Rhinoptera bonasus ( Mitchill, 1815 )

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 : 301

Rhinoptera bonasus ( Mitchill, 1815) —cownose ray, American cownose ray

Synonyms:

Myliorhina lalandii (Valenciennes, 1841)

Raja bonasus Mitchill, 1815

Raja quadriloba Lesueur, 1817

Rhinoptera lalandii Valenciennes, 1841

Rhinoptera quadriloba (Lesueur, 1817)

Distribution. This species occurs throughout the northern GOM in shallow waters, including bays and estuaries. Although it can be found from the Texas/ Mexico border to southern Florida, there is some evidence that this species may be more prevalent in the northeastern than in the northwestern GOM ( Jones et al. 2017). This species regularly occurs from close to shore out to waters 30 m in depth, although NMFS SEFSC trawl surveys have captured individuals in waters up to 96 m in depth.

First Record in GOM. The first record of this species occurring in the northern GOM is a report by Goode and Bean (1879) of a single specimen ( USNM 21221 , verified by first author) collected by Silas Stearns between 1887 and 1889 in the vicinity of Pensacola , Florida .

Remarks. Recent studies ( Naylor et al. 2012, Jones et al. 2017) have indicated the presence of a second rhinopterid species, Rhinoptera brasiliensis Müller, 1836 , in the northern GOM (see below). The two species are morphologically very similar and therefore difficult to differentiate without detailed examination and/or genetic verification. It is likely, based upon historic reports ( Bigelow and Schroeder 1953, Acero and Garzon 1982, Isaís and Dominguez 1996), that Rhinoptera brasiliensis has been present in the northern GOM for several decades, if not longer, bringing into question the validity of reports and research focusing on this species without confirming species identity ( Jones et al. 2017). Care should be taken in applying the results of research focused on this species in the northern GOM until species-specific results can be obtained and compared.

Conservation Status. Near Threatened, although this status will likely change given the recent identification of a congener co-occurring throughout most of the species’ range.