Geosesarma is genus of small freshwater or terrestrial crabs, typically less than 10 mm (0.4 in) across the carapace.[2] They live and reproduce on land with the larval stages inside the egg. They are found from India,[3] through Southeast Asia, to the Solomon Islands and Hawaii.[2]
| Geosesarma | |
|---|---|
| |
| Geosesarma aurantium | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Malacostraca |
| Order: | Decapoda |
| Suborder: | Pleocyemata |
| Infraorder: | Brachyura |
| Family: | Sesarmidae |
| Genus: | Geosesarma De Man, 1892 |
| Type species | |
| Sesarma noduliferum [1] de Man, 1892
| |
In the pet trade, they are sometimes called vampire crabs. This has nothing to do with their feeding habits, but rather with the bright, contrastingly yellow eyes of some Geosesarma species.[4]
Species
editGeosesarma contains these species:[5]
- Geosesarma aedituens Naruse & Jaafar, 2009
- Geosesarma albomita Yeo & Ng, 1999
- Geosesarma ambawang Ng, 2015
- Geosesarma amphinome (De Man, 1899)
- Geosesarma anambas Ng, Wowor & Yeo, 2023
- Geosesarma angustifrons (A. Milne-Edwards, 1869)
- Geosesarma araneum (Nobili, 1899)
- Geosesarma aurantium Ng, 1995
- Geosesarma batak Manuel-Santos, Ng & Freitag, 2016
- Geosesarma bau Ng & Jongkar, 2004
- Geosesarma bicolor Ng & Davie, 1995
- Geosesarma bintan T. M. Leong, 2014
- Geosesarma cataracta Ng, 1986
- Geosesarma celebense (Schenkel, 1902)
- Geosesarma clavicrure (Schenkel, 1902)
- Geosesarma confertum (Ortmann, 1894)
- Geosesarma danumense Ng, 2003
- Geosesarma dennerle Ng, Schubart & Lukhaup, 2015
- Geosesarma foxi (Kemp, 1918)
- Geosesarma gordonae (Serène, 1968)
- Geosesarma gracillimum (De Man, 1902)
- Geosesarma hagen Ng, Schubart & Lukhaup, 2015
- Geosesarma hednon Ng, Liu & Schubart, 2003
- Geosesarma ianthina Pretzmann, 1985
- Geosesarma insulare Ng, 1986
- Geosesarma johnsoni (Serène, 1968)
- Geosesarma katibas Ng, 1995
- Geosesarma krathing Ng & Naiyanetr, 1992
- Geosesarma larsi Ng & Grinang, 2018
- Geosesarma lawrencei Manuel-Santos & Yeo, 2007
- Geosesarma leprosum (Schenkel, 1902)
- Geosesarma maculatum (De Man, 1892)
- Geosesarma malayanum Ng & Lim, 1986
- Geosesarma mirum Shy & Ng, 2019[6]
- Geosesarma nannophyes (De Man, 1885)
- Geosesarma nemesis Ng, 1986
- Geosesarma noduliferum (De Man, 1892)
- Geosesarma notophorum Ng & C. G. S. Tan, 1995
- Geosesarma ocypodum (Nobili, 1899)
- Geosesarma penangense (Tweedie, 1940)
- Geosesarma peraccae (Nobili, 1903)
- Geosesarma protos Ng & Takeda, 1992
- Geosesarma rathbunae (Serène, 1968)
- Geosesarma rouxi (Serène, 1968)
- Geosesarma sabanum Ng, 1992
- Geosesarma sarawakense (Serène, 1968)
- Geosesarma scandens Ng, 1986
- Geosesarma serenei Ng, 1986
- Geosesarma solomonense (Serène, 1968)
- Geosesarma starmuhlneri Pretzmann, 1984
- Geosesarma sumatraense Ng, 1986
- Geosesarma sylvicola (De Man, 1892)
- Geosesarma ternatense (Serène, 1968)
- Geosesarma teschi Ng, 1986
- Geosesarma thelxinoe (De Man, 1908)
- Geosesarma tiomanicum Ng, 1986
- Geosesarma vicentense (Rathbun, 1914)
As of March 2015, professor Peter Ng of National University of Singapore has named 20 Geosesarma species, and he "has another half a dozen or so newly collected Geosesarma species from Southeast Asia in his lab, and these species still need to be named and described."[4][7]
Threats
editGeosesarma dennerle and Geosesarma hagen, both originally from Java, are threatened by illegal overcollection for the aquarium trade.[8]
Geosesarma in captivity
editGeosesarma (Vampire Crabs) have become extremely popular in the exotic animal hobby over recent years. However there is a lot of misconception about how to best keep them. They are often mistaken for aquatic crabs and kept in unsuitable conditions with excessive amounts of water, which will ultimately leads to shortened life spans. The ideal captive environment for Geosesarma species is one that consists of 80% land and 20% water. With natural soil and dense planting making up the majority of the terrestrial area. As these species live in the ground, primarily in burrows, soil is vital for their well being, stress reduction and breeding. [9]
While they also require water to survive, it is primarily used for molting and hydration. Both of which can easily be met with a small water volume, enough to cover their entire body completely will suffice. However it is advised to have a depth of at least double their body height to account for any evaporation. Without access to water Geosesarma crabs will dry out and perish.
It is also important never to mix any other species of Geosesarma together. While they are a semi social species of crab, they are extremely aggressive towards other species and will almost always kill other species present in their territory.
Environmental Parameters for keeping Geosesarma crabs in captivity
Water temperature: 22–25°C (71–78°F)
Air Temperature: 22–28°C (71–82°F)
PH: Between 7.5–8.0
KH (carbonate hardness): Between 0–10
GH (general hardness) Between 4–16
Ammonia: 0
Nitrite: 0
Nitrate: Lower than 20 ppm
References
edit- ^ Peter Davie (2012). "Geosesarma de Man, 1892". WoRMS. World Register of Marine Species. Retrieved November 8, 2012.
- ^ a b Hartnoll, Richard G. (1998). "Evolution, systematics, and geographical distribution". In Warren W. Burggren; Brian R. McMahon (eds.). Biology of the Land Crabs. Cambridge University Press. pp. 6–54. ISBN 9780521306904.
- ^ Pati, S. K.; Dev Roy, M. K.; Sharma, R. M. "Freshwater crabs" (PDF). Checklist of Indian fauna. Zoological Survey of India. Archived from the original (PDF) on September 17, 2013. Retrieved November 8, 2012.
- ^ a b Blaszczak-Boxe, Agata (March 19, 2015). "Mystery of the 'Vampire Crabs' Solved". livescience.com.
- ^ "Geosesarma". Global Biodiversity Information Facility.
- ^ Shy, Jhy-Yun; Ng, Peter K. L. (2019). "Geosesarma mirum, a new species of semi-terrestrial sesarmid crab (Crustacea, Decapoda, Brachyura) from central Taiwan". ZooKeys (858): 1–10. doi:10.3897/zookeys.858.35198. ISSN 1313-2989. PMC 6614171. PMID 31312087.
- ^ Blaszczak-Boxe, Agata (19 March 2015). "Mystery of the 'Vampire Crabs' Solved". LiveScience. Retrieved 2021-02-11.
- ^ Mahbu, Amri (March 23, 2015). "New Species of Javan Vampire Crabs Face Potential Exploitation".
- ^ Gusmeroli, Jascha (September 19, 2024). "Everything you need to know about Geosesarma Vampire Crabs". www.indoorecosystem.net.
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External links
edit
Data related to Geosesarma at Wikispecies
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