614 



Fishery Bulletin 90(3). 1992 



Figure 4 



Paralichthys microps larvae: (A) Early yolksac, l.SmmNL; (B) late yolksac, 3.0mm 

 NL; (C)early preflexion, 3.4mmNL; (D) middle preflexion, 5.3 mm NL; (E) late flex- 

 ion, 7.0mmNL. Drawings at right are dorsal head views. Bars = 1.0 mm. 



anterior one-third of the tail. A 

 dense zone of melanophores devel- 

 ops on the middle one-third of the 

 tail and associated dorsal and ven- 

 tral iinfold regions (Fig. 4). Pigment 

 is less dense on more anterior re- 

 gions of the finfold and is absent on 

 the posterior one-third of the tail 

 and finfold. Head pigmentation is 

 restricted to the jaws, dorsal brain, 

 and opercle. 



During the flexion stage, the 

 melanistic zone on the tail and asso- 

 ciated finfold region intensifies. The 

 paired series along the dorsum and 

 the epaxial region remains visible, 

 while the embedded series dorsal to 

 notochord is less visible due to the 

 development of musculature. The 

 number of ventral and ventrolateral 

 abdominal melanophores increases. 

 The ventral region of the gut has 

 small melanophores, while those on 

 the side of the gut are larger and 

 stellate. The series above the gut 

 and along its ventral midline are 

 less apparent. 



The pattern of melanophores on 

 the head remains about the same, 

 with brain melanophores the most 

 conspicuous. Head pigmentation 

 consists of small melanophores on 

 the jaws, palate, preoperculum, 

 operculum, and gular region, and 

 larger and stellate melanophores in 

 the brain region. The small melano- 

 phores located at the ventral mar- 

 gin near the tip of the notochord 

 disappear with development of the 

 caudal fin. Melanophores increase 

 in number on the dorsal-fin crest 

 and on the interradial m^embranes 

 of the dorsal and anal fins during 

 the postflexion stage (Fig. 5A). 



Finally, during the metamorpho- 

 sis stage (Fig. 5C) melanophores in- 

 crease in numbers on the head and 

 body, especially on the left side. 

 Body melanophores are associated 

 with myosepta. The paired dorsal 

 series remains visible. Melano- 

 phores on the dorsal and anal fins 

 are arranged in groups. The elong- 

 ated dorsal-fin rays are covered with 

 melanophores. The rear margins 



