New records for the shallow-water chiton fauna (Mollusca, Polyplacophora) of the Azores (NE Atlantic)

Sérgio Ávila,Julia Sigwart

doi:10.3897/zookeys.312.4768

Abstract

Published records, original data from recent field work on all of the islands of the Azores (NE Atlantic), and a revision of the entire mollusc collection deposited in the Department of Biology of the University of the Azores (DBUA) were used to compile a checklist of the shallow-water Polyplacophora of the Azores. Lepidochitona cf. canariensis and Tonicella rubra are reported for the first time for this archipelago, increasing the recorded Azorean fauna to seven species.

Highlights

IntroductionPolyplacophorans (or “chitons”) include over 900 extant species worldwide that mostly live in shallow waters, usually on rocky substrates
The marine molluscs of the Archipelago of the Azores are probably the best studied marine invertebrate group from these Atlantic Islands
One was a synonym of A. fascicularis, and three were deep-water species (Stenosemus exaratus, Stenosemus albus and Placiphorella atlantica); only four shallow-water species of chitons were reported from the Azores by this author

Summary

Introduction

Polyplacophorans (or “chitons”) include over 900 extant species worldwide that mostly live in shallow waters, usually on rocky substrates. They are oval in shape and dorso-ventrally flattened, neither tentacles nor eyes are present in the head region, and they possess eight distinctive overlapping shell plates or valves located on the dorsal side. These longitudinally arranged valves are surrounded by a muscular girdle, and the girdle covering or perinotum is ornamented with scales, spicules, bristles or other protuberances (Kaas and Van Belle 1985a; Schwabe 2010). The present work is based on a review of new material collected from all the islands of the Azores, and updates the published information, documenting for the first time the occurrence of the polyplacophoran molluscs Lepidochitona cf. canariensis (Thiele, 1909) and Tonicella rubra (Linnaeus, 1767) in these oceanic islands

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