132 



Asterinidae 



The bipinnaria is relatively small, up to 1,000 fj.m in length, the arms (espe- 

 cially the preoral and postoral) are short, less movable, and devoid of pig- 

 ment. Locomotion is performed by beating of the ciliated band. The brachiolaria 

 stage is present. The brachiolar arms are relatively short; the middle brachiolar 

 arm has no papillary crown but has two lateral rows of papillae on the ventral 

 surface. Metamorphosis begins in the planktonic stage and terminates in the 

 attached stage. In species with lecithotrophic larvae the bipinnaria is absent 

 and the brachiolaria is modified. 



Patina pectinifera (Miiller and Troschel) is found in Peter the Great Bay 

 and its larva has already been described (Mortensen, 1921; Kasyanov, 1977; 

 Dautov and Kasyanov, 1981). 



Asteriidae 



The processes of the late bipinnaria are long, movable, and orange at the tips. 

 Locomotion is mediated by the beating cilia of the ciliated band and flexion 

 of the processes. The brachiolaria stage is present and the brachiolaria are 3— 

 4 mm long. The brachiolar arms are relatively long and the middle brachiolar 

 arm is identical in structure to the lateral ones. The brachiolariae of different 

 species of the family Asteriidae can be distinguished by the disposition and 

 number of papillae at the base of the attachment disk. Metamorphosis begins 

 in the planktonic stage and ends in the attached stage. In species with 

 lecithotrophic larvae, the bipinnaria is absent and the brachiolaria is modified. 

 The following species are found in Peter the Great Bay; Lysastrosoma 

 anthostricta Fisher, larva not described; Distolasterias nipon (Doderlein), 

 larva not described; Lethasterias fusca Djakonov, larva not described; 

 Aphelasterias japonica Bell, larva not described; Asterias amurensis Liitken, 

 larva described (Kume and Dan, 1968; Dautov and Kasyanov, 1981); Evasterias 

 retifera tabulata Djakonov, larva not described; and Evasterias echinosoma 

 Fisher, larva not described. 



PATIRIA PECTINIFERA (MULLER AND TROSCHEL) 



(Asterinidae) 



Egg 



The eggs of the Patina are yellow, 1 70 )im in diameter, and surrounded 

 by vitelline and jellylike membranes. Cleavage is radial, with weakly ex- 

 pressed bilaterality, and somewhat asynchronous (see Figure 65). The stage 

 of 4— 16 blastomeres is attained 2-3 hr after fertilization at 18 — 22°C. A 



