Homalometron pallidum

It is an endoparasite of the mummichog, Fundulus heteroclitus, a small fish found in brackish water along the east coast of the United States and Canada.

The original description of Homalometron pallidum was given by Linton in 1899 and reads:[2] "Body very minutely spinose, white, translucent; acetabuhuni and oral sucker about same size; outline of body, long oval; neck short, continuous with body; greatest breadth in region of testes, near posterior end; ecaudate; acetabuhum sessile; ranii of intestines simple, elongate ; esophagus as long as pharynx; testes, two, in median line behind uterus; seminal vesicle dorsal to ovary and posterior border of acetabulum; ovary between acetabulum and testes, on right side; pharynx, subglobular; genital aperture in front of acetabulum, on median line; vitelline glands lying at posterior end and along sides of body as far as acetabulum; ova few, relatively large."

It is found in the tidal creeks, estuaries and salt water marshes where its host species occur.

[2] Eggs are ejected from the host fish in its faeces and are ingested by a small aquatic snail, Hydrobia minuta.

[2] Other fish have been identified as also acting as a host to the adult worms, including Menticirrhus saxatilis, Morone americana, Pseudopleuronectes americanus, Tautoga onitis, and Bairdiella chrysura.