The influence of season on the gonad index and biochemical composition of the sea urchin Paracentrotus lividus from the Golf of Tunis.

Seasonal variation in the gonad weight and biochemical composition of the sea urchin Paracentrotus lividus from the Golf of Tunis (Tunisia) were studied between September 2003 and August 2004. The highest gonad indices occurred in March (16.71%).

Lipids and fatty acids composition in the tissues and by-products of two Tunisian shrimp species from the north and south regions.

Total lipid and fatty acid composition was determined in the muscle and by-products (heads, shells and tails) of Penaeus kerathurus and Metapenaeus monoceros caught off the North and South coasts of Tunisia. Shrimp total lipid levels in by-products ranged between 2 to 3.15% (p < 0.

Tissue parameters of the sea urchin (Paracentrotus lividus): the effects of magnesium and transport stress.

The present study investigates some biochemical and biological variables in sea urchins (Paracentrotus lividus) that were stressed in the course of collection, transportation and laboratory conditioning and the effect thereon of pre-treatment with a test compound; magnesium chloride (MgC12). Handling and transportation for 5h resulted in significantly decreased gonadal indices due to unplanned spawning. The pre-treatment of sea urchins with 5 mmol 1(-1) MgCl2 reduced unplanned spawning during all of the experiments.