FISHERY BULLETIN: VOL. 87. NO. 3, 1989 



and is broader in the latter species, although in 

 both species it subsequently expands anteriorly 

 to completely cover the sides of the body. Late 

 larvae and pelagic juveniles of all three species 

 are heavily pigmented; G. nigricans maintains a 

 strong midlateral stripe, M. californiensis be- 

 comes uniformly pigmented, and H. azurea de- 

 velops a mottled or barred pattern. 



The three species differ in body depth, with 

 G. nigricans the most slender and H. azurea 

 the most robust. Developmental events occur 

 at a smaller size in H. azurea than in the 

 other species. Notochord flexion occurs be- 

 tween 4.1 and 5.8 mm in H. az2irea, and be- 

 tween 5.8 and 8.6 mm in G. nigricans and M. 

 californiensis. Transformation to pelagic 

 juveniles occurs at about 11-12 mm in H. 

 azurea, ca. 17 mm in G. nigricans and ca. 12 

 mm in M. californiensis. Head spination is 

 more developed in M. californiensis than in the 

 other two species. 



Dorsal and anal fin ray counts are distinct for 

 all three species at about 10 mm SL. Hennosilla 

 azurea has XI, 11 dorsal rays and III, 10 anal 

 rays while these fin formulas are D: XII-XIV, 

 12-15, A: III, 10-13 for G. nigricans and D: 

 IX-X, 22-27, A: III, 17-21 for M. californiensis 

 (Miller and Lea 1972). 



Girella nigricans 

 Figures 1-3 



General Morphology 



Our smallest yolk-sac larvae are ca. 3.0 mm, 

 have unpigmented eyes, a rudimentary mouth, 

 and a large oval yolk sac which extends from the 

 head to ca. midintestine and contains a single 

 posteriorly located oil globule (ca. 0.16-0.20 mm 

 diameter). Larvae are 3.5-3.7 mm long when the 

 yolk is completely absorbed. Prefiexion larvae 

 are moderately slender with a relatively short 

 coiled gut which extends slightly less than 40% 

 of body length (Tables 1, 2). A small gas bladder 

 is positioned anteriorly above the gut. The head 

 is relatively small, with a blunt snout, and with 

 round to slightly elongate (horizontally) eyes 

 (Fig. 2). 



Development is gradual during flexion and 

 postflexion with no abrupt changes in body form 

 or proportions. Most body parts increase rela- 

 tive to body length throughout the larval period 

 with snout-anus length, head length, and body 

 depth showing the greatest changes (Table 2). A 

 small blunt spine develops at the angle of the 



preopercle in late prefiexion larvae, and remains 

 inconspicuous during later larval stages. No 

 other head spines develop in larvae; however, 

 one or more additional minute preopercular 

 spines may appear in early pelagic juveniles. 

 These specimens also develop an opercular and a 

 minute supracleithral spine. 



Notochord fiexion begins at ca. 5.8 mm length 

 and is completed by ca. 8.6 mm. Transformation 

 into the pelagic juvenile stage is indicated by the 

 appearance of scales (first seen in a 15.7 mm 

 specimen), completion of fin ray elements, and 

 attainment of juvenile pigment at about 17 mm 

 (Fig. 3). 



Fin Formation and Meristics 



The first rays to calcify are the central prin- 

 cipal caudal rays beginning late in the prefiexion 

 stage at ca. 5.8 mm (Table 3). The full comple- 

 ment of 9+8 principal rays is present midway 

 through fiexion and the procurrent rays begin to 

 calcify at the end of flexion. The full complement 

 of 10-12 + 9-10 procurrent rays is acquired in 

 early pelagic juveniles (Table 3). 



The dorsal and anal soft rays begin to calcify 

 during flexion. Addition is posteriad with full 

 complements attained in early postflexion. 

 Dorsal and anal spines appear during early post- 

 flexion and are added in an anteriad direction. 

 Full dorsal and anal fin complements (D: XII- 

 XIV, 12-15; A: III, 10-13) are present in post- 

 fiexion larvae 10.7 mm and larger. 



The pectoral fins are initially rounded with 

 rounded bases and retain this shape throughout 

 the larval period; they become more elongate in 

 pelagic juveniles. Calcification of rays begins 

 midway through fiexion; the upper rays are the 

 first to appear and addition is ventrad. The full 

 complement of 18-20 is present just before 

 transformation into the pelagic juvenile. 



The pelvic fins are the last to form. Fin buds 

 appear midway through flexion and calcification 

 of rays begins just after flexion is completed. 

 The full complement of 1,5 rays was present in 

 specimens 10.7 mm and larger. 



Initial vertebral ossification was not apparent 

 in our stained series; however, the anteriormost 

 22 vertebral centra were already ossifying in a 

 6.7 mm larva. Ossification proceeds in a poste- 

 riad direction and the full complement of 27 

 vertebrae is present by the end of fiexion. The 

 branchiostegal rays begin to ossify late in pre- 

 fiexion and the full complement of six pairs of 

 rays is present late in fiexion. 



748 



