WASHINGTON ET AL.: SCORPAENIFORMES 



411 



LIO 



APO-4^ 



pp6-4 



PPO-3 



— LOP 



B 



TM 



UIO-4 



PPO-5 



LIO-I 



LIO-2 



— PPO-3 



PPO-5 



APO-4 



PPO-4 



Fig. 220. Head spines in 6.2 mm (A), 8.2 mm (B). 10.0 mm (C) and 16.0 mm (D) stained larvae of Sehasles melanostomus. Abbreviations 

 of head spines: APO-2, 2nd anterior preopercular; APO-3, 3rd anterior preopercular; APO-4, 4th anterior preopercular; CL, cleithral; lOP, 

 interopercular; LIO-1, 1st lower infraorbital; LlO-2, 2nd lower infraorbital; LOP, lower opercular; LPST, lower posttemporal; NA, nasal; NU, 

 nuchal; PA, parietal; PPO-1, 1st posterior preopercular; PPO-2. 2nd posterior preopercular; PPO-3, 3rd posterior preopercular; PPO-4, 4th 

 posterior preopercular; PPO-5, 5th posterior preopercular; PRO, preocular; PSO, postocular; PT, pterotic; SC, supracleithral; SPO, supraocular; 

 TM, tympanic; UIO-1, 1st upper infraorbital; UIO-2, 2nd upper infraorbital; UIO-3. 3rd upper infraorbital; UIO-4, 4th upper infraorbital; UOP, 

 upper opercular; UPST, upper posttemporal. From Moser and Ahlstrom, 1978. 



Structures concentrated along the dorsal and ventral margins. 

 Notochord flexion occurs at about 6-12 mm and transformation 

 at 15-25 mm (Table 107). Many species have a distinct pelagic 

 juvenile stage which can reach almost 60 mm body length. 



Preflexion larvae have a slender body (body depth 1 3-23% 

 of body length) and compact gut; snout-anus distance increases 

 from about 40-50% of body length to over 60% in some species 

 during the larval period. The caudal and pectoral fins begin 

 forming first, followed by the pelvics and then the dorsal and 

 anal fins. The pectoral fins range from short and rounded to 

 elongate and fan-shaped, reaching almost 50% of body length 

 in 5. levis (Fig. 221). The pectoral fin base is shallow (typically 

 7-13% of body length) in comparison with other subfamilies. 

 Ossification of skeletal elements begins early in the larval period 



and proceeds rapidly as in other scorpaenoids; vertebral ossi- 

 fication follows the pattern of other scorpaeniforms, with the 

 neural arches ossifying before the centra (Moser, 1972). 



Pigmentation in newborn larvae consists of a melanistic sheath 

 over the gut and a postanal series along the ventral midline. 

 Some species also have a dorsal midline series which may de- 

 velop gradually. Pigment increases with development, appear- 

 ing on the head (above brain, on jaws and opercular region), 

 fins, and caudal peduncle. Often the pectoral fins (both base and 

 blade) have diagnostic pigment patterns. Several of the western 

 Pacific species are heavily pigmented with the head and body 

 covered by a sheath of melanophores (Fig. 221). 



Head spines are a prominent feature of all Sebastes larvae. 

 Pterotics, parietals (usually serrated), and preopercular spines 



