Theoretical growth during the recruitment period and estimation of growth parameters of the japanese mantis shrimp Oratosquilla oratoria in Tokyo bay [Japan]

Growth after recruitment completion and life span of the Japanese mantis shrimp Oratosquilla oratoria in Tokyo Bay have been already determined by the authors in the previous paper. For the stock assessment of this species, however, growth parameters for its whole life cycle including the recruitment period are indispensable. So we here tried to estimate those parameters by the following two steps: First, we attempted to describe the growth on that period of O. oratoria theoretically, using both laboratory data on the size increment at molting and the frequency of molting and field data on bottom water temperature in Tokyo Bay. Secondly, we estimated growth parameters from the mean body lengths of each instar and the frequency of molting throughout whole life after settlement of this species. It was found that O. oratoria had 14 instars during the recruitment period and reached 10.54 cm in body length at the first molting after recruitment completion in this bay. Growth of O. oratoria was expressed by the Pauly and Gaschuetz equation. Estimated growth parameters were L arrow left =13.99, K=1.102 for female and L arrow left =15.68, K=0.898 for male. Units of L arrow left and K are cm and per year, respectively.