Table 2. 



FISHERY BULLETIN: VOL. 78, NO. 2 



-Measurements (millimeters) of plankton caught larvae oflsopsetta isolepis. (Specimens between dashed lines are under- 

 going notochord flexion.) 



Table 3. — Body proportions of I sopsetta isolepis larvae. Values given are percentages: mean 



in parentheses. 



standard deviation, and range 



'Except W = 29 for snout length and N = 16 for upper jaw length. 

 ^Except N = 19 for snout length. 



of stain may be affected by length of preservation. 

 Terminology of bones generally follows 

 Richardson and Joseph (1973) and Frame et al. 

 (1978) except as noted. 



Most of the meristic characters of /. isolepis 

 larvae begin ossifying during notochord flexion 

 (10-14 mm); only gill rakers and pectoral fin rays 

 begin to ossify at larger sizes (Table 4; Figure 6). 

 The following discussion roughly parallels the 

 sequence of development of meristic characters, 

 and we note their first appearance as well as the 

 onset of ossification as indicated by the acceptance 

 of Alizarin Red stain. 



Paired conical teeth may be observed on the 

 dentary of 5.3 mm larvae, and on the premaxil- 



410 



laries by 5.8 mm. Teeth continue to increase in 

 number as the larvae grow. Teeth are consistently 

 more numerous on the left (ultimately the blind) 

 side of the head than the right side. The smallest 

 specimen in which teeth accepted alizarin stain 

 was 12 mm, possibly an artifact of preservation. 

 Larval teeth develop in approximately two non- 

 parallel rows. The outer row consists of conical, 

 caninelike teeth, and the inner row is composed of 

 smaller, curved teeth. Most teeth are ossified in 18 

 mm larvae. By transformation (ca. 20.0 mm), but- 

 ter sole larvae possess approximately 37 larval 

 teeth on the left dentary (27 in the outer row; 10 

 smaller teeth on an inner row) and about 37 large 

 conical teeth on the left premaxillary arranged in 



