Diplectanidae

The Diplectanidae are a family of monopisthocotylean monogeneans. They are all parasitic on the gills of fish (marine or freshwater). Diplectanids are small animals, generally around 1 mm in length. As parasites, they can be extremely numerous, up to several thousand on an individual fish.
History.
The family Diplectanidae was proposed by the Italian parasitologist Monticelli in 1903 (as subfamily Diplectaninae). The status of the family and its components was later examined by various authors, including Johnston & Tiegs