May 21, 2012

New Thaumastus

A paper with a description of a new Thaumastus species from southern Brazil has just been published (Colley, 2012).

It describes a new species from Paraná, São José dos Pinhais e Guaratuba, Hydro-electric Powerplant Guaricana, Thaumastus straubei n.sp., for which also the anatomy (mandibula, radula and genitalia) is described. The holotype is in the Rio de Janeiro museum (MNRJ 11890).

Reference:

Colley, E., 2012. Nova espécie de Thaumastus da Floresta Atlântica do Paraná, Brasil (Mollusca, Gastropoda, Pulmonata, Bulimuloidea). - Iheringia 102: 43-47.

May 18, 2012

Bothriembryon types

A new paper was just published (Breure & Whisson, 2012) on types of Bothriembryon snails from Australia. Not Neotropical, but from the Gondwanan part of the Orthalicoidea.

Besides the documentation of all extant type material, we have tried to make an overview of the type localities of the taxa and to include remarks on taxonomic problems which may be solved in future studies.

Also included are the fossil taxa for this group. Not many in absolute numbers (seven), but compared to the South American groups it is relatively good representation. The type of Bothriembryon gunnii (Sowerby, 1845), the only fossil taxon of which type material is kept outside Australia, is figured as a photograph for the first time.

Reference:

Breure, A.S.H. & Whisson, C.S., 2012. Annotated type catalogue of Bothriembryon (Mollusca, Gastropoda, Orthalicoidea) in Australian museums, with a compilation of types in other museums. ZooKeys 194: 41-80.

Link to the open access paper: http://www.pensoft.net/journals/zookeys/article/2721/abstract/annotated-type-catalogue-of-bothriembryon-mollusca-gastropoda-orthalicoidea-in-australian-museums-with-a-compilation-of-, doi: 10.3897/zookeys.194.2721.

May 9, 2012

Quarternary terrestrial gastropods from Argentina

Some months ago, a big paper on the subject mentioned above was published by Miquel & Aguirre (2011). The abstract of the publication reads as follows:

This systematic review synthesizes our updated knowledge of 33 species and subspecies of Stylomatophoran gastropods, which belong to the genera Gastrocopta, Succinea, Radiodiscus, Retidiscus, Rotadiscus, Cecilioides, Austroborus, Megalobulimus, Bulimulus, Discoleus, Naesiotus, Plagiodontes, Spixia, Scolodonta, Miradiscops and Epiphragmophora . We provide published and unpublished records of the terrestrial molluscan taxa and a critical review, including data from the most important collections deposited in institutions from Argentina and abroad.

All the taxa described have modern representatives; only two, Succinea rosariensis and Scolodonta argentina, still require confirmation regarding their taxonomic validity. The genera with confirmed older than Quaternary records are Austroborus, Megalobulimus, Radiodiscus, Rotadiscus and Succinea, which occur since the Paleogene.

Regarding the modern geographical distribution, well known records involve part of Argentina (Subtropical and Pampean Dominia of the Guayanian-Brazilian Subregion and the Central Dominion of the Andean Subregion, both in the Neotropical Region). The best-known fraction of the fossil molluscs recovered corresponds to species of medium to large-size dimensions, whereas taxa of less than 5 mm have very seldom been mentioned before. Approximately 60% of the species recorded belong to the Orthalicidae (=Bulimulidae), the Strophocheilidae represent ca. 15%, while other families like the Xanthonychidae, Charopidae and Scolodontidae provide ca. 10% each. This review made evident that the main contributions on this subject were published by Joaquín Frenguelli who was responsible for having formed and organize the most important Quaternary terrestrial collection from Argentina, made of over a hundred lots deposited at the Museo de La Plata (Invertebrate Palaeontology Department). The synthesis on the distribution and ecological requerimients of the taxa identified provide the basic source of reference necessary to carry out future palaeoenvironmental and palaeoclimatical interpretations, complementary of research work performed based on mammals, pollen and phytoliths, as well as to select significative and reliable taxa for geochronological and isotope analyses on shells from Neogene sediments traditionally known as chronostratigraphical units (Platense, Cordobense, Bonaerense, Ensenadense of the local literature).

