Mesoplodon eueu, Carroll & McGowen & McCarthy & Marx & Aguilar & Dalebout & Dreyer & Gaggiotti & Hansen & Helden & Onoufriou & Baird & Baker & Berrow & Cholewiak & Claridge & Constantine & Davison & Eira & Fordyce & Gatesy & Greg Hofmeyr & Martín & Mead & Mignucci-Giannoni & Morin & Reyes & Rogan & Rosso & Silva & Springer & Steel & Olsen, 2021

Carroll, Emma L., McGowen, Michael R., McCarthy, Morgan L., Marx, Felix G., Aguilar, Natacha, Dalebout, Merel L., Dreyer, Sascha, Gaggiotti, Oscar E., Hansen, Sabine S., Helden, Anton van, Onoufriou, Aubrie B., Baird, Robin W., Baker, C. Scott, Berrow, Simon, Cholewiak, Danielle, Claridge, Diane, Constantine, Rochelle, Davison, Nicholas J., Eira, Catarina, Fordyce, R. Ewan, Gatesy, John, Greg Hofmeyr, G. J., Martín, Vidal, Mead, James G., Mignucci-Giannoni, Antonio A., Morin, Phillip A., Reyes, Cristel, Rogan, Emer, Rosso, Massimiliano, Silva, Mónica A., Springer, Mark S., Steel, Debbie & Olsen, Morten Tange, 2021, Speciation in the deep: genomics and morphology reveal a new species of beaked whale Mesoplodon eueu., Proceedings of the Royal Society B 288 (1961), pp. 1-10 : 5-6

Mesoplodon eueu sp. nov.

Holotype NMNZ MM003000 , a pregnant, 5.06 m long adult female named Nihongore by Te Rūnanga o Makaawhio. Collected by Ramari Stewart, Nathaniel Scott and Don Neale after beachcast on 27 November 2011. The complete skeletons of the female and fetus are held by Museum of New Zealand Te Papa Tongarewa ( NMNZ, Wellington, Aotearoa New Zealand; specimen MM003000), and a tissue sample is held in the New Zealand Cetacean Tissue Archive (NZCeTA, Universityof Auckland, Auckland, Aotearoa New Zealand; all institutional abbreviations in electronic supplementary material, S1).

Type locality

Waiatoto Spit , South Westland , Aotearoa New Zealand.

Paratypes Adult females ( PEM N0136 and PEM N3438 ) and adult male ( PEM N1114 ) held at Port Elizabeth Museum (Gqeberha, South Africa) and adult males ( SAM-ZM-041596 and SAM- ZM-039840 ) held at Iziko South African Museum (Cape Town, South Africa). Full description of paratypes is found in electronic supplementary material S2.

Etymology

The scientific and common names acknowledge links with Indigenous communities in South Africa and Aotearoa New Zealand, respectively, and were chosen in consultation with these peoples. Most of the South African strandings come from territory inhabited by the Khoisan peoples. Guided by the Khoisan Council, we chose the name //eu//’eu (simplified to eueu to fit nomenclature standards; correct pronunciation available in associated audio clip a 1 in the electronic supplementary material), which means ‘big fish’ in Khwedam (from the Khoe language family). In Aotearoa New Zealand, Māori cultural expert Brad Haami developed a shortlist of potential names meaningful in the Māori language, whichwasthen sent for comment to Te Rūnanga o Ngāi Tahu. The selected common name, Ramari’ s beaked whale, pays homage to Māoritohunga (expert) Ramari Stewart, who has kept traditional knowledge alive, contributed extensively to scientific research on marine mammals, and helped prepare the skeleton of the holotype. The word ‘Ramari’ means a rare event in the Māori language, reflecting the elusive nature of most beaked whales.

Diagnosis

Molecular characteristics

M. eueu differs from M. mirus based on nuclear DNA markers, and from M. mirus and its closest relatives M. europaeus , M. ginkgodens and M. bidens using mtDNA markers ( figure 2). M. mirus is distinct from all other mesoplodont species based on previous mitochondrial and nuclear DNA trees [7,20,24].

Mitochondrial DNA: analysis of mitochondrial data includes sequences from the holotypes of both M. mirus and M. eueu at all sequence lengths. Over the 304 bp mitochondrial control region segment, M. eueu is distinguished by seven fixed differences from M. mirus , with F ST = 0.85 (p <0.01), dA = 0.04 between the two species. At the full mitochondrial genome lengths, M. eueu is distinguished by 579 fixed differences from M. mirus with F ST = 0.96 (p <0.01) and dA = 0.04 (electronic supplementary material, table S2).

Nuclear DNA: reduced representation sequencing with ddRAD showed M. eueu had a distinct admixture pattern to M. mirus ( figure 2), and an F ST = 0.64 (p <0.0001) wasestimatedbetween the twospecies. M. mirus and M. eueu weredistinguished by 1909 fixed differences (12%, per SNP allele error rate = 0.002), across a dataset of 15671 SNPs found between or within both species. Comparison of one whole nuclear genome each from M. mirus and M. eueu showed a level of nucleotide divergence of 0.28%.

Morphological characters

M. eueu is a larger (5.3 m) species of Mesoplodon differing from all other members of the genus except M. mirus , M. hectori and M. perrini in having tusks positioned at the tip of the mandible. It also differs from M. hectori and M. perrini in having smaller, less triangular tusks and from M. mirus in having a relatively shorter rostrum with a wider base, a shorter mandibular symphysis, wider premaxillary sac fossae and crests, and a taller cranium.

External appearance

The external appearances of M. eueu and M. mirus are not known to be consistently distinguishable. Both species are rotund mesoplodonts with bodies that taper towards the tail and rostrum, with somewhat bulbous and well-defined melons, a mostly straight beak and short, straight gape. Colouration is generally grey with a dark eye patch in both species, but there may be specific colouration patterns linked to M. eueu ; for example, a female that stranded in South Africa showed a whitish dorsal colouration from the fin to caudal peduncle [ 14]. However, Aguilar et al. [ 6] reported M. mirus with varying dorsal and ventral white colouration in the Canary and Azores Islands, so colouration patterns linked to species cannot yet be conclusively defined.

Distribution

M. eueu probably occurs throughout temperate SH waters, with reports from several locations. Genetic methods have confirmed at least some of these records in South Africa ([ 20], this study), Australia [ 20] and Aotearoa New Zealand [ 11].

Nomenclatural acts

This published work and the nomenclatural acts it contains are registered in ZooBank (http://zoobank.org/), the online registration system for the International Commission on Zoological Nomenclature (ICZN). The ZooBank Life Science Identifier is urn:lsid:zoobank.org:pub:C61A1A33-B234-476E-AA24-86C6ED130C10 , and for the new species is urn:lsid:zoo bank.org:act: C56121C4-1E15-4A07-A270-D92AF43AE74A.