FISHERY BULLETIN: VOL. 77. NO 1 



129° 



125° 



121° 



40' 



35< 



30' 



25' 



20' 



40° 



MAGDALENA 



115° 



Figure 22. — Distribution of eggs and larvae of Hypsopsetta gut- 

 tulata examined in this study. (Open circles represent larvae, 

 closed circles eggs and larvae.) 



The right eye is beginning to migrate in a speci- 

 men 9.1 mm SL and transformation is almost 

 complete at 11.7 mm SL. 



In early preflexion larvae of Hippoglossina, the 

 gut is shaped like that in Pleuronichthys larvae; 

 however, coiling begins at about 4.5 mm NL and 

 the gut assumes a more compact shape than in 

 Pleuronichthys. This is reflected in the relatively 

 shorter snout-anus length. Mean relative snout- 

 anus length remains at about 4CK7c of the body 

 length throughout the larval period, in contrast to 

 Pleuronichthys larvae in which there is a gradual 

 decrease in relative gut length during larval de- 

 velopment (Table 5). In juveniles, however, there 

 is a decrease in snout-anus length to about 33% of 

 body length, a value comparable with that in 

 Pleuronichthys juveniles. 



The head is similar in size and shape to that in 

 Pleuronichthys. Relative head length increases 

 gradually during larval development. The same is 

 true for relative snout length and is thus opposite 

 to the condition in Pleuronichthys; however, it de- 

 creases somewhat in juveniles. Relative eye width 

 undergoes a moderate diminution during larval 

 development as in Pleuronichthys, but increases 

 moderately in juveniles. 



Small preopercular spines develop on larvae 

 from ca. 5.5 mm NL, become most conspicuous on 

 flexion stage larvae, and undergo resorption dur- 

 ing transformation from 9.5 mm SL. This spina- 

 tion is distinctive of H. stomata when compared 

 with Pleuronichthys and Hypsopsetta. 



Larvae oi Hippoglossina have a slender appear- 

 ance compared with .some of the deeper bodied 

 species of Pleuronichthys. Body depth at the anus 

 is comparatively small in preflexion larvae and 

 remains so in flexion and postflexion larvae and 

 early juveniles (Table 5). 



As in Hypsop.'ietta, the caudal peduncle is longer 

 and more slender than in Pleuronichthys, except 

 for P. ocellatus postflexion larvae. 



Fin formation. — Larvae of Hippoglossina stomata 

 are comparable with those of P. coenosus with 

 regard to size at which the caudal fin develops. 

 Caudal fin formation occurs between 6.2 and 8.8 

 mm NL (Table 19). Although about six caudal rays 

 are formed on a 7.0-mm NL specimen with a 

 straight notochord, all other specimens with 

 caudal rays have the notochord flexing. The 

 smallest, fully flexed specimen is 7.1 mm SL. 

 Postflexion specimens <9.0 mm SL lack the full 

 complement of I8V2 caudal rays. The ural bones 

 supporting the caudal rays are made up of two 

 superior and two inferior hypurals; there is no 

 epural. The lack of an epural bone is a specific 



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