FISHERY BULLETIN: VOL. 80, NO. 1 



known larvae of western North Atlantic Cithar- 

 ichthys and Etropus species. In preflexion lar- 

 vae, before pelvic rays form, one or two melano- 

 phores are present on the ventral body margin at 

 the future site of the pelvic fin. By 4.6 mm and 

 throughout development (at least to 13 mm), a 

 few external melanophores are present along the 

 posterior surface of the gut loop. A small melano- 

 phore is found over the posterodorsal surface of 

 the midgut of preflexion larvae. 



Flexion larvae (Fig. 6B) usually have 15-20 

 melanophores on the dorsal one-third of the left 

 side of the gas bladder. The caudal band is 

 mostly confined to the body and contains myo- 

 septal pigment. Visible internal notochordal 

 pigment is restricted to the vicinity of the exter- 

 nal caudal band. The dorsal surfaces of one or 

 two forming centra are darkened at about 5 mm. 

 By about 6 mm and throughout development (at 

 least to 13 mm), there may be a few melano- 

 phores along the ventral surface of the gut loop. 

 By late flexion, notochordal pigment appears as 

 fine dashes along four to six centra of caudal ver- 

 tebrae 13-19. By late flexion, pigment along the 

 posterodorsal surface of the midgut extends to 

 the gas bladder and appears as a black lining 

 over the gut. 



By postflexion (about 8 mm, Fig. 7A), both 

 sides of the gas bladder usually are obscured by 

 body musculature, and pigment in this area ap- 

 pears diffuse. Small melanophores appear on the 

 left pelvic fin membrane along both sides of the 

 elongate second ray. Body musculature tends to 

 obscure notochordal pigment in larvae longer 

 than 12 mm. 



Morphology (Figs. 6, 7; Tables 3, 6) 



General morphological features are similar to 

 those of C. comutus, with the qualification that 

 the smallest C. gymnorhinus specimen examined 

 was 4.6 mm NL. Adult morphometries given in 

 the following discussion were derived from 

 Gutherz and Blackman (1970) and Topp and 

 Hoff (1972). 



The mouth is relatively large in larvae and 

 adults. Larval upper jaw length/BL is fairly con- 

 stant at 9.3-9.5%. Adult upper jaw length/BL is 

 11.2%, range 9.9-13.0%. Larval upper jaw length/ 

 HL decreases greatly from 38% (preflexion) to 

 33% (flexion and postflexion). Adult upper jaw 

 length/HL is 41%, range 39-45%. Larval lower 

 jaw length/BL increases from 11.5% to 12.7%. 

 Adult lower jaw length/BL is 13.2%, range 11.6- 



14.8%. Larval lower jaw length/HL decreases 

 slightly from 46% to 44% and is only slightly less 

 than that of C. comutus. Adult lower jaw length/ 

 HL is 48%, range 43-53%. 



The larval snout is pointed but relatively short. 

 Larval snout length/BL increases slightly from 

 5.2% to 6.1%. Adult snout length/BL is 5.4%, 

 range 4.6-6.6%. Larval snout length/HL is con- 

 stant at 21%. Adult snout length/HL is 20%, 

 range about 18-20%. 



The eye is relatively large in larvae and adults 

 (only slightly smaller than that of C. comutus). 

 Larval eye diameter/BL is constant at about 

 8.8%. Adult orbit length/BL is 9.6%, range 8.0- 

 11.4% (Topp and Hoff 1972); eye diameter/BL is 

 10.1%, range 9.1-11.0% (Gutherz and Blackman 

 1970). Larval eye diameter/HL decreases from 

 35% to 31% and is similar to that of C. comutus. 

 Adult orbit length/HL is 35% (Topp and Hoff 

 1972); eye diameter/HL is 36.5%, range 33-38% 

 (Gutherz and Blackman 1970). 



The head is fairly long but shallow in larvae 

 and of moderate length in adults. Larval head 

 length/BL increases greatly from 25% to 29%. 

 Postflexion head length/BL is similar to those of 

 C. arctifrons and C. comutus. Adult head length/ 

 BL is 27%, range 25-29%. Larval head depth/BL 

 increases from 29% to 33% and is similar to that of 

 E. crossotus. 



Larval snout to anus length is fairly great until 

 postflexion. Snout to anus length/BL increases 

 slightly from 43% (preflexion) to 44% (flexion) 

 and then decreases to 40% (postflexion). This 

 length is similar to that of E. crossotus during 

 flexion and postflexion. 



With the exception of a relatively deep caudal 

 peduncle, the body is of moderate depth in larvae 

 and adults. Larval body depth at pelvic fin/BL 

 increases from 30% to 39%. Larval body depth at 

 loop of gut/BL increases from 29% to 44%. Larval 

 body depth at anus/BL increases greatly from 

 25% to 42% and during flexion and postflexion is 

 similar to that of E. crossotus. Larval body depth 

 at third hemal spine/BL increases greatly from 

 14% to 35%. Adult body depth/BL is 47%, range 

 39-50%. Larval caudal peduncle depth/BL in- 

 creases from 11.6% (flexion) to 13.2% (postflex- 

 ion). Adult caudal peduncle depth/BL is 11.5%, 

 range 10.5-12.6%. 



Fin and Axial Skeleton Formation 



Caudal skeleton development is similar to that 

 of C. comutus. Size ranges of available speci- 



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