EFFECTS OF WATER TEMPERATURE, SALINITY AN D SUBSTRATA ON BURROWING BEHAVIORS OF THE 3 BIVALVES, PSEUDOCARDIUM-SACHALINENSIS, MACTRA-CHINENSIS, AND RUDITAPES-PHILIPPINARUM

This paper analyzed the effects of water temperature, salinity and par ticle size of the substratum on the burrowing behaviors of the three V eneroid bivalves, Pseudocardium sachalinensis, Mactra chinensis, and R uditapes philippinarum. The starting time for burrowing behavior (STBB ) and mean burrowing velocity (MBV) of the three bivalves in 15-25 deg rees C tended to be more rapid than those in 5-10 degrees C. In 5-10 d egrees C, STBB and MBV of P. sachalinensis were the most rapid, and th e burying depth of this species in 5-10 degrees was deeper than that i n 15-25 degrees C. In R. philippinarum, the ranges of optimum salinity and particle size for burrowing were wide compared with the other spe cies. It was concluded that the burrowing behaviors of P. sachalinensi s and R. philippinarum are well adapted to the dynamic swash condition s in high latitudes and to sites with fresh water, fluctuation of wate r temperature and low sorting sediment.