FISHERY BULLETIN: VOL. 70, NO. 4 



Teeth 



At 5 mm, widely spaced small conical teeth are 

 visible on the premaxillaries (Figure 3A). By 

 6.5 mm teeth are fairly closely spaced all along 

 the premaxillaries and medially on the dentaries 

 (Figure 3B). By 10 mm the teeth on the pre- 

 maxillaries are very closely spaced and slightly 

 recurved; those on the dentaries are enlarged 

 and more widely spaced posteriorly but resemble 

 those on the premaxillaries anteriorly. 



Axial Skeleton 



Ossification of the vertebral column proceeds 

 posteriorly beginning between 4.5 and 5.0 mm. 

 Neural and hemal spines form concurrently with 

 their associated vertebrae. By 5 mm the anteri- 

 or 12 vertebrae have ossified. By 6.5 mm all of 

 the vertebrae are ossified except two or three an- 

 terior to the urostyle. The urostyle ossifies at 

 6 mm. The penultimate and antepenultimate 

 vertebrae ossify last at 7 mm (Table 1). The 

 first caudal supports to ossify are the medial four 

 hypurals at 6.5 mm, Hypural 1 is ossified at 

 8.0 mm and hypural 6 is ossified at 8.5 mm. The 

 uroneural and epurals form at 10 mm. 



The structure of the caudal region at 11.8 mm 

 (Figure 7) varies only slightly from the typical 

 perciform type described by Gosline (1961). As 



in other serranids, the two separate uroneurals 

 have fused, but no fusion of the hypurals has oc- 

 curred. Otherwise the caudal skeleton is typical, 

 having three epurals, a urostyle with a single os- 

 sification, and the hemal arch on the antepenulti- 

 mate and penultimate vertebrae being autog- 

 enous (not fused to the vertebrae). There are 

 15 branched segmented rays supported by six 

 hypurals, 7 ventrally on hypurals 1, 2, and 3 and 

 8 dorsally on hypurals 4, 5, and 6. One ray dorsal 

 and one ray ventral to these are also segmented 

 but not branched. About eight raylets form 

 dorsally and an equal number form ventrally an- 

 terior to the segmented rays. If the first hypural 

 is considered a parhypural (Nybelin, 1963), 

 black sea bass have only two ventral hypurals. 



Branchiostegal Rays 



The first branchiostegal rays form at about 

 4.5 mm. By 5 mm four to six rays have formed 

 and at 6.5 mm the adult complement of seven 

 rays is reached, with the medial ones being the 

 last to form (Table 1). 



Caudal Fin 



From 2 to 4 mm the finfold is symmetrical 

 around the tip of the notochord. Actinotrichs 

 are formed adjacent to the posterior 10 9f of the 



UNBRANCHEO RAY 



Figure 7. — Caudal skeleton of a 

 black sea bass larva 11.8 mm SL. 

 APU = antepenultimate vertebra; 

 EP = epural; HS = hemal spine; 

 HY ^ hypural ; NS = neural spine ; 

 PU = penultimate vertebra; UN 

 = uroneural; UR = urostyle. 



UNBRANCHEO RAY 



1250 



