A recent paper by Barahona-Segovia et al. discusses the details of the ecology of a Chilean Plectostylus species. Their abstract is “Terrestrial mollusks are one of the least studied groups of terrestrial invertebrates, especially in the Neotropics. In Chile, there is scarce biological and ecological information about many genera, even though the group is quite diverse and occupies different habitats along the country. Plectostylus araucanus is the most recently described species and one of the few arboreal species found only in the coastal native forest of central-south of Chile. In this study, we recorded a new locality for P. araucanus in the del Maule Region and described ecological and physiological characteristics. The new locality is placed 204 km northwards of the type locality. Based on different records, Plectostylus araucanus is proposed as an endangered (EN) species under the distribution criterion of IUCN. Most of the specimens of P. araucanus were found living in tree cavities and away from the edge of native forest fragments. Physiological measures showed monthly differences, especially between some months of summer and fall and between months of the same season (i.e., summer). We discuss the implications of our results in the microhabitat selection, thermoregulation and habitat use by this tree snail, and the importance of this data in management and conservation for other native malacofauna”.
This is an interesting study, as detailed ecological research on Neotropical snails is scarce and the available data gives a very partial view on the requirements of the malacofauna; the handles for conservation management are thus also extremely limited, which is a concern with the increasing threats of anthropogenic influences.
Barahona-Segovia, R.M. et al., 2019. Shelter, ecophysiology and conservation status of Plectostylus araucanus (Pulmonata: Bothriembryontidae) in the fragmented Bosque Maulino, central Chile. – Revista Mexicana de Biodiversidad, 90: e902703 (12 pp.).
Freshly pressed: a paper by Francisco Cádiz and co-authors describing how they used land snails to decipher the origin and isolation in forest relicts in northern Chile.
The abstract reads: “Among the questions surrounding the biogeographical history of the Chilean biota, none has gathered more interest than the origin of the Fray Jorge (FJ) for- est relict and its biota. Inserted in a semi‐desert area, this forest enclave exists due to the existence of a very particular microclimate in this region. The age of the disjunction and the historical relationship between the FJ biota with the remaining components of South America are explained by two distinct, competing hypotheses: the first suggests that it would have become isolated during the climatic changes of the Paleogene/Neogene, while the second suggests that the isolation is a product of Quaternary glaciations. To discriminate between these competing hypotheses, we used DNA sequence phylogeny methods and molecular genetic dating to the study of a genus of land snails (Plectostylus) that occurs in the FJ relict and throughout Chile. The phylogeny shows a clear distinction between forest and arid clades, and each of these clades is formed by many geographically circumscribed populations. The FJ fragment snails form a clade that is sister to all other forest clades. The separation between the Fray Jorge clade and the other forest clades dates back to the Paleogene/Neogene. Our data suggest that the FJ forest is a relict from the forests that occupied that landscape during the Paleogene/Neogene and retreated due to the aridification of the region. We also observe that the current taxonomy of the Plectostylus genus must be re‐evaluated”.
An interesting paper that uses molecular data of an endemic land snail group to sort out competing hypotheses of ancient landscape genesis. More often, ecological data are used to support a hypothesis of the taxonomy of species; this time it is the other way around. While working on this study the authors also collected data on the taxonomy of this group, but this will be dealt with in a future paper.
Cádiz, F.J. et al., 2018. Phylogeography of Plectostylus Beck, 1837 (Gastropoda, Stylommatophora: Orthalicoidea): Origin and isolation of the Fray Jorge forest relicts in northern Chile. – Journal of Zoological Systematics and Evolutionary Research, doi: 10.1111/jzs.12241 (10 pp.) (advance publication).
Dulack Richards posted two pictures of a living Plectostylus species on his Facebook page, which I re-post here as such pictures are not too often found. As the locality is not given (other than ‘Chile’), I just copy his identification as Plectostylus cf coquimbensis Broderip in Broderip & Sowerby I, 1832.
Today a paper was published about the Chilean Atacama region. This is in the coastal desert and is a harsh environment for snails. The authors, Araya & Catalán, have made a laudable effort to chart the species and provide a key for easy identification. This paper is limited to the non-bulimulid terrestrial snails, i.e. the families Bothriembryontidae, Charopidae, Ellobiidae, Pupillidae, Strophocheilidae, and Helicidae.
Terrestrial mollusca are sparsely studied in Chile and, for the first time, a formal record of the diversity of land snails in northern Chile is reported. Coastal and desertic areas in the Region of Atacama, in the border of the Atacama desert and the Pacific Ocean, were surveyed with the aim to describe the presence and distribution of this poorly known fauna. Of the fourteen species recorded, the geographic distribution records for nine species are extended, and some taxa are recorded for the first time since their original descriptions. All, except one, of the fourteen terrestrial molluscan species occurring in the area are endemic to Chile; they are all terrestrial species, most of them have a restricted geographic distribution, and none of them is currently protected by law. The results reveal that the region of Atacama has one of the most diverse terrestrial snail biodiversity in Chile, ranking only after the Juan Fernandez Archipelago. Distribution records of all the studied species and a taxonomic key are also provided.
Araya, J. F. & Catalán, R. (2014): A review of the non-bulimulid terrestrial Mollusca from the Region of Atacama, northern Chile — ZooKeys 398: 33–51. http://bit.ly/1mI5w4r.