Molecular and morphological systematics of Bursatella leachii de Blainville, 1817 and Stylocheilus striatus Quoy & Gaimard, 1832 reveal cryptic diversity in pantropically distributed taxa (Mollusca : Gastropoda : Heterobranchia)
|Author(s)||Bazzicalupo Enrico1, Crocetta Fabio2, Gosliner Terrence M.3, Berteaux-Lecellier Véronique4, Camacho-García Yolanda E.5, 6, 7, Chandran B. K. Sneha8, Valdés Ángel1|
|Affiliation(s)||1 : Department of Biological Sciences, California State Polytechnic University, 3801 West Temple Avenue, Pomona, CA 91768, USA
2 : Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Villa Comunale, I-80121 Naples, Italy.
3 : Department of Invertebrate Zoology, California Academy of Sciences, 55 Music Concourse Drive, San Francisco, CA 94118, USA.
4 : UMR 250/9220 ENTROPIE, IRD-CNRS-UR, LabEx Corail, 101, promenade Roger-Laroque, Anse Vata BP A5, 98848 Nouméa cedex, New Caledonia.
5 : Museo de Zoología, Escuela de Biología, Universidad de Costa Rica, Apartado 11501-2060, San Pedro de Montes de Oca, San José, Costa Rica.
6 : Centro de Investigación en Ciencias del Mar y Limnología (CIMAR), Ciudad de la Investigación, Universidad de Costa Rica, Apartado 11501-2060, San Pedro de Montes de Oca, San José, Costa Rica.
7 : Centro de Investigación en Estructuras Microscópicas (CIEMIC), Ciudad de la Investigación, Universidad de Costa Rica, Apartado 11501-2060, San Pedro de Montes de Oca, San José, Costa Rica.
8 : Department of Aquatic Biology and Fisheries, University of Kerala, Thiruvananthapuram, Kerala 695581, India.
|Source||Invertebrate Systematics (1445-5226) (CSIRO Publishing), 2020 , Vol. 34 , N. 5 , P. 535-568|
he ragged sea hare (Bursatella leachii) and the long-tailed sea hare (Stylocheilus striatus) are two widely distributed species of benthic heterobranch sea slugs. In this paper, integrative taxonomic analyses have been conducted to detect possible cryptic diversity. Our results revealed that both nominal species are actually species complexes, consisting of five genetically distinct taxa. Two of them belong to the genus Bursatella and three to the genus Stylocheilus. The name B. leachii is retained for a widely distributed species, present in the Atlantic, the Mediterranean, and parts of the Indo-Pacific region. The name B. ocelligera is resurrected for the other species, restricted to the Indo-Pacific and co-occurring with B. leachii in that area. With the present data, it is not possible to test whether B. leachii and B. ocelligera have evolved allopatrically in the Atlantic and Indo-Pacific or sympatrically in the latter. Bursatella leachii has been able to maintain gene flow between the Atlantic and the Indo-Pacific Oceans, possibly because of a combined effect of the Agulhas Leakage process and the ability to survive the colder waters of South Africa. On the contrary, the three species of Stylocheilus are allopatric; the name S. striatus is retained for an Indo-Pacific species, while the names S. polyomma and S. rickettsi are resurrected for species inhabiting the Western Atlantic and the Eastern Pacific respectively. Finally, the discovery of a museum specimen mistakenly identified as B. leachii, but bearing a shell in its adult form, led to the resurrection of the genus Phycophila, previously synonymised with Aplysia. Phycophila euchlora, the only species described to date, is distributed in the Central and Western Pacific Ocean.