Author Archives: bramb

New Cuban Cerion

In a not so current journal, a new species of Cerion was just described from Cuba.

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Cerion milerae sp. nov. is described from the type locality Punta Bejuquera, Gibara, Holguín province, Cuba. It is compared conchologicaly with Cerion paucicostatum paucicostatumCerion paucicostatum harringtoni and Cerion caroli aedilii. Anatomically it is compared with Cerion paucicostatum paucicostatum. With its description the number of species known from Cuba is increased to 148 and to 35 the number of species and subspecies known from Holguín province. An extensive survey in the zone showed that Cerion milerae sp. nov. is microlocalized, associated to Bayhops (Ipomoea pes-caprae), in sandy substrate”.

Suárez, A., 2018. Especie nueva de Cerion (Mollusca: Pulmonata: Cerionidae) de Holguín, Cuba. – Novitates Caribaea, 12: 43-48.


When the cure kills

Today something about policy. Often boring and uninteresting (seemingly), but sometimes politicians take decisions which are affecting the work of taxonomists. Therefore the recent paper by Prathapan et al. which appeared in the journal Science is worth mentioning.

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The Convention on Biological Diversity (CBD) commits its 196 nation parties to conserve biological diversity, use its components sustainably, and share fairly and equitably the benefits from the utilization of genetic resources. This last objective was further codified in the Nagoya Protocol (NP).

The authors state that the NP mechanism seem to work out counter-productive, leading to all sorts of national legislature in biodiverse countries which hamper the study of its biodiversity by biologists. Conservation approaches are very strict and deny that effective conservation also demands the scientific understanding of species. In practice, legislative processes have been tightened in many countries to such extent that biological research has been hampered by permits. Permitting processes are sometimes becoming vulnerable to fraud and corruption, the responsible persons using their for their own benefit and blocking permits to foreign colleagues who are not their favourites. While some South American countries are playing these games and EU-based museum curators adhere strictly to the official rules, it leads to a total stand-still of taxonomic research which needs e.g. live collected animals for molecular study.

The authors, supported by 172 co-signatories from 35 countries, make a strong plea to the CBD to “do more to raise the legal curtain that has fallen between biodiversity scientists and the biodiversity that they strive to discover, document, and conserve”.

Prathapan, K.D. et al., 2018. When the cure kills–CBD limits biodiversity research. – Science, 360 (6396): 1405-1406.

Helicina: anatomical data

Luiz Simone just published a paper on the anatomy of Helicina variabilis, a typical member of the family Helicinidae, which occurs in Brazil.

Helicina variabilis Wagner, 1827 (Neritimorpha, Helicinidae) is redescribed based on a sample collected in Nanuque, northern Minas Gerais, Brazil. The species description, previously based only on the shell, is expanded to the phenotypic features. The study revealed absorption of the internal shell whorls; a diaphragm muscle connected to the floor of the pallial cavity; a monoaulic pallial oviduct, with the female genital aperture inside the anal aperture, and the lack of a seminal receptacle and provaginal sac; and the pleural ganglia of the nerve ring connected with each other. The significance of these findings is discussed in the light of current taxonomic and phylogenetic knowledge”.

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In the discussion of the paper Simone highlights the features that are interesting for the taxonomy of the group. The bursa copulatrix has a branched structure which may be useful in distinguishing different species. Comparisons are being made to related groups such as the Neritidae and to recent studies on the higher systematics of these groups. All in all an excellent paper, especially by the nicely detailed anatomical figures.

Simone, L.R.L., 2018. Phenotypic features of Helicina variabilis (Gastropoda: Neritimorpha) from Minas Gerais, Brazil. – Papéis Avulsos de Zoologia, 58: e20185832 (9 pp.).

Snails and forest relicts in Chile

Freshly pressed: a paper by Francisco Cádiz and co-authors describing how they used land snails to decipher the origin and isolation in forest relicts in northern Chile.

The abstract reads: “Among the questions surrounding the biogeographical history of the Chilean biota, none has gathered more interest than the origin of the Fray Jorge (FJ) for- est relict and its biota. Inserted in a semi‐desert area, this forest enclave exists due to the existence of a very particular microclimate in this region. The age of the disjunction and the historical relationship between the FJ biota with the remaining components of South America are explained by two distinct, competing hypotheses: the first suggests that it would have become isolated during the climatic changes of the Paleogene/Neogene, while the second suggests that the isolation is a product of Quaternary glaciations. To discriminate between these competing hypotheses, we used DNA sequence phylogeny methods and molecular genetic dating to the study of a genus of land snails (Plectostylus) that occurs in the FJ relict and throughout Chile. The phylogeny shows a clear distinction between forest and arid clades, and each of these clades is formed by many geographically circumscribed populations. The FJ fragment snails form a clade that is sister to all other forest clades. The separation between the Fray Jorge clade and the other forest clades dates back to the Paleogene/Neogene. Our data suggest that the FJ forest is a relict from the forests that occupied that landscape during the Paleogene/Neogene and retreated due to the aridification of the region. We also observe that the current taxonomy of the Plectostylus genus must be re‐evaluated”.

