FISHERY BULLETIN: VOL. 69. NO. 3 



Figure 2. — Left side (left photo) and right side (right photo) of head of 39.6 mm TL abnormal Achirus lineatiis 

 reared in the laboratory. Ambicoloration, hooked dorsal fin, incomplete eye migration, and presence of a left 

 pectoral fin. 



Usually the fin was associated with a hooked 

 dorsal fin and failure of eye migration (Figures 

 2 and 3), but a pectoral fin also was present on 

 some individuals without those abnormalities 

 (Figure 5). 



HOOKED DORSAL FIN 



Seventeen specimens had a hooked dorsal fin. 

 In normal metamorphosis, the left eye of A. 

 lineatus migrates across the dorsal midline under 

 the projecting dorsal fin ; the "hook" of the 

 dorsal fin subsequently grows down toward the 

 snout, eventually becoming adnate to the head. 

 Development of the dorsal fin during metamor- 



phosis was described for normal A. lineatus by 

 Futch, Topp, and Houde. ' In normal lined soles 

 the first five dorsal fin pterygiophores articulate 

 with serrations in the supraoccipital bone. The 

 three anteriormost pterygiophoi-es are dii-ected 

 anteriad, lying nearly parallel to the axis of the 

 neurocranium. A fleshy connection is estab- 

 lished between the dorsal fin and the prefrontal 

 complex of the neurocranium. Radiographs of 

 abnormal lined soles revealed that rotation of 

 the frontal and prefrontal bones was incomplete 

 during metamorphosis. The anteriormost pter- 



" Futch, C. R., R. W. Topp, and E. D. Houde. De- 

 velopmental osteology of the lined sole, /lc/i/n(s lineatus 

 (Pisces: Soleidae). (Unpublished manuscript.) 



540 



