Georissa
| Georissa | |
|---|---|
| |
| Georissa shikokuensis | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Subclass: | Neritimorpha |
| Order: | Cycloneritida |
| Family: | Hydrocenidae |
| Genus: | Georissa Blanford, 1864[1] |
| Synonyms | |
| |
Georissa is a genus of minute land snails, terrestrial gastropod mollusks in the family Hydrocenidae. [2]
Description
[edit](Original description in Latin) The shell is imperforate or scarcely perforate. It is very small, and conical, displaying an amber-colored or reddish hue. It is usually spirally grooved or striated.
The operculum appears semi-oval, lacking any trace of spiral structure, and presents eccentric striations. It is testaceous (shell-like) and transparent.
The animal is small and is equipped with hemispherical lobes in place of tentacles. Its eyes are normal, and its foot is short and rounded. [3]
Distribution
[edit]Although the species are best known for living on the surface of limestone rocks, they are often also found in and on the vegetation and on non-calcareous rocks. One species, Georissa filiasaulae, is cavernicolous. It is only known from two caves in the Sepulut area of Sabah, Malaysian Borneo, where its above-ground sister species, Georissa saulae, inhabits the rocks outside of the cave, and is connected to the cave snail via narrow zones of hybridization at the cave entrances. Possibly, G. filiasaulae has evolved without ever having been fully separated from its ancestor, a process known as speciation-with-gene-flow.[4][5]
Species
[edit]Species within the genus Georissa include:
- Georissa anyiensis Khalik, Hendriks, Vermeulen & Schilthuizen, 2018[6]
- Georissa bangueyensis E. A. Smith, 1895
- Georissa bauensis Khalik, Hendriks, Vermeulen & Schilthuizen, 2018[6]
- Georissa biangulata Quadras & Möllendorff, 1894
- Georissa borneensis E. A. Smith, 1895
- Georissa elegans Quadras & Möllendorff, 1894
- Georissa everetti E. A. Smith, 1895
- Georissa filiasaulae Haase & Schilthuizen, 2007[7]
- Georissa gomantongensis E.A. Smith, 1894
- Georissa hadra Thompson & Dance, 1983
- Georissa hosei Godwin-Austen, 1889
- Georissa japonica Pilsbry, 1900[8]
- Georissa kinabatanganensis Khalik, Hendriks, Vermeulen & Schilthuizen, 2018[6]
- Georissa kobelti Gredler, 1902
- Georissa laevigata Quadras & Möllendorff, 1894
- Georissa laseroni (Iredale, 1937)
- Georissa mawsmaiensis Das & Aravind, 2021
- Georissa monterosatiana Godwin-Austen & Neville, 1879
- Georissa muluensis Khalik, Hendriks, Vermeulen & Schilthuizen, 2018[6]
- Georissa niahensis Godwin-Austen, 1889
- Georissa pachysoma Vermeulen & Junau, 2007
- Georissa purchasi
- Georissa pyrrhoderma Thompson & Dance 1983
- Georissa pyxis (Benson, 1856) - type species of the genus Georissa[7]
- Georissa rufula von Möllendorf, 1900
- Georissa saulae (van Benthem-Jutting, 1966)
- Georissa scalinella (van Benthem-Jutting, 1966)
- Georissa semisculpta
- Georissa sepulutensis Khalik, Hendriks, Vermeulen & Schilthuizen, 2018[6]
- Georissa shikokuensis Amano, 1939
- Georissa silaburensis Khalik, Hendriks, Vermeulen & Schilthuizen, 2018[6]
- Georissa similis E.A. Smith, 1894
- Georissa vesta Thompson & Dance, 1983
- Georissa williamsi Godwin-Austen, 1889 (including Georissa hungerfordi)
References
[edit]- ^ Blanford W. T. (1864). "On the Classification of the Cyclostomacea of Eastern Asia". Annals and Magazine of Natural History (3)13: 441-465, page 463.
- ^ MolluscaBase eds. (2025). MolluscaBase. Georissa W. T. Blanford, 1864. Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=818273 on 2025-04-21
- ^ Blanford, W.T. (1864). "On the classification of the Cyclostomacea of eastern Asia". nnals and Magazine of Natural History. 3 (13 (78)): 463. Retrieved 21 April 2025.
This article incorporates text from this source, which is in the public domain.
- ^ Schilthuizen M., Rutten E. J. M. & Haase M. (2012). "Small-scale genetic structuring in a tropical cave snail and admixture with its above-ground sister species". Biological Journal of the Linnean Society 105: 727-740. doi:10.1111/j.1095-8312.2011.01835.x
- ^ Schilthuizen M., Cabanban A. S. & Haase M. (2005). "Possible speciation with gene-flow in tropical cave snails". Journal of Zoological Systematics 43: 133-138. doi:10.1111/j.1439-0469.2004.00289.133–138.
- ^ a b c d e f Khalik, Mohd Zacaery; Hendriks, Kasper; Vermeulen, Jaap J.; Schilthuizen, Menno (9 July 2018). "A molecular and conchological dissection of the "scaly" Georissa of Malaysian Borneo (Gastropoda, Neritimorpha, Hydrocenidae)". ZooKeys (773): 1–55. Bibcode:2018ZooK..773....1K. doi:10.3897/zookeys.773.24878. PMC 6048177. PMID 30026659.
- ^ a b Haase M. & Schilthuizen M. (2007). "A new Georissa (Gastropoda: Neritopsina: Hydrocenidae) from a limestone cave in Malaysian Borneo". Journal of Molluscan Studies 73(3): 215-221. doi:10.1093/mollus/eym020.
- ^ Noseworthy R. G., Lim N.-R. & Choi K.-S. (2007). "A Catalogue of the Mollusks of Jeju Island, South Korea". Korean Journal of Malacology 23(1): 65-104. PDF.
External links
[edit]
Media related to Georissa at Wikimedia Commons
 | This Neritimorpha-related article is a stub. You can help Wikipedia by expanding it. |