Monthly Archives: January 2016

New book on Martinique

The non-marine malacofauna of the West Indies is very rich, with many endemic species especially on the larger islands. Faunal overviews in the modern literature are, however, limited to e.g. Cuba, Jamaica, Saba, and Dominica for terrestrial snails. Just published now: a new book on non-marine snails from Martinique (Delannoye et al., 2015), which gives a promising first impression.

Delannoye1

The book is divided into two parts. The first part is a general introduction covering the island Martinique and the Lesser Antilles (including geography, geology, natural environments), a general introduction to molluscs and their communities, the history of malacological surveys and studies of Martinique, and threats by mankind and conservation issues. The second, a species guide, starts with an illustrated glossary and general key, followed by a systematic list of the non-marine molluscs of the island. The rest of the book deals with respectively freshwater gastropods and bivalves, and land snails and slugs. Each group has illustrated keys to families and species, followed by a systematic treatment with the primary reference, synonyms, size range, ecology, status and remarks. All species are illustrated with photographs of different shell views, as well as in most cases living animals and a map with the distribution on the island. A list of references, a synthesis of inventories and species status (‘patrimonial’, endemic, regional endemic, native (not endemic), introduced, extinct or uncertain), a glossary, and indices to species and the common French and English names complement the book.

Delannoye2

In the general part the diversity of the malacofauna on the island is compared with several other islands in the West Indies. Martinique is in the middle of the range; the legends of the graphs explaining this are slightly cryptic, so one should consult the main text. The historical account of collecting in Martinique is beautifully illustrated, and contain observations that go well beyond those for the island alone. In the part on systematics, the well-illustrated keys and maps make the information easily accessible to lay-people, and the authors have put much effort in illustrating animals and, where appropriate, specific elements of the habitat of different species. Illustrations of the genitalia are provided for freshwater gastropods only. A total of 31 (terrestrial) species is listed as ‘espèce patrimoniale’, a confusing category as it is not the same as endemic species, nor as ‘native’ species. Clear definitions seem to lack for these categories. Many species treated in the book have a wider distribution than Martinique alone, and the excellent illustrations will definitely be helpful to identify material from other localities. Different colour morphs of the species are well represented on the plates. Only two species, described by Drouët, have not been recollected after their description and their original figures are given. Several species remain identified as ‘sp.’, either because the taxonomy of the group needs more in-depth studies, or because they are new to science. All together, this book is thus not the final one for this island fauna, but certainly a major leap forward and a very attractive possession for those interested in Antillean non-marine molluscs.

Delannoye3

Reference:
Delannoye, R., Charles, L., Pointier, J.-P. & Massemin, D., 2015. Mollusques continentaux de la Martinique. Non-marine molluscs of Martinique, Lesser Antilles. Biotope, Mèze/Muséum national d’Histoire naturelle, Paris: 1-328, 23 + 9 + 76 text-figs, 76 pls, 3 tables, many unnumbered text-figs, photos and maps, indices. French/English. ISBN 978-2-36662-013-9 (Biotope)/978-2-85653-781-7 (MNHN). € 30 excl. postage.

Jorge Vaz

Jorge Vaz (1917-2004) was a Brazilian malacologist, trained as health physician, and  active in medical malacology. He made surveys of freshwater molluscs, but his private collection incorporated marine and terrestrial species as well. After his death part of his collection was sold to different private collectors worldwide, but the remainder has now been incorporated in the Museu de Zoología da Universidade de São Paulo (MZSP).

Cavallari&Simonef2

The new MZSP acquisition comprises 2673 lots and most of it are shells only, but part of it is preserved in ethanol. Further studies should reveal the importance of this collection, being brought together during decades when Brazilian habitats were less degraded.

Reference:
Cavallari, D.C. & Simome, L.R.L., 2015. Incorporation of the Jorge Vaz collection into the Museu de Zoologia da Universidade de São Paulo. – Strombus 22: 29–36.

Geomelania minor

The following post on – barely – a landsnail from Jamaica, was found on the Facebook account of Richard Goldberg.

Geomelania minor C.B. Adams, 1849 [Family: Truncatellidae] 8.4mm. old section of Mandeville, Manchester Parish, Jamaica; buried in loose red particulate soil at the base of high concrete garden wall.

Seventeen described and two or more undescribed species of Geomelania are known and endemic to Jamaica. Most have a limited geographic distribution on the island.

Its close relatives in the genus Truncatella live in environments that are not exclusively marine or terrestrial, living in extreme high tide areas whereas Geomelania are exclusively land dwellers typically found at higher elevations. Geomelania thus represents an offshoot of Truncatella that became exclusively terrestrial.

All Geomelania are small, the largest being one of the undescribed species that only attains a size of about 10 to 12mm.

Photo & Text: Richard L. Goldberg & worldwideconchology.com © 2016.

