Pleurolucina from the western Atlantic and eastern Pacific Oceans: a new intertidal species from Curaçao with unusual shell microstructure (Mollusca, Bivalvia, Lucinidae).

John D Taylor,Emily A Glover

doi:10.3897/zookeys.620.9569

Abstract

A new shallow water species of the lucinid bivalve Pleurolucina is described from Curaçao in the southern Caribbean Sea and compared with known species of the genus from the western Atlantic and eastern Pacific Oceans. Although confused with the Floridian species Pleurolucina leucocyma, it is most similar to the eastern Pacific Pleurolucina undata. As in all studied lucinids, the new species possesses symbiotic bacteria housed in the ctenidia. The shell microstructure is unusual with repeated and intercalated conchiolin layers that have sublayers of ‘tulip-shaped’ calcareous spherules. Predatory drillings by naticid gastropods frequently terminate at the conchiolin layers.

Highlights

The tropical and subtropical western Atlantic is one of the major centres of marine molluscan diversity and bivalves in the speciose family Lucinidae, with an estimated 46 species in this ocean, have been the focus of many studies since the discovery of their chemosymbiosis with sulphide-oxidising bacteria (e.g. Giere 1985, Fisher and Hand 1984, Frenkiel and Mouëza 1995, Frenkiel et al 1996, Gros et al 1998, 1998, 2012)
We describe this new Pleurolucina from Curaçao in comparison with other western Atlantic and Eastern Pacific species, detail its phylogenetic position and illustrate its unusual shell microstructure with calcified conchiolin layers
Pleurolucina is a genus of seven living species from the tropical to subtropical western Atlantic and eastern Pacific with none recognised from the eastern Atlantic or IndoWest Pacific

Summary

Introduction

The tropical and subtropical western Atlantic is one of the major centres of marine molluscan diversity and bivalves in the speciose family Lucinidae, with an estimated 46 species in this ocean, have been the focus of many studies since the discovery of their chemosymbiosis with sulphide-oxidising bacteria (e.g. Giere 1985, Fisher and Hand 1984, Frenkiel and Mouëza 1995, Frenkiel et al 1996, Gros et al 1998, 1998, 2012). A recurring pattern is of congeneric pairs, one largely restricted to the Gulf of Mexico and Florida and the other with a more southerly Caribbean range as exemplified by Lucinisca nassula and L. muricata (Taylor and Glover submitted) This dual distribution is similar to that proposed by Petuch (1982) as a relict of the Caloosahatchee-Gatunian pattern dating from the Pliocene but possibly inherited by present day taxa. Thought to be related to Lucina or Cavilinga (Britton 1972, Bretsky 1976) and included by Taylor et al (2011) in the subfamily Lucininae, no Pleurolucina species has previously been included in molecular analyses We describe this new Pleurolucina from Curaçao in comparison with other western Atlantic and Eastern Pacific species, detail its phylogenetic position and illustrate its unusual shell microstructure with calcified conchiolin layers.

Material and methods

Discussion