FISHERY BULLETIN: VOL. 80, NO. 3 



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Son Onofre Kelp 



18m 



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FIGURE 1.— Chart of the sampling area and its position off the 

 southern California coast. SONGS = San Onofre Nuclear Gen- 

 erating Station. 



and 139 field larvae. These were collected in 1978 

 and 1979 between the 6 and 20 m isobaths near 

 the San Onofre Nuclear Generating Station (Fig. 

 1; Barnett and Sertic footnote 3). 



Eggs used only for egg description were main- 

 tained at ambient air temperature (ca. 20°C) 

 while those reared for larval description were 

 maintained near their collection temperatures 

 (13.4°-14.3°C). The sequence of developmental 

 events in reared specimens was confirmed by 

 comparison with field specimens. 



Plankton samples were preserved in the field 

 in 5% seawater-Formalin 4 and specimens later 

 sorted in the laboratory. These were stored in 

 2.5-5% seawater-Formalin. Reared specimens 

 were preserved in 2.5% seawater-Formalin. 



Because reared Genyonemus larvae often are 

 more heavily pigmented than field specimens, 

 the latter were used as the principal descriptive 

 source. Yolk-sac larvae were primarily reared 

 specimens, owing to the difficulty of obtaining 

 undamaged field specimens of this size. Twenty 



4 Reference to trade names does not imply endorsement by 

 the National Marine Fisheries Service, NOAA. 



field specimens from the early larval stage 

 through transition to the juvenile were cleared 

 and stained with alizarin following the method of 

 Hollister (1934) to determine the sequence of 

 skeletal ossification. 



Measurements were made to the nearest 0.03 

 mm at 25X using a binocular dissecting micro- 

 scope equipped with an ocular micrometer. 

 Drawings were made with the aid of a camera 

 lucida. Pigmentation illustrated for yolk-sac lar- 

 vae represents fresh material; the pattern is 

 largely lost after several weeks of preservation. 



Developmental stages follow the terminology 

 of Ahlstrom and Ball (1954), except that the tran- 

 sitional period between the larval and juvenile 

 stages is considered to begin when the first scales 

 appear and to end when scalation is essentially 

 complete. All fin rays and myomeres (preanal 

 plus postanal) were counted on each specimen, 

 when distinguishable. Dimensions measured 

 were body depth, eye diameter, head length, pre- 

 anal length, preanal fin length, snout length, and 

 standard length. These dimensions are defined 

 in the literature (e.g., Saksena and Richards 

 1975; Powles 1980). 



EMBRYONIC DEVELOPMENT 



The G. lineatus egg is pelagic, spherical or 

 nearly so, and transparent, with an unsculptured 

 chorion and unsegmented yolk (Fig. 2). It usually 

 contains a single colorless to slightly yellowish oil 

 droplet, although in the early stage it may con- 

 tain two or three oil droplets which later co- 

 alesce. Thirty-eight live eggs collected from the 

 plankton averaged 0.85 mm (SD = 0.02 mm) in 

 diameter, with a single oil droplet of 0.23 mm 

 (SD = 0.02 mm). The perivitelline space was very 

 small (<0.04 mm). These dimensions are similar 

 to those given by Morris (1956) for G. lineatus 

 eggs collected from the plankton: egg diameter 

 0.9 mm and oil droplet diameter 0.2 mm. 

 Twenty -one eggs preserved for 111 d in 2.5% sea- 

 water-Formalin were slightly oval, averaging 

 0.84 by 0.83 mm (SD = 0.02 mm) in diameter, 

 with a single oil droplet of 0.21 mm (SD = 0.01 

 mm) and a perivitelline space of 0.05 mm (SD = 

 0.02 mm). 



The embryo is unpigmented through gastrula- 

 tion (Fig. 2a, b). During eye capsule formation 

 the first few small melanophores appear on the 

 distal side of the oil droplet and on the yolk adja- 

 cent to the oil droplet (Fig. 2c). Midlateral, mid- 

 dorsal, and a few scattered dorsolateral trunk 



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