This is an important paleontological contribution, since most of the known fossils of land snails are from Argentina, Brazil and Uruguay. The percentage of 60% for the contribution of the Orthalicidea (Orthalicoidea) agrees well with current number for some countries in the northern part of the continent (Breure & Mogollón 2010: fig. 1); it would be interesting to compare it with the percentage of modern Orthalicoidea in the Argentinan malacofauna.

Interesting was also to see the references with publication dates of Döring's papers in the 1870s in Argentinan journals. In some cases they differ from the dates given by Neubert & Janssen (2004), which may have some importance since Döring published many new species. Thus datings may always be critical in case priority rules have to be applied. Unfortunately, the paper of Miquel & Aguirre doesn't give any further details.

References:

Breure, A.S.H. & Mogollón Avila, V., 2010. Well-known or little-known: miscellaneous notes on Peruvian Orthalicidae (Gastropoda, Stylommatophora). - Zoologische Mededelingen 84: 15-35.

Miquel, S.E. & Aguirre, M.L., 2011. Taxonomía de los gastrópodos terrestres del Cuartenario de Argentina. - Revista Española de Paleontología 26: 101-133.

Neubert, E. & Janssen, R., 2004. Die Typen und Typoide des Natur-Museums Senckenberg, 84: Mollusca: Gastropoda: Pulmonata: Orthalicoidea: Bulimulidae (2), Orthalicidae, Placostylidae - Archiv für Molluskenkunde 133: 193-297.

May 2, 2012

Counting as science

Does counting count as science? Yes, it does in taxonomy.

Apart from all sorts of morphological features which may be counted, sometimes the mere counting of specimens can be interesting. Especially when it involves the original type series.

In the Berlin museum I found several types of Placostylidae described by Bernhard Rensch from the Solomon Islands. This material became available to him through Eugen Paravicini, curator at the Anthropological Museum in Basel (now integrated in the current Naturhistorisches Museum Basel; NMB). During the 1920s Paravicini had made expeditions to the (then) British Solomon Islands where he also collected land mollusks.

In a letter of 21.i.1931 to Rensch, he asked for help with the identifications and offered to let him study the material.

In 1934, together with his wife Ilse, Rensch published a brief paper with diagnoses of several new species, some of which had been named after the collector, i.e. Paravicini (I. & B. Rensch, 1934). A more extensive paper based on the same material followed a year later (I. & B. Rensch, 1935). In the latter paper, Rensch had taken up the good habit of mentioning the number of shells with each description.

A few years ago, André Delsaerdt (2010) published his revision of the Placostylids from the Solomon Islands, and treated also the taxa described by Rensch. For each taxon the depository of the holotype was mentioned and the number of paratypes, which he had found in the NMB.

Bernhard Resch was curator of Malakozoologie at the Zoologisches Museum in Berlin (ZMB, now Museum für Naturkunde, Humboldt-Universität). Thus it was not surprising to find some "Typen" material in the ZMB collection of species described by him. All together material of 4 out of the 7 taxa described in his 1934/1935 papers were found with labels indicating "Paratypen".

Putting my data together, I checked the number of specimens mentioned in Rensch's papers and looked up his notes on the Basal material in Delseardt's book. Two taxa need a special mentioning.

When describing Placostylus paravicianus Rensch mentioned "Es liegen 10 Schalen … vor". In NMB, Delsaerdt found not only the holotype but also 10 paratypes; in the Berlin collection I found 2 paratypes. All together 13 specimens! Thus something has gone wrong, but where and how?

A similar problem occurs with Placostylus sanchristovalensis vicinus for which Rensch mentions in total 8 specimens. When I combine the data from Delseardt and myself, there are 10 specimens (including the holotype).

