Vol. 61, 2022

(update: 2022.12.23)

Morphological and Molecular Evidence Reveals Zearaja brevicaudata (Marini, 1933) to be a Senior Synonym of Dipturus lamillai Concha, Caira, Ebert & Pompert 2019

*, Gavin Naylor

²

^3,4

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^1,5

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¹Laboratorio de Biotaxonomia Morfológica y Molecular de Peces, Instituto de Investigaciones Marinas y Costeras (IIMYC), Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata–CONICET, CC1260, Funes 3350, 7600 Mar del Plata, Argentina. *Correspondence: E-mail: vgabbanelli@mdp.edu.ar (Gabbanelli).
E-mail: astarloa@mdp.edu.ar (Díaz de Astarloa); emabraga@mdp.edu.ar (Mabragaña)
²Florida Museum of Natural History, 1659 Museum Rd. Gainesville, FL 32611 USA. E-mail: gnaylor@flmnh.ufl.edu (Naylor); leiyangslu@gmail.com (Yang)
³Elasmo-Lab, Elasmobranch Research Laboratory, Sophie-Rahel-Jansen-Str. 83, 22609 Hamburg, Germany
⁴Leibniz Institute for the Analysis of Biodiversity Change (LIB), Centre for Taxonomy and Morphology, Zoological Museum, Martin-Luther-King-Platz 3, 20146 Hamburg, Germany. E-mail: simon.weigmann@elasmo-lab.de (Weigmann)
⁵Instituto Nacional de Limnología, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional del Litoral, Santa Fe, Argentina. E-mail: dmvazquez91@gmail.com (Vazquez)
⁶CSIRO The Commonwealth Scientific and Industrial Research Organisation, Division of Marine and Atmospheric Research, Castray Esplanade, Hobart, TAS, 7001, Australia. E-mail: peter.last@csiro.au (Last)

Received 23 December 2021 / Accepted 8 September 2022
Communicated by Felipe Ottoni

Longnose skates have great economic importance in South American fisheries, and in order to preserve them it is important to have a well-defined taxonomic status of their species. Dipturus lamillai was recently described for Malvinas Islands waters based on morphological and molecular comparisons with Zearaja chilensis. Although D. lamillai has been compared with several congeneric species, it was not properly compared with the morphologically similar Zearaja brevicaudata, the most abundant longnose skate in the Southwest Atlantic. Here, these species were compared by morphological and molecular analyses, in order to evaluate their conspecificity. Linear morphometric variables of holotype and paratypes of D. lamillai and 69 specimens of Z. brevicaudata were compared and investigated using Principal Component Analysis. In addition, thorn patterns, denticle distributions, color, and clasper morphology were compared. No body proportions or other single character that could differentiate D. lamillai from Z. brevicaudata were found. Molecular analyses comprised of the comparison of the cytochrome oxidase subunit I (COI) and the NADH dehydrogenase subunit 2. The results of the Maximum Likelihood (ML) carried out for each molecular marker showed that sequences from D. lamillai clustered together with those of Z. brevicaudata, and the molecular distance determined by Kimura two- parameter were lower than the expected for different species. Additionally, Automatic Barcode Gap Discovery method and the Bayesian implementation of the Poisson tree processes were carried out with COI sequences to explore species limits, and their results were consistent with ML analyses. In summary, the results obtained showed that there are no morphological or molecular differences between these nominal species of the valid skate genus Zearaja, leading to the conclusion that they are conspecific. Therefore, we designated Z. brevicaudata as a senior synonym of D. lamillai.

Key words: Integrative taxonomy, Longnose skates, Rajiformes, Synonyms, Southwest Atlantic.

Citation: Gabbanelli V, Naylor G, Weigmann S, Yang L, Vazquez DM, Last P, de Astarloa JMD, Mabragaña E. 2022. Morphological and molecular evidence reveals Zearaja brevicaudata (Marini, 1933) to be a senior synonym of Dipturus lamillai Concha, Caira, Ebert & Pompert 2019. Zool Stud 61:76. doi:10.6620/ZS.2022.61-76.

Supplementary materials: Table S1丨Table S2丨Table S3