Vertiginidae

Vertiginid land snails are tiny and constitute a tiny (but yet ill-studied) group of the Neotropical fauna. Apart from a monograph by Pilsbry in his Manual of Conchology, hardly any recent studies are known on this faunal element. For the Nearctic vertiginids Jeff Nekola has done much work and he has just published a note on the supraspecific taxonomy of the family (Nekola & Coles, 2016).

Nekola2016f2

A detailed phylogenetic study revealed that there are two clades, the Vertiginidae and Nesopupinae. The latter comprising tropical species. The paper discusses the use of genetical markers, and the interpretation of the results in the light of the number of taxa included in a family. The authors plead for a reconsideration of supraspecific concepts within the Orthurethra.

Reference:
Nekola, J.C. & Coles, B.F. Supraspecific taxonomy in the Vertiginidae (Gastropoda: Stylommatophora). – Journal of Molluscan Studies 82: 208–212.

Florida Cerion

A while ago Haraewych published a detailed study on West Indian Cerion species, which has recently completed by a similar study on the species from Florida (Shrestha et al., 2015).

Shresta ea 2015 fig1

The abstract reads as follows: “The systematic relationships and phylogeography of Cerion incanum, the only species of Cerion native to the Florida Keys, are reviewed based on partial sequences of the mitochondrial COI and 16S genes derived from 18 populations spanning the range of this species and including the type localities of all four described subspecies. Our samples included specimens of Cerion casablancae, a species introduced to Indian Key in 1912, and a population of Cincanum x Ccasablancae hybrids descended from a population of Ccasablancae introduced onto Bahia Honda Key in the same year. Molecular data did not support the partition of Cincanum into subspecies, nor could populations be apportioned reliably into subspecies based on morphological features used to define the subspecies. Phylogenetic analyses affirmed the derived relationship of Cincanum relative to other cerionids, and indicated a Bahamian origin for the Cerion fauna of southern Florida. Relationships among the populations throughout the Keys indicate that the northernmost populations, closest to the Tomeu paleoislands that had been inhabited by Cerion petuchi during the Calabrian Pleistocene, are the oldest. The range of Cerion incanum expanded as the archipelago that is the Florida Keys was formed since the lower Tarantian Pleistocene by extension from the northeast to the southwest, with new islands populated as they were formed. The faunas of the High Coral Keys in the northeast and the Oölite Keys in the southwest, both with large islands that host multiple discontinuous populations of Cerion, are each composed of well supported clades that are characterized by distinctive haplotypes. In contrast, the fauna of the intervening Low Coral Keys consist of a heterogeneous series of populations, some with haplotypes derived from the High Coral Keys, others from the Oölite Keys. Individuals from the Cincanum x Ccasablancae hybrid population inhabiting the southeastern coast of Bahia Honda Key were readily segregated based on their mitogenome lineage, grouping either with Cincanum or with Ccasablancaefrom Indian Key. Hybrids with Ccasablancae mitogenomes had haplotypes that were more divergent from their parent mitogenome than were hybrids with Cincanum mitogenomes”.

Shresta ea 2015 fig6

The paper is published as open access.

Reference:
Shresta, Y., Wirshing, H.H. & Harasewych, M.G. (2015) The Genus Cerion (Gastropoda: Cerionidae) in the Florida Keys. – PLoS ONE 10 (9): e0137325. Link: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0137325

Evolution and biogeography of Urocoptidae

Just published, the very interesting paper by Dennis Uit de Weerd et al. presents new data on the phylogenetics of the land snail family Urocoptidae. They also tested some biogeographical hypotheses using the phylogeny and present as results: “Urocoptidae has been present on the Greater Antilles Arc from at least Middle Eocene onwards. Morphologically diverse and previously unrecognized clades evolved on most Caribbean (palaeo)islands. Jamaica was colonized at least twice. Dispersal multiplier matrices with moderately constrained dispersal between areas without direct land connections describe the phylogeographical history of the family with higher DEC and DEC+J lnL scores than uniform matrices”.

UitdeWeerd2016

As their main conclusions they present: “Urocoptids constitute an old element of the Greater Antillean biota, predating a proposed GAARlandia landspan connection to South America. The biogeographical history and evolution of Urocoptidae were shaped primarily by the geographical distribution of Caribbean landmasses, in combination with occasional oversea dispersal. Oversea dispersal allowed colonization of palaeogeographically isolated areas, such as Jamaica and presentday western Cuba, where presumably the absence of ecological competitors led to independent radiations into similar shell types”. In a future paper a taxonomic revision of the family and of the genus Brachypodella will be published.

Reference:
Uit de Weerd, D., Robinson, D.G. & Rosenberg, G. (2016) Evolutionary and biogeographical history of the land snail family Urocoptidae (Gastropoda: Pulmonata) across the Caribbean region. – Journal of Biogeography [advanced access]: 1–15.