Morphometric and length-weight relationships of the mussel Perna perna from the mamelles coast, Dakar, Senegal

Abstract

This study focused on relationships between length-weights (length-total weight), sex ratio, size distribution, and the condition index of Perna perna. The length-weight relationship for the whole population of P. perna showed regression coefficients b=2.4467 an intercept with Y-axis, “a’ = 0.2565, and R² = 0.871. The allometric coefficient of the specimens sampled in this study is b<3, implying the negative allometry shown by the tested specimens. The present study showed that the size of P. perna varied between 4-13 cm. The most common harvest size was between 7-10 cm. In P. perna, the gonads enter two distinct maturation periods, a very brief maturation phase from december to reach the maximum value of 36.36 in March. The second phase of laying begins in September, with an increase from 29.12 to 28.25 of the condition index (CI), which lasts 3 months, from December to February. Regarding the sex ratio, it is favorable to males for 9 months out of 12, against 3 months for females (February, March and November). Regarding the size of individuals, the sex ratio is in favor of females for individuals of large size, from 11 cm.