Table 19. Measurements (mn} of larvae of Sebastes sp, [Gulf of California Type A], 

 (Specimens between dashed lines are undergoing notochord flexion.) 



Figure 14. — Stations in the Gulf of 

 California at which larvae of 

 Sebastes cortezi were talien on 

 CalCOFI cruises during 1956 and 

 1957. 



Sebaates sp.— Gulf of California Type A, Figure 15 

 Literature. — See previous species account. 



Distinguishing features. — At birth, Type A larvae 

 are 4.0 to 5.0 mm long. The maximum size obtained 

 before transformation is not known since the largest lar- 

 va in the collection is 10.8 mm. 



Type A larvae, like those of S. cortezi, have short pec- 

 toral fins. Pectoral fin length is 6 to 9% of the body length 

 before onset of notochord flexion, and thereafter in- 

 creases to 20% in the longest larva (Table 19). At com- 

 parable sizes, the parietal spines are longer in Type A 

 than in S. cortezi. 



Type A larvae have a distinctive pattern of 

 melanophores. As in S. cortezi, newborn larvae of Type A 

 have a shield of pigment over the gut and a series of 

 melanophores along the ventral midline of the tail (mean 

 of 16 with a range of 12 to 21 for 13 larvae). Unlike S. cor- 

 tezi larvae, those of Type A have a blotch of pigment at 

 the symphysis of the lower jaw, that persists in larvae up 

 to about 8 mm. The pectoral fins have fine melanophores 

 distributed over the entire blade of the fin and have the 

 medial surface of the fin base covered with large 

 melanophores. At about 8 mm, pigment appears above 

 the brain. No pigment forms on the dorsal surface of the 

 tail as in S. cortezi. The pigment pattern is similar to 

 that of the subgenus Sebastomus from outer coastal 



waters, suggesting that Type A larvae might be referable 

 to S. (Sebastomus) exsul. 



Distribution. — Eight CalCOFI cruises into the Gulf in 

 1956 and 1957 and an FAO cruise in March of 1972, 

 provide information on the distribution and abundance 

 of Type A larvae. Their latitudinal range, from Gonzaga 

 Bay south to Concepcion Bay, is more constricted than 

 that of S. cortezi, but they are not nearly so restricted to 

 the western side of the Gulf as are larvae of S. cortezi 

 (Fig. 16). Their heaviest concentration is around Tiburon 

 and Angel de la Guarda islands in the upper Gulf. Table 

 18 shows that spawning occurs during the cold-water 

 months with a possible peak in February. 



Sebastes marinus (Linnaeus), Figure 17 



Literature. — The numerous descriptions and illus- 

 trations of intraovarian and planktonic larvae of North 

 Atlantic Sebastes were cited above in the literature 

 review for the genus. Those of Taning (1961) are es- 

 pecially useful, since they incorporate observations on 

 chromatophores that can only be made in live material. 

 A series of illustrations from Taning's (1961) paper are 

 reproduced here. The larvae used for our study are from 

 the Dana collections and were identified by A. V. Tan- 

 ing, but Eschmeyer (pers. commun.) has suggested that 

 the series may contain some specimens of S. mentella 

 and that the identification should be considered ten- 

 tative until additional material is available. These were 

 measured to establish a table of morphometries, which to 

 our knowledge has not yet appeared in the literature. The 

 following description, which includes morphometric and 

 other previously overlooked characters, is intended as a 

 supplement to the extensive literature on S. marinus lar- 

 vae. 



Distinguishing features.— At birth the larvae of S. 



marinus are considerably larger than those of the eastern 

 Pacific species. A series of full-term intraovarian larvae 

 ranged in length from 6.7 to 7.2 mm. Also, they reach a 

 comparatively large size before undergoing a gradual 

 transformation into pelagic juveniles. In the measured 

 series the transition occurs at about 24 mm (Table 20). 



26 



