Tag Archives: bostryx

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 As unpublished DNA results of species from this genus from different countries reveal, this genus may well be polyphyletic.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.

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More on Argentinian Bostryx

María José Miranda has recently published a new study on several Bostryx species from central western Argentina. As always, this is a thorough paper with lots of anatomical data.

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The abstract reads: “The genus Bostryx Troschel, 1847 is endemic to South America, extending from Ecuador to Chile and Argentina. The southernmost Argentinian species of the genus that inhabit San Luis, San Juan and Mendoza provinces, specially the pre-Andes, Andes and Sierras Pampeanas mountain ranges, were examined. This is the first time the anatomy of Bostryx pastorei (Holmberg, 1912), Bostryx reedi (Parodiz, 1947) and Bostryx strobeli (Parodiz, 1956) has been described. Bostryx cordillerae (Strobel, 1874) is re-described regarding shell and anatomy due to new morphological data. The main differences among the species examined are based on shell characters. The distribution of Bostryx mendozanus (Strobel, 1874) and Bostryx cuyanus (Pfeiffer, 1867), other species found in this region, was also discussed”.

As she cited my publication about the subfamily Bostrycinae (Breure, 2012), I feel entitled to correct a possible misinterpretation. From her text it gives the impression that I have a very restricted view of this subfamily, leaving out all species not listed in my 2012 paper. The contrary is true. Page 3 of my paper explicitly stated that the list presented is incomplete, and further research should show which other species belong to this monophyletic clade. As the shell shape may be very misleading, which is corroborated in Miranda’s paper, I invited further research using anatomical and molecular data. Miranda’s paper is a welcome contribution to this end, although she has not presented phylogenetic data which could supplement the available data in GenBank. Hence there is room for further additions…

References:
Breure, A.S.H., 2012. The status of the genus Bostryx Troschel, 1847, with description of a new subfamily (Mollusca, Gastropoda, Bulimulidae). – ZooKeys 216: 1-3.
Miranda, M.J., 2015. The genus Bosoryx in central western Argentina: anatomical and distributional description of four of its southernmost species (Gastropoda, Bulimulidae). – Iheringia, Zoologia 105: 484–498.

Chilean bulimulids

Just published in a not-so-common journal for a taxonomical paper: Juan Francisco Araya’s new paper on Bulimulidae from the Atacama region in Chile. This desert-like environment is only seemingly unfavorable for snails and is little researched so far.

ArayaT1

The abstract reads: “The bulimulid genus Bostryx Troschel, 1847 is the most species-rich genus of land snails found in Chile, with the majority of its species found only in the northern part of the country, usually in arid coastal zones. This genus has been sparsely studied in Chile and there is little information on their distribution, diversity or ecology. Here, for the first time, a formal analysis of the diversity of bulimulids in the Region de Atacama, northern Chile, is reported. Of the seventeen species recorded for the area, most of themwere efectively found in the field collections and one record was based on literature. Five taxa are described as new: Bostryx ancavilorum sp. nov., Bostryx breurei sp. nov., Bostryx calderaensis sp. nov., Bostryx ireneae sp. nov. and Bostryx valdovinosi sp. nov., and the known geographic distribution of seven species is extended. Results reveal that the Region de Atacama is the richest region in terrestrial snails in Chile, after the Juan Fernandez Archipelago. All of the terrestrial molluscan species occurring in the area are endemic to Chile, most of them with restricted geographic distributions along the coastal zones, and none of them are currently protected by law. Further sampling in northern Chile will probably reveal more snail species to be discovered and described”. The study of Araya is thus a welcome additional to our knowledge of the Neotropical malacofauna.

Reference:
Araya, J.F. (2015). The Bulimulidae (Mollusca: Pulmonata) from the Region de Atacama, northern Chile. – PeerJ 3: e1383. Available at https://peerj.com/articles/1383.pdf

Bostryx tortoranus complex

Maria José Miranda, a young researcher from Argentina, has just published a new paper on some Bostryx species from that country. As it is advance access, the printed version will follow later.

