Karstama Davie & Ng, 2007 Karstarma is a genus of karst-dwelling crabs formerly included in Sesarmoides.

Karstarma is distinguished from the closely related Sesarmoides by the lack of a stridulatory structure on the cheliped which is present in the latter genus.

[3] All species in the genus Karstarma are typically found in anchialine pools[3] across the Indo-Pacific.

[3] It has been frequently misspelt Karstama, including in the original description.

[2][4] A new species, K. vulcan, was also described from Réunion in 2018; this species is unique from all others as it is found in the western Indian Ocean rather than the eastern Indian or Pacific Oceans.