Tag Archives: chile

Ecology and conservation of Plectostylus

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”.

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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.

Reference:
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.).

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New Chilean Charopid

Araya & Miquel recently published a paper in which they introduced a new micromollusc: “Stephacharopa paposensis n.sp. is described from shells collected in coastal areas of Paposo, Región de Antofagasta, northern Chile, associated with native bromeliads and cacti living among rocks and coarse sand. This is the second species of Stephacharopa found in northern chile and one of the northernmost species of Charopidae found in this country”.

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Micromolluscs have been largely overlooked so far in the Neotropical fauna, and much more novelties are to be expected when malacologists focus on these groups during collecting in the various countries.

Reference:
Araya, J.F. & Miquel, S.E., 2018. A new Stephacharopa (Gastropoda: Punctoidea: Charopidae) from Paposo, northern Chile. – Journal of Conchology, 43 (2): 129-132.

Bostryx voithianus

In an overlooked paper, Martinez de los Rios (2017) published new data on the distribution of this Chilean species. His abstract reads: “Bostryx voithianus (Pfeiffer, 1847) is reported, for the first time since its description, from northern Chile. In the origi-nal description, a particular type locality was not given for this species, but to it was described as collected in Chile by Thomas Bridges for the Hugh Cuming collection. Herein, the type locality is assigned to the Chilean Coastal Range between the places Cuesta La Arena (28.5721° S) and Quebrada Honda (29.5952° S), northern Chile”.

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These Chilean Bostryx species are still a relatively understudied group, despite some recent literature, and it is always good to have new reports on their occurrences.

Reference:
Martinez de los Rios, E., 2017. Rediscovery of Bostryx voithianus (Pfeiffer, 1847) (Gastropoda, Pulmonata) in northern Chile, with notes on the type locality. – CheckList, 13 (6): 1125-1129.

Snails and forest relicts in Chile

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”.

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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.

Reference:
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).

Rediscovery of an achatellinid

Just published by Araya et al., a paper on the rediscovery of an achatellinid snail on Easter Island. The abstract reads: “The achatinellid Pacificella variabilis Odhner, 1922, is reported for the first time since its original description from its type locality, Easter Island (Rapa Nui), South Pacific Ocean, Chile. Specimens were found living on the bark of a lemon tree in Hanga Roa town and among the endemic grass Paspalum forsterianum on Motu Nui Islet. A redescription of the shell based on scanning electron microscopy (SEM) is provided. This represents the first report of the habitat of the species on Easter Island.”

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It always nice to see a rediscovery of a species nearly a century after its initial description 🙂

Reference:
Araya, J.F. et al., 2018. Rediscovery of Pacificella variabilis (Gastropoda: Achatinellidae) on Easter Island. – Pacific Science, 72 (3): 329-334.

Bostryx voithianus rediscovered

Just published: a rediscovery of one of the very rare Bostryx species from the Chilean coast by Martínez (2017).

Bostryx voithianus (Pfeiffer, 1847) is reported, for the first time since its description, from northern Chile. In the original description, a particular type locality was not given for this species, but to it was described as collected in Chile by Thomas Bridges for the Hugh Cuming collection. Herein, the type locality is assigned to the Chilean Coastal Range between the places Cuesta La Arena (28.5721° S) and Quebrada Honda (29.5952° S), northern Chile”.

This paper gives a good overview of the historical background of the material collected by Bridges, and a useful indication of the localities. Only empty shells were collected, the challenge to check if the species is extant still exists.

Reference:
Martínez, E., 2017. Rediscovery of Bostryx voithianus (Pfeiffer, 1847) (Gastropoda, Pulmonata) in northern Chile, with notes on the type locality. – CheckList, 13 (6): 1125-1129. https://doi.org/10.15560/13.6.1125

New records of Chilean snails

Based on a small collection already made in 1982, Araya et al. have just published a paper on the snail fauna near Antofagasta.

New records for Bostryx holostoma (Pfeiffer, 1846), Pupoides minimus (Philippi, 1860), Stephacharopa calderaensis Miquel & Araya, 2013 and an unidentified charopid species are presented on the basis of specimens collected near the city of Antofagasta, in northern Chile. This is the first record for S. calderaensis after its description, extending its known distribution about 350 km northwards. Details on the protoconch of B. holostoma are presented for the first time, and this species extends its distributional range 145 km southwards. The microhabitat of these species in litho-refugia may explain the presence of these minute terrestrial mollusks in hyper arid northern Chile, further highlighting the need of additional studies of this neglected fauna”.

Especially the protoconch structure of Bostryx holostoma is interesting, as this reveals a spiral structure which is not present in other Chilean Bostryx species. As unpublished DNA results of species from this genus from different countries reveal, this genus may well be polyphyletic.

Reference:
Araya, J.F. et al., 2017. New records of terrestrial mollusks (Gastropoda: Stylommatophora) from Antofagasta, northern Chile. – Revista Mexicana de Biodiversidad, 88: 769-772.