36 



Fishery Bulletin 93|1). 1995 



The snout is initially slightly concave in profile, 

 but after flexion, this gradually changes to straight 

 or slightly convex. The eye is round. The mouth ini- 

 tially reaches to below the center of the eye but ex- 

 tends only to the anterior margin of the eye in 

 postflexion larvae. Four to six small villiform teeth 

 are present on the premaxilla by 4.7 mm. The num- 

 ber of teeth increases to 7 or 8 during flexion (4.8- 

 6.5 mm). Head spination is only weakly developed. 

 A single minute preopercular spine is present by 7.8 

 mm but is not visible after settlement (12.5 mm). A 

 weak posttemporal ridge is present by 7.2 mm and 

 is retained; however, no posttemporal spines develop. 

 The single opercular spine is first visible by 12.7 mm 

 and is retained in juveniles. 



Scales develop after settlement and are first vis- 

 ible around the gut and lateral midline of the tail by 

 approximately 16.0 mm. 



The development of fins in larval and juvenile S. 

 bassensis is summarized in Table 1. Completion of 

 fin development occurs in the following sequence: 

 caudal; pectoral; anal, first dorsal and second dorsal 

 fins (almost simultaneously); and pelvic. 



The rays of the caudal fin are present just prior to 

 flexion in larvae of 4.4 mm. Flexion commences by 

 4.8-5.0 mm and is complete by 6.8 mm. Pectoral fin 

 buds are present in the smallest specimen (2.3 mm), 

 incipient rays form during flexion (5.8-6.0 mm), and 

 a full complement of 15 or 16 rays is present by 10.0 

 mm. Anal-fin and second-dorsal-fin anlagen appear 

 during flexion. Distinct bases are present by 6.5—7.0 

 mm, incipient rays by 6.8-7.1 mm, and ossification 

 of posterior rays has regularly commenced by 7.2 mm. 

 Ossification of dorsal and anal elements proceeds 

 anteriorly and both fins complete development by 

 10.0-10.5 mm. The first dorsal fin anlage is present 

 by 7.0 mm. Distinct bases are present by 7.5-8.0 mm 

 and ossification of spines has commenced by 8.0-8.5 

 mm. Development of the first dorsal fin is complete 

 by 10.0-10.5 mm. Pelvic fin buds are present in 7.0- 

 7.2 mm larvae below the pectoral fin bases. Develop- 

 ment of the pelvic fin is complete by 12.5 mm. 



Larval pigment — S. bassensis larvae were the least 

 pigmented of the three sillaginid species examined. 



Pigment on the head in preflexion larvae is lim- 

 ited to the angle of the lower jaw and internally to 



