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...

A commercial red tilapia farm was diagnosed with Streptococcus agalactiae infection using histopathology, microbiology and immunohistochemistry. One hundred fish were randomly taken from different weight/age groups including broodstock, market fish (larger than 150 g), on-growing fish between 20 and 150 g, juveniles and larvae. Fish were clinically examined, anaesthetised and necropsied. Sample...

A study was carried out to evaluate polymerase chain reaction (PCR) for the detection of white spot syndrome virus (WSSV) in postlarvae and broodstock of Penaeus monodon and in potential crustacean carriers from India. Primer pairs designed for WSSV affecting Penaeus japonicus (WSSV PJ) and P. monodon (WSSV PM) were used. Both the primer pairs gave positive assay results for crustaceans showing...

Captive breeding and rearing are central elements in conservation, management, and recovery planning for many endangered species including Rio Grande Silvery Minnow, a North American freshwater cyprinid. Traditionally, the sole purpose of hatcheries was to produce as many fish as feasible for stocking and harvest. Production quotas are also an important consideration in hatchery programs for en...

Intraperitoneal injection of virulent infectious pancreatic necrosis virus (IPNV) into yearling brook trout Salvelinus fontinalis induced an asynlptomatic, chronic w u s infection that persisted for at least 76 wk post-lnlection (wpl) in spite of the production of a strong humoral immune response. At 8 wpi, 100 % of the fish in one of the injected groups were IPNV camers , as determined by orga...

Sichuan taimen (Hucho bleekeri), a critically endangered species, is listed as first-class protected species in China. The natural population has been missing from most of its known distribution areas for many years but was rediscovered the Taibai River 2012, providing an important resource conservation stocking taimen. In this study, 43 wild adult collected were determined gamete maturity arti...

A major prerequisite for the successful growth of aquaculture is ability to properly manage sexual maturation and spawning, as well production huge numbers high-quality seeds. One most critical variables impacting a cultured organism’s reach its genetic potential reproduction proper nutrition. Broodstock diet has long been known affect fecundity, fertilisation rate, egg quality, embryo developm...

—We evaluated the influence of two broodstock feeding practices on fatty acid composition and viability of eggs in white bass Morone chrysops. The two dietary groups tested were (1) white bass females fed a commercially formulated feed (crude protein, 45%; crude fat, 16%) and (2) white bass females maintained on live food (fathead minnow Pimephales promelas and golden shiners Notemigonus crysol...