Common name

White, William T, Corrigan, Shannon, Yang, Lei, Henderson, Aaron C, Bazinet, Adam L, Swofford, David L & Naylor, Gavin J P, 2018, Phylogeny of the manta and devilrays (Chondrichthyes: obulidae), with an updated taxonomic arrangement for the family, Zoological Journal of the Linnean Society 182 (1), pp. 50-75 : 57

Common name : Atlantic devilray

Nomenclatural discussion: Bancroft (1831) designated a new species name, C. hypostomus , to a devilray specimen from Jamaica. He only distinguished this new species from his C. manta Bancroft, 1829 (= Mobula birostris ) in the form of the anterior margin of pectoral fins, a ventrally positioned mouth, and a rounded spiracle located on ventral plane and not dorsal plane of disc. Although the specimen is mentioned to have been included in the collection, there is no mention of the type being preserved. No neotype was designated by Notarbartolo di Sciara (1987) as there was no species identification issues with this species in the western Atlantic.

In 1836, Müller designated the name C. olfersii for a Brazilian species based on a skeleton and head (ZMB syntypes) and a dry specimen (MNHN specimen). This has been considered a junior synonym of M. hypostoma ( Bigelow & Schroeder, 1953; Notarbartolo di Sciara, 1987). Two other new combinations were designated for Jamaican material in subsequent decades, that is, C. massenoidea Hill, 1862 and C. robertsii Boulenger, 1897 , with both being junior synonyms of M. hypostoma .

Vaillant (1879) described C. rochebrunei from a single specimen from Senegal in the Eastern Atlantic ( Fig. 3 ). Bigelow & Schroeder (1953) considered this species a synonym of M. hypostoma and included Senegal in the range of this species. In contrast, Krefft & Stehmann (1973) listed it as a synonym of M. mobular . Notarbartolo di Sciara (1987) concluded that M. rochebrunei was distinct from M. hypostoma based on newly acquired morphometric data for several characters, for example, distance between first gill slits and predorsal length, dentition (tooth crown crenulated on labial edge vs. smooth).

Remarks: This study provides a substantial amount of molecular data allowing a direct comparison of M. rochebrunei to M. hypostoma . Analysis of the mitochondrial genome data shows an extremely close relationship between the holotype of M. rochebrunei and M. hypostoma ( Fig. 1 ). The observed uncorrected p -distance between these taxa was the lowest of all pairwise comparisons within Mobulidae , and likely within the realm of representing intraspecific variation. Thus, based on these results, we conclude that M. rochebrunei is a junior synonym of M. hypostoma , with the latter species confirmed as occurring in both the Western and Eastern Atlantic. The morphometric and dentition differences highlighted by Notarbartolo di Sciara (1987) were based on low sample sizes. The differences seen in several characters most likely represent intraspecific variation. A more detailed taxonomic review of the Eastern versus Western Atlantic M. hypostoma populations is required to elucidate whether there are population-level differences, or whether those differences simply reflect the low sample size available.

Figures

Figure 1. Phylogenetic tree showing the relationships among mobulid species, relative to three outgroups (Aetobatus narinari, Myliobatis aquila and Rhinoptera bonasus). The tree was derived from a Maximum Likelihood analysis of an alignment of the protein coding components of the mitochondrial genomes (11442 sites) under a partitioned model of molecular evolution. Bootstrap support values are displayed on the nodes.

Figure 3. Dorsal view of the dry, stuffed holotype of Mobula rochebrunei: MNHN A9967, adult male 108.5 cm DW.