Contribution a la biologie des Rajidae des cotes tunisiennes. 17. Raja radula Delaroche, 1809: relations taille - poids du corps, du foie, des gonades et des glandes nidamentaires; poids du corps - poids du foie, des gonades et des glandes nidamentaires

Abstract

A study of size - total weight relationships and cubic coefficient condition points out that total weight increases with size more rapidly in the adults of both sexes than in the young. Size of liver, weight and size of gonads, weight relationships present similar characteristics but are subjected to important monthly changes in adults males and females. The analysis of relative coefficient condition points out that breeding takes an important part in these changes which increase in females owing to the weight of nidamental glands and genital tracts. The part of ecological factors is not to be omitted but it is difficult to delimite it considering the lack of precise data. The part of diet is more apparent because there is relation with breeding in one hand and with zoological biotops in the other hand.