Growth of the Manila clam Ruditapes philippinarum in Sanbanse, the shallow coastal area in Tokyo Bay

Abstract

A new cohort of the Manila clam Ruditapes philippinarum was established in Sanbanse (the shallow coastal area of Tokyo Bay) during October-November 1998. Growth of clams within this cohort was monitored monthly or bimonthly at five stations along an inshore-offshore transect in Sanbanse through November 1999. Mean shell length was about 0.4 mm in November 1998 and increased gradually to about 1 mm in March 1999. The clams then grew rapidly during the warm season and mean shell length reached 25-29 mm in November 1999 at each station. Comparisons of growth among stations in terms of shell length and soft-body dry weight suggest that the growth of R. philippinarum was faster at offshore than inshore stations during warm periods.