Salvador et al. just published a brief paper on Brazilian Helicinidae. “The present study stems from initial efforts in surveying the terrestrial gastropod fauna of Acre state, an undersampled Amazonian region in northwestern Brazil. Herein, we report the first record of the operculate snail Helicina chionea Pilsbry, 1949 in Brazil, alongside the first records of two other helicinids from Acre: H. juruana Ihering, 1905 and H. laterculus F.C. Baker, 1914. With the present new record, there is a total of 38 helicinid species reported from Brazil“.
Salvador et al., 2020. First report of Helicina chionea Pilsbry, 1949 from Brazil (Gastropoda, Helicinidae) and new records of Helicina spp. from Acre. – CheckList 16(1): 63-66. Link: https://doi.org/10.15560/16.1.63
Just published by Walther & Gryl, a new paper : “Bostryx koehleri n. sp. is described from a dry riverbed in the Atacama Desert north of Paposo, Chile. The new species has been found in an extremely arid region that gets some humidity only through mist from the nearby sea“.
As the species was found on the alluvial fan of a river, the authors state “it cannot be excluded that we are dealing with a fossil or subfossil species whose shells are washed out and deposited on the alluvial fan as the result of occasional flooding events“. Their suggestion is that the actual habitat of this species is higher up in the mountains.
Walther, F. & Gryl, I., 2019. A new species of Bostryx (Gastropoda: Bulimulidae) from the Atacama Desert (Chile). – Archiv für Molluskenkunde, 143 (2): 111-115.
In the flush of the ‘end-of-the-year’ papers, a brief note was published by Lenoble & Charles on a rare species from Guadeloupe. Their abstract is “A shell of Laevaricella guadeloupensis (L. Pfeiffer, 1856) (Gastropoda, Oleacinidae) was found on Mahault Ridge, within the Guadeloupe National Park. This locality is the second where this endemic species to Basse-Terre has been identified since it was listed as extinct by IUCN in 1996“.
Besides an interesting record, it shows that one should be careful to list species as extinct, but at the same time it is clear that this specific species is extremely vulnerable.
Lenoble, A. & Charles, L., 2019. Nouvelle station de Laevaricella guadeloupensis (L. Pfeiffer, 1856), une espèce endémique rare de Guadeloupe (Mollusca, Gastropoda). – MalaCo, 15: 11-13.
An extensive analysis just appeared from Darrigan et al. (advance online) about the occurrence of non-native molluscs throughout South America. Their abstract is “Non-native species have been introduced at escalating rates during the last decades, mainly due to the dispersion generated by the increasing trade and transport worldwide. Mollusks, the second largest metazoan phylum in terms of species richness, are no exception to this pattern, but, to date, a comprehensive synthesis of non-native mollusk species (NNMS) in South America was not available. For this purpose, an e-discussion group was formed with malacologists and taxonomists from South America, where we exchanged and analyzed bibliography, databases and information about NNMS, providing expert opinion to this assessment. The first list of non-native mollusk species for South America, considering terrestrial, freshwater and marine environments, includes 86 NNMS distributed in 152 ecoregions (terrestrial, freshwater and marine) of the 189 recognized for the South American continent. Information on their native region, vectors, first record for South America and distribution, are also provided. In the analysis of the distribution of the NNMS and the entry points of each species (e.g., ports, cargo and passenger airports, cities) and status of conservation of the ecoregions, four hot spots were recognized: Subtropical-Atlantic, Northern Andes, Central Andes and Southern Andes. This work, thus, sets the baseline on NNMS for South America, a key piece of information regarding the development of policies targeting the management of biological invasions and their socio-ecological impacts“.
An interesting study that was totally done by South American malacologists. The paper contains a number of graphs and figures that illustrates the rapid increase over the past decades of non-native species in this understudied continent. It will be a good basis for further studies.
Darrigan, G. et al., 2020. Non-native mollusks throughout South America: emergent patterns in an understudied continent. – Biological Invasions (advance online): 19 pp. https://doi.org/10.1007/s10530-019-02178-4.
More and more attention is being given to conservation issues and duely so as the Neotropical area seems to be understudied in this respect. González Guillén et al. just published a paper on a Cuban Liguus species, with the following abstract: “The Liguus blainianus lineage from western Cuba is presented, with a discussion of its placement as a subspecies of Liguus fasciatus, current and historical range, distribution maps, comments about past and recent field work and it’s hybridization with L. f. archeri. Color images of live animals and their habitat are included. An argument is made for creating a protected area to avoid the extinction of this beautiful and important race of tree snails“.
After the recent book on Liguus, this is a more detailed discussion of the status of this taxon and its distribution.
González Guillén, A. et al., 2019. Liguus blainianus, an Endangered Lineage of Liguus from the Rosario Range in Western Cuba. – Festivus, 51(4): 265-272.
At the end of the year there is a usual flush of publications, and here is another one: Silva et al. on a collection of shells from Rio Grande do Sul state in Brazil.
Their abstract is “The malacological collection of the Universidade Federal de Santa Maria, curated by Dr. Carla B. Kotzian, has been recently donated to the Museu de Zoologia da Universidade de São Paulo (MZSP, Brazil). The collection is rich in well preserved specimens of terrestrial gastropods from central Rio Grande do Sul state, in southernmost Brazil. That region, centered in the municipality of Santa Maria, represents a transitional area between the Atlantic Rainforest and Pampas biomes and has been scarcely reported in the literature. Therefore, we present a taxonomical study of these specimens, complemented by historical material of the MZSP collection. Overall, we report 20 species, mostly belonging to the Stylommatophora, from which four represent new records for Rio Grande do Sul: Adelopoma brasiliense, Happia vitrina, Macrodontes gargantua, and Cyclodontina corderoi. The present report of C. corderoi is also the first from Brazil. Two introduced species were found in the studied material: Bradybaena similaris and Zonitoides sp.“.
Silva, F.S. et al., 2019. Taxonomic study on a collection of terrestrial mollusks from the region of Santa Maria, Rio Grande do Sul state, Brazil. – Arquivos de Zoologia, 50(3): 175-190.
Just published as advance access: a paper by Phillips et al. on colonisation and speciation in the Galápagos archipelago, based on an extensive study of DNA.
The abstract reads as follows: “Newly arrived species on young or remote islands are likely to encounter less predation and competition than source populations on continental landmasses.The associated ecological release might facilitate divergence and speciation as colonizing lineages fill previously unoccupied niche space. Characterizing the sequence and timing of colonization on islands represents the first step in determining the relative contributions of geographical isolation and ecological factors in lineage diversification. Herein, we use genome-scale data to estimate timing of colonization in Naesiotus snails to the Galápagos islands from mainland South America. We test inter-island patterns of colonization and within-island radiations to understand their contribution to community assembly. Partly contradicting previously published topologies, phylogenetic reconstructions suggest that most Naesiotus species form island-specific clades, with within-island speciation dominating cladogenesis. Galápagos Naesiotus also adhere to the island progression rule, with colonization proceeding from old to young islands and within-island diversification occurring earlier on older islands. Our work provides a framework for evaluating the contribution of colonization and in situ speciation to the diversity of other Galápagos lineages“.
This is a very interesting study that focusses entirely on the island fauna and the within-archipelago speciation. The colonisation from the mainland and the relationship between the the mainland and off shore species of Naesiotus remains open for future work.
Phillips, J.G. et al., 2019. Archipelago-Wide Patterns of Colonization and Speciation Among an Endemic Radiation of Galápagos Land Snails. Journal of Heredity: 1-11 (advance access) doi:10.1093/jhered/esz068