Heteromysis

The body is rather moderately robust. Telson trapezoidal, apically with cleft. Eyes with well developed cornea. Pereiopod 1 carpopropodus always in possession of some either smooth or modified spiniform setae. Pereopod 2 carpopropodus multisegmented. Uropodal endopod with spiniform setae on its inner margin. Members of the genus are not known to share any unique characters. Compared to other genera of the subfamily Heteromysinae, Heteromysis is most similar to Ischiomysis, Platymysis and Retromysis. It differs from Ischiomysis by the absence of the acute process on the preischium of the pereiopod 6, the absence of the flagellated spiniform setae on its ischium, and the absence of the large apical lobes. From Platymysis it is distinguished by the general body shape, which is not compressed dorsoventrally, laking also the abdominal pleurites, the prominent distolateral lobes on the eyes and the pereiopod 1 carpopropodus segments clearly separate. Finally, Heteromysis differs from Retromysis by the distomedial setae of the antennal peduncle, directed forward instead of backwards, the absence of the posteromedial lobe on the male process of antennula and the sternal plate not projecting behind the marsupium. ==Distribution==

Cosmopolitan. Temperate, subtropical and tropical seas of the World Ocean. Mostly concentrated in tropical and subtropical waters. ==Environment and habitat==

Exclusively marine. Shallow water. Commensals of various invertebrates: sponges, corals, hydroids, hermit crabs, cephalopods. Some species were recorded to be facultative commensals, also inhabiting adjacent bottom substrates. ==Life history==

Copulation was observed in H. formosa. At night time, immediately after the release of the juveniles from the female pouch, the male takes position under the molted female, clasping pereiopods around the abdomen, head to tail and the ventral surface to the ventral surface, inserting the penis between the pouch plates and ejecting sperm into the pouch chambers. Female carry two eggs in the marsupium. ==Classification==

Contrasting to the absence of common unique generic characters, the species of the genus group into four subgenera: ==References==