Development of pigment pattern in later larval stages 

 is also similar to that in the S. marinus group of the At- 

 lantic. The ventral series on the tail becomes embedded 

 and obscure; beginning at the anterior end of the series 

 this process gradually proceeds posteriad until, in 15-mm 

 larvae, only those melanophores posterior to the anal fin 

 are visible. With further development, these too are ob- 

 scured. The dorsal series follows an opposite course. 

 Melanophores are added anteriorly to form streaks on 

 either side of the developing dorsal fin. Melanophores are 

 also added posteriorly so that the dorsum is pigmented 

 from head to caudal fin. Melanophores begin to appear 

 on the side of the tail just anterior to the caudal fin in lar- 

 vae of about 15 mm in length. Also, the posterior mar- 

 gins of the hypural elements become outlined with em- 

 bedded pigment. 



At transformation, which begins in specimens about 27 

 mm long, the upper half of the body above the lateral line 

 begins to be covered with fine melanophores. These 

 melanophores are more concentrated at the myosepta 

 and accent them. The streaks along the soft dorsal fin 

 and the streak above the caudal peduncle are darker 

 than on the more anterior region of the dorsum. In 40- 

 mm pelagic juveniles, the general body pigmentation 

 begins to extend below the lateral line, but even in later 

 juveniles and in adults, the ventral region of the body is 

 paler than the dorsal half. The pectoral and pelvic fins 

 develop no melanistic pigmentation in larvae or pelagic 

 juveniles. 



Distribution.— According to Miller and Lea (1972), S. 

 jordani ranges from British Columbia south to Cape Col- 

 nett, Baja California (about lat. 31°N). A 45.2-mm 

 juvenile (SIO 71-120) dip netted off west San Benito Is- 

 land (lat. 28°18.0'N, long. 115=34.25^) extends the 

 range of this species about 270 km south. The dis- 

 tribution of S. jordani larvae in the CalCOFI sampling 

 area during 1966 is shown in Figure 10. The sampling 

 area obviously stops short of the northward extent of 

 spawning, however, it shows the southern extent of lar- 

 val occurrence to be just south of the border with Mexico 

 (CalCOFI Line 100). Another obvious feature is the 

 coastal nature of S. jordani distribution. All larvae were 

 taken in the shoreward region of the sampling grid and 



the largest individual catches were made on stations next 

 to the coast. 



Frequency of occurrence of S. jordani is 7.7% off cen- 

 tral California and decreases to 5.7% off southern 

 California and 1.5% off northern Baja California (Table 

 14). Percentage of S. jordani larvae to total Sebastes lar- 

 vae was highest (20%) off southern California. Spawning 

 occurs over a short time period compared with other 

 species studied (Table 15); it extends from January to 

 April with a peak in February or March. 



_L 



Figure 10.— Stations at which larvae of Sebaates jordani were col- 

 lected by CalCOFI plankton Burveys during 1966. Solid circle* in- 

 dicate stations where number of larvae exceeded mean number (43.8) 

 for all positive stations. Area of ft'equent occupancy is outlined. 



Table 14. Relative abundance and frequency of occurrence of Sebastes Jordani in CalCOFI collections for 1966. 



21 



