Uca inversa (Hoffmann, 1874)

Family: Ocypodidae

Zone: A. marina landward and barren areas (Hartnoll, 1975; Gillikin, 2000).

Habitat: Burrowing to about 50 cm depth.

Food: Detritus sorted from sand (Icely and Jones, 1978). In the picture above, you can see the feeding pellet in the crabs mouth and on the lower right of the picture; the minor cheliped is grabbing the next mouthful.

Ecological notes: Most heat tolerant of Kenyan Uca (Edney, 1965). Can survive in sediments with low organic matter (Gillikin, 2000) and in habitats where soil water salinity approaches 100 salinity units (Gillikin, 2004).

Distinguishing characteristics: Claw yellow-orange; broad front; mobile claw tip is forked (see photos) (carapace width about 2.5 cm)

Geographical range: Red Sea to Natal and Madagascar (Vannini and Valmori, 1981)

References:

Cannicci, S., F. Dahdouh-Guebas and L. Montemagno, 1993. "Field Keys for Kenyan Mangrove Crabs." Museo Zoologico "La Specola", Dipartimento di Biologia Animale e Genetica dell'Università Degli Studi di Firenze, Via Romana 17, I-50125 Firenze, Italia.

Edney, E.B., 1961. "The water and heat relationships of fiddler crabs (Uca spp.)." Trans. roy. Soc. Afr. Vol. XXXVI, part 2, March 1961, p71-91.

Gillikin, D.P., 2000. Factors controlling the distribution of Kenyan brachyuran mangrove crabs: Salinity tolerance and ecophysiology of two Kenyan Neosarmatium species. M.Sc. Thesis, Free University of Brussels, Brussels, Belgium.

Gillikin, D.P., 2004. Osmoregulatory ability of Chiromantes ortmanni (Crosnier, 1965) subjected to dilute and hypersaline seawater. Crustaceana 77(1): 67-74 (reprint)

Hartnoll, R.G., 1975. "The Grapsidae and Ocypodidae (Decapoda: Brachyura) of Tanzania." J. Zool. Lond. 177:305-328.

Icely, JD and DA Jones, 1978. Factors affecting the distribution of the genus Uca (Crustacea: Ocypodidae) on an East African Shore." Estuarine and Coastal Marine Science 6:315-325.

Macnae, W., 1968. "A General Account of the Fauna and Flora of Mangrove Swamps and Forests in the Indo-West-Pacific Region." Advanced Marine Biology 6:73-270.

Vannini, M. and P. Valmori, 1981. Researchers on the coast of Somalia. The shore and the dune of Sar Uanle. 31. Ocypodidae and Gecarcinidae (Crustacea Brachyura). Monitore Zoologico Italiano 14: 199-226.

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