My tentative conclusion is that in these cases the number of paratypes has either been enlarged or someone has mis-counted the shells on his desk.

Creative counting or just a stupid mistake? That's the puzzling question that remains...

References:

Delsaerdt, A., 2009 [2010]. Land shells on the Solomon Islands, I. Placostylidae. L'Informatore Piceno, Ancona, 132 pp.

Rensch, I. & Rensch, B., 1934. Diagnosen neuer Landschnecken von der Salomonen. - Sitzungsberichte der Gesellschaft Naturforschende Freunde zu Berlin (1933): 451-453 [published 29.v.1934].

Rensch, I. & Rensch, B., 1935. Systematische und tiergeografische Studien über die Landschnecken der Salomonen auf Grund der Sammlungen von Dr. E. Paravicini und Dr. H. Hediger. Teil I. - Revue Suisse de Zoologie 42 (4): 51-86.

May 1, 2012

Land snails of Malpelo Island, Colombia

Just published, a paper on land snails of Malpelo Islands, Colombia (Hausdorf et al., 2012).

The fauna of the volcanic island Malpelo located west of Colombia’s Pacific coast includes only two species of land snails. One is a new endemic species of the subulinid genus Ischnocion, with which Rectobelus, Microbeliscus and Nannobeliscus are provisionally synonymized. Ischnocion conica new species differs from other species of the genus in the conical shell with radial palatal folds in juvenile stages. The other land snail species from Malpelo Island represents a new endemic thysanophorid genus. This genus, Malpelina (type species: Malpelina labiata new species), differs from other taxa of the Thysanophoridae in the yellowish-brown, depressed-globular shell with a distinctly thickened peristome, a broad glandular genital atrium, the lack of a vagina, a long penis, a long and exposed talon and the lack of entocones from all radular teeth. Malpelina is more closely related to Central American taxa than to thysanophorids from the Colombian mainland. Thus, it is more likely that Malpelo Island has been colonized by Malpelina from the north in accordance with palaeotectonic reconstructions. It is less clear whether Ischnocion reached Malpelo Island from Central or from South America, because the genus is distributed in both regions. Both species are patchily distributed on Malpelo and live under rocks in high densities. Their abundances increase towards higher altitudes. There is some segregation concerning the resting sites. Ischnocion conica rests on the soil or partially buried, while M. labiata almost always hangs from the underside of rocks.

Reference:

Hausdorf, B., Kroll, O. & López-Victoria, M., 2012. The land snails of Malpelo Island, Colombia. - Journal of Molluscan Studies 78: 157-165.

April 26, 2012

Berlin types

The Berlin collection (ZMB) is one of the important malacolgical sources for type material within Europe. Thanks to a SYNTHESYS grant I was able to work for two weeks in the collection. The result? A whole bunch of as yet undocumented types, supplementary to the annotated catalogue published by Frank Köhler in 2007.

Although I focussed mainly on the Odontostomidae, Placostylidae and Orthalicidae, also types from a substantial number of taxa belonging to the Bulimulidae were found.

My preliminary counts are as follows (including the ones listed by Köhler):

Amphibulimidae - 17

Bulimulidae - 151

Odontostomidae - 24

Placostylidae - 14

Orthalicidae - 37

Total for the Orthalicoidea: 243.

Compare this for instance with the listing of Neubert & Janssen (2004) for the Senckenberg collection (SMF):

If we discount the 'Originalserien' (which I haven't taken into account for ZMB), both collections are about equal size.

I still have to tally the different categories, but that's 'food for connoisseurs'. However, neither of the two collections can rival with London (about 650 taxa represented in my listings).

April 25, 2012

Handwritings again

Handwritings of malacologists are often the best kept secrets of natural history museums. One has to have a special interest in them and to inquire, otherwise one won't get to see them.

