Taxonomic identity of Distaplia stylifera (Tunicata, Ascidiacea), a new arrival to the eastern Pacific displaying invasive behavior in the Gulf of California, Mexico

By

Moreno, Betzabé
Huato, Leonardo
Gómez-Gutiérrez, Jaime
Galván-Tirado, Carolina
Sánchez Ortiz, Carlos A.,
Alcoverro, Teresa
Balart, Eduardo F.
Turon, Xavier

Type

Article

Date of Publication

2023

Original Publication

ZooKeys

Volume

1157

Pages

109--125

Subjects

Ascidian , Gulf of California , introduced species , mass mortality , taxonomy , tunicate

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers

Identifiers

DOI: https://doi.org/10.3897/zookeys.1157.95986

 

Abstract

A colonial ascidian of the genus Distaplia caused a mass mortality of the pen shell Atrina maura (Sowerby, 1835) during June 2016 in the southwest of the Gulf of California (Mexico), with a significant socio-economic cost. Tentatively identified in previous works as Distaplia cf. stylifera, a precise taxonomic determination was still lacking. In the present work, based on a detailed morphological study, it is confirmed that this aggressive species is Distaplia stylifera (Kowalevsky, 1874). Originally described from the Red Sea, the species currently has a wide circumtropical distribution (with the exception of the Eastern Pacific to date) and is reported as introduced in parts of its range. The present account thus represents an important range extension of this species. However, when revising the original description and later observations, the reported variability of several characters makes it likely that the binomen is in fact a complex of species, as is common in other ascidians with wide distributions. A complete morphological and genetic study including populations from the entire range of distribution would be necessary to settle the status of D. stylifera. Taxonomic uncertainties hinder a correct interpretation of biogeographical patterns and inference on the origin of the studied population. Nevertheless, the known introduction potential of the species, coupled with an explosive growth in an anthropized environment, and the lack of any previous reports in the Eastern Pacific, strongly suggest that the investigated population represents yet another instance of ascidian introduction. From the point of view of management, its invasive behavior is cause for great concern and warrants mitigation measures.