NOTE: This item is not available outside the Texas A&M University network. Texas A&M affiliated users who are off campus can access the item through NetID and password authentication or by using TAMU VPN. Non-affiliated individuals should request a copy through their local library's interlibrary loan service.
The systematics of the Bathyraja and Rhinoraja (Rajidae) species of the Bering Sea and adjacent areas in the North Pacific Ocean
Abstract
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.
Description
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 digital@library.tamu.edu, referencing the URI of the item.Includes bibliographical references.
Collections
Citation
Craig, Johanna Capps (1993). The systematics of the Bathyraja and Rhinoraja (Rajidae) species of the Bering Sea and adjacent areas in the North Pacific Ocean. Master's thesis, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1993 -THESIS -C886.
Request Open Access
This item and its contents are restricted. If this is your thesis or dissertation, you can make it open-access. This will allow all visitors to view the contents of the thesis.