Working in the Berlin museum at the moment, I asked if they had a collection of handwritings. And yes, they showed me a folder with correspondence of many malacologists and collectors. I have made a list of people relevant for Neotropical malacology (and some for the Gondwanan orthalicids).

Two of the surprises for me were letters of Menke and Philippi, but as you may see, the list is quite substantial.

Albers, J.C.; Berlin - 1850

Biolley, P.; San José - 1891

Boettger, O.; Frankfurt a.M. - 1874-1910

Bohls, J.; Hamburg - 1894

Bonnet, A.; Paris - 1909

Champion, C.; London - 1890-1898

Charpentier, J. de; Devens near Bex - 1852-1853

Cox, J.C.; Sydney - 1869-1870

Cuming, H.; London - 1864-1865

Dall, W.H.; Washington D.C. - 1897-1905

Dautzenberg, Ph.; Paris - 1928-1931

Dohrn, A.; Stettin / Berlin - 1876, 1901

Dunker, W.; Cassel / Marburg - 1901-1904

Ernst, A.; Caracas - 1871

Eyerdam, W.; Seattle - 1930

Fulton, H.C.; London - 1909

Göldi, E.A.; Rio de Janeiro - 1888-1889

Gundlach, J.; Habana - 1874-1881

Haas, F.; Heidelberg - 1909

Hedley, C.; Sydney - 1906

Hidalgo, J.G.; Madrid -1913

Ihering, H. von; São Paulo - 1897-1898

Iredale, T.; London - 1914

Kobelt, W.; Schwanheim - 1892-1912

Martens, E. von; Berlin - 1858-1899

Menke, K.Th.; Pyrmont - 1843, 1853

Mousson, A.; Zürich - 1860

Oberwimmer, A.; Mitterarnsdorf -1924

Odhner, N.; Stockholm - 1929

Paetel, F.; Berlin - 1855

Paravicini, E.; Basel - 1931

Pfeffer, G.; Hamburg - 1896-1931

Pfeiffer, L.; Kassel - 1841-1868

Pilsbry, H.A.; Kansas - 1910?

Pittier, H.; San José - 1891, 1893

Preston, H.B.; London - 1912

Reibisch, T.; Dresden - 1853, 1855

Robson, G.C.; London - 1828, 1830

Rolle, H.; Berlin - 1927

Schomburgk, A.; Hainan - 1882

Smith, E.A.; London - 1897-1900?

Sowerby, G.B. III; London - 1906

Strebel, H.; Hamburg - 1874, 1877

Strobel, P.; Pavia - 1871

Suter, H.; Christchurch - 1897-1914

Thiele, J.; Dresden - 1892

Troschel, H.; Bonn - 1864-1871

Vernhout, J.H.; Leiden - 1913

Wessel, C.; Hamburg - 1874

I also noticed a remarkable difference in handwritings within the lifetime of a person. E.g., the 'young' Strebel from 1874 and the 'old' one in 1909. Something one has to keep in mind when trying to link a label to a person.

(download)

April 18, 2012

Slug(gish) science (and revisited)

Today two papers are summarized, one that I missed so far to mention in this blog (Glaubrecht, 2010) and one very recent (Glaubrecht and Zorn, 2012). These papers have a lot in common: both are dealing with tropical pulmonate slugs, both have biohistorical data, and both are centering on the Museum für Naturkunde in Berlin (ZMB).

The families treat in both papers are the Vaginulidae, Agrolimacidae, Limacidae and Urocyclidae. The use of the Vaginulidae needs some special remark, as this is a group usually referred to by authors dealing with the Neotropics as Veronicellidae. Glaubrecht (2010: 321-322) has given arguments for both the Vaginulidae Gray, 1847 and Veronicellidae Gray, 1840 being available names for the same group. Following the ICZN rules, the name should have priority which was used by most authors, i.e. Vaginulidae.

