List of non-marine molluscs of Dominica
The non-marine molluscs of Dominica are species of land and freshwater molluscs, i.e. land snails, land slugs and one small freshwater clam that are part of the wildlife of Dominica, an island in the Lesser Antilles. In malacology, the non-marine molluscs of an area are traditionally listed separately from the marine molluscs.
Dominica is a Caribbean island, part of the Windward Island chain of the Lesser Antilles. Fifty-five species of non-marine molluscs have been found in the wild in Dominica, including sixteen endemic species of land snails, species which occur nowhere else on Earth.
Dominica is a mountainous,, volcanic, tropical island. It is undeveloped compared with most other Caribbean islands, and it is known for its wildlife and unspoiled natural landscapes. The rugged terrain includes a great deal of tropical rainforest, numerous rivers, and several officially protected areas, including Morne Trois Pitons National Park and Cabrits National Park. The rich natural landscapes of Dominica provide suitable habitat for a wide range of different species of wildlife, including many rarities, and a relatively large number of species of non-marine molluscs, both native and introduced.
Living in the wild in Dominica there are 54 species of gastropods, and 1 species of freshwater bivalve.
| Numbers of molluscs by habitat | Number of species |
| Freshwater gastropods | 11 |
| Land gastropods | 43 |
| Total number of non-marine gastropods | 54 |
| Freshwater bivalves | 1 |
| Total number of non-marine molluscs | 55 |
History of surveys of land gastropods
The first records of land gastropods from Dominica were published by the English naturalist Robert John Lechmere Guppy in 1868. During his visit Guppy collected a total of 20 species from Dominica. Out of these twenty, he described 9 as new species.Subsequently, additional records were added by Thomas B. Bland, A. D. Brown, George French Angas, Edgar Albert Smith and Henry Augustus Pilsbry. Four surveys of the terrestrial malacofauna were carried out in the 2000s: 2001, 2003, 2005 and 2008. These studies were summarized in 2009.
Land gastropods overview
The list of Dominican land gastropods contains 43 species, making it one of the richest known faunas of land snails and slugs in the Lesser Antilles.Of these, 16 species are endemic to the island. The endemic species of Dominican gastropods are mainly found on the leeward side of the island. Amphibulima pardalina, Diplopoma sp., Laevaricella perlucens, Naesiotus stenogyroides and Veronicella sp. are very restricted in range, and probably meet the IUCN-criteria for Critically Endangered species. Amphibulima browni and Lucidella sp. are likely to meet the criteria for being listed as endangered species.
There are striking faunal relationships with the islands of Guadeloupe and Martinique. Furthermore, 9 of the species are widespread, and 13 species are considered to have been introduced into Dominica.
The landsnail fauna can be analyzed according to the elevational range of the species. There is a distinction between the windward and leeward side of the island, according to the parishes in which the localities are situated. While most species exhibit a rather wide elevational range, several are restricted in this respect. Very few species only occur at lower elevations: Diplopoma, Allopeas, Beckianum and Huttonella species. These taxa are largely introduced species. Some species are restricted to higher localities: Lucidella sp., veronicellids, Naesiotus stenogyroides, Amphibulima pardalina and Laevaricella perlucens. These do not occur, however, on the upper slopes of the higher peaks, but seem to be restricted to the hygrophytic vegetation zone, i.e. the cloud forest.
Many localities have a rather low species richness. For example, in surveys from 2001–2008, at six localities no snails were encountered; at the remaining 64, species richness ranged from 1 to 17. Taking into account the rareness of species, the southeast of the island scores well when the total diversity is considered.
The area of Freshwater Lake in Morne Trois Pitons National Park is a biodiversity hotspot for land snails. However, several other localities situated in the national parks are also important areas for the occurrence of endemic species: the Syndicate Parrot Preserve and the Lake Boeri area. These national parks lie on the leeward side of the island at relatively high elevations.
Freshwater gastropods
The systematic list uses scientific names including the authority, and is arranged according to families:Neritidae
- Neritina punctulata – Native.
- Neritina virginea – In brackish water.
- Puperita pupa – In brackish water.
- Biomphalaria glabrata – This species was reported from Dominica in 1980, but it seems that it was replaced by other Biomphalaria species, or it was eradicated nor by Reeves et al. ).
- Biomphalaria kuhniana – Previous reports of Biomphalaria straminea were probably Biomphalaria kuhniana.
- Gundlachia radiata – First recorded in 2008.
- Helisoma trivolvis – Introduced.
- Melanoides tuberculata – Introduced. Its initial introduction to Dominica was probably around 1975. Previous reports of Tarebia granifera from Freshwater Lake in Dominica were probably large Melanoides tuberculata.
