Reproductive cycle and shell growth of the tellin Nitidotellina nitidula (Dunker) in Hakodate bay [Japan]
1993
Kawai, K. (Hokkaido Univ., Hakodate (Japan). Faculty of Fisheries) | Goshima, S. | Nakao, S.
The developmental processes of gonads exhibit an annual cycle, as follows: recovery period (December-June), growing period (March-July), mature period (May-September), spawning period (May-October), and spent period (November-December). Rings are annually formed on the shell from August to November. The growth curve in shell length is estimated by external growth rings. The growth equation was calculated as follows: Lt=24.72(1-exp(-0.38(t+0.47))), were Lt is the theoretical shell length (mm) at time t (year). Shell length at the first sexual maturity defined as the length class at which 50% of the animals mature is 14-18 mm in both sexes. The age corresponding to the size at sexual maturity is 2 years old. The growth rate is better than, and the age at sexual maturity is a little older than those of other tellinid bivalves
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