Schermafbeelding 2015-01-14 om 15.39.36

The abstract reads: “Morphology of the shell, radula, jaw, anatomy and sculpture of the inner wall of the reproductive system are described and compared for three species belonging to the Bostryx tortoranus species complex. On the basis of these characters, the following changes are proposed: Bostryx martinezi (Hylton Scott, 1965) is removed from synonymy with Bostryx tortoranus (Doering, 1879) and Bulimulus (Scansicochlea) cicheroi Hylton Scott, 1967 is transferred from synonymy with B. tortoranus to synonymy with B. martinezi. As a result of these changes, the number of species of Bostryx known from Argentina has increased to 19 species. Bostryx tortoranus and B. martinezi are redescribed, also the radula and anatomy of Bostryx rudisculptus (Parodiz, 1956) are described for the first time. The main distinctive morphological characters of the three species are: the structure of the shell’s protoconch and teleoconch, radular morphology, location of the secondary ureter opening, the length of the free oviduct with respect to the vagina and the epiphallus with respect to the penis and the bursa copulatrix duct’s inner wall sculpture. Bostryx martinezi and B. rudisculptus have restricted distributions and are ecologically endemic, whereas B. tortoranus has a wide distribution and is located in different dry ecoregions”.

Reference:
Miranda, M.J. (2015) Bostryx tortoranus (Doering, 1879) species complex (Gastropoda: Stylommatophora: Bulimulidae), a review of taxonomy and distribution of endemic species from Argentina. – Journal of Natural History, DOI: 10.1080/00222933.2014.981313 (advance access).

A ‘blanket’ of Bostryx

Edmundo Martinez kindly send me some pictures which show an extraordinary wind accumulation of Bostryx shells on a sandy slope of the coastal range in northern Chile. The hill is 450 meters high and the shells are distributed from the top to the base.

Cliff

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Bostryx accumulation

This phenomenon is so evident, that can even be seen from a plane looking down, as shown on this photo in Google Earth (2014 image, see marker); the simulated ‘flight height’ is 9.6 km.

Schermafbeelding 2015-01-11 om 11.00.08

Revision of Bostryx stelzneri complex

Miranda & Cuezzo have now published a long awaited paper, presenting a revision of a species group from northern Argentina, the Bostryx stelzneri complex. This paper partly resulted from Miranda’s Ph.D. thesis work.

The abstract reads: “The Bostryx stelzneri species complex is taxonomically reviewed with the description of a new species. This complex is formed by Bostryx stelzneri (Dohrn, 1875), B. peristomatus (Doering, 1879), B. scaber (Parodiz, 1948) and Bostryx roselleus n. sp., all distributed in Argentina. Bostryx peristomatus and B. scaber are elevated to specific status on the basis of morphological characters. This complex has the spire less than half the total shell height and the aperture higher in relation to total shell height than in any other species of the genus. Traditional shell morphometry and a geometric morphometric analysis were used to document shell variation in size and shape among species. Radula, jaw and shell morphology were examined with SEM. All species in the complex are described or redescribed using new morphological information. In this species complex, pallial organs are very similar among species and vary only in the degree of opening of the secondary ureter. The genitalia differ in the relative proportion of organs, such as length of vagina relative to free oviduct and penis or epiphallus length relative to penis length. Sculpture of the inner wall of the flagellum and epiphallus is similar in all species studied, whereas sculpture of the inner wall of the penis is variable. Geometric morphometric analysis allows an objective interpretation of shell shape variation detecting differences in shape components irrespective of the differences in size between Bostryx Troschel, 1847 species of the stelzneri group.”

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In the introduction (p. 74) I saw a sentence that shows a misinterpretation of my 1979 thesis. “Breure (1979) listed 23 species of Bostryx in Argentina, while Miquel (1993, 1995) recognised only 13 valid species using shell morphology similarities to justify his synonymic actions.” The misinterpretation lies within the suggestion that in my thesis the species lists under each genus were lists of valid species. There were not; my thesis was a revision of the genera within the subfamily (now regarded as family Bulimulidae), the lists of ‘species’ under each genus were actually a list of taxon names from literature that had been placed in the genus. Nothing less, nothing more. The later work of Miquel was a more detailed taxonomic revision of the species from Argentina; of the available taxa he considered 10 as junior subjective synonyms, and thus ended up with 13 species.
Finally, in the discussion (p. 89), the authors state “he [Breure 1979] did not describe the inner penial anatomy which is unknown in all Bostryx species”. Possibly the authors had the Argentinean species in mind? In Breure 1979: fig. 63-64 schematic reconstructions of two (Peruvian) Bostryx species are given, while in a previous paper the histology is described of the inner genitalia from nine Bostryx species, among which B. stelzneri (Breure 1978: 127-128). But indeed, “the reproductive system is very simple in comparison to other genera of Bulimulidae” as the authors state (p. 89).

