Powell and Henley: Larval development of Paralichthys albigutta and P lethostigma 



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B 



Figure 4 



Developmental stages of transforming, postflexion laboratory-reared gulf flounder, 

 Paralichthys albigutta (P=preopercular spines). (A) 8.2-mm-SL larva, 34 days old; (B) 

 9.0-mm-SL larva, 45 days old. 



pelvic fin. Melanophores on the lateral surface of the 

 body in the caudal area began to align with the 

 myosepta. Pigment on the lateral surface of the body 

 increased with increasing size (Fig. 4). The extended 

 third dorsal ray was pigmented, and pigment was 

 scattered on the developing dorsal- and anal-fin rays. 

 This pigment increased in area during development 

 (Fig. 4). Pigment was scattered in no apparent pat- 

 tern medially on the dorsal- and anal-fin ptery- 

 giophores. The anal-fin pterygiophores were rela- 

 tively more pigmented than those on the dorsal fin. 

 Pigment increased in these areas during development 

 (Fig. 4). The characteristic almost-paired, almost- 

 contiguous dorsal and ventral midline pigment was 

 located at the proximal edge (base) of the dorsal- and 

 anal-fin pterygiophores. Pigment in the head region 

 of early postflexion larvae was similar to that of flex- 

 ion larvae (Fig. 3D) but increased in intensity dur- 

 ing development (Fig. 4). 



During transformation, P. albigutta larval body 

 pigment increased in intensity (e.g. compare Fig. 4, 

 A and B). Melanophores occurred along the entire 

 base of the caudal fin, but most of the fin was not 

 pigmented. A blotchy pigment pattern was observed 

 on the pterygiophores, caudal peduncle, and lateral 

 line from mid-body anterior to the cleithrum. Mel- 

 anophores along the lateral line from mid-body to 

 the caudal peduncle formed a streak of pigment in 

 later transforming larvae (ca. 8.7 mm SL). Numer- 

 ous melanophores on the lateral surface of the cau- 

 dal area were aligned with the myosepta. This pig- 

 ment occurred mainly in the posterior two-thirds of 

 the caudal area and extended more anteriorly in the 

 dorsolateral area (Fig. 4). The dorsal and anal fins 

 were pigmented along the entire length of their base 

 (i.e. proximally). On the medial portion of the dor- 

 sal- and anal-fin rays on earlier (ca. 7.8 mm SL) trans- 

 forming larvae, pigment appeared as blotches on the 



