1034 



Fishery Bulletin 97(4), 1999 



Figure t 



Eggs of Cheilopogon xenoptenis. (A) stage VI, 1.8 mm (8910JD. station 3-1021; (B) stage 

 VIII, 1.8 mm (9210JD, station 1-008); (C) stage X, 1.9 mm (8910JD, station 3-100). 



Description of larvae 



Morphology 



Larvae hatch at about 2.9-3.3 mm length and have 

 Httle remaining yolk, functional mouth, fully flexed 

 notochord, and rays forming in all fms (Fig. 2). Lar- 

 vae moderately elongate, with preanal length near 

 807c BL at hatching, become increasingly elongate 

 with preanal length decreasing to near lO^c BL by 

 ca. 8 mm (Table 2). Eyes initially oval (vertical axis 

 about 707( horizontal axis), gradually becoming 

 nearly round. Pectoral- and pelvic-fm rays initially 

 short (near 10% BL), rapidly elongate to ca. 25-50^^ 

 and 20-409f BL, respectively. Height of dorsal fin 

 increases from about 15% BL in large lai'vae ( IS- 

 IS mm) to about 28% BL in small juveniles (by ca. 

 36 mm). A pair of mandibular barbels forms at about 

 4 mm. Barbels originate as low, anteroventral thick- 

 ening that elongates into a slender, flattened flap on 

 each side of lower jaw. Barbels broaden, develop 



frilled margins, and fuse mesially at their bases by 

 about 8.3 mm (Figs. 2-4). Scales form along lateral 

 line beginning at about 13-14 mm and cover body by 

 26 mm. There are 27-30 predorsal scales and seven 

 scale rows between dorsal-fin origin and lateral line. 



Vertebral column and fin development 



Notochord flexion begins during embryonic stage VIII 

 (dorsal, anal, caudal finfolds first visible in this stage) 

 and is completed early in stage IX. Vertebral column 

 ossification begins soon after hatching. Neural and 

 haemal arches and spines apparently form first, be- 

 fore corresponding vertebral centra. Ossification of 

 arches apparently anterior to posterior: in 3.8-mm 

 specimen all arches ossifying except last three neu- 

 ral arches, last haemal arch, and last three or four 

 neural and haemal spines (all present as cartilage). 

 Direction of ossification of individual arches appar- 

 ently distad from base: in 3.8-mm specimen haemal 

 arches 11-13 appear to be ossifying from near base 



