Feeney: Post-yolksac development of two southern California sculpins 



457 



The Bightwide program began in 1982 and samples 

 were taken bimonthly at the four "expanded" 316b 

 transects. During the Bightwide program, a fifth sta- 

 tion (75 m) was added to each transect. Only oblique 

 bongo samples were taken during the Bightwide phase. 

 Additional details are provided in Lavenberg et al. 

 (1986). 



Estimates of larval abundance (n/lOm- of sea sur- 

 face) for each taxon were estimated (for methods, see 

 Smith and Richardson 1977). These abundances were 

 plotted against variables, such as transect, station 

 depth, gear type and date, to determine patterns of 

 local occurrence. 



Identification 



Yolksac and small post-yolksac larvae of Clinocottus 

 analis and Orthonopias triads were identified by com- 

 parison with descriptions of reared larvae (Eigenmann 

 1892, Budd 1940, Bolin 1941). Larger preflexion and 

 flexion larvae were associated to postflexion larvae and 

 juveniles using pigment characters, number of preoper- 

 cular spines, length of gut, and location of the anus. 

 Washington (1986) was helpful in linking postflexion 

 C. analis individuals to juveniles using melanophore 

 patterns and meristics. For definition of terms, see 

 Feeney (1987). 



Results 



Description of Clinocottus analis larvae 



Distinguishing characters Distinguishing characters 

 of Clinocottus analis preflexion larvae include heavy 

 dorsoposterior gut pigment, nape pigment (usually with 

 a nape bubble), 18-25 postanal ventral melanophores 

 (PAVM), and melanophores on the head over the mid- 

 brain. Late preflexion larvae may develop up to 33 

 PAVM. Larger flexion and postflexion larvae develop 

 multiple preopercular spines (9-12) similar to other 

 Clinocottus and Oligocottus species (Washington 1986). 

 Transforming larvae develop a W-shaped patch of pig- 

 ment under the 2d dorsal and have an advanced anus. 

 In juveniles, the preopercular spines coalesce to one 

 bifurcate spine; small, prickly scales begin to develop 

 under the 2d dorsal fin. The anus advances about 

 halfway to pelvic fin origin. 



Morphology Clinocottus analis yolksac larvae hatch 

 at lengths of 3.7-4.5 mm (Eigenmann 1892, Budd 

 1940); preserved field-collected larvae are found as 

 small as 8.1 mm (due to shrinkage during preservation). 

 Larvae are robust with fully pigmented eyes at hatch- 

 ing. Dorsal gut diverticulae (wings) as seen in some 

 Artedius (Washington 1986) are absent; however. 



sometimes a bump can be seen in that area. 



The preanal length averages 46% of notochordal 

 length (NL), which is closer to Eigenmann's illustra- 

 tion (est. 44% ) than to Budd's illustration (est. 33%); 

 the minimum preanal length from field-collected speci- 

 mens was 40% NL (Table 1). During flexion the preanal 

 length increases slightly to an average of 47%. In 

 postflexion larvae, preanal length increases to an aver- 

 age 51.5% standard length (SL). In juveniles, the pec- 

 toral fin and head lengthen to an average 35 and 37% 

 SL, respectively (Table 1). 



In postflexion larvae, the anus is slightly advanced 

 of the anal fin origin. In transforming postflexion lar- 

 vae, the anus advances from the anal fin to about one- 

 third the distance to the pelvic fin origin. In juveniles, 

 the anus advances almost halfway to the pelvic fins. 



At 9.8mm a cirrus appears on each dorsal orbit 

 (Fig. 3B). 



Fin development In postflexion larvae, fin elements 

 start to form; the caudal rays become segmented. 

 Pelvic fins appear as buds (Table 2). At 9.8mm, fin 

 rays, including the pelvics, are well-formed. 



