, spawning and parental care stages. T and 11KT were at their highest mean levels during the p...

The greater amberjack Seriola dumerili is a large teleost fish with rapid growth and excellent flesh quality, whose domestication represents an ambitious challenge for aquaculture. The occurrence of reproductive dysfunctions in greater amberjack reared in captivity was investigated by comparing reproductive development of wild and captive-reared individuals. Wild and captive-reared breeders wer...

The aim of this study was to compare, under controlled conditions, reproduction results of cultured and wild stock of the chub. Wild fish spawned only once a season whereas the cultured stock spawned at least two times. In the multiple-spawn stock, fewer fish spawned and the weight of produced oocytes was reduced compared to the single-spawn stock. Larvae obtained from the multi-spawn forms wer...

Samples of Alburnus mossulensis were collected from the south part Euphrates River, Chybaish, Iraq November 2013 to October 2014 using electro fishing. The spawning period started in February according GSI values and histological examination for gonads during season. results examinations revealed that this species has a short season female ovaries contained different maturing stages ova, matura...

The present work focused to explore reproductive biology of fish from different Indian major rivers and its tributaries by comparing ovarian protein, fecundity, oocyte weight, oocyte diameter and condition factor during the spawning period. Correlation between fish reproductive parameter of different Indian major rivers and its tributaries showed a significant relationship. Among studied parame...