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Fishery Bulletin 93(3), 1995 



Figure 3 



Developmental stages of laboratory-reared gulf flounder, Paralichthys 

 albigutta (C=cranial spines, P=preopercular spines). (A) 3.5-mm-NL 

 preflexion larva, 10 days old; (B) 5.8-mm-NL early flexion larva, 25 

 days old; (C) 6.2-mm-NL late flexion larva, 21 days old; and (D) 7.1- 

 mm-SL postflexion larva, 31 days old. 



istic throughout the larval stages (Fig. 3 A). The al- 

 most-paired dorsal and ventral midline melano- 

 phores merged into one row of dorsal and ventral 

 punctate melanophores in the future caudal-fin re- 

 gion. The most posterior melanophores generally 

 were opposite each other. The dorsal midline pigmen- 

 tation extended anteriorly to the forebrain. Melano- 

 phores were first observed on the lateral portion of 

 the caudal region at approximately 3.5 mm NL (Fig. 

 3A). Embedded notochord pigment extended anteri- 

 orly ventral to the brain and continued through the 

 eye, giving the appearance of a stripe through the 



eye. Pigment occurred over most of the 

 ventral finfold and more prevalently in the 

 middle one-third of the dorsal finfold. In 

 the gut region of preflexion larvae, mel- 

 anophores occurred along the ventral mid- 

 line, extending anterior of the cleithral 

 symphysis and along the lateral surface 

 of the gut. Melanophores occurred along 

 the dorsal surface of the gut as a continu- 

 ation of ventral midline pigment and gen- 

 erally terminated in a distinct melano- 

 phore at the junction of the operculum 

 (Fig. 3A). In most specimens a distinct mel- 

 anophore occurred on the ventral area of 

 the base of the pectoral-fin blade. In the 

 head region, melanophores occurred on the 

 operculum and on the dorsum of the mid- 

 brain (cranial bump). Pigment was first 

 observed on the dorsum of the cranial 

 bump during early preflexion (2.9 mm NL), 

 but only 20% of the specimens examined 

 (n=10) had a melanophore here at this 

 time. With increasing size the cranial- 

 bump melanophore occurred at a greater 

 frequency, and by 4.0 mm NL all speci- 

 mens had a melanophore in this region. 

 In the lower-jaw region, melanophores oc- 

 curred both along the lower-jaw rami and 

 at the lower-jaw angle (Fig. 3A). A punc- 

 tate melanophore was observed on both 

 sides of the premaxilla or maxilla, or both. 

 This pair of melanophores was first ob- 

 served on early preflexion larvae (2.9 mm 

 NL) and was observed on every laboratory- 

 reared specimen examined. Vomerine pig- 

 ment was first observed on 3.2-mm-NL 

 preflexion larvae and occurred thereafter 

 on all specimens examined. 



Pigment on flexion larvae was similar 

 to that observed on late preflexion larvae 

 (Fig. 3, B and C). Melanophores occurred 

 on the lateral surface of the body in the 

 caudal area on all specimens. The most 

 anterior melanophore on the dorsal surface of the 

 gut at the junction of the operculum was stellate and 

 was seemingly isolated from the other gut pigmen- 

 tation (Fig. 3, B and C). Pigment occurred along the 

 proximal base of the developing caudal-fin rays. In 

 the late flexion stage (6.4 mm NL), pigment first 

 appeared on the third elongated dorsal ray. Most of 

 the lateral surface of the hind gut was pigmented. 

 The ventro-lateral surface of the mid- and foregut 

 was pigmented (Fig. 3, B and C). 



On early postflexion larvae (Fig. 3D), pigment was 

 observed on the base of the caudal fin and on the 



