| Abstract: | The gonad morphology of the sea cucumber Isostichopus badionotus, collected during the months of May to November 1996 in Morrocoy Bay on the northwestern Venezuelan coast, was analyzed. The gonadal cycle was characterized by five stages of development: post-spawning, recovery, growth, advanced growth and maturity. Maturation did not proceed at the same pace in all gonad tubules of any one animal. Due to this asynchronous gonad development an Individual Weighted Maturity Index (IWMI) was devised to determine reproductive state. It was calculated from the proportion of the different tubule stages observed in each specimen. The maximum value attainable is 5 if all tubules are in the mature stage. Towards the months of July and August, most, but not all, of the ovarian and testicular tubules had reached maturity as indicated by IWMI values of 4.32 and 4, respectively. IWMI represents a quantitative estimation of gonad maturation in holothurians exhibiting asynchronous development as it revealed the maturation pattern underlying gonadal chronological development. |
