LAROCHE: DEVELOPMENT OF LARVAL SMOOTH FLOUNDER 



Table l. — Measurements (millimeters) of larval Liopsetta putnami. Specimens above dashed line are yolk-sac larvae. 



the abdominal region of preflexion larvae, >6.2 

 mm, as metamorphosis begins and the juvenile 

 pattern of dense melanophore covering begins to 

 develop. 



A vertical band of concentrated melanophores of 

 various sizes is present across the center of the 

 postanal region in the smallest larva (2.4 mm). 

 External melanophores are aligned in irregular 

 rows on both sides of the ventral midline between 

 the anus and the postanal band. A single irregular 

 row of melanophores extends along the ventral 

 surface from the vertical band nearly to the 

 notochord tip. An irregular row is also present 

 along the dorsal midline extending posteriorly 

 nearly to the notochord tip. Only a few scattered 

 melanophores appear laterally. A row of internal 

 melanophores over the notochord is present on all 

 larvae longer than =3.2 mm. The postanal band 

 becomes less distinct, usually represented by only 

 a few large stellate melanophores, in larvae >5.0 

 mm. Scattered external melanophores begin to 



appear over the lateral surfaces of preflexion lar- 

 vae >5.6 mm and continue to increase in number 

 through the larval period. Concentrated pigment 

 spots develop along the dorsal and ventral body 

 surfaces in transforming larvae >5.8 mm. 



The fin folds of the smallest P americanus larva 

 are not pigmented. Various authors ( Sullivan 1915; 

 Breder 1924; Bigelow and Schroeder 1953; Lippson 

 and Moran 1974) have illustrated small larvae 

 with melanophores extending onto the dorsal and 

 anal fin folds ( probably no melanophores were cen- 

 tered on the fin folds) from the vertical postanal 

 band. Their illustrations were of artificially 

 reared larvae. I observed no melanophores extend- 

 ing onto the dorsal and anal fin folds of field- 

 collected larvae; however, reared larvae commonly 

 have somewhat increased pigment due mostly to 

 light conditions which can be altered to change the 

 size of melanophores (Milos and Dingle 1978). A 

 few small melanophores appear along the margin 

 of the pectoral fin fold at 3.5 mm and disappear 



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