FISHERY BULLETIN: VOL. 72, NO. 4 



Figure 2. — Opisthonema ogUnum larva 4.0 mm total length. 



5 



Figure 3. — Opisthonema oglinum larva 10.7 mm standard length. 



H. jaguana by Houde et al. (1974). They noted 

 that the second ural vertebra ossified first. 

 Epural development displayed some variation 

 (tw^o instead of the normal three in some speci- 

 mens), as was also noted in Harengula by Houde 

 et al. (1974). Holhster (1936) noted this varia- 

 tion in Harengula but not in Opisthonema. 

 Other than these differences, caudal develop- 

 ment was essentially the same for Opisthonema 

 and Harengula. For a more complete account, 

 consult Houde et al. (1974). 



At 10.5 mm, ossification also started on verte- 

 brae 12 through 40. This ossification starts on 

 the dorsal and ventral surfaces of the centra, 

 thus making it quite easy to count vertebrae. 

 The degree of ossification of these vertebrae 

 indicates that the middle ones were most ossified, 

 with ossification proceeding anteriorly and pos- 

 teriorly. By 12.5 mm, dorsal and ventral ossi- 

 fication of the centra is complete on vertebrae 

 2 through 41, while only the ventral centrum 

 surface has ossified on the first vertebra and the 



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