In this paper Miranda & Cuezzo have thoroughly studied all available material at hand, and propose a new classification. The 13 species have been reduced to four, with additionally a number of “morphological or population variations” within Bostryx stelzneri.

MC2014f10

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References:

Breure, A. S. H. 1978. Notes on and descriptions of Bulimulidae (Mollusca, Gastropoda). — Zoologische Verhandelingen 164: 1–255.
Breure, A. S. H. 1979. Systematics, Phylogeny and Zoogeography of Bulimulinae (Mollusca). — Zoologische Verhandelingen 216: 1–98.
Miquel, S. E. 1993. Las especies del género Bostryx Troschel, 1847 en la República Argentina (1ra. parte) (Gastropoda Stylom- matophora: Bulimulidae). — Archiv für Molluskenkunde 121: 157–171.
Miquel, S. E. 1995. Las especies del género Bostryx Troschel, 1847 en la República Argentina (2da. y última parte) (Gastropoda Sty- lommatophora: Bulimulidae). —Archiv für Molluskenkunde 124: 119–127.
Miranda, M.J. & Cuezzo, M.G. (2014). Taxonomic revision of the Bostryx stelzneri species complex, with description of a new species (Gastropoda: Orthalicoidea: Bulimulidae). — American Malacological Bulletin 32: 74-93.

Gray’s Spicilegia

Peter S. Pallas, who is mainly known for his explorations in Russia, published between 1767 and 1780 his ‘Spicilegia zoologica‘. In this work in Latin, consisting of a series of brief ‘fasciculus‘, he gathered information and gave illustrations of mammals, birds, fish and some frogs. This set up must have inspired John E. Gray in the late 1820s to write his own ‘Spicilegia zoologica; or Original Figures and Short Systematic Descriptions of New and Unfigured Animals’. The first part appeared in 1828, the second in 1830 and there seems also to be a later part 3; I have been unable to trace it.

Unlike the book of Pallas, the work of Gray is not available in BHL and for many years remained rare and difficult to consult. The first two parts are available here (http://bit.ly/1flyTce), but the quality of the illustrations is mediocre. Its significance for Neotropical malacology lies in the first part, where on p. 5 two species are mentioned, one of which described as new to science.

The first one, mentioned without further details about its locality, is Plectostylus peruvianus (Bruguière, 1789). Although described from “Pérou”, it actually is a Chilean species.
The second species is Bostryx hennahi (Gray, 1828), described from “Plains near Arica”; this is in (nowadays) northernmost Chile (see my post at https://breure.wordpress.com/2011/02/25/history-matters/). From the text on this page it becomes clear that the type was not part of the NHM collection, as for other species (e.g., Achatina nitens) “Mus. Brit.” indicated that the type is in the London museum. Gray’s species also occurs in (nowadays) southernmost Peru, shown by the type locality “Tacna” of the junior synonym Helix cactorum d’Orbigny, 1835, for which type material is present in NHM.

I’m grateful to Jonathan Ablett for scans from Gray’s paper and bibliographical data.

References:
Gray, J.E. (1828). Spicilegia zoologica; or Original Figures and Short Systematic Descriptions of New and Unfigured Animals, part 1: 1-8, pl. 1-6. London (Treüttel, Würtz & Co. & Wood).
Gray, J.E. (1830). Spicilegia zoologica; or Original Figures and Short Systematic Descriptions of New and Unfigured Animals, part 2: 9-12, pl. 7-11. London (Treüttel, Würtz & Co. & Wood).