En Hydrobiologie Marine Et Continentale Spécialité: RESSOURCE HALIEUTIQUE ET EXPLOITATION DURABLE

Abstract

A study of the reproduction of the black sea urchin Arbacia lixula from Mostaganem coastline was conducted at once site rocky, rich in photophilous algae but disturbed by pollution (urban and industrial discharges) and high port activity. This work, spread over 3 months (febraury 2016-april (Salamander) 2016) and performed on 81 individuals, consisted to follow the monthly evolution of physiological indices (gonad index and index of repletion), the Sex-ratio. The Sex-ratio is slightly in favor of males with a slight monthly alternating between the sexes. According to the gonad index, the Spawning period is located in the mars and is possibly trigger by temperatures (20-23 C°). The Allometric relationships between different morphological parameters, diameter and height of the test without spines, height and diameter of Aristotle’s lantern, diameter of the test without spines and diameter of Aristotle’s lantern, test diameter without spines and wet weight, test height without spines and wet weight, demonstrate the existence of a more than average allometric relationship between these different growth parameters and reflect the flattening test of the black sea urchin A.lixula that can be regarded as a form of adaptation to its middle.