Random amplified polymorphic DNA (RAPD) markers were successfully used in discrimination of sexes in Nile tilapia fish (Oreochromis niloticus) using linear discriminant function analysis. The results provide support for the view that major genetical sex determining factors exist in tilapia.

Streptococcus iniae is one of the most economically important Gram-positive pathogens in cultured fish species worldwide. The USDA-ARS Aquatic Animal Health Research Unit developed a modified (contains concentrated culture supernatant) S. iniae bacterin that has been demonstrated to be efficacious, and protection is mediated by specific anti-S. iniae antibodies. Although effective, the specific...

Two immunization trials were conducted to evaluate host protection of Nile tilapia, Oreochromis niloticus against Ichthyophthirius multifiliis (Ich). Immunizations were done with live theronts or sonicated trophonts by bath immersion and intraperitoneal (IP) injection. The immunized fish were challenged with theronts 21 days post-immunization in trial I and 180 days post-immunization in trial I...

A growth trial was conducted to estimate the optimum levels of dietary phosphorus (P) for juvenile hybrid tilapia (Oreochromis niloticus × O. aureus) fed fishmeal-free practical diets. Hybrid tilapia (1.68 ± 0.08 g) were fed diets containing various levels (0.0%, 0.2%, 0.4%, 0.6%, 0.8% and 1.0%) of additional inorganic phosphorus for 10 weeks using two different sources of phosphorus:calcium di...

In mammals, skeletal muscle mass is negatively regulated by a muscle-derived growth/differentiating factor named myostatin (MSTN) that belongs to the transforming growth factor-beta superfamily. Although putative MSTN homologs have been identified from several vertebrates, nonmammalian orthologs remained poorly defined. Thus, we isolated and characterized MSTN complementary DNA clones from the ...

Mixed rearing of tilapia (GIFT; Genetically Improved Farmed Tilapia) with shrimp (Penaeus monodon) in brackishwater rice-shrimp system was assessed for its impact on dry season's shrimp production. The experiment was conducted in pre-selected farmer's field located at Paikgacha Upazila of Khulna district and designed with three different densities (treatment) of GIFT, viz, 0.3, 0.4 and 0.5/m2 w...

Ichthyophthirius multifiliis Fouquet (Ich) and Streptococcus iniae are 2 major pathogens of cultured Nile tilapia Oreochromis niloticus (L). Currently there is no information available for the effect of coinfection by Ich and S. iniae on fish. The objective of this study was to determine the effects of parasite load and Ich development size on fish mortality following S. iniae infection. Low mo...

The concentrations of norepinephrine in hypothalamus and norepinephrine and epinephrine in head kidney were significantly decreased in treated tilapia (Oreochromis aureus) during the time course of cold exposure (12 degrees) as compared to the control (25 degrees). The elevation of norepinephrine and epinephrine in plasma was detected earlier than that of cortisol in cold-treated tilapia. Phago...

Stocking density is considered one of the important factors affecting fish growth. But, information related to impact of stocking density on growth performance of monosex tilapia population under the ecological conditions of Gangetic plains in West Bengal, India is limited. The aim of our study was to compare the growth potential of monosex tilapia at various stocking densities and to determine...

Tilapia, a tropical freshwater fish native to Africa, is an increasingly important global food commodity. The World Wide Fund for Nature (WWF), a major environmental nongovernmental organization, has established stakeholder dialogues to formulate farm certification standards that promote "responsible" culture practices. As a preface to its "tilapia aquaculture dialogue," the WWF for Nature comm...