Etude de la variabilité du taux de fécondité chez espèce d’échinoderme Paracentrotus lividus (Lamarck 1816)

Abstract

The edible sea urchin Paracentrotus lividus (lamarck1816) which has a large geographic distribution is the subject of this study, the samples were taken at depths between 1 m and 3 m during the period from March 2022 to May 2022 in two sites, namely Stidia and Sidi El Medjdoub. The results showed an imbalance in the overall ratio between the sexes in the two sites, where the proportion of females was much higher than that of males with 85.18% in the site of Stidia compared to the site of Sidi El Medjdoub 46.66 %. Analysis of biometric relationships showed that the relationship between diameter and height describes changes in the shape of the test during growth. The height of the sea urchin was recorded with a value of 73% and the symmetry coefficient b equal to -2518 in the sites of Stidia and Sidi El Medjdoub. For total weight and height of sea urchins, the relationship represents a lower variance measure since b < 3 at both study sites; As for the fertility results, the sea urchins are at their optimum fertility in the month of May; however, this result needs to be confirmed with further testing.