Zuniga and Acuna. Development of Paralichthys spp, larvae 



615 



of the hypural plates become pig- 

 mented, as do the bases of the 

 caudal-fin rays. 



Fin development Pterygiophores 

 and fin rays of the dorsal fin ap- 

 pear at 5.5mmNL; full com- 

 plements are present at 7.7mm 

 SL (Table 2). Anal-fin pterygio- 

 phores and rays appear at 6.5 

 mmNL and have full comple- 

 ments at 7.7mmSL. The pelvic- 

 fin rays begin to develop at 7.0 

 mmNL and all are present at 8.1 

 mmSL; pterygiophores begin to 

 develop at 10.1 mmSL and all are 

 present at ll.SmmSL. The first 

 pectoral-fin rays appear at ~9.5 

 mmSL; full complements are 

 present at ll.SmmSL. The hypu- 

 ral complex develops between 

 6.2 and 7.2mmNL. The number 

 of caudal-fin rays is 18, plus 2 

 procurrent rays. 



Morphology The sphenotic spine 

 is more developed than in P. 

 adspersus preflexion larvae (Fig. 

 2) (max. length is 24% eye diam- 

 eter) and disappears with the ap- 

 pearance of the elongated dorsal- 

 fin rays. At ~5mmNL, up to 4 

 spines may be found at the pre- 

 opercular margin; up to 3 spines 

 are found in the upper region of 

 opercle. At this size, the gut be- 

 comes coiled and the larva is 

 moderately slender. Preanal dis- 

 tance is 41.2% NL; body depth 

 (BD) is 13.3% NL, and upper jaw 

 length (UJL) is 34.6% HL (Table 



1)- 



At '^'6mmNL, three elongated 

 rays appear on the dorsal fin 

 crest. They correspond to the 

 second, third, and fourth rays of 

 the adult fin. The middle ray of 

 the crest is the longest. There are 

 34 (11-12 preanal and 22-23 

 postanal) myomeres at the end of 

 the stage. 



The flexion stage is character- 

 ized by development of the hypu- 

 ral elements of the caudal fin. 

 Body depth increases to 25.6% 



B 



Figure 5 



Paralichthys microps larvae. (A) early postflexion, 7.4mmSL; (B) early to middle 

 metamorphosis, 8.7mmSL: (C) juvenile, 15.5mmSL. Bars = 1.0mm. 



