Monthly Archives: April 2014

Photo of the day (152): Helicina

Another series of photos today received from Alex Popovkin.

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This is a subadult specimen; still not fully convinced about the specific identity, but the closest I can get is Helicina cf. carinata (d’Orbigny, 1835).

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Photo of the day (151): Bahiensis

Alex Popovkin, field botanist in Mateiro, Bahia, Brazil, sent me several pictures and asked for an identification.

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This is undoubtedly an Odontostomidae, of which several closely related genera do occur in this region. Although the variation in this group is not well studied, my best guess for the moment is Bahiensis bahiensis (Moricand, 1833).

P1390246

Snail from Atacama region, Chile

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&Catalan

Reference:
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.

Snails of Trinidade Island, Brazil

In a brief research note Salvador et al. (2014) report the find of living specimens of two species. “For four decades it has been suspected that the endemic land snails of Trindade Island, Brazil, were extinct. Here we report finding live Succinea lopesi Lanzieri, 1966 and a species of Happia Bourguignat, 1889 on top of the island’s highest peaks. Happia is a new record for the island and possibly also a new endemic species. As Trindade’s environment has suffered much degradation due to introduced feral goats, such remote places might have acted as refuges for the snails. With the ongoing recovery of the native fl ora after the eradication of the goats, the snails’ populations might re-establish themselves.”  Of the other endemic species of Trindade, namely Bulimulus brunoi  (Ihering, 1917), Naesiotus arnaldoi  (Lanzieri and Rezende, 1971) and Vegrandinia trindadensis (Breure and Coelho, 1976) it still remains to be seen if they are extant or not.

Trindade_f2

Reference:
Salvador, R.B., Silva, N.G., Cunha, C.M., Simone, L.R.L. & Alves, R.J.V. (2014): Rediscovery of living snails on Trindade Island, Brazil — American Malacological Bulletin 32: 140–142.

More on Mexican snails

Edna Naranjo-García published (quite) recently two other papers on terrestrial land snails from Mexico. Not having seen the papers so far, I can only make you aware of their existence and copy the abstracts.

The first paper by Araiza & Naranjo-García (2013) is about the state of Veracruz. “Previous studies about the gastropod diversity of Atoyac, demonstrated the presence of 37 terrestrial gastropods species. However, due to the disappearance of the natural landscape due to the increase in recent years of coffee and cane crops in the municipality and the lack in  Mexico of specimens reported in those studies, it is interesting to  document the actual diversity of the municipality, using collecting  techniques directed to the study of the terrestrial malacofauna, so 21  localities were visited in Atoyac, Veracruz in 2007 and 2008. Fifty seven species, 21 subspecies and 19 families of terrestrial gastropods were found. The families with the largest number of species are Spiraxidae (with 17 species), Subulinidae (11), Euconulidae (8), Helicinidae (7) and Orthalicidae (6). The species with the widest distributions are: Hawaiia minuscula minuscula, Helicina (Tristamia) zephyrina zephyrina, Schasicheila (Atoyac) alata and Leptopeas micra.
The malacofauna known in Atoyac increases in 21 species, 10 subspecies and 7 families; 5 species Pyrgodomus simpsoni, Pupisoma dioscoricola, Salasiella camerata, Pseudosubulina minuta and Punctum minutissimum are registered for the first time for Veracruz and 7 are possible new species.”

The second paper is by Naranjo-García on the biodiversity of terrestrial snails. “The land Mollusca are exclusively from the class Gastropoda. They are diverse in shapes, sizes (1 to 200-300 mm), habits, environments (by  climate and vegetation), life cycles and life spans. Prosobranchia has the least number of species, Pulmonata is the richest. They are either preys or predators. Towards the end of the 19th century and beginning of the 20th century comprehensive works compiled the known diversity. We recognize 8 families in Prosobranchia, and 39 in Pulmonata, with 5 families: Cerionidae, Eucalodiidae, Holospiridae, Epirobiidae, Echinichidae, recently added. Endemism among the lesser families attains 62%; the 1184 known Mexican terrestrial species represent 3.4% of the global molluscan diversity; 2 200 additional species are estimated yet  to be found. The population patterns of the families Holospiridae and  Epirobiidae are well established since they are defined by the presence of calcite and/or dolomite in the soil. Land American mollusks are solitary; however, some develop abundant populations (Xerarionta, Praticolella, Humboldtiana). Lysinoe ghiesbreghti is utilized locally for food consumption. Nine families are the most diverse: Spiraxidae, Orthalicidae, Holospiridae, Helicinidae, Eucalodiidae, Helminthoglyptidae, Vertiginidae, Polygyridae and Humboldtianidae.
Richness per state is unequal; Veracruz is the best known, whereas  Aguascalientes and Tlaxcala possess no records. Between the years 1891-1895 and 1926-1930, a great number of species were described. Studies on life cycles, behavior and ecology are still needed in the group.”

References:
Araiza, V. & Naranjo-García, E. (2013). Systematic checklist of the terrestrial malacofauna from Atoyac, Veracruz. — Revista Mexicana de Biodiversidad 84: 765–773.
Naranjo-García, E. (2014). Biodiversity of terrestrial molluks in Mexico. — Revista Mexicana de Biodiversidad 85: S431–S440.