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An interesting paper that uses molecular data of an endemic land snail group to sort out competing hypotheses of ancient landscape genesis. More often, ecological data are used to support a hypothesis of the taxonomy of species; this time it is the other way around. While working on this study the authors also collected data on the taxonomy of this group, but this will be dealt with in a future paper.

Cádiz, F.J. et al., 2018. Phylogeography of Plectostylus Beck, 1837 (Gastropoda, Stylommatophora: Orthalicoidea): Origin and isolation of the Fray Jorge forest relicts in northern Chile. – Journal of Zoological Systematics and Evolutionary Research, doi: 10.1111/jzs.12241 (10 pp.) (advance publication).

Xolotrema and the collation of Ferussac’s ‘Histoire naturelle…’

Harry Lee regularly adds insightful tidbits which go way beyond the limited distribution of the home-made journal in which he publish them. One such tidbit is the correct publication date of a Polygyrid snail occurring in Florida and described by Férussac. While has has struggled to get everything right, he now presents an updated collation of Férussac’s Histoire naturelle…, which deserves a wider audience. Reason why I copy his whole article here in this blogpost.

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Lee, H.S., 2018. Xolotrema denotatum (Férussac, 18xx), its iconography and taxonomy – resolution. – Shell-O-Gram, 59 (4):2-4.

Taxonomy of Omalonyx

A group of Brazilian authors have made a comprehensive study on the succineid genus Omalonyx, with interesting results.

“The genus Omalonyx d’Orbigny, 1837, includes neotropical semi‐aquatic succineid slugs and comprises six recognized species to date. Field surveys across continental South America recovered five of the six recognized species. According to the morphological characters traditionally included in Omalonyx descriptions, the specimens were tentatively identified as O. matheroni, O. pattersonae, O. convexus, O. geayi and O. unguis. Employing sequences of mitochondrial cytochrome oxidase I (COI) alone or combined with the nuclear second internal transcribed spacer (ITS2) in discovery methods of species delimitation (GMYC and STACEY) led to species delimitation hypotheses that, except for unambiguously supporting O. convexus, have no correspondence to morphologically based assignments. To choose the delimitation model that best fit our data, the hypotheses recovered by GMYC, STACEY and morphology and created by merging species recovered by those methods had their marginal likelihood estimated and compared using the Bayes factors. The best‐supported hypothesis distinguished two species besides O. convexus: one widespread over most of South America and the other restricted to Rio de Janeiro State, Brazil. Furthermore, the pattern of genetic structuring supports pathways connecting the Amazonian and Atlantic forests. This pattern is similar to that observed in terrestrial taxa (e.g., forest‐dwelling small mammals) and is different from the pattern for fully aquatic taxa.”

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This is a well-executed study that uses different methods to formulate several hypotheses. The best-supported one leads the authors to conclude that there are two species to be recognised: O. convexus (Martens, 1868) and O. matheroni (Potiez & Michaud, 1835). This result is interesting, the more since this group is extremely difficult to study using the morphology alone. Such integrative studies are thus the way forward, and should be attempted also for other groups of Neotropical snails.


Vidigal, T.H.D.A. et al., 2018. Integrative taxonomy of the neotropical genus Omalonyx (Elasmognatha: Succineidae). – Zoologica Scripta, 47 (2): 174-186.

Rediscovery of an achatellinid

Just published by Araya et al., a paper on the rediscovery of an achatellinid snail on Easter Island. The abstract reads: “The achatinellid Pacificella variabilis Odhner, 1922, is reported for the first time since its original description from its type locality, Easter Island (Rapa Nui), South Pacific Ocean, Chile. Specimens were found living on the bark of a lemon tree in Hanga Roa town and among the endemic grass Paspalum forsterianum on Motu Nui Islet. A redescription of the shell based on scanning electron microscopy (SEM) is provided. This represents the first report of the habitat of the species on Easter Island.”

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It always nice to see a rediscovery of a species nearly a century after its initial description 🙂

Araya, J.F. et al., 2018. Rediscovery of Pacificella variabilis (Gastropoda: Achatinellidae) on Easter Island. – Pacific Science, 72 (3): 329-334.