Tag Archives: scolodontidae

Brazilian cave snails

Another freshly pressed paper is by Salvador et al. on Brazilian cave snails. The abstract reads “A sample of land and freshwater snails, mainly pulmonates, was recently collected in caves in Goiás and Bahia states, Brazil. Twenty-one species were found in the material. The following species are reported for the first time for Goiás state: Cecilioides consobrina (Ferussaciidae), Dysopeas muibum and Stenogyra octogyra (Subulinidae), Entodina jekylli and Prohappia besckei (Scolodontidae; also reported for the first time for Bahia state), Pupisoma dioscoricola (Valloniidae). A new species from Goiás is described here-in: Gastrocopta sharae sp. n. (Gastrocoptidae). The new records and species addressed here constitute important findings, helping to fill distributional gaps and improving the knowledge of the local molluscan fauna, an essential step for future conservation efforts”.

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Besides the species newly reported for the two states, there are also additional records of the following land snails: Helicina angulata Sowerby, 1873 (Helicinidae), Cyclodonta sexdentata (Spix in Wagner, 1827) and Ringicella luetzelburgi Weber, 1925 (Odontotomidae), Happia glaberrima Thiele, 1927 (Scolodontidae), Allopeas micra (d’Orbigny, 1835) and Leptinaria concentrica (Reeve, 1849) (Subulinidae); five species are identified only to genus level.

This study complements earlier studies on the cave malacofauna in Brazil from part of the authors (see here and here).

Reference:
Salvador, R.B., Cavallari, D.C. & Simone, L.R.L., 2017. Taxonomical study on a sample of land and freshwater snails from caves in central Brazil, with description of a new species. – Zoosystema and Evolution, 93 (1): 193-141.

New Ecuadorian Zilchistrophia

The Ecuadorian malacofauna is poorly known and the family Scolodontidae is not well-researched within South America. A new paper by Páll-Gergely & Asami (2014) supplies new data on both topics.

The abstract reads: “Two new species of the genus Zilchistrophia Weyrauch, 1960 are described from Eastern Ecuadorian rain forest: Zilchistrophia hilaryae sp. n. and Z. shiwiarorum sp. n. These two new species extend the distribution of the genus considerably northwards, because congeners have been reported from Peru only. For the first time we present anatomical data (radula, buccal mass, morphology of the foot and the genital structure) of Zilchistrophia species. According to these, the genus belongs to the family Scolodontidae, subfamily Scolodontinae (=“Systrophiini”). The previously assumed systematic relationship of Zilchistrophia with the Asian Corillidae and Plectopylidae based on the similarly looking palatal plicae is not supported”.

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The presentation of anatomical data for these two species makes this paper very interesting. The discussion of the systematic position within the family rests on relatively few data from the literature. Molecular data for this group are very scanty and are not given for this material, but having tried in vain to sequence orthalicid material from the same collector this leads to no surprise.

Reference:
Páll-Gergely, B. & Asami, T. (2014). Description of two new Ecuadorian Zilchistrophia Weyrauch, 1960, with the clarification of the systematic position of the genus based on anatomical data (Gastropoda, Stylommatophora, Scolodontidae). – ZooKeys 453: 1–17.

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.

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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.

DNA barcodes in Systrophia

A paper that appeared already last year is Pedro Romero’s study on Systrophia from Peruvian Amazonia (Romero & Ramirez, 2011). 

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DNA barcoding analysis is based on the comparison of genetic distances to identify species using a segment of Cytochrome C Oxidase I (COI) gene. Species identification through DNA barcoding challenges problems in groups with high genetic diversity as molluscs. Thus, our aim was to estimate intraspecific divergence in the Amazonian land snail Systrophia helicycloides (Gastropoda, Scolodontidae) and evaluate the use of DNA barcoding in molecular identification of this land snail. Nucleotide sequences were compared with Genbank and BOLD (Barcode of Life Data Systems) databases. We conducted distance analyses using the Neighbour Joining method. Systrophia helicycloides showed two groups of haplotypes and intraspecific genetic distances higher than 4%. We observed an overlap between intraspecifical and interspecific distances. The high divergence may be related to rapid mutation rate in the snail mitochondrial genome, to population distribution that influences genetic isolation and differentiation, and to ancestral DNA polymorphisms. COI profiles uploaded in BOLD are the first records of this species and can identify Systrophia helcycloides from other species. These profiles corroborated the high variation in the land snail genome. Therefore, species identification in this group needs a combined analysis of genetic distances, informative sites, and conventional taxonomy.
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Reference:
Romero, P. & R. Ramirez, 2011. Divergencia intraespecifica y codigo de barras de ADN en Systrophia helicycloides (Gastropoda, Scolodontidae). – Revista Peruana de Biologia 18(2): 201-208.