Genetic Differences between Two Color Morphotypes of Redfish, Sebastes scythropus (Osteichthyes : Scorpaenidae)

Abstract

Genetic differences between two color morphotypes of Sebastes scythropus (Jordan and Snyder, 1900) were estimated from partial sequences of the mitochondrial (mt) DNA tRNA genes and control region. A phylogenetic tree was constructed using the neighbor-joining method and incorporating sequences from the congeners S. inermis Cuvier, 1829, S. joyneri Gunther, 1878, S. owstoni (Jordan and Thompson, 1914), and S. thompsoni (Jordan and Hubbs, 1925), as well as Sebastiscus marmoratus (Cuvier, 1829) (outgroup). Individuals of each color morphotype of S. scythropus were reciprocally monophyletic, with bootstrap values of 100%. The mean sequence difference between the two morphotypes was 10.1%, which was comparable to, or even larger than, the interspecific differences among the other four Sebastes species (5.9-10.8%). Sympatric occurrence of the two morphotypes with such a high degree of genetic differentiation indicates that they are reproductively isolated and stand as distinct species.