Data Paper |
Corresponding author: Ward Langeraert ( langeraert.ward@gmail.com ) Academic editor: Menno Schilthuizen
© 2020 Ward Langeraert, Dimitri Brosens.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Langeraert W, Brosens D (2020) New records of the land and freshwater molluscs of Gran Canaria (Canary Islands, Spain). ZooKeys 985: 1-13. https://doi.org/10.3897/zookeys.985.53974
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“Land and freshwater molluscs of Gran Canaria (Spain)” is an occurrence dataset containing 389 observations of 59 different taxa of land and freshwater molluscs encountered on Gran Canaria, an island central in the Canarian archipelago (Spain). Of these 59 different (sub)species, 27 are with certainty currently endemic to the island of Gran Canaria. Various sites were inspected in a period between 1988 and 2020. The dataset is published as a standardized Darwin Core Archive and includes for each observation a stable occurrence ID, scientific name, date, and location of the observation, as well as information on life stage and organism quantity. It also contains supplementary remarks on the determination and the observation itself and links to associated media. We have released this dataset to the public domain under a CC0 1.0 Universal (CC0 1.0) Public Domain Dedication. The aim is to contribute to the knowledge on the ecology and distribution of these species on the island, such that it may aid conservation and research of these organisms in the future.
Issues with the dataset can be reported at https://github.com/BelgianBiodiversityPlatform/landsnails-occurrences
freshwater, Gran Canaria, observation, occurrence, open data, snails, terrestrial
Canary Islands (Spain) is an archipelago off the coast of northwest Africa. Gran Canaria is the third-largest island and located in the centre of the archipelago (
Land and freshwater molluscs do not comprise a monophyletic taxonomic group, but are all mollusc species that live in respectively land and freshwater habitats. On land, only gastropods occur (class Gastropoda, snails and slugs) and in freshwater, both Gastropoda and bivalves (class Bivalvia) occur. No observations on bivalves are present in this dataset. The dataset includes 389 observations of 59 species and subspecies (Fig.
Species determination was mainly done during two meetings concerning the land snails of Gran Canaria organized by the Dutch Malacological Society (Nederlandse Malacologische Vereniging, NMV), coordinated by Theo Ripken. These meetings took place on 21 April 2018 and 23 February 2019 in, respectively, Leiden and Den Haag (Netherlands). Reference material and expert knowledge provided many identifications. Determinations were further based on the following articles:
Taxonomy is according to MolluscaBase eds. (2020) except for the taxon Pomatias adjunctus (Mousson, 1872). This species is known under the name Pomatias canariensis (d’Orbigny, 1840) in that database, but this name is a synonym of Pomatias laevigatus (Webb & Berthelot, 1833), which is a species other than P. adjunctus (see below; Theo Ripken personal comment;
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Families: Achatinidae, Enidae, Ferussaciidae, Geomitridae, Helicidae, Lauriidae, Lymnaeidae, Oxychilidae, Physidae, Planorbidae, Pomatiidae, Pristilomatidae, Punctidae, Streptaxidae, Trissexodontidae, Valloniidae, Vertiginidae, Vitrinidae
Species: Ancylus striatus, Caracollina lenticula, Cernuella virgata, Cochlicella acuta, Cochlicella barbara, Cornu aspersum, Ferussacia folliculum, Gibbulinella aff. dealbata, Gibbulinella aff. dewinteri, Gyraulus parvus, Hawaiia minuscula, Hemicycla berkeleii, Hemicycla ethelema, Hemicycla cf. gaudryi, Hemicycla glasiana, Hemicycla guamartemes, Hemicycla psathyra psathyra, Hemicycla psathyra temperata, Hemicycla psathyra cf. temperata, Hemicycla saponacea, Hemicycla saulcyi carta, Hemicycla spec., Insulivitrina nogalesi, Insulivitrina parryi, Lauria cylindracea, Monilearia arguineguinensis, Monilearia montigena, Monilearia phalerata, Monilearia cf. praeposita, Monilearia pulverulenta, Monilearia tumulorum, Monilearia spec., Napaeus exilis, Napaeus interpunctatus, Napaeus isletae, Napaeus josei, Napaeus moquinianus, Napaeus myosotis, Napaeus obesatus, Napaeus validoi, Napaeus venegueraensis, Napaeus cf. venegueraensis, Obelus despreauxii, Obelus pumilio, Otala lactea, Oxychilus draparnaudi, Paralaoma servilis, Physella acuta, Pomatias adjunctus, Pomatias aff. laevigatus, Pseudosuccinea columella, Radix auricularia, Rumina decollata, Theba arinagae, Theba geminata, Theba grasseti, Theba pisana, Truncatellina atomus, Vallonia costata, Vallonia pulchella, Xerotricha conspurcata, Xerotricha aff. orbignii
Two species of Gibbulinella were found on the island: Gibbulinella aff. dealbata and G. aff. dewinteri. The shells of Gibbulinella aff. dealbata are wider and more solid than those of G. aff. dewinteri. These identifications were made on the meetings concerning the land snails of Gran Canaria organized by the Dutch Malacological Society where it was hypothesised that the shells found on Gran Canaria differ from those of G. dealbata (Webb & Berthelot, 1833) and G. dewinteri Bank, Groh & Ripken, 2002 from other islands. Indeed, we could find no published records of G. dewinteri from Gran Canaria and although this species was originally described as Pupa (=Gibbulinella) dealbata var. minor by Mousson (
Hemicycla gaudryi (d’Orbigny, 1839) and H. ethelema (J. Mabille, 1882) show strong similarities but the shells of H. ethelema have a characteristic granulation. Our specimens from the Jardín Botánico Viera y Clavijo (botanical garden Tafira Alta) are old shells and it is not clear whether the granulations are lacking because the shells belong to H. gaudryi or because they are old and withered. Therefore, we used the name H. cf. gaudryi. Also, the shells were found at the overlap/edges of the distribution areas of both species but the distribution of H. gaudryi is not well known. Furthermore, at the meetings of Dutch Malacological Society it was stated that the correct name for this taxon should be Hemicycla themera (J. Mabille, 1883) (Theo Ripken personal comment). More research is necessary on this species.
