101 



BANKIA SETA CEA (T YRON) 

 (Teredinidae) 



Veliconcha 



The veliconcha shell is equi valve and symmetric. In the initial period of 

 this stage the larva is round; as the shell grows and the umbones become 

 isolated, the shell expands dorsoventrally but is never as highly drawn as in 

 T. navalis. Compared to the latter, the shell of Bankia setacea is thinner and 

 also transparent. The larva is entirely light-colored and devoid of bright pig- 

 mentation. Dark and light bands occur along the margin of the shell. The hinge 

 system is identical to that of T. navalis (Figure 64). The prodissoconch I varies 

 in length from 100-130 |a.m. The larval shell before settling varies in length 

 from 240-280 ^m, with a hinge line of 100 ^im (Quayle, 1953). 



Ecology 



In Busse Lagoon, Aniva Bay (Sea of Okhotsk), and Vostok Bay, release 

 of gametes and development of larvae in the plankton occur in warmer months 

 of the year (July-September) — at 14-17°C in Busse Lagoon and 15-23°C in 

 Vostok Bay. During the autumn, as the water cools to 7-10°C, larvae settle and 

 metamorphose. Judging from published data, B. setacea exhibits similar eco- 

 logical characteristics in other parts of its range. Ryabchikov (1957) recorded 



Figure 64: Veliconcha of Bankia setacea. 



