A New Species of Patelloida (Gastropoda: Lottiidae) from Western Bo Ron Ga Island, Northern Rakhine Coastal Region, Myanmar

Abstract

Lottiid limpets (Lottiidae, genus Patelloida) occur on the rocky shore of the upper intertidal zone in marine habitats, providing many ecosystem goods and services. In this study, the species identification of an “adulterant” limpet with a small body size, which is often misidentified as a “young individual” of other sympatric species, including P. saccharina and P. novacula, was determined for the first time, based on molecular markers (partial mitochondrial cox1 and rrnL genes), phylogenetic analysis, and morphometric approaches. This novel species, P. arakanensis, commonly known as the “boulder limpet” in Myanmar, appears to potentially influence the efficiency of P. novacula. Phylogenetic analyses confirm its status as the basal taxon of the Indo-Pacific Patelloida. A comparative study of the shell characteristics of P. arakanensis, and other Patelloida species revealed several distinctive morphological traits, including generally smaller body size, a deeply cupped shell that is convex in adults but flat in young individuals. Other distinctive features of the new species include growth concentric line traits that are unique compared with the sympatric P. novacula and P. saccharina species, such as a deeper growth line in the fast-growth phase after settlement, followed by a significantly shallower growth line and mass disperse during subsequent life stages. This study provides the basic information necessary for further ecological and population genetic studies on this new species.