Biology:Amphithrax
Amphithrax is a genus of saltwater crabs belonging to a group (superfamily Majoidea), often known as spider crabs or decorator crabs.
Description
On the iNaturalist page comparing pictures of the various Amphithrax species it is seen that they all share these features:[1]
- spoon-shaped claw tips
- legs armed with tubercles and sometimes hairlike or sharp projections
- the fronts of their carapaces bear various pointed projections, sometimes with those around the eyes particularly developed
Habitat
Amphithrax species occur among coral rocks and rubble, beneath sea anemones and in rock crevices in intertidal zones to subtidal zones of up to 60 meters depth (~200 feet).[2]
Range
The map registering observations of Amphithrax species at iNaturalist documents the genus's presence in tropical and subtropical waters of the Americas.[3] Amphithra armatus has been recorded in the western Pacific, in Taiwanese waters, as an invasive species.[4]
List of species
In 2025, these are the accepted species of the genus Amphithrax:[5]
- Amphithrax aculeatus (Herbst, 1790)
- Amphithrax armatus (de Saussure, 1853)
- Amphithrax bellii (Gerstaecker, 1856)
- Amphithrax besnardi (Melo, 1990)
- Amphithrax braziliensis (Rathbun, 1892)
- Amphithrax caboverdianus (Türkay, 1986)
- Amphithrax clarionensis (Garth, 1940)
- Amphithrax hemphilli (Rathbun, 1892)
- Amphithrax pilosus (Rathbun, 1892)
- Amphithrax tuberculatus (Stimpson, 1860)
- Amphithrax verrucosus (H. Milne Edwards, 1832)
References
- ↑ "Observations: Amphithrax". https://www.inaturalist.org/observations?subview=map&taxon_id=992714&view=species.
- ↑ Parasram, Nadeshinie; Santana, William; Vallès, Yvonne; Windsor, Amanda M.; Vallès, Henri (January 26, 2024). "Morphological and molecular support for Amphithrax verrucosus (H. Milne Edwards, 1832) and Amphithrax aculeatus (Herbst, 1790) (Crustacea, Decapoda, Brachyura) as valid species". Zoosystematics and Evolution (Sofia, Bulgaria: Pensoft Publishers) 100 (1): 15–30. doi:10.3897/zse.100.109192. https://zse.pensoft.net/article/109192/element/7/0/Amphithrax/. Retrieved September 11, 2025.
- ↑ "Amphithrax". https://www.inaturalist.org/taxa/992714-Amphithrax.
- ↑ Ng, P.K.; Ho, P.H.; Lin, C.W.; Yang, C.H. (February 2018). "The first record of an eastern Pacific invasive crab in Taiwanese waters: Amphithrax armatus (Saussure, 1853) (Brachyura: Majoidea: Mithracidae), with notes on the taxonomy of the genus". Journal of Crustacean Biology (The Crustacean Society and Oxford University Press) 38 (2): 198–205. doi:10.1093/jcbiol/rux109. https://www.researchgate.net/publication/323105280.
- ↑ "Search Amphithrax". Species 2000: Leiden, the Netherlands. https://www.catalogueoflife.org/data/taxon/847NY.
Wikidata ☰ Q98638779 entry
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