Gelasimus vomeris
Gelasimus vomeris is a species of fiddler crab found in the southwest Pacific Ocean. In Australia, it is found in the east and north from Darwin to Sydney.[1]
| Two-toned fiddler crab | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Malacostraca |
| Order: | Decapoda |
| Suborder: | Pleocyemata |
| Infraorder: | Brachyura |
| Family: | Ocypodidae |
| Subfamily: | Gelasiminae |
| Genus: | Gelasimus |
| Species: | G. vomeris |
| Binomial name | |
| Gelasimus vomeris (McNeill, 1920) | |
It is commonly known as the two-toned fiddler crab, orange-clawed fiddler crab or Southern calling fiddler crab, however the common name orange-clawed fiddler crab is also used for the fiddler crab Tubuca coarctata.[2] Previous binomial names include Uca vomeris and Uca vocans vomeris.
Description
The carapace is up to 30 mm across,[3] black-brown with blue patches to varying extent. Adult males have an enlarged claw with a grey or pink upper finger, and orange lower finger and hand.[3] Like other fiddler crabs the claw is used to scare or fight other males, and in waving displays to attract females. The lower male claw has a large triangular protection in the most distant part from the body.[4]
If caught, the colors of Gelasimus vomeris crabs will become less brilliant within minutes,[5] and in response to the presence of predators in an area, the blue color of these fiddler crabs will change over a few days to a dull muddy brown.[6]
Distribution and habitat
The preferred habitat of these crabs is unshaded sandy mud. They are found in bays, estuaries and creeks,[1] living in burrows at lower tide levels which they stay close to, typically <1 m while feeding.[7] There is a predominance of right handed individuals in colonies, one study finding left handed individuals forming only 1.4% of the study population.[8]
References
- "Gelasimus Vomeris". Solitary Islands Underwater Research Group. Solitary Islands Underwater Research Group. 2022. Retrieved 2022-06-14.
- "Gelasimus Vomeris". Fiddler Crab Info. 2022. Retrieved 2022-06-14.
- "Gelasimus Vomeris". Queensland Museum. Queensland Museum. 2022. Retrieved 2022-06-14.
- "A Revision of the Fiddler Crabs of Australia Ocypodinae (Uca)". Fiddler Crab Info. Western Australian Museum. 2022. Retrieved 2022-06-14.
- Hemmi, J. M.; Marshall, J.; Pix, W.; Vorobyev, M.; Zeil, J. (2006). "The variable colours of the fiddler crab Uca vomeris and their relation to background and predation". The Journal of Experimental Biology. The Company of Biologists. 209 (20): 4140–4153. doi:10.1242/jeb.02483. PMID 17023607. S2CID 18350093.
- "Crabs Change Colour to Escape Hungry Birds". Australian Broadcasting Corporation. Australian Broadcast Corporation. 2006. Retrieved 2022-06-12..
- Ziel, J. (1998). "Homing in fiddler crabs (Uca lactea annulipes and Uca vomeris : Ocypodidae)". Journal of Comparative Physiology. 183: 367–377.
- Backwell, P. R. Y.; Matsumasa, M.; Double, M.; Roberts, A.; Murai, M.; Keogh, J.; Jennions, M. D. (2007). "What are the consequences of being left-handed in a predominantly right-clawed fiddler crab". Proceedings of the Royal Society. 274 (1626): 2723–2729. doi:10.1098/rspb.2007.0666. PMC 2279209. PMID 17711842.