[Effect of dietary lipid source on the lipid and fatty acid profiles of parthenogenic versus bisexual uromiah lade artemia]

ABSTRACT

One of the most important live food source for developing aquaculture in Iran is the Iranian brine shrimp [Artemia urmians] [AU]. But the latest nutritional study on its cysts and nauplii have showed [Ahamadi et al. 1990], that the natural population of brine shrimp collected from the Uromiah lake may be inadequate as a food for cultured marine organisms. Therefore a better nutritional quality might be obtained by intensive culturing of AU fed with cultured algae. However, the newly hatched parthenogenic and Bisexual AU [instar I-II] were transferred separately to the different jars and then feed them with the three experimental diets with the theoretical fatty acid composition as follows a] Algae Tetraselmis [low levels of 205w3, high levels of 183w3], b] Unidentified algae [high levels in 205w3, low levels of 183w3] c] Rice bran [lack of w3 fatty acids]. After feeding and when the AU [Parthenogenic and Bisexual] reached adulthood, the total lipids and fatty acid profile of both culture were analyzed. This study showed that 1] Parthenogenic AU reached to sexual maturity 2 to 3 days sooner than bisexuals fed the same diets. Parthenogenic AU fed Tetraselmis matured in 15 days and bisexuals took 18 days to reach sexual maturity. Parthenogenic and bisexual AU fed rice bran reached sexual maturity in 25 and 30 days, where those fed the unidentified algae reached sexual maturity in 18 and 20 days, respectively. The highest mortality was observed in the bisexual AU fed rice bran during the grow out period. The AU fed Tetraselmis appeared to have the least mortality. 2] Iranian brine shrimp, generally reflects the different types of fatty acids contained in their diets. 3] AU are able to elongate the shorter-chain-fatty-acid to longer-chain-fatty-acids. 4] Fattay acid 181w9 seems to be the most abundant in AU and is similar to the other Artemia in the world. 5] Only a few differences between the fatty acid distribution of bisexuals versus parthenogenics which fed the same diet, were observed