FISHERY BULLETIN: VOL. 74, NO, 1 



Table 3.- 



-Age distributions ofCottus asper in successive 5-mm intervals of total length, sexes combined. Number in parentheses 

 indicates total number of fish when not all fish in the length interval were aged. 



14.5-19.4 



19.5-24.4 



24.5-29.4 



29.5-34.4 



34.5-39 4 



39.5-44.4 



44.5-49.4 



49.5-544 



54.5-59.4 



59.5-64.4 



64.5-69.4 



69.5-74.4 



74.5-79.4 



79.5-84.4 



84.5-89.4 



89 5-944 



94.5-99.4 



99.5-104.4 



104.5-109.4 



109.5-114.4 



114.5-119.4 



119.5-124.4 



124.5-129 4 



129.5-134.4 



134.5-139.4 



139.5-144.4 



Total fish 



(3) 



(25) 

 3(51) 

 6(55) 

 1(41) 

 5(33) 

 8(13) 

 1 



1 

 5 

 8 

 8 

 11 

 8 

 2 



1 

 7 



15 

 8 

 2 

 5 

 1 



(4) 

 (16) 



1(39) 

 9(46) 



18(49) 



33(38) 



26 



11 



1(3) 



2(19) 



8(30) 



11(27) 



24 



10 

 3 



(2) 



1(3) 



8(21) 



7(17) 



9 



5 



4 



(8) 

 1(9) 



(1) 

 7 

 2 

 1 1 



1 



2 



2 

 6 



3 

 2 1 



1 1 



222 



43 39 7 



1 229 



16 



116 



13 22 



61 



28 



4 14 



Table 4. — The autumnal distribution of sculpin (Coitus) 

 biomass in three streams. 



Stream Zone 



C. aleuticus 



C. asper 



Table 5. — The autumnal distribution of sculpin iCottus) 

 biomass by age-class in three streams, expressed as a per- 

 centage of species biomass. 



2.038 3.41 



2.79 81.8 



0.62 18.2 



lower stream zone was nearly equal in Lymn 

 Creek but was predominantly C. aleuticus (85%) 

 in Cabin and Waterloo creeks. 



The two sculpins differed in relative distribu- 

 tion of biomass by age group within their popula- 

 tions (Table 5). Whereas C. asper in their third 

 growth season (age II) constituted 35-47% of 

 population biomass, the biomass of C. aleuticus 

 populations in Lymn and Waterloo creeks was 

 more evenly distributed in older age groups. The 

 contribution of age I to population biomass of 

 C. aleuticus was considerably higher in the two 

 smaller streams than in Lymn Creek and 3-5 

 times higher than for C. asper in these two 

 streams. 



Length-Weight Relations 



The annual growth of both sculpins showed a 

 consistent ranking in three streams. Growth was 

 most rapid in Lymn Creek, intermediate in 

 Waterloo Creek, and slowest in Chef Creek (Fig- 

 ure 8) although the growth of C. asper in Lymn 

 and Waterloo was not statistically different. Dis- 

 similarities in rate of grovvi:h were greatest for 

 C. aleuticus, possibly reflecting its greater re- 

 liance on the productivity of the freshwater 

 stream than in the case of C. asper, which spends 

 considerably more time in the estuary through- 

 out its life history. 



C. asper grew more rapidly than did C. aleuti- 

 cus, the age-specific disparity in weight gain 

 increasing with age. Growth of the Lymn Creek 



138 



