Three isoform-specific antibodies, 6F against the α1-isoform of the avian sodium pump, HERED against the rat α2-isoform, and Ax2 against the rat α3-isoform, were used to detect the expression of Na+-K+-ATPase α-subunits in gills of a teleost, the tilapia ( Oreochromis mossambicus). Tilapia gill tissue showed positive reactions to antibodies specific for α1- and α3-isoforms. The results of immun...

Approximately 50 years ago, Nile tilapia were accidentally introduced to Brazil, and the decline of pearl cichlid populations, which has been intensified by habitat degradation, in some locations has been associated with the presence of Nile tilapia. There is, however, little strong empirical evidence for the negative interaction of non-native fish populations with native fish populations; such...

Nutrition is vital in fish farming because feed costs represent 40–50 % of the total variable production costs (SHANG, 1992; CRAIG and HELFRICH, 2002). For several decades, fishmeal has been used as the main source of protein in fish feeds (TACON and JACKSON, 1985; TACON, 1993; EL-SAIDY and GABER, 2004; ALCESTE and JORY, 2000). However, the periodically occurring low availability, competition a...

In this study, the effect of initial heterogeneity of weight and density on heterogeneous growth (HetG) evaluated by the coefficient of the variation of weight in the young Nile tilapia Oreochromis niloticus of the territorial species was tested. Fish were maintained in a glass aquarium (8 and 2 L of water) with two levels of initial heterogeneity of weight: low and high, under two density cond...

The objective of this study was to investigate the effects of bovine insulin on growth responses in tilapia. Juvenile hybrid male tilapia (Oreochromis niloticus x O aurea; n = 135) were subjected to 1 of 3 treatments. Each treatment was subdivided into 3 replicates of 15 fish each. The fish were immersed into 1 of 2 doses (10 and 100 micrograms/100 ml water) of insulin or no hormone for 15 min ...