See text Maritrema is a genus of trematodes (flukes) in the family Microphallidae, although some have suggested its placement in the separate family Maritrematidae.

[2] Species of the genus usually infect birds, but several have switched hosts and are found in mammals, such as the marsh rice rat.

[3] Several species use the fiddler crab Uca pugilator as an intermediate host.

I", is known from clapper rails (Rallus crepitans) and marsh rice rats (Oryzomys palustris) in the eastern United States.

[4] M. heardi was placed in a separate genus Floridatrema upon its description in 1994 on the basis of a morphological difference, but was reassigned to Maritrema in 2005, as molecular data indicated that Maritrema would be paraphyletic without the inclusion of the species.