Original paper

Snails found among herbarium specimens of Galapagos lichens and bryophytes, with the description of Scolodonta rinae (Gastropoda: Scolodontidae), a new species of carnivorous micro-mollusk

Miquel, Sergio E.; Bungartz, Frank

Abstract

For the first time we document several species of micro-mollusks in the Galapagos inhabiting lichens and bryophytes, possibly using them as part of their diet. Eight species of micro-mollusks were found as a by-catch among 10% of 400 herbarium specimens collected throughout the archipelago. Nine species of lichens and 6 of bryophytes were inhabited. The endemic Pupisoma galapagorum was the most common micro-mollusk, particularly frequent among Heterodermia, occasionally found on Cyphellostereum, Squamidium nigricans, and among hepatics (Frullania, Bryopteris). Other micromollusks were Tornatellides chathamensis, Pupisoma dioscoricola, Helicina sp., and Succinea sp. Examination of the digestive tract of P. galapagorum detected green algae, hyphae, spores, and fragments of bryophyte leaves (possibly S. nigricans). This endemic micro-mollusk apparently uses lichens and bryophytes not only for shelter but also as food. Another snail found repeatedly is a predator, described here as Scolodonta rinae n. sp. It is a member of Scolodontidae, a Neotropical family considered endemic to continental South America, and here for the first time documented from the Galapagos. Pupisoma galapagorum, previously known from Floreana, Isabela, San Cristóbal, and Santa Cruz, is reported also from Pinta and Santiago. Ambrosiella floreanae, previously considered endemic to Floreana, is reported from Santa Cruz.

Keywords

Ecological interactionsland snailmicrohabitatsfood-chain