WASHINGTON ET AL.: SCORPAENIFORMES 



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Fig. 233. Larvae of Dactylopteridae. (A) Daayloplerus voliians. 2.4 mm (from Padoa, 1956e); (B) Dactylopterus volitans. 7.5 mm (ibid.). 



long and slender at hatching with moderately long guts (44 to 

 60%) and rounded snouts. They become increasingly deep-bod- 

 ied with development. 



Larvae are relatively heavily pigmented with melanophores 

 over the head and gut. Scorpaenichthys larvae have dense pig- 

 ment covering the body except for the caudal peduncle while 

 Hemilepidotus spp. have postanal pigment concentrated on the 

 dorsal and ventral body midlines. Lateral melanophores de- 

 velop above and below the notochord in Hemilepidotus. 



Hemilepidotus and Scorpaenichthys larvae develop four 

 prominent preopercular spines. Hemilepidotus possess numer- 

 ous head spines while Scorpaenichthys develop bony bumps in 

 corresponding areas. Larvae of this group develop unique pitted 

 dermal bones on the head. In addition, the uppermost pectoral 

 radial is tiny and fuses to the scapula in larval Scorpaenichthys 

 and nearly so in Hemilepidotus. 



Myoxocephalus group (Figs. 227 and 228). — This is the least 

 well-defined and most diverse cottid group containing 1 3 genera. 

 Where known, size at hatching varies from 2.9 to 10 mm. Trans- 

 formation to the benthic juvenile stage vanes from 7.6 to 20 

 mm. 



Members of this group are generally slender-bodied with 

 pointed snouts; however, Enophrys is stout-bodied, and Or- 

 thonopias has a blunt, rounded snout. 



Pigmentation is variable. Heavy pigment on the dorsal surface 

 of the gut, on the nape and along postanal ventral midline is 

 characteristic of many members of this group. Several genera 

 possess heavy melanistic pigmentation on the lateral body sur- 

 face (e.g. Radulinus, some Myoxocephalus). Head pigment may 

 be present. 



Larvae of this group develop four preopercular spines and a 



distinctive bony preopercular shelf. Parietal, nuchal, supra- 

 cleithral, posttemporal and occasionally, postocular spines de- 

 velop in late-stage larvae. 



Artedius group (Fig. 229, Table 107).— This group contains 3 

 genera, Artedius (in part), Clinocottus and Oligocottus and the 

 larvae have been described by Washington (1981). Larvae hatch 

 at 3 to 5 mm and transform to benthic juveniles at approxi- 

 mately 10 to 13 mm. Larvae are stubby-bodied with a slightly 

 humped appearance at the nape. Snouts are rounded and guts 

 trail distinctively below the ventral body midline. Several species 

 oi Artedius develop dorsal gut diverticula while Clinocottus acu- 

 ticeps develops long hindgut diverticula. 



Larvae are relatively lightly pigmented and characterized by 

 pigment on the nape, over the gut and along the postanal ventral 

 midline. Head pigment is present in some species. 



Larvae develop a unique preopercular spine pattern with 6 

 to 24 spines. Parietal and supracleithral spines are variable in 

 this group and may form in clusters, individually or not at all. 



Leptocottus group (Fig. 229).— This group includes the genera 

 Leptocottus and Coitus. Hatching occurs at 4 to 5 mm and 

 transformation ranges from 8 to 12 mm. Larvae are relatively 

 slender-bodied with rounded snouts and moderately short guts. 

 Pigmentation is usually light with melanophores on the nape, 

 over the gut and widely spaced along the postanal ventral mid- 

 line. Head pigment may be present. 



Where known, these larvae develop four weak preopercular 

 spines; however, other head spines are lacking. 



Psychrolutes group (Fig. 230).— This group includes two genera 

 Psychrolutes and Gilbertidia. Larvae hatch at a relatively large 