The shells designated as Hemicycla psathyra cf. temperata were found at a location outside the known range of H. psathyra temperata (Mousson, 1872) (northwest of the island), but we believe these shells can be contained within morphological variation of H. psathyra temperata. Hemicycla psathyra cf. temperata was treated together with H. psathyra temperata for the generation of Figs
A single shell was identified as Hemicycla spec. This is a juvenile shell too small for precise determination. It belongs to either H. glasiana (Shuttleworth, 1852) or Hemicycla guamartemes (Grasset, 1857). This observation was removed for the generation of Figs
In Barranco de Guayadeque, shells were found that are very convex, have an obtuse apex, and are larger than Monilearia phalerata (Webb & Berthelot, 1833). This description agrees nicely with the original description of Monilearia praeposita (Mousson, 1872) and the location agrees with the range given by the IUCN assessment of this species (
The name Monilearia spec. is applied to Monilearia specimens where the shell is diamond shaped and has an open umbilicus. It is however not as high as M. phalerata. Monilearia spec. was observed in the northwest and from the west to the south of the island. Because of its open umbilicus and its range, this species could be M. caementitia (Shuttleworth, 1852). However, because we observed this species outside its known range (
Several shells were found similar to Napaeus venegueraensis Artiles, Santana & Deniz, 2011 but smaller and with a more pointed top. These were designated as N. cf. venegueraensis and are possibly subadult shells of N. venegueraensis. Napaeus cf. venegueraensis was treated together with N. venegueraensis for the generation of Figs
The identifications of Pomatias aff. laevigatus were made in the meetings organized by the Dutch Malacological Society where it was hypothesised that the shells found on Gran Canaria differ from the P. laevigatus known from Tenerife. Pomatias aff. laevigatus is entirely smooth and occurs in the west of Gran Canaria, while P. adjunctus is ribbed and occurs in the northwest-northcentral part of the island. More research on this genus is needed in the Canary Islands.
Shells of Xerotricha aff. orbignii were found at several locations in the west of the island which look very much like X. orbignii (d’Orbigny, 1836), a species endemic to Tenerife. No endemic Xerotricha species are reported from Gran Canaria in recent checklists (
The dataset comprises three trips taken to Gran Canaria (Canary Islands, Spain; Fig.
West: 15°46,9642'W; East: 15°23,3691'W; North: 28°9,6014'N; South: 27°44,3515'N
1988-04-08 to 2020-02-08
Sampling was done at random along random routes. Locations were not predefined, but some regions were specifically visited because of known species richness or the occurrence of endemics. On site, observations were incidental, but microhabitats or elements that were thought to be favourable for snails were given more attention (e.g. dead wood, north facing slopes etc.). Collection of specimens was mainly done by hand on sight. In some cases, a soil sample was taken that was later examined at home.
Individuals were observed as living snails or empty shells (recent or (sub)fossil). Juveniles were treated as individuals with a shell that lack adult characteristics, like an underdeveloped peristome or the presence of a keel that is not present in adult shells. Following this practice, subadult specimen were often classified as juveniles.
The following steps were used from data collection up to final data publication:
The following Darwin Core terms (https://dwc.tdwg.org/terms/) are used in the dataset: occurrenceID, family, scientificName, identificationQualifier, genus, scientificNameAuthorship, eventDate, year, basisOfRecord, lifeStage, organismQuantity, organismQuantityType, decimalLatitude, decimalLongitude, geodeticDatum, coordinateUncertaintyInMeters, locality, municipality, stateProvince, island, islandGroup, country, countryCode, recordedBy, identifiedBy, identificationRemarks, occurrenceRemarks, associatedMedia, kingdom, taxonID, language, license, rightsHolder, datasetID, institutionCode, datasetName, taxonRank, nomenclaturalCode
Object name: Land and freshwater molluscs of Gran Canaria (Spain)
Format name: Darwin Core Archive format
Format version: 1.0
Character encoding: UTF-8
Language: English
License: https://creativecommons.org/publicdomain/zero/1.0/
Usage norms: https://www.inbo.be/en/norms-data-use (Desmet et al. 2014)
Publication date: 2020-03-12
Distribution: https://ipt.biodiversity.be/resource?r=snail-gran-canaria-occurrences
The data are standardized to Darwin Core (
Empty shells were collected for over 75% of the occurrences in the dataset and deposited in the private collection of first author. For 282 of the 389 observations, links to 101 images of living animals, empty shells and habitats can be found in associatedMedia.
The Darwin Core Archive creation and the publication of the data is part of the ‘Integrated Biodiversity research Project’ course organized in the ‘Master of Science in Biology’ program of Ghent University (Belgium).
We would like to thank Theo Ripken for the coordination of the two meetings on the land snails of Gran Canaria organized by the Dutch Malacological Society and also for his numerous helpful remarks and answers regarding determination and systematics of the land and freshwater molluscs of the Canaries. We would also like to thank Henk Menkhorst his donating tree shells of Monilearia arguineguinensis.