Taxonomy and distribution of species of Gastrocopta Wollaston 1878 (Mollusca: Gastropoda: Gastrocoptidae) from the Galápagos Islands (Ecuador)

ABSTRACT

A revision of Gastrocopta from the Galápagos Islands (Ecuador) is made. Four new species from Pinzón, Santa Cruz and Floreana Islands are described; species previously known are redescribed and new locations are added. Gastrocopta (Gastrocopta) reibischi is revalidated through new records from Floreana, Isabela and San Bartolomé Islands. Shell shape and the number, morphology and disposition of the apertural barriers support the discrimination of the taxa. The species have cylindrical to pupoid shells; the number of apertural barriers – differentiated as lamellae, folds and nodulae – varies between 4 and 11, almost completely occluding the aperture in the more complex cases. These structures are: angular-parietal, infraparietal, supracolumellar, columellar, subcolumellar lamellae, and supernumerary, basal, infrapalatal, lower-palatal, interpalatal, upper-palatal and suprapalatal folds. In addition to this classic scheme, a supernumerary fold and a nodule are added. Calcareous concretions – pustulae – are found in several species, mainly located in the peristome. The aulacognathous jaw and radular dentition formulae of Gastrocopta (Gastrocopta) clausa and Gastrocopta (Gastrocopta) munita, are described and photographed for the first time.

KEYWORDS:

• Eupulmonata
• Pupilloidea
• South America
• new species
• Charles Darwin Foundation
• Galápagos National Park

Acknowledgements

We thank to the Charles Darwin Foundation for the Galápagos Islands and National Park of Galápagos for allowing the study of the samples of Gastrocopta, Henri W. Herrera for curating the samples; the personnel of the CDF for sending the specimens; B. Delgado (CDF) for the cartographic information; C. Parent, for trusting the authors with the study of specimens collected in Pinzón; F. Bungartz, former chief of Herbarium of CDF, for allowing the inspection of lichens, mosses and hepatics, where some snails were found; P. Callomon and N. Shoobs, for providing images of specimens from ANSP (USA); N. Phillips (ANSP), K. Schniebs (SNSD, Germany) and J. Ablett (NHMUK, England) for information about their collections. We also thank the following staff of the MACN: A. Tablado, chief of Invertebrates Division, for revision of the manuscript; F. Tricárico for photographs taken in the Scanning Electronic Microscopy Service; and A. González for drawing maps. We also thank the anonymous reviewer. The opinions expressed here are the responsibility of the authors. S. E. Miquel belongs to the Career of Scientific Research of Consejo Nacional de Investigaciones Científicas y Técnicas. This publication is contribution number 2200 of the Charles Darwin Foundation for the Galápagos Islands.

Disclosure statement

No potential conflict of interest was reported by the authors.