In both papers biohistorical data are presented. Glaubrecht (2010) gives interesting information about the slug expert Heinrich Simroth (1851-1917). The recent paper by Glaubrecht and Zorn (2012) presents brief biosketches of Karl Eduard von Martens (1831-1904), Johannes Thiele (1860-1935), Carl Gottfried Semper (1832-1893), and David Friedrich Heynemann (1829-1904).

Finally, both papers give annotated type catalogues of slug species present in the ZMB collection. In total 26 types of Neotropical Vaginulid species are present in the Berlin collection.

For those wondering why preparing annotated type catalogues is still considered useful work, I would highly recommend to read the introduction of Glaubrecht and Zorn (2012, and references therein) about taxonomic redundancy.

References:

Glaubrecht, M., 2010. Slug(-gisch) science, or an annotated catalogue of the types of tropical vaginulid and agriolimacid pulmonates (Mollusca, Gastropoda), described by Heinrich Simroth (1851-1917), in the Natural History Museum Berlin. - Zoosystematics and Evolution 86: 315-335.

Glaubrecht, M. and Zorn, C., 2012. More slug(-gish) science: Another annotated catalogue on types of tropical pulmonate slugs (Mollusca, Gastropoda) in the collection of the Natural History Museum Berlin. - Zoosystematics and Evolution 88: 33-51.

(download)

April 16, 2012

Landsnail ecology

A recent paper by Nunes and Santos (2012) describes the different environmental factors affecting land snail populations on two hill sides at Ilha Grande, Brazil.

The abstract reads:

The distribution and abundance of terrestrial molluscs are affected by environmental factors, but data are lacking for Brazilian land snails. The aim of this study was to understand the relationship between measured environmental factors and the land-snail species composition of two hillsides covered with Atlantic Rain Forest on Ilha Grande. On each hillside, five plots located at 100 m intervals between 100 to 500 m asl were chosen. Each plot was sampled by carrying out timed searches and collecting and sorting litter samples from ten quadrats of 25 × 75 cm. A range of environmental data was measured for each of the quadrats in a plot. A Cluster Analysis was carried out for the richness and abundance data. The environmental variables were analysed using a Pearson Correlation Matrix and Discriminant Analysis. Our results show that the two mountains are similar in species richness, but species composition and abundance are different, probably reflecting observed differences in environmental conditions. The environmental factors associated with compositional variation between the two mountains were: atmospheric temperature, soil temperature, litter depth, and relative air humidity. Distinct luminosity and canopy closure conditions were related to the composition of the land-snail community of one hillside.

The series of sites were only separated by a relatively low hill crest (some 100s of meters). Remarkably the altitude of the sites within each series is of great influence. In the discriminant analysis, the sites at 200-400 m at the 'oceanic hillside' grouped together, while at the 'continental hillside' the plot of 200 m forms a group on its own, and the plots 300-500 m group together. The environmental factors that seem to be influential may be summarized as follows:

This is the first time that this kind of ecological study has been undertaken with Neotropical snail populations. It would be interesting to do a similar study in the Andes, where in some places there seems to be influence from the afternoon wind blowing upward to the seaward slopes.

Reference:

Nunes, G.K.M. & S.B. Santos (2012). Environmental factors affacting the distribution of land snails in the Atlantic Rain Forest of Ilha Grande, Angra dos Reis, RJ, Brazil. - Brazilian Journal of Biology 72: 79-86.

April 13, 2012

congress announcement

Two congresses that may be interesting for those (Neotropical) snail lovers who like to stay updated with scientific news.

The first one is the American Malacological Society meeting in Philadelphia, U.S.A., 16-21 June. During the last days, Philippe Bouchet and Ira Richling will organize a symposium on "Magnitude of Molluscan Diversity, the known and unknown". For info on the AMS meeting, see http://www.malacological.org/meetings/index.php.

From 25-29 September, the XI ICMAM (International Congress on Medical and Applied Malacology) will be held in Rio de Janeiro, Brazil.