FISHERY BULLETIN: VOL. 72, NO. 4 



Figure 3. — Developmental stages ofSebastolobus altivelis from mid-water trawl samples. Above, 16.3-mm transforming specimen. 



Below, 26.8-mm pelagic juvenile. 



the head and the gut (Figure IB). The space 

 gradually diminishes as the gut enlarges and is 

 absent in larvae larger than 6.0 mm. Relative gut 

 length increases markedly during development. 

 Snout-anus distance averages 41% of the body 

 length up to the stage of notochord flexion, 46% 

 during flexion, and 56% in post-flexion larvae up 

 to 10 mm in length. In larvae and transforming 

 specimens of 10- to 20-mm S. altivelis there is an 

 increase to a mean of 64% and in 20- to 56-mm 

 pelagic juveniles there is a further increase to a 

 mean of 68% . In early benthic juveniles snout- 



anus length averages 64% of body length. The gut 

 is slightly shorter in S. alascanus; snout-anus 

 length averages 61% of body length for the larvae 

 and for the pelagic and early benthic juveniles. 



The head is moderate in size in early larval 

 stages but enlarges markedly with development. 

 Head length increases from 23% of body length at 

 hatching to an average of 31% during notochord 

 flexion and is 37% in 7.5- to 10.0-mm larvae. Rela- 

 tive head length in larvae and pelagic juveniles of 

 S. altivelis in the 10.0- to 40.0-mm size range av- 

 erages 41%. A slight decrease to a mean of 39% 



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