Monthly Archives: March 2011

A new book on Chimant??

Those who follow me, know that I have a weakness for the magnificent landscape of Venezuelan Guayana.This week a new book appeared, describing the cave systems that are present in some of these sandstone table-top mountains (geologically very unusual) and the biodiversity of the Chimant?? massif. All framed in nearly 300 pages, with 500 beautiful and often stunning pictures. It is called ‘Entra??as del Mundo Perdido’ and was written by Charles Brewer-Carias and Marek Audy. At the moment the book is only available as Spanish text; an English translation might follow.


And yes, snails are also represented in the book, referring to the material that was described from the 2009 expedition to Chur??-tepui.


Besides being a beauty to the eye, this book also gives a sound and splendid overview of some of the secrets of the Lost World that were uncovered only recently.

Brewer-Carias, C., Audy, M., 2011. Entra??as del Mundo Perdido: 1-291. Published by Brewer-Carias, Caracas.

Systematisches Conchylien-Cabinet

In the BHL scans have been added of Martini & Chemnitz Systematisches Conchylien-Cabinet. This is one of the famous old malacological works of great importance to taxonomists. The URL is here:

One of caveats of old literature is that in several cases no publication dates are given, or not precisely enough. Fortunately, for many cases later authors have documented these dates on the basis of research on e.g. original wrappers. 
For this publication there are two sources available. One related to the copy in G??ttingen:  Welter-Schultes, F.W., 1999. Systematische Conchylien-Cabinet von Martini und Chemnitz (1837-1920), bibliography of the volumes in G??ttingen. – Archives of Natural History 26 (2): 157-203. 
The other paper is by E.A. Smith and H.W. England, related to the copy in the London museum; this paper may be found online here:

Lissachatina again

Lissachatina fulica is marching up rapidly and causing new problems.

On 12-10-2010 I reported a new finding of this pest species in Colombia, Dept. Putumayo, Puerto Asis (see old snailblog on The past week saw a new report of a Colombian occurrence of this species, in Dept. Cauca, Cali. This is a major expansion as L. fulica now has reached the western part of Colombia. As Cali is a major city with many transport links, there is now a real chance for a rapid, further expansion.


At the same time I came across a paper describing the first finding of Schistosoma mansoni eggs in feces and mucous secretion of L. fulica in Venezuela (Libora et al, 2010). The implications for public health are immediately eminent, as this is a known vector of bilharzia.

Francisco Borrero, who gave me the info on the new Cali record, mentions that there are several pathways that seems to contribute to the rapid expansion of this species. One that we came across earlier in Ecuador, is the increasing popularity of baba de caracol (snail mucous) as health care product. If it wasn’t so serious it would be ridiculous. But the Venezuelan paper precisely shows why this is so alarming.

Although the authorities are well aware of the health risks and several citizens seem to be alarmed about the risks they are exposed to, one major risk seems to be highly neglected: the effects that these Giant African Snails can have on the local snail fauna. A serious threat that deserves serious attention. But as long as snail biodiversity has no monetary value, this probably will remain wishful thinking…

Libora, M., Morales, G., Carmen, S., Isbelia, S., Luz, P., 2010. Primer hallazgo en Venezuela de huevos de Schistosoma mansoni y de otros helmintos de inter??s en salud p??blica, presentes en heces y secreci??n mucosa del molusco terrestre Achatina fulica (Bowdich, 1822). – Zootecnia Tropical 28: 383-394.

Preparing figures for publication

I have this mentioned before, but SimpleMappr comes in really handy when you have to prepare figures for a manuscript showing distribution records. Now I found out that they have improved the site, with two options for showing the relief of the area of your choice. This can be done either in grey tones or in (decent) colours.

Very neat!

You may find the website at <a href="<p>


Tropical forest snails

Recently a review was published by Menno Schilthuizen (2011) on land snail communities in tropical forests. Although the examples he shows in this paper are focussed on studies in Malaysia, this work is of importance for Neotropical malacologists as well. The abstract of his paper, which was originally presented as a key note on the WCM 2010 in Phuket, is given here:

Since Solem’s provocative claim in the early 1980s that land snails in tropical forests are neither abundant nor diverse, at least 30 quantitative-ecological papers on tropical land snail communities have appeared. Jointly, these papers have shown that site diversity is, in fact, high in tropical forests; often more than 100 species have been recorded per site, which is somewhat more than normally found at sites in higher latitudes. At the same time, however, point diversities (which usually range between 10 and 30 species per quadrat) appear to be no different from the ones recorded for temperate localities, which suggests that the number of ways in which syntopic resource space can be subdivided among different land snail species has an upper limit that is no higher under tropical conditions. The available data do not allow much analysis of the ecological structuring processes of communities besides very coarse ones, e.g. the proportions of carnivores versus herbivores and Pulmonata versus non-pulmonates. Also, these first 30 years of research have shown that a number of serious methodological and conceptual issues need to be resolved for the field to move ahead; in particular whether empty shells from the forest floor may be used as a proxy for the contemporaneous communities. I make a number of suggestions for ways in which these obstacles may be removed. First, studies should be preceded by exploratory nested sampling in contiguous quadrats of increasing size, spanning several orders of magnitude. The shape of the triphasic species-area curve and nonlinear regression of the small-area end of the curve will help identify the quadrat and site areas that allow ecologically more meaningful studies. Second, researchers should be more aware of the trophic levels of species and restrict their analyses within guilds and within body size classes as much as possible. Testing species abundance distributions against ecologically explicit theoretical models may be a fruitful avenue for research. Finally, I argue that studies of this nature require species abundances that may only be found in tropical land snail communities that live on calcareous substrate, and therefore I suggest that malacologists aiming to understand community structure focus on limestone sites initially.

