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Systematics, phylogeny and biogeography
RESEARCH ARTICLE

Phylogenetic systematics of the shelled sea slug genus Oxynoe Rafinesque, 1814 (Heterobranchia : Sacoglossa), with integrative descriptions of seven new species

Patrick J. Krug A , John S. Berriman A and Ángel Valdés B C
+ Author Affiliations
- Author Affiliations

A Department of Biological Sciences, California State University, Los Angeles, CA 90032-8201, USA.

B Department of Biological Sciences, California State Polytechnic University, 3801 West Temple Avenue, Pomona, CA 91768, USA.

C Corresponding author. Email: aavaldes@cpp.edu

Invertebrate Systematics 32(4) 950-1003 https://doi.org/10.1071/IS17080
Submitted: 27 January 2017  Accepted: 11 April 2018   Published: 20 August 2018

Abstract

An integrative approach to investigate the species-level diversity in Oxynoe (Mollusca, Heterobranchia, Sacoglossa) revealed the existence of 11 distinct taxa. Oxynoe viridis (Pease, 1861) and Oxynoe antillarum Mörch, 1863 are redescribed; Oxynoe natalensis E. A. Smith, 1903 and Oxynoe azuropunctata Jensen, 1980 are regarded as valid. Species originally described from empty shells are regarded as nomina dubia. Seven new species are described, four from the tropical Indo-West Pacific: Oxynoe kylei, sp. nov., Oxynoe neridae, sp. nov., Oxynoe jordani, sp. nov. and Oxynoe jacksoni, sp. nov.; and two from the tropical Atlantic: Oxynoe struthioe, sp. nov. and Oxynoe ilani, sp. nov. The name Oxynoe panamensis Pilsbry & Olsson, 1943 has been applied to eastern Pacific specimens, but was introduced based on material collected from the Caribbean; therefore, the new name Oxynoe aliciae, sp. nov. is introduced for eastern Pacific specimens. Species are delineated using molecular and morphological traits, as well as algal host and reproductive biology. Results from morphological comparisons are concordant with molecular and integrative species delimitation analyses, providing robust evidence for species hypotheses. As Oxynoe is one of the few groups specialised to feed on the green algal genus Caulerpa, which includes highly invasive species, clarifying the taxonomy of Oxynoe may inform efforts to predict community response to disruptive algal invasions.

Additional keywords: external morphology, host use, integrative taxonomy, molecular systematics, Oxynoidae, reproductive anatomy, species delimitation.


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