A snail with an U-loop

Cornu aspersum (O.F. Müller, 1774) is a common European snail with a ground colour of yellowish brown , and mostly with some darker spiral bands and irregular light and dark blotches (Jansen, 2015). Recently in a Dutch zoo a new tropical greenhouse was installed with plants imported from Costa Rica. Herman Creemers sent me a picture of snails collected in this greenhouse (on the right side), together with some specimens from the Netherlands (on the left side). He wondered if this species was known from Costa Rica or not.

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Barrientos (2003) has given an overview of Costa Rican species and said: “El escargot, Helix aspersa [the old name], fue introducido has más de 100 años y está restringido a jardines urbanos en San José”; the species is thus more than a century present in Costa Rica, but still restricted to gardens in the capital. The different coloration of shells presumably originating from Costa Rica, imported together with plants, is somewhat different. This might be due to the prolonged isolation, but only detailed DNA research could tell whether some divergence has occurred or not.

References:
Barrientos, Z., 2003. Estado actual del conocimiento y la conservación de los moluscos continetales de Costa Rica. – Revista de Biologia Tropical 51, Supplemento 3: 285–292.
Jansen, A.W., 2015. Veldgis slakken en mossels. Zeist, KNNV, 272 pp.

New paper published

Freshly pressed (but in bytes only): a new paper on the drawings of Vietnames land- and freshwater snails that was found in the Bavay archive, and the person who initiated this.

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We have added biographical data and a list of eponyms of Victor Demange, who was a contact of Bavay.

Reference:
Breure, A.S.H. & Ablett, J.D. The ‘Demange drawings’: known and unknown malacological contributions of Victor Demange (1870-1940). — Folia conchyliologica 36: 1–9. 95_demange

Crossing the border

The borders of a discipline are often quite interesting, also because less research has been done and one can try out novel approaches. Some time ago I did this with the project on snails in art, and this time I ventured to explore the social sciences to get more insight in the history of malacology. Last week I crossed the border in a double meaning, not only to the domain of the social sciences, but also to Germany where I participated in the 10. Trier Summer School on Social Network Analysis.

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The week consisted of two days on the theory of social network analysis (SNA), and 3.5 days of application with different software programmes and own research projects. And as the whole course was in German, my mastering of that language did improve as there is no progress without exercise🙂

As I have elaborated here, malacologists operate (and have operated), like all scientists, in a social network. The question is what research questions are possible, especially when focussing on the 19th and early 20th centuries? For a better understanding of how malacology as a discipline developed, it would e.g. be interesting to understand how the links between malacologists in the past were functioning (see here), and who played an important role or acted as a broker between different parts of the network. But the question is how to reconstruct these links from the past that tied together the malacologists in an ancient science network.

Since historical research depends on the quality of the data sources, I was happy to have had access to the Dautzenberg archive (Breure, 2015, in press), and to work on the Crosse archive. This allowed for a validation of the idea that eponyms are a proxy for contacts between malacologists. Eponyms have been given, especially during the 19th and early 20th centuries as a tradition, to collectors providing material and to collegial authors. The validation process (Breure, in preparation) proved to confirm the idea that eponyms may act as a proxy for contacts, provided that contextual information is used.

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The figure above is the result of gathering the eponyms given and received by six French malacologists: Crosse, Drouët, Mittre, Morelet, and Petit de la Saussaye. The size of the name reflects the importance in the network, as calculated by statistics in Gephi. Interesting is that Morelet is the most important person in the network of six, and not Crosse as one might have expected.

These results are interesting enough to attempt a follow-up on this interdisciplinary avenue. To be continued…

References:
Breure, A.S.H., 2015. The malacological handwritings in the autograph collection of the Ph. Dautzenberg archives, Brussels. — Folio Conchyliologica 33: 1–111.
Breure, A.S.H., in press. Philippe Dautzenberg (1849–1935) and his time, towards the reconstruction of an ancient science network. — Basteria 80 (in press). Preprint available at DOI: 10.13140/RG.2.1.3672.4726

New paper

In the latest issue of the Journal of Conchology a paper appeared by Araya et al. about the occurrence of Bostryx hennahi (J.E. Gray, 1828) in northern most Chile and southernmost Peru.

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This species appears confined to fog oasis in the extreme arid deserts in the region, and is thus an example of a harnessed species to harsh conditions.

Reference:
Araya, J.F., Madrid, M. & Breure, A.S.H., 2016. Bostryx hennahi (Gray, 1828) the largest Chilean bulimulid (Mollusca: Pulmonata) rediscovered among Tillandsia communities in northern Chile. — Journal of Conchology 42: 161–165.

New Megalobulimus from Peru

Borda & Ramirez (2016) have just published a new paper on Peruvian Megalobulimus species, in which they also describe two new species.

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The abstract of their paper is: “A major taxonomic problem around the genus Megalobulimus Miller,1878, the largest land snails in the Neotropics, is plasticity of conchological characters. Here we re-describe Megalobulimus leucostoma (Sowerby, 1835) and describe two new species of Megalobulimus from Southern Peru, Megalobulimus tayacajus sp.nov. and Megalobulimus inambarisense sp.nov. These descriptions are based on both conchological and soft anatomical characters. Megalobulimus leucostoma is characterized by the presence of a retractor muscle with two insertions to the buccal mass, two small bulges on pre-rectal valve, and a geographical distribution appears limited to Cusco. Megalobulimus tayacajus sp.nov. is characterized by the presence of a retractor muscle that divides near the buccal mass, two lobed bulges on pre-rectal valve, and to date, has been found only in Huancavelica. Megalobulimus inambarisense sp.nov. is characterized by the presence of a retractor muscle with one insertion to the buccal mass, two big bulges on pre-rectal valve, and a distribution appears limited to Puno. The digestive system appears to serve as useful characters to discriminate these species and, when combined with shell and reproductive characters, may help to understand better the evolution and ecology of these snails”.

Reference:
Borda, V. & Ramirez, R., 2016. The genus Megalobulimus (Gastropoda: Strophocheilidae) from Peruvian Andes: Re-description of Megalobulimus leucostoma and description of two new species. – American Malacological Bulletin 34: 15–27.

On the history of malacology

Just launched: a new site on the history of malacology! It is named Malacohistory and can be found following the link in the picture below.

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The introduction reads “Some regard Aristotle as the first malacologist (Coan & Kabat, 2016), but it is not that far that we like to go back in time with this site on malacohistory. Rather we prefer to focus on the 19th and 20th century when malacology became fashionable among amateurs and also the first professional malacologists appeared as staff members of natural history museums. Collecting shells, however, started much earlier (see e.g. Dance, 1966 for an extensive review), and the interest for snails as such is notable in literature and visual arts from early on in history (see the site Huntingforsnails). For practical reasons, we will focus especially on European malacologists, their collections and their fate, and the context in which they operated. (…) Both well-known persons will come across as well as hitherto completely unknown people who contributed (often in a modest way) to European malacology. We intend to publish on this site data that we obtained through our research, background data used for publications, and preliminary data. This can be either biographical data, data on the location of (part of) collections, and other facts that help to explain the development of malacology in Europe. Also new insights from literature and methodological notes may find its place here in blog posts”.

Big questions, small bricks
Is this site a hobby-ish endeavour or is it aimed at contributing to a ‘Bigger Picture’? The latter sounds pretentious, but nevertheless it is possible to come up with some big questions to which this site may lead to (or is at least hoped for) helping formulate some answers. How did malacology develop in Europe? Where were the centres of activity and how did these develop over time? Who were the driving persons and how were they linked? What was the role of scientific societies in relation to malacology in different parts of the continent? What other factors did influence the development of molluscan studies? What was the role of amateurs, professionals, and shell dealers, and how did the balance between these groups change over time? What was the role of women? How did specialised journals foster the discipline of malacology? To summarise: how was the ancient science network of malacology shaped in Europe during these centuries (and especially the period 1850–1950)?
Clearly a lot of questions and for the moment in most cases only a beginning of an answer or a vague feeling in which direction we have to search for it. However, hopefully the posts on this site will act as small bricks from which a solid building can be erected in the end. And, as one of my tutors, Pieter Wagenaar Hummelinck always said: “We can not all be masons, there must also be people who bring the stones”.

So far, only a limited number of posts have been published, but contributions of readers are very welcomed. The site is edited by Cédric Audibert (Musée des Confluences, Centre de conservation et d’étude des collections, Lyon, France) and myself.

Cerion genomics

Harasewych and his team have focused on different aspects of the Cerionidae, but have now added a phylogenetic paper with state-of-the-art technique. “The complete mitochondrial genome of the neotype of Cerion incanum (Leidy, 1851) was sequenced using high-throughput sequencing and found to be a circular genome 15,117 bp in length with a GC content of 34.3%. It is the largest mitogenome presently known in Stylommatophora, with the difference in size due primarily to intergenic regions and to a lesser extent to larger sizes of individual genes. Gene content is identical to that of other stylommatophorans, but differs in having the tRNA-Gln gene situated on the major coding strand. Gene order of C. incanum was similar to that in Helicidae, differing in the regions between COX1 and NADH5, and between tRNA-Ser2 and tRNA-Ile. The potential origin of replication was located in a 50-bp noncoding region between COX3 and tRNA-Ile. Phylogenetic analyses using Bayesian inference and maximum-likelihood analyses of nucleotide data for all protein-coding and large and small ribosomal genes resulted in a well-resolved tree. This tree was similar to trees derived from nuclear or a combination of nuclear and mitochondrial genes, differing from previous phylogenetic reconstructions based on mitogenomes in the placement of Hygrophila. The phylogenetic position of Cerionidae as sister taxon to Helicoidea is consistent with previous findings after allowing for more limited taxon sampling in the mitogenome tree. The mitogenome tree is sufficiently populated to refute the inclusion of Cerionidae in Clausiloidea, as advocated by some authors, but at present lacks the representatives of the Orthalicoidea or Urocoptoidea needed to resolve more precisely its relationships with those taxa”.

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The last sentence of their abstract is intriguing, and in Leiden we had hoped to be able to contribute to this knowledge by supplying data from a Bulimulus and a Drymaeus species. However, the PCRs have failed and the project has been dropped.

Reference:
González, V.L., Kayal, E., Halloran, M., Shresta, Y. & Harasewych, M.G., 2016. The complete mitichondrial genome of the land snail Cerion incanum (Gastropoda; Stylommatophora) and the phylogenetic relationships of Cerionidae within Panpulmonata. – Journal of Molluscan Studies: 1–9 (advance access doi:10.1093/mollus/eyw017).