First record of albinism in the rockfish Sebastes pachycephalus complex (Scorpaeniformes: Scorpaenidae)

Abstract

Albinism, a condition resulting from a group of genetically determined disorders of the melanin pigmentary system (Kinnear et al. 1985), occurs in two forms: (1) complete albinism, which is phenotypically expressed as a lack of integumentary and retinal melanin, indicating defects in the integumentary and retinal melanophores, and (2) partial albinism or leucism. The latter describes an individual with reduced or absent integumentary pigment, but with pigmented retinas, resulting in diminished or no body coloration and darkly pigmented eyes. Primarily used in herpetological literature, the term leucism has recently been suggested as appropriate for ichthyology (Clark 2002). Complete albinism and leucism have been reported in numerous teleost species (e.g., Follett and Dempster 1966; Huzita and Nishino 1966; Dawson 1967; Shinohara and Amaoka 1993; Delgado et al. 2009; Mansur 2011; Pillai and Somvanshi 2011), as well as among chondrichthyans (e.g., Talent 1973; Ishihara et al. 2001; Bottaro et al. 2005; Sandoval-Castillo et al. 2006; Reum et al. 2008; Veena et al. 2011). However, in rockfishes of the genus Sebastes Cuvier 1829, only one record of albinism has been documented to date [Follet and Dempster 1966, as Sebastodes melanostomus (Eigenmann and Eigenmann 1890)], an unusual example of leucism, termed ‘‘melanalbinism’’ by the authors. On 28 February 2012, a single leucistic individual of Sebastes pachycephalus complex was captured alive in a basket trap in Kamaishi Bay, Iwate Prefecture, Japan (Fig. 1). A brief description of the specimen is given below. Morphological characters were examined following Muto et al. (2011) except for the lower jaw length, which was taken as the distance between the symphysis and the posteriormost point of the dentary, after fixation in 10 % formalin and preservation in 70 % ethanol. Terminology of the head spines follows Randall and Eschmeyer (2001). Counts and measurements were taken from the right side of the body, the left side having been damaged. The specimen was deposited in the Kyoto University Fish Collection (FAKU). Description (based on FAKU 134960, 245.3 mm in standard length). The following measurements are expressed as percentage of standard length: head length 41.3; snout length 10.5; orbital length 8.6; postorbital length 22.6; upper jaw length 18.3; lower jaw length 16.6; body width 25.6; caudal peduncle depth 12.1; preanal length 68.2; predorsal length 32.7; prepelvic length 46.9; longest dorsal-fin spine (both fourth and fifth) length 15.3; longest dorsal-fin soft ray (fourth) length 16.4; first anal-fin This article was registered to the Official Register of Zoological Nomenclature (ZooBank) as DE8B323D-8BC9-4B36-90D5-6F3EC46CACE5. This article was published as an Online First article on the online publication date shown on this page. The article should be cited by using the doi number.