Hawkins et al.: Genetic variation of Sebastes aleulianus and 5. boreahs 



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Results 



Shortraker rockfish and rougheye rockfish had different 

 common alleles (fixed) for 10 of 29 loci examined (sAH*, 

 CK-A1*, GPI-A*, G3PDH*, IDHP-2*, PEPA*, PEPB*. 

 PEP-LT*, PGM-2*, and SOD*). These are inexpensive 

 markers that can be used to differentiate shortraker 

 rockfish from rougheye rockfish when precise field iden- 

 tification, particularly in younger fish, is necessary but 

 difficult. 



Shortraker rockfish 



Nine loci (31%) were monomorphic for all regions, 11 loci 

 (38%) were variable (with the frequency of the common 

 allele greater than 0.95 for all regional groups), and 9 

 loci (31%) had a common allele frequency of less than 

 0.95 for at least one regional group. For the Russian 

 collection, data were unavailable from five loci {FH*, 

 mIDHP*, MPI*, PGM-2*, and TPI-2*). Average heterozy- 

 gosity of each regional group fell within a narrow range 

 of 0.09-0.11, and produced an overall average for 29 loci 

 of 0.10. All regional genotypic proportions closely agreed 

 with those expected under Hardy-Weinberg equilibrium; 

 of 128 chi-square tests, only four (3%) differed sig- 

 nificantly (P<0.05) from expected values. No significant 

 (P<0.05) heterogeneity was detected with G-tests among 



regional groups, and thus no subpopulations or stock 

 structure was evident with this suite of allozymes. 



Although no genetic differentiation was detected 

 among shortraker rockfish throughout their geographic 

 distribution, size of fish and depth of capture differed 

 between shortraker rockfish from the Aleutian Islands 

 and those from Southeast Alaska. Aleutian Island 

 shortraker rockfish were significantly smaller (mean 

 43.6 cm [±SD 7.0], range: 24-70 cm) and were caught 

 in deeper water (309-407 m) than Southeast Alaska 

 shortraker rockfish (mean 66.5 cm [±SD 10.5], range: 

 45-101 cm at 138-260 m depths). A regression of fish 

 length on depth of capture yielded a significant r 2 value 

 of 0.452 (P<0.001). 



Rougheye rockfish 



Significant departure from Hardy-Weinberg equilib- 

 rium occurred in 37 out of 226 possible tests (16%); a 

 value greater than the 11 that would be expected by 

 chance alone at the P=0.05 level of probability (Table 4). 

 Thirty-six of the departures were due to an absence of 

 heterozygotes, a situation known as the Wahlund effect, 

 which typically indicates the presence of a mixture of 

 populations for presumably neutral genetic loci. Most 

 of the departure from Hardy-Weinberg expectations 

 occurred at ACP*, IDDH*, MPI*, PGM-2*, andXO*. Only 



