Breviraja spinosa Bigelow and Schroeder, 1950

Jones, Christian M., Driggers Iii, William B., Hannan, Kristin M., Hoffmayer, Eric R., Jones, Lisa M. & Raredon, Sandra J., 2020, An annotated checklist of the chondrichthyan fishes inhabiting the northern Gulf of Mexico Part 1: Batoidea, Zootaxa 4803 (2), pp. 281-315 : 306-307

Breviraja spinosa Bigelow and Schroeder, 1950 —spinose skate

Synonyms: None

Distribution. The single representative of this species from the region (USNM 222437, Figure 16 ) was reportedly collected south of Destin off the Florida panhandle at a depth of approximately 670 m. Trawl data from NMFS SEFSC suggests that this species occurs throughout the northern GOM, in depths as shallow as 78 m. Generally accepted to occur off the east coast of the U.S. from North Carolina to the Florida Straits in depths ranging from 365 to 670 m.

First Record in GOM. Although they do not include the northern GOM in their reported distribution of this species, McEachran and Matheson (1985) include specimen USNM 222437, and provide the associated location data, in their list of material examined.

Remarks. McEachran and Fechhelm (1998) include this species in their guide to the fishes of the GOM but specify that the data associated with the USNM specimen are questionable. This assessment was backed up by McEachran and Matheson’s (1985) decision to exclude the northern GOM from the distribution of B. spinosa despite including USNM 222437 in their material examined. If the specimen did, in fact, originate from the location proposed, it was not identified as B. spinosa in the field as the original datasheets do not record that species among those captured (SEFSC, unpublished data). If the identification was changed upon arrival at the USNM, the reason for the change was not recorded. It is possible that the specimen was collected outside the GOM during a previous survey, conducted earlier in the same year off Central and South America, but that would again put the specimen outside the known range for the species. Several specimens of B. spinosa were collected during that survey but would later be designated a separate species, Breviraja nigriventralis McEachran and Matheson, 1985 . While USNM 222437 lacks any discernible markings (the specimen is either leucistic or has been bleached by preservation), its morphology and skeletal anatomy appear to match the description for B. spinosa provided by McEachran and Matheson (1985). Furthermore, between 1977 and 2014, 39 individual skates collected by NMFS SEFSC trawl surveys have been identified as B. spinosa in the field. However, further examination of specimens deposited in research collections has revealed that all individuals originating from the northern GOM that were originally identified as B. spinosa , with the exception of USNM 222437, were misidentified. Misidentifications appear to be common, with several species often identified as B. spinosa in the field (C. Jones unpublished data). If the species does occur in the northern GOM it is extremely rare and if collected in the future, representative specimens should be deposited in research collections with accurate locality data.

Conservation Status. Data Deficient

Figures

FIGURE 16. Dorsal (A) and ventral (B) perspectives of a specimen of Breviraja spinosa (USNM 222437) proposed to have been collected from the northern Gulf of Mexico. Photographs by Sandra J. Raredon, USNM.