FISHERY BULLETIN: VOL 77. NO 1 



Table 1 1. — Measurements (millimeters) of larvae and juveniles of Sehastes helvomaculatus from waters off Oregon Specimens 



above dashed line are undergomg notochord flexion, 



E m 





? 



U 



i 



n 2 * 



I .S 



^a 



2y= -sBfi "£ 



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£ ti 



(0 "* — 



: 3! a? 





rather long, averaging 24-269!^ SL during the 

 pelagic period. Depth of the pectoral fin decreases 

 from 12''f in flexion larvae to 97? in benthic 

 juveniles. 



Pelvic fin spines and developing rays are visible 

 on the 7.7 mm larva. The adult complement of I, 5 

 is countable on the smallest postflexion larva, 8.8 

 mm. The relative length of the pelvic fin increases 

 from 14 to 23'7r^ SL with development. The pelvic 

 spine, always shorter than the pelvic fin rays, in- 

 creases from 8% SL in flexion larvae to IS'/r in 

 transforming larvae and then decreases to 15'% in 

 benthic juveniles. 



The adult complement of 8 + 7 principal caudal 

 fin rays can be counted on the 7.7 mm preflexion 

 larva. Flexion is completed by 8.8 mm. Superior 

 and inferior secondary caudal rays on two stained 

 juveniles 22.4 and 23.8 mm long, were 12 + 12 and 

 11 + 11, respectively. 



Bases of dorsal and anal fin spines and rays are 

 visible on the 7.7 mm larva. Rays and spines (in- 

 cluding "prespines"! are fully formed by 9.9 mm 

 and the adult complements can be counted. "Pre- 



34 



spines" become spines in specimens >19 mm. The 

 longest dorsal spine increases from 19% HL in 

 postflexion larvae to 377f in benthic juveniles. The 

 longest dorsal ray, always longer than the longest 

 dorsal spine, increases from 23 to 43*^7^ HL during 

 development. The longest anal spine increases 

 from 16 to 49^r HL. 



Spination iTables 4, 12). — Spines on the left side 

 of the head of the smallest S. helvomaculatus (1.1 

 mm) include the parietal; first and third anterior 

 preopercular spines; second, third, and fourth 

 posterior preopercular spines; postocular; pterotic; 

 inferior posttemporal; and first spine of the 

 superior infraorbital series. 



The parietal spine and ridge are deeply serrated 

 in larvae and pelagic juveniles, but the serrations 

 are no longer visible by 41.6 mm. The parietal 

 spine is very long in flexion larvae, averaging 27'^ 

 HL. Its length decreases with development to 3% 

 HL in benthic juveniles. The much smaller nuchal 

 spine, which appears by 8 mm, averages 29f HL in 

 flexion larvae and increases to 4 or 5'S in postflex- 