- Physa marmorata – Previous reports of Physa cubensis = Physa acuta from Dominica were probably Physa marmorata.
- Neritilia succinea – On a riverbank.
- Pomacea glauca – Native.
Land gastropods
- Helicina fasciata – First reported in 2009.
- Helicina guppyi Pease, 1871 – First reported in 2009.
- Helicina platychila – First reported in 2009.
- Helicina rhodostoma Gray, 1824 – Endemic.
- Lucidella sp. – Endemic. First reported in 2009. This species lives in moist leaf litter or on ferns in undisturbed forested areas of the island. Although Robert John Lechmere Guppy reported the Lesser Antillean Lucidella plicatula from Dominica, no evidence was found of the occurrence of that species. The endemic Dominican Lucidella is considerably larger and differs in sculptural details. Like many helicinid species, there are red and yellow colour morphs. Further research is required to establish the taxonomic position of these specimens.
- Alcadia conuloides – Endemic.
- Amphicyclotulus amethystinus – Endemic.
- Amphicyclotulus dominicensis Bartsch, 1942 – Endemic.
sp. from Dominica.|alt=apertural view
sp. from Dominica|alt=live snail on a twig
- Succinea sp. – Endemic. First reported in 2009. Because West Indian succineid taxonomy is in complete disarray, Robinson et al. simply placed this material in the genus Succinea, pending a comprehensive study of this poorly understood group. More than one Succinea species appears to be present in Dominica.
- Omalonyx matheroni – Introduced. There are slight differences in the mantle pattern compared to typical Omalonyx matheroni. Further work is needed to establish the taxonomic position of this material from Dominica.
- Omalonyx unguis – This species was reported by the Austrian-French Hydrobiological Mission in 1979, but see also comments to Omalonyx matheroni above.
|alt=live snail with banded shell
- Bulimulus diaphanus fraterculus – First reported in 2009. It is possible that it was introduced from one of the more northerly islands, where it was listed by Breure.
- Bulimulus guadalupensis – Introduced.
- Bulimulus limnoides – First reported in 2009.
- Drymaeus laticinctus – Endemic.
- Naesiotus stenogyroides – Endemic.
- Amphibulima patula dominicensis Pilsbry, 1899 – Endemic.
- Amphibulima pardalina Guppy, 1868 – Endemic.
- Amphibulima browni Pilsbry, 1899 – Endemic.
- Laevaricella perlucens – Endemic.
|alt=live yellow-green snail
dominicana|alt=live brown snail with brown shell
- Pleurodonte dentiens – First reported in 2009.
- Pleurodonte guadeloupensis dominicana Pilsbry & Cockerell, 1937 – This subspecies is endemic to Dominica.
- Pleurodonte josephinae – First reported in 2009.
- Pleurodonte nigrescens – First reported in 2009.
- Helicina antillarum – The identity of this taxon remains uncertain. Brown’s report might be a misidentification of Helicina guppyi Pease, 1871.
- Lucidella plicatula – This helicinid has been reported from throughout the West Indies. However, the Dominican Lucidella is clearly different.
- Amphicyclotulus schrammi – Brown incorrectly synonymized the Dominican Amphicyclotulus amethystinus with the Guadeloupe taxon.
- Succinea approximans Shuttleworth, 1854 – This taxon occurs on Puerto Rico and has not been reported from intermediate islands. The reports from Thomas B. Bland and George French Angas are thus dubious.
- Vaginulus buergueri – This slug was reported from “Salilia, Dominica” by Forcart. This locality is not known in the island and could not be found in any gazetteer. However, the taxon is reported from the Dominican Republic, so confusion seems likely.
- Veronicella tenax H. B. Baker, 1931 – This Cuban endemic species was reported from Dominica by Forcart, based on some specimens that — judging from his descriptions — probably belong to either Veronicella cubensis or Veronicella floridana.
- Drymaeus liliaceus – This species was reported from Dominica by Angas and Smith. Férussac’s species is from Puerto Rico and Pilsbry mentions that he had not seen Dominican specimens. So far, no trace was found of any material that could confirm the presence of this taxon on Dominica. However, the occurrence of a Drymaeus species with a “uniform pale primrose colour” from the island should be further investigated.
- Drymaeus multifasciatus – This name was used by several authors for the endemic Dominican species that is here recognized as Drymaeus laticinctus.
- Amphibulima rubescens – This species has been reported by various workers from Guadeloupe, Marie-Galante, Dominica and Martinique. It is assumed now that this taxon is endemic to Martinique and that all other reports are misidentifications.
Freshwater bivalves
- Pisidium punctiferum – Up to the 1980s there were no reports of any freshwater bivalves on Dominica. This very small species is the only known freshwater bivalve on Dominica. It was discovered by the Austrian-French Hydrobiological Mission in 1979.