
MESA: Rougheye Rockfish Stock Structure
Several recent studies on the genetic differences between the observed types of rougheye rockfish indicate two distinct species. The southern species of rougheye rockfish, now proposed as S. aleutianus or rougheye rockfish, is typically lighter in coloration with spots absent from the spinous dorsal fin and possibly has mottling on the body. The northern species of rougheye rockfish, now proposed as S. melanostictus or blackspotted rockfish, is often darker in body coloration with distinct spots present on the dorsal fin and body. The two species occur in sympatric distribution with rougheye extending farther south along the Pacific Rim and blackspotted extending into the western Aleutian Islands. The overlap is quite extensive; however a potential difference in depth distribution may occur.
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Unidentified adult rougheye rockfish in boulder field as seen from Delta submersible. |
At present there appears to be difficulty in accurate field identification between the two species. Methods should be developed and tested that would enable rapid and accurate field identification of the two species by observers and scientists so that population estimates and catch accounting can occur. In addition, studies should be undertaken that assess whether the two species have significantly different life history traits (i.e., age of maturity and growth). Until such information and studies occur it will be difficult to undertake distinct population assessments. Ongoing research in this area may determine particular habitat preferences that might be useful for separating the species, and phenotypic research may determine a distinct combination of characters for onboard identification.
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Color morphs of unidentified rougheye rockfish. |
Contact:
Kalei Shotwell
Auke Bay Laboratories
Alaska Fisheries Science Center, NOAA Fisheries
Ted Stevens Marine Research Institute
17109 Pt Lena Loop Rd
Juneau AK 99801
Kalei.Shotwell@noaa.gov
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