One of the interesting results is showing that the perceived species richness of limestone habitats is an illusion created by higher abundances. The link to the full paper is given below.
Schilthuizen, M., 2011. Community ecology of tropical forest snails: 30 years after Solem. – Contributions to Zoology 80: 1-15.

Keys are key

The beginning of wisdom is to call a thing by its right name. That’s a key phrase for any taxonomist; and for all disciplines that are building on the wisdom provided by taxonomy. It is also the motto of a new initiative, IdentifyLife.


It’s a global, collaborative project providing ways to identify the world’s living organisms ( Yes, in the end, because it will take some time before this has been realized. However, the goal has my sympathy, although it has to compete with other priorities and projects.
Key-building software has been available for some time, and DELTA has been a pioneering piece of software that was developed in Australia. This project has been down for a while, but is now revived by transferring it to a Java environment. It is called OpenDelta (<a href="</p>


A Windows version is already available on the Download page, but the Java version does not work for me as yet.

Another Java application that is using the DELTA format, is NaviKey ( This is also a project in progress, currently in version 5.01, and interestingly with “NaviKey mobile” on their ToDo list, meant for handhelds and smartphones.


Whatever is clear, key are keystone to any future taxonomy.

Descriptions and (type) specimens

Species are described on the basis of one or more shells, the type series. In case of the latter situation, one specimen is selected holotype by its author(s); the other(s) thus become automatically the paratype(s). In modern works, the type series is completely listed and any shell not mentioned in the original publication cannot be regarded a type specimen.

This practice is ruled by the International Code on Zoological Nomenclature, and their Code can be found at, with its many detailed regulations and subsequent jurisdiction in its Bulletin.

For those of you who don’t care about all the juridical finesses, a practical example.  
In 1901, S.I. da Costa described a new species as Drymaeus exoticus from “The hot country, Upper Magdalena River, Colombia”. As measurements he gave “Long. 23.5, diam. 11 mm”. Apart from the description and the type locality, there were no further remarks on this species. At that time, it wasn’t uncommon not to state explicitly on how many specimens a description was made. 
In my 1979 review of genera, I listed the species under Drymaeus (Drymaeus), and the single specimen that I had found in the London museum as “holotype”. Upon my return to London, last September, I re-studied the specimen, which is accompanied by a label in da Costa’s handwriting. As you may see, the locality matches the one given in the original publication. The shell proved to be slightly bigger than da Costa’s measurements: shell height 24.8, diameter 12.2 mm. Still, I had little doubt to question the “holotype” labeling.


In December last year, when working in the Brussels museum, I found a shell labelled as “D. exoticus d.C. Bogota” in the Dautzenberg collection. Dautzenberg usually had added his own label, stating on which date he acquired specimens from whom. But in this case not. It is clearly a label in da Costa’s handwriting, and we know that he was a shell dealer. However, it is not clear when he sold this specimen to Dautzenberg, and whether it was already in his possession when da Costa described the species in 1901 or not. The Brussels shell is 24.3 mm shell height.

Although the Brussels specimen isn’t labeled as “type” and bears no collection date, it cannot be excluded that it was in da Costa’s possession when he described Drymaeus exoticus, and formed part of the type series. Thus my 1979 listing becomes a lectotype designation under Art. 74.6 ICZN.

By the way, notice the imprecise (and incorrect) locality on the Brussels label: “Bogota”. This was a habit in the 19th and early 20th century of many collectors and shell dealers, viz. to mention the capital of the country instead of the exact locality. It makes taxonomy often a puzzling occupation…

Determinanda (1)

A new series of posts with photographs of snails for which I don’t have the full identification. These are mainly from species beyond my own group of specialization, or of Orthalicoid species for which the pictures don’t allow a conclusive result. My intention is to update the post once I have reached a satisfying identification or when additional pictures of the species under consideration have become available. Until then, enjoy the pictures just as they are!

The first pictures are probably of an Aperostoma species. They were taken by Adri??n Gonz??lez in Ecuador, Prov. Imbabura, Valle de Intag.


Orthalicid radulae (11): Plekocheilus

Another species of this genus, Plekocheilus (Eudolichotis) aurissciuri (Guppy, 1866),  collected at Paramaribo, Suriname. From upper right clock-wise: half row (note that is probably a truncated radula), marginals 14-16, marginal 4, marginal 1, marginals 8-18, central and first eight lateromarginals.


The formula is C/1 + L 1/1 + M 15+x/2; x = 3, possibly more.