125 



Figure 84: Lecithotrophic larva of Astropecten latespinosus with aboral (A) and oral (B) 

 sides of disk of definitive asteroid (from Komatsu, 1975). 



(McBride, 1896; Chia, 1968) have observed the precursors of gametes in the 

 cellular wall separating the left and right somatocoels. Lender and Delavault 

 (1968) were the first to identify the primary gametes in the wall of the coelom 

 of the madreporal interradius in an 1 1 -day-old brachiolaria of Asterina gibbosa; 

 later, these were observed in the circular genital cord encompassed V'^ the 

 aboral perihemal ring. Processes of the genital cord in the ray of the asteroid 

 are gonadal rudiments. 



LECITHOTROPHIC LARVAE 



Many species of sea stars produce large eggs — 200-3,450 |im — with a 

 large yolk mass. The larval stages, or the bipinnaria stage, are generally 

 bypassed in the development of such asteroids; only a highly altered 

 brachiolaria is retained, which lacks a ciliated band and a functional diges- 

 tive system. The body of such a brachiolaria is oval and provided with an 

 attachment apparatus — brachiolar arms and disk (Figure 85), which have 

 been partially described for Solaster endeca (Gemmill, 1912), Henricia 



