In teleosts, the thyroid gland is mostly found in the subpharyngeal region. However, in several species thyroid follicles are found in, for example, heart, head kidney and kidney. Such heterotopic thyroid follicles are active, and considered to work in concert with the subpharyngeal thyroid. In Mozambique tilapia (Oreochromis mossambicus) thyroid activity is, indeed, restricted to the subpharyn...

Dietary supplements phosphatidylcholine and β-carotene, a dimer of vitamin A have been shown have positive effectson a variety of physiological and immunological parameters in humans and other vertebrates. Previous studies have demonstrated that these neutraceuticals enhance growth of Nile tilapia reared under optimal temperature. However, in those studies specially formulated diets were used. ...

This study was to assess effects of the pretreatment in allplant based diets with microbial phytase on phosphorous utilization and growth performance of Nile tilapia (Oreochromis niloticus). Pretreatment trials were conducted using phytase at graded doses to determine the optimal dose of phytase. Available phosphorus (P) levels increased significantly with the increased doses of phytase and the...

This study aimed to determine the regulation of the de novo myo-inositol biosynthetic (MIB) pathway in Mozambique tilapia (Oreochromis mossambicus) brain following acute (25 ppt) and chronic (30, 60 and 90 ppt) salinity acclimations. The MIB pathway plays an important role in accumulating the compatible osmolyte, myo-inositol, in cells in response to hyperosmotic challenge and consists of two e...

The regulation of triglyceride mobilization by catecholamines was investigated in the teleost fish Oreochromis mossambicus (tilapia) in vivo and in vitro. In vitro experiments were carried out with adipocytes that were isolated for the first time from fish adipose tissue. For the in vivo experiments, cannulated tilapia were exposed to stepwise decreasing oxygen levels (20, 10, and 5% air satura...

Metabolic mechanisms underlying the divergent response of rainbow trout (Oncorhynchus mykiss) and Nile tilapia (Oreochromis niloticus) to changes in dietary macronutrient composition were assessed. Fish were fed one of four isoenergetic diets having a digestible protein-to-digestible energy (DP:DE) ratio above or below the optimal DP:DE ratio for both species. At each DP:DE ratio, fat was subst...

Recently, tilapia have become increasingly important in aquaculture and fisheries worldwide. They are one of the major protein sources in many African countries and are helping to combat malnutrition. Therefore, maintenance and conservation genetics of wild populations of tilapia are of great significance. In this study, we report the population genetic structure and genetic diversity of the re...

One important factor limiting tilapia culture development in Honduras as well as in the rest of the Central America is the lack of supply of fingerlings in sufficient quantity and quality. To assess the situation, we endeavored to obtain information and purchase fingerlings from every seed producer in Honduras. Sixteen tilapia fingerling producers were visited and interviewed during September 2...

Hepatic microsomes and cytosols of channel catfish (Ictalurus punctatus), rainbow trout (Oncorhynchus mykiss), Atlantic salmon (Salmo salar), red tilapia (Oreochromis sp.), largemouth bass (Micropterussalmoides), striped bass (Morone saxatilis), hybrid striped bass (M. saxatilis x M. crysops), and bluegill (Lepomis macrochuris) (n=8) were used to study the kinetics of phase I (ECOD, EROD, PROD,...

Three attenuated Aeromonas hydrophila vaccines were developed from the virulent 2009 West Alabama isolates through selection for resistance to both novobiocin and rifampicin. When channel catfish (Ictalurus punctatus) were IP injected with 4×105 colony-forming unit (CFU) of the mutants, no fish died. However, when the same age and size matched channel catfish were IP injected with similar amoun...