The systematics of the Bathyraja and Rhinoraja (Rajidae) species of the Bering Sea and adjacent areas in the North Pacific Ocean

• Main Author: Craig, Johanna Capps
• Format: Thesis
• Language: English
• Published: Texas A&M University 1993
• Subjects: wildlife and fisheries sciences; Major wildlife and fisheries sciences; Bering Sea; Pacific
• Online Access: http://hdl.handle.net/1969.1/ETD-TAMU-1993-THESIS-C886

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [e-mail], referencing the URI of the item. Includes bibliographical references. A morphological and meristic study of the Bathyraja and Rhinoraja skates (Rajidae) of the Bering Sea and adjacent areas in the North Pacific Ocean was conducted. Nine putative species were encountered in the 310 specimens examined. The specimens examined fell into three morphological subgroups and each of these was analyzed separately to simplify the study: 1.) The first morphological subgroup consisted of Bathyraja aleutica and B. parmifera that were clearly distinct from the remainder of the species and were analyzed separately to glean information on intraspecific variation during ontogeny to apply to the other less readily identifiable species. 2.) The species in the second morphological subgroup, B. hubbsi, B. interrupts, B. kincaidii, B. violacea, Rhinoraja longi, R. taranetzi, and a new Bathyraja species, were clearly distinct from the remainder of the species and were analyzed separately to elucidate the systematics of this morphologically similar group of species. 3.) The third morphological subgroup was comprised of three morphs within B. trachura, a species that is clearly distinct from the remainder of the species and displayed intraspecific variation in morphology and meristics. The specimens in Bathyraja trachura were analyzed separately to elucidate the systematics of this putative supraspecific assemblage. The first assemblage consisted of B. aleutica and B. parmifera that were distinct but the characters used to distinguish between them in the literature are not valid over their entire size range. The second assemblage consists of seven species, B. hubbsi, B. interrupts, B. kincaidii, B. violacea, Rhinoraja longi, R. taranetzi, and B. sp. The status of R. taranetzi and B. violacea could not be assessed because the type specimens of these species were unavailable. However, the character used to separate Bathyraja from Rhinoraja, absence or presence of a basal segment in the rostral cartilage, is likely an artifact of preservation and dissection. The third assemblage is comprised of three forms within B. trachura that are distinct from B. trachura and among themselves.