FISHERY BULLETIN: VOL. 87, NO. 4, 1989 



benthic juveniles, ranging from 10.9 to 16.8 mm 

 BL, were also examined. Ten representative 

 larval G. marmoratus were deposited in the 

 Western Australian Museum (Perth) under the 

 catalogue number P-29814-001. 



Measurements and Counts 



Larval and juvenile G. marmoratus were 

 measured to the nearest 0.1 mm using a Wild 

 M8' dissecting microscope fitted with an ocular 

 micrometer. Terminology and body measure- 

 ments of larvae follow Leis and Rennis (1983). 

 All lengths except body length (BL, mm), i.e., 

 the notochord length in preflexion and flexion 

 larvae and the standard length in postflexion 

 larvae, are expressed as a percentage of body 

 length. Myomere counts and fin ray counts of 

 paired fins were made on the left side of the 

 body. Pigment refers to melanin. Illustrations 

 were done with the aid of a drawing tube. 



Six larval, one transforming, and three juve- 

 nile G. martnoratus were cleared and double 

 stained for bone and cartilage following the tech- 

 nique of Potthoff (1984), as modified from 

 Dingerkus and Uhler (1977). These specimens 

 were used to count fin rays and vertebrae, to 

 determine the sequence of bone ossification, and 

 to describe the development of both the head 

 spines and the caudal complex. The term "ossi- 

 fied" refers solely to structures stained posi- 

 tively for bone. The terminology used for de- 

 scribing the head spination and the caudal com- 

 plex was modified from that of Washington et al. 

 (1984a) and Feeney (1986) respectively. 



RESULTS 



Identification 



Larvae were identified as scorpaenids by the 

 well-developed head spination, the continuous 

 dorsal fin, and the large, fan-shaped, pigmented 

 pectoral fins (Leis and Rennis 1983). Specimens 

 were initially assembled in a series according to 

 the degree of formation of the pectoral fins 

 which, when fully formed, have 11 fin rays. 

 Large specimens were identified as G. 

 marmoratus by dorsal and anal fin ray counts of 

 XIII, 9 and III, 6 respectively and the elong- 

 ate infraorbital spine (Scott et al. 1980; Last et 

 al. 1983). Fin ray counts, head spination, and 



'Reference to trade names does not imply endorsement by 

 the National Marine Fisheries Service, NOAA. 



body pigment were used to link larvae and 

 juveniles. 



Description of Larvae 



Larvae of G. ynarmoratus are pelagic prior to 

 transformation. Larvae are initially elongated, 

 becoming deep-bodied (12-36% BL) and laterally 

 compressed with development (Table 1, Figs. 1, 

 2). The smallest larva illustrated (3.3 mm. Fig. 

 lA) possesses pectoral fin buds and a dermal sac 

 enclosing most of the body but has neither head 

 spines nor traces of yolk sac. The head length 

 increases from 13% BL in preflexion larvae to 

 38% BL in postflexion larvae (Table 1). The 

 mouth is formed by 3.3 mm and teeth appear 

 along the premaxilla and dentary at 6.8 mm. The 

 gut is coiled and short in small larvae. The preanal 

 length increases from 35% BL in preflexion 

 larvae to 61% BL in postflexion larvae (Table 1, 

 Figs. 1, 2). There is a moderate gap between the 

 anus and the origin of the anal fin in postflexion 

 larvae (Fig. 2). A prominent swimbladder 

 becomes visible above the gut from about 3.3 mm, 

 but it is no longer externally visible by 10 mm. 



Larval G. marrnoratus possess 29 myomeres. 

 Double-stained specimens have 28 vertebrae 

 (Table 2). Notochord flexion commences by 4.8 

 mm and is complete by 6.0 mm. Transformation 

 from the pelagic larva to the benthic juvenile 

 occurs between 6.8 and 10.9 mm (Fig. 2A, B). 



Fin Development 



The development of fins in larval and juvenile 

 G. marmoratus is summarized in Table 2. Pec- 

 toral fins develop very rapidly, attaining a 

 length of 44%' BL in postflexion larvae (Table 1, 

 Fig. 2A). Incipient fin rays of the pectoral fin are 

 visible by 3.3 mm, and all 11 fin rays are formed 

 by 4.7 mm. The caudal fin starts to form by 4.6 

 mm and is completely developed shortly after 

 notochord flexion is complete (Figs. 2A, 4C). 

 The dorsal and anal fin anlagen appear by 5.0 

 mm, i.e., prior to completion of notochord flex- 

 ion, and the rays start to form sequentially from 

 tail to head. Rays and spines, both dorsal (XIII, 

 9) and anal (III, 6), are developed by 9.0 mm 

 (Table 2). Pelvic buds are visible by 4.8 mm and 

 fin rays ai'e formed by 9.3 mm. 



Pigmentation 



Larval G. marmoratus are lightly pigmented 

 prior to transformation. In preflexion larvae, the 



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