Revisiting Anthopleura cascaia (nomen nudum): Description of Anthopleura correae sp. nov. and the taxonomic challenges of a variable lineage...

Jeferson A. Durán-Fuentes, Ricardo González-Muñoz, Aurora Vassallo-Avalos, Alonso Delgado, Marymegan Daly & Sérgio N. Stampar. Mar. Biodivers. 55, 111 (2025). DOI: 10.1007/s12526-025-01585-2

Abstract

Anthopleura correae sp. nov. (Actiniaria: Actinioidea: Actiniidae) is a newly described sea anemone, previously identified as A. cascaia (nomen nudum) and Psammanthus caraguaensis (nomen nudum), both endemic to coastal Brazil. Anthopleura cascaia and P. caraguaensis were originally documented in unpublished theses by Corrêa (1964) and Rosso (1984), respectively. In this study, we address nomenclature, identity, and variability of A. correae sp. nov., examining specimens representing different morphotypes of this species. We compared external morphology, internal anatomy, cnidom, and cnida size range. Additionally, we analyzed the sequences from five genetic markers commonly used in phylogenetic studies of Actiniaria: mitochondrial markers 12S, 16S, and CO3, and nuclear markers 18S and 28S, across 14 samples. We also sequenced ultraconserved elements (UCEs) and exons via target capture methods in six samples. Our results identified seven morphotypes of A. correae sp. nov., including those previously described by Corrêa (1964), Dube (1977), and Rosso (1984). Four of these morphotypes did not have acrorhagi on the marginal projections. Phylogenetic analyses based on the PCR-derived markers revealed that the morphotypes we examined form a single clade with minimal genetic variability. The target capture sequences grouped the samples into two clades, but these clades did not exhibit clear or consistent morphological or geographic differences.