FISHERY BULLETIN: VOL. 80. NO. 3 



pears at ca. 6.6 mm. By 8 mm additional bones 

 ossified include the epiotic, sphenotic, supraoc- 

 ciptal, parietal, nasal, and the first circumorbit- 

 al. The skull is essentially complete by ca. 14.5 

 mm. 



None of the bones of the splanchnocranium are 

 ossified at the beginning of the larval stage. By 4 

 mm they are all ossifying. Teeth first appear at 

 ca. 4.3 mm; four are present on the premaxillary. 

 Four to six dentary teeth are acquired by 5.6 

 mm; 18 premaxillary teeth are present at this 

 size. Numbers of teeth increase through subse- 

 quent larval development: an 8 mm specimen 

 has 26 premaxillary and 18-20 dentary teeth 

 while a 14.5 mm specimen has 60 and more than 

 30, respectively. 



Bones of the suspensorium begin ossifying at 

 ca. 4.2 mm; the hyomandibular and symplectic 

 are first. The ectopterygoid begins to ossify at ca. 

 6 mm and the quadrate at ca. 6.1 mm. The meta- 

 pterygoid is next (8 mm). The suspensorium is 

 essentially complete by 14.5 mm. 



The opercular apparatus begins ossification at 

 ca. 4 mm with the opercular and preopercular 

 bones. The subopercular is added at ca. 4.2 mm 

 and the interopercle at ca. 4.3 mm. Subsequent 

 development consists of spination and further 

 ossification of these bones. 



Ossification of the branchial apparatus com- 

 mences by 4 mm with the ceratobranchials of the 

 outer two arches. By ca. 4.3 mm the ceratobran- 

 chials of four arches are ossified and the hypo- 

 branchials are just beginning to ossify. Two 

 pairs of pharyngeal teeth appear at ca. 4.4 mm 

 although the associated pharyngobranchial 

 bones remain unossified until ca. 8 mm. Gill 

 rakers on the outer arch first appear at ca. 5.1 

 mm — 5 lower rakers are present. By 8 mm the 

 number of gill rakers on the outer arch increases 

 to three upper + one at the angle + nine lower 

 rakers. Epibranchials begin to ossify at this size. 

 The basibranchial ossifies between 10.5 and 14.5 

 mm but the hypohyal remains unossified into the 

 early juvenile stage. The gill raker count at the 

 end of the larval stage is 4+1+15 on the outer 

 arch. 



The first three branchiostegal rays are ossify- 

 ing by 4 mm. A fourth branchiostegal ray and 

 the posterior part of the ceratohyal begin ossifi- 

 cation at ca. 4.2 mm; the fifth branchiostegal fol- 

 lows at ca. 4.6 mm. All seven branchiostegals, the 

 epihyal, and interhyal are present by 5.6 mm. 

 Ceratohyal ossification is complete and urohyal 

 ossification is beginning by 6.3 mm. The hyoid 



apparatus is essentially complete by 14.5 mm, 

 except for the unossified hypohyal. 



Vertebral ossification begins with the anterior 

 centra and proceeds posteriorly. Each vertebra 

 ossifies from its ventral midline toward its dorsal 

 midline. Ossification is first evident in a 5.6 mm 

 specimen in the staining of the anterior seven 

 vertebral centra and first four neural arches. In 

 this same specimen centra 8 through 11 are 

 stained ventrally only. By 6 mm the first 10 cen- 

 tra are completely stained, the next 3 on the ven- 

 tral half only, and the next 2 on the ventral mid- 

 line only. At this size the first 20 neural arches 

 and 5 haemal arches (originating at the twelfth 

 centrum) are becoming ossified. At 6.3 mm the 

 first 18 centra, 20 neural arches, and 7 haemal 

 arches are stained. By 6.6 mm the anterior part 

 of the urostyle and all except the last centrum are 

 ossified, along with 23 neural arches and 12 hae- 

 mal arches. The final complement of 25 neural 

 and 14 haemal arches is attained by 8 mm. The 

 first four pleural ribs and three epipleural ribs 

 develop during the transitional period, atca. 14.5 

 mm. 



The cleithra are the first bones to ossify in the 

 pectoral girdle (by 2.6 mm). The supracleithra 

 begin to ossify at ca. 4.6 mm and the postcleithra 

 at ca. 5.6 mm. The first pectoral radial, coracoid, 

 and scapula begin to stain during the transition 

 to juvenile, after most of the pectoral rays are 

 already ossified. The basipterygia of the pelvic 

 girdle begin to ossify at this time as well. 



The general sequence of dorsal and anal fin 

 pterygiophore differentiation is described above 

 under Fin Development. Ossification in both fins 

 begins after 10.5 mm and is completed during 

 the transition to the juvenile stage. 



Pterygiophores of the anal spines are fused. 

 Except for the pterygiophores of the first and 

 last soft rays, each successive pair lies between 

 adjacent haemal spines (Fig. 6). 



The first two dorsal pterygiophores (bearing 

 the first two dorsal spines) fuse during ossifica- 

 tion. The pattern of dorsal pterygiophore place- 

 ment between adjacent neural spines is some- 

 what variable (Table 2). Three predorsal bones 

 develop during the transitional period. 



The central three hypural elements begin to 

 ossify at ca. 6.1 mm and all hypurals are ossified 

 by 8 mm. These are distinguishable as separate 

 elements throughout larval development. All but 

 one of the principal caudal rays are associated 

 with these elements; the other is associated with 

 the haemal spine of the penultimate vertebra 



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