and the American form, larvae of these species lack the 

 obvious patch of melanophores that is present in S. 

 viviparu.s. Gut pigmentation is slightly different in S. 

 viviparus larvae compared with the other species. The 

 dorsolateral surfaces of the gut are covered with a 

 melanistic shield as in the other species; however, in S. 

 viviparus a covering of less densely distributed 

 melanophores extends ventrad over the ventral surface of 

 the gut. The ventral surface of the gut is unpigmented at 

 comparative larval stages in S. marinus and S. fas- 

 ciatus. 



The most outstanding difference in pigmentation is in 

 the pectoral fins. Sebastes marinus and S. fasciatus lack 

 pectoral fin pigment throughout the larval period while 

 S. viviparus larvae have distinctive pectoral fin pig- 

 ment. At about 6.0 mm, the medial surface of each fin 

 base begins to develop a covering of melanophores, which 

 remains throughout the larval stages available to us. 

 Also, a series of fine melanophores forms along the bases 

 of the rays and may extend distally for a short distance 

 between the rays in some specimens. This character 

 should be of considerable help in separating larvae of S. 

 viviparus from those of other North Atlantic species. 



The few early larvae of S. viviparus available to us 

 precludes analysis of the number of melanophores in the 

 ventral midline series. Of the three smaller larvae 

 counted, the ventral row began on the 3rd or 4th postanal 

 myomere and terminated on the 19th or 21st myomere. 

 The number of melanophores ranged from 18 to 29 with a 

 mean of 25. This suggests that the mean number of 

 melanophores is greater in S. viviparus than in S. 

 marinus, a supposition that can only be verified by anal- 

 ysis of an adequate sample of intraovarian larvae. 



Distribution, — See Templeman (1961). 



Sebastes fasciatus (Storer), Figure 21 



Literature. — Bigelow and Welsh (1925) briefly de- 

 scribed and illustrated a series of Sebastes larvae from 

 the Gulf of Maine. Barsukov (1968, 1972) and Barsukov 

 and Zakharov (1972) have established that the common 

 form of this region is specifically distinct and should be 

 referred to as S. fasciatus Storer. This is confirmed by 

 Eschmeyer's recent work on gas bladder myology (cited 

 in Hallacher 1974). A larval series oi Sebastes (Table 23) 

 collected off New England from lat. 38°52'N to lat. 

 44°22'N by the NMFS Laboratory, Narragansett, is de- 

 scribed briefly below and compared with those of S. 

 marinus and S. viviparus. 



Distinguishing features. ~\t would appear that lar- 

 vae of this form are born at a smaller size than those of S. 

 marinus (Tables 17, 20); however, judging from the ap- 

 pearance of our small specimens of S. fasciatus, this dif- 

 ference could be a result of shrinkage in preservative. 

 Larvae of both forms begin notochord flexion at about 8.5 

 mm; however, flexion is completed at 10.0 mm length in 

 S. fasciatus and at about 11.8 mm in S. marinus. Infor- 



mation on the size of transformation is not available 

 since the largest larva is 17.1 mm. 



Developmental changes in body proportions follow 

 closely those of S. marinus and need not be repeated here 

 (Tables 20, 23). One feature which appears to differ is 

 relative body depth. Table 22 shows that mean relative 

 body depth is greater during the three larval phases in S. 

 fasciatus than in S. marinus. Mean relative eye diameter 

 is greater in S. fasciatus than in S. marinus for preflexion 

 larvae and larvae undergoing flexion, but is less in post- 

 flexion larvae. Mean relative pectoral fin length is 

 greater in S. fasciatus than in S. marinus in preflexion 

 larvae but is less during and after flexion. 



Pigmentation is similar to that of S. marinus; however, 

 analysis of our specimens has revealed some differences 

 which have not been previously reported. As in S. 

 marinus larvae, the initial pigment pattern consists of a 

 group of melanophores above the brain, a gut shield, an 

 embedded spot at the nape, and a series of melanophores 

 along the dorsal and ventral midlines. There appears to 

 be a difference in the number of melanophores com- 

 posing the ventral midline series of S. marinus and S. 

 fasciatus larvae. Ventral melanophores were counted in 

 10 late-stage intraovarian larvae from each of 12 females 

 of S. fasciatus taken in the Gulf of Maine. The mean 

 numbers of melanophores for the 12 samples were as fol- 

 lows: 31.4, 32.2, 32.6, 32.8, 32.8, 33.3, 34.9, 35.2, 35.5, 

 37.5, 38.3, 40.4. The range for all specimens was 26 to 

 42. In a sample of 18 S. marinus larvae of comparative 

 developmental stage from Greenland, the mean was 18.0 

 with a range of 11 to 24. Also, the ventral pigment line is 

 relatively longer in S. fasciatus, beginning on the 1st to 

 4th (mean of 2.9 ± 0.40 SD for 112 specimens) postanal 

 myomere and ending on the 19th to 23rd (mean of 

 21.3 ± 0.85) postanal myomere. In the sample of S. 

 marinus the series begins on the 4th to 7th (mean 

 5.4 ± 0.78 for 18 specimens) postanal myomere and ends 

 on the 19th to 22nd (mean of 20.9 ± 0.86) postanal 

 myomere. The dorsal midline row appears to contain 

 fewer melanophores in S. fasciatus compared with S. 

 marinus. Mean counts for the 12 samples are: 3.0, 5.4, 

 6.6, 6.9, 7.2, 7.2, 7.3, 7.6, 7.9, 8.0, 8.6, 9.1. In the sample 

 of S. marinus the mean was 13.1 with a range of 8 to 21. 

 In the samples of S. fasciatus the dorsal series began on 



Table 23. Measurements (mn} of larvae of Sebastes fasciatus . {Spectmens between dashed 

 lines are undergoing notochord flexion.) 



33 



