Enigmonia aenigmatica

Enigmonia is a genus of saltwater clams, a marine bivalve mollusc in the family Anomiidae, the jingle shells. Enigmonia aenigmatica, the mangrove jingle shell clam, is the only species in this monotypic genus. It is found living on mangroves in the Indo-Pacific Ocean.

== Description == The mangrove jingle shell clam can grow to a length of about . The shell is thin and delicate. Although this species is a bivalve, only the upper valve is normally visible, and that valve is elongated or oval with a low dome, and thus the general appearance which is like that of a limpet. The umbone of the shell is off centre, near the dorsal margin of the shell. A few fine ridges radiate from the umbone and there is a sculpting of concentric growth rings. The lower valve has a hole or notch in it through which byssus threads pass which attach it to a hard surface, usually a branch, leaf or aerial root of a mangrove tree. The lower valve is curved so as to adhere closely to the surface on which it rests. Unlike most other bivalves, but like others in the genus, it has a single adductor muscle holding the two valves together.