214 



Figure 167: Ophiothrix oerstedi (Mladenov, 1977**). 



Formation of the larval skeleton in the lecithotrophic larva. 



al — anterolateral arms; pi — posterolateral arms. 



noted that larvae of Ophiolepis elegans were able to swim as well as creep 

 for some time before they actually settled down. 



In addition to development with planktotrophic and lecithotrophic larvae, 

 viviparity has been confirmed for many species of brittle stars. A majority of 

 these species live in polar regions or at great depths. Among them, some 

 species occur only in specific regions, for example, Stegophiura vivipara 

 (Matsumoto, 1915) off the coast of Japan. On the other hand, there are 

 cosmopolitan species, such as Amphipholis squamata, found almost univer- 

 sally in temperate latitudes. Wide distribution has also been reported for some 

 deep water species, such as Ophiomusium lymani (Tyler, 1980) reported for 

 the Atlantic as well as the Pacific Ocean. 



arc/i 



Figure 168: Ophioderma longicauda 



(Fenaux, 1969). 



Formation of hydrocoel processes. 



arch — archenteron; bl — blastopore; 



hep — hydrocoel processes. 



Figure 169: Ophiolepis elegans (Slancyk, 1973). 

 Formation of the transverse ciliated bands in the 



doliolaria-type larva. 



amp — rudiment of ambulacral podia; cb ( 1 . 2, 



3, 4) — transverse ciliated bands; oo — oral 



opening; pol — preorai lobe. 



