91 



Ecology 



K. californiense larvae are found in the plankton of Peter the Great Bay 

 in August- September. 



No data on the development of this species were found in the 

 literature. 



BALTIC MXCOMA, MACOMA BALTHICA (LINNE) 



(TelUnidae) 



Veliconcha 



The length of the veliconcha shell is initially slightly more than its height. 

 The anterior shoulder is much longer than the posterior. The larva lengthens 

 as it grows due to the extension of its anterior end (see Figure 42). The 

 maximum size of the larval shell is 300—3 1 5 \im. 



Ecology 



In Vostok Bay (Peter the Great Bay) and in Busse Lagoon (southern 

 Sakhahn), this species reproduces from July to September at 17-24°C. In 

 other parts of its area of distribution, reproduction of the species also occurs 

 in the warmer part of the year — in spring and summer. Along the Danish 

 coast, the veligers of M balthica are found (Jorgensen, 1946) in the plankton 

 from April-May to mid-August. In the Great Sahna Strait, macoma larvae are 

 found in July at 7-ll°C (Mileikovskii, 1960). 



The larva of M balthica has been described by Werner (1939), J0rgensen 

 (1946), and Sullivan (1948). 



TALL SILIQUA, SILIQUA AL TA 

 (BRODERIP AND SOWERBY) 



(Cultellidae) 



Veliconcha 



The description of this species corresponds to that given for the family. 

 The shell is pale yellow, almost white, its surface smooth, and the anterior part 

 thinner than the posterior. The shell is slender, semitransparent, and not broad. 

 The shoulders are straight and slope somewhat ventrally. The maximum length 

 of the larval shell is 380 |a.m (see Figure 50). 



Ecology 



In Busse Lagoon (Sea of Okhotsk), S. alta larvae appear in the plankton 

 mid- July. Their number is maximum in August. Mass settling of larvae occurs 



