Portal de Periódicos da CAPES

Larval stage composition and morphological change during larval development of the Japanese mantis shrimp, Oratosquilla oratoria (De Haan, 1844) (Stomatopoda, Squillidae) in Tokyo Bay, Japan

2005; Brill; Volume: 78; Issue: 11 Linguagem: Inglês

10.1163/156854005776759843

1568-5403

Jun Ohtomi, Hironori Kawazoe, Toshio Furota,

Marine Biology and Ecology Research

In order to examine the larval stage composition and morphological change during larval development of the Japanese mantis shrimp, Oratosquilla oratoria (De Haan, 1844) (Stomatopoda, Squillidae), sampling surveys using a plankton net with a 50 cm mouth diameter, 170 cm length, and 0.497 mm mesh were conducted in Tokyo Bay, Japan, at 8-30 m depth. Two procedures, slope towing and bottom horizontal towing, were adopted. All eleven larval stages occurred, and larvae in stage III, which is the first pelagic stage, were numerically dominant in the present study. Bottom horizontal towing collected significantly more later stages than slope towing. For slope towing, the estimated density tended to decrease from stage III to the final stage XI, reflecting natural mortality. For bottom horizontal towing, the density apparently increased during the three latest stages, IX to XI. This was probably caused by the transition from pelagic to demersal life. The growth of both carapace length (CL) and total length (TL) per larval stage were best described by a logistic equation. Based on the minimum value of the residual sum of squares in the regression analysis, the relative growth of TL to CL was divided into two phases: early phase, stages I to VIII, and late phase, stages IX to XL The estimated slope of the regression line for the late phase was significantly greater than that for the early phase, reflecting relative growth of the abdomen during the late phase.