A new species of Petrolisthes (Crustacea, Anomura, Porcellanidae) inhabiting vermetid formations (Mollusca, Gastropoda, Vermetidae) in the southern Caribbean Sea.

Alexandra Hiller,Bernd Werding

doi:10.3897/zookeys.876.37244

Alexandra Hiller, Bernd Werding

Open Access

https://doi.org/10.3897/zookeys.876.37244

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Abstract

Petrolisthes virgiliussp. nov. from the Caribbean Sea of Colombia is described. The new species resembles P. tonsorius morphologically but differs from it principally by its color and habitat. Petrolisthes tonsorius is brown or blueish brown and occurs under intertidal boulders strongly exposed to water movement. Petrolisthes virgiliussp. nov. is pale brown to beige and lives exclusively in intertidal areas dominated by vermetid snails, exposed to heavy wave action. The entangled tubular shells of vermetids are cemented to each other and to a hard substrate like beach rock, forming a microhabitat for the new crab species and other porcellanids of the genera Neopisosoma and Clastotoechus. Large genetic distances between DNA sequences of the mitochondrial 16S rDNA gene from P. virgiliussp. nov. and P. tonsorius confirmed that they comprise different species. Petrolisthes virgiliussp. nov. is the 53rd member of the West Atlantic porcellanid fauna.

Highlights

The porcellanid fauna of the western Atlantic has been studied intensively in the last 60 years
Morphological re-examination of this color morph, and genetic distances estimated between DNA sequences of the 16S rDNA gene from this new form and P. tonsorius confirmed that they comprise different species
In the West Atlantic this group is represented by two trans-isthmian species, P. tridentatus Stimpson, 1859, and P. tonsorius Haig, 1960, and by P. quadratus Benedict, 1901, P. gertrudae Werding, 1996, P. hispaniolensis Werding & Hiller, 2005, and P. virgilius

Summary

Introduction

The porcellanid fauna of the western Atlantic has been studied intensively in the last 60 years. With the last additions by Ferreira and Tavares (2017, 2019) and Werding and Hiller (2017), consisting of three new species of Pachycheles Stimpson, the number of western Atlantic species rose to 52. Werding (1978) found individuals of Petrolisthes inhabiting vermetid formations in the Colombian Gulf of Urabá, and assigned them to P. tonsorius Haig, 1960, but warned that coloration and habitat of the crab specimens were atypical. Petrolisthes tonsorius inhabits the rocky intertidal of both the Caribbean and the tropical East Pacific and exhibits a brown to dark-brown color (Fig. 1a), sometimes blueish (Fig. 1b). Morphological re-examination of this color morph, and genetic distances estimated between DNA sequences of the 16S rDNA gene from this new form and P. tonsorius confirmed that they comprise different species. We describe the new form as Petrolisthes virgilius sp. nov

Materials and methods

Discussion