LAROCHE and RICHARDSON DEVELOPMENT AND OCCURRENCE OF ROCKFISHES 



spines until most of them have a melanophore. 

 Melanophores are added along the caudal fin base, 

 often appearing as a line, and onto the fin mem- 

 brane. Pigment decreases on the pectoral and pel- 

 vic fins and is usually absent on larvae by =16-20 

 mm. 



During the transformation period, =23-27 mm 

 in S. flavidus and =23-31 mm in S. melanops, 

 pigment gradually increases over the head and 

 body. Melanophores are added on the lips, lower 

 jaw, snout, and dorsolateral areas of the head. 

 Pigment becomes continuous Eiround the orbit. 

 Melanophores are added ventrolaterally beneath 

 the midline band and increase along the ventral 

 body surface above the anal fin. 



Pelagic juveniles, =28-56 mm in S. flavidus 

 and =33-52 mm in S. melanops, undergo a gen- 

 eral increase in pigment with development. The 

 upper head, snout, lips, lower jaw, maxillary, 

 cheek, and gular region become increasingly 

 pigmented with small melanophores. Opercular 

 pigmentation appears less distinct due to scale 

 covering at =33 mm. On the side of the body, 

 melanophores are added ventrolaterally until all 

 but the ventral one-eighth is pigmented. Small 

 melanophores increase in number along the ven- 

 tral surface of the caudal peduncle. Me- 

 lanophores are added anteriorly and proximally 

 on the first dorsal fin and are eventually scattered 

 over it. A dark blotch develops in the posterior 

 portion of the spinous dorsal fin by =35 mm and 

 persists on all larger pelagic juveniles. 

 Melanophores are added to the proximal half of 

 the soft dorsal fin. A few scattered melanophores 

 are added to the pectoral fin and proximal half of 

 the caudal fin. Pigment distinctly lines the caudal 

 fin base. 



Benthic juveniles, >60 mm, have essentially 

 the same melanistic pigment pattern as the 

 largest pelagic juveniles. Pigmentation at the an- 

 terior tips of the lips and along the ventral 

 edge of the maxillary intensifies and ^ dark bar 

 extends from the posteroventral margin of the 

 eye across the cheek. In S. melanops a second 

 dark bar forms dorsal to the first and extends 

 from the eye across the opercle becoming distinct 

 by 76 mm. Melanophores appear on patches of 

 scales covering the dorsal half of the body in both 

 species. These patches overlie the pigment de- 

 scribed for pelagic juveniles creating darker 

 patches with lighter areas interspersed where 

 pigmentless scales overlie pigmented Eireas. The 



dorsal half of the body has a mottled appearance 

 as a result of this. Melanophores first appesir on 

 the pectoral fin base of S. flavidus in a patch 

 which extends onto the fin membrane and on the 

 underside of the fin base. Later, additional small 

 melanophores lightly cover the pectoral, anal, 

 and caudal fins while only a few small 

 melanophores appear on the pelvic fin. Benthic 

 juvenile S. melanops have melanophores cover- 

 ing all fins, however, the distal margins of those 

 in smaller specimens are usually pigmentless. 

 Although already covered by melanophores, the 

 pectoral fin in small benthic (<63 mm) S. 

 melanops has a patch of large melanophores 

 which spread over the dorsal half of the pectoral 

 ray bases and adjacent fin base in the same area 

 which first appears pigmented on the pectoral fin 

 of S. flavidus. The spinous dorsal fin, anterior to 

 the black blotch, appears mottled in S. melanops. 

 On the soft dorsal fin a more lightly pigmented 

 bar runs through the proximal third of the fin. 

 This bar becomes faint or indistinguishable on 

 specimens >67 mm long. Previously described 

 pelagic juvenile body pigment along the anal fin 

 base, at the articulation of the anal fin rays, and 

 on the caudal peduncle becomes completely 

 obscured by scales and tissues on both species, 

 and small melanophores on the scales are alone 

 visible. In general benthic juvenile S. flavidus are 

 more lightly pigmented than S. melanops taken 

 over similar substrate, however, the pigment pat- 

 terns are very similar. 



Color of Fresh Specimens. — Yellow chromato- 

 phores are visible interspersed with melanophores 

 over all body surfaces on pelagic and benthic 

 juveniles of both S. flavidus and S. melanops. In S. 

 melanops they are not numerous enough to give 

 the fish a distinctly yellow cast. The concentration 

 of yellow chromatophores is generally greatest in 

 the areas where melanistic pigment is densest, 

 e.g., the base of the caudal fin, the pigment bar 

 radiating from the posteroventral margin of the 

 eye, darker eireas on fins. Yellow pigment is not 

 concentrated around the dorsal fin black blotch. 

 Juveniles generally appear darkly mottled with 

 faintly yellow fins, yellowish areas on the head 

 and body, and cream colored ventrally. However, 

 considerable variation in the intensity of the 

 melanistic pigment of benthic juveniles may occur 

 seemingly dependent upon bottom substrate. 

 When melanistic pigment is less intense, yellow 

 pigment is more outstanding. The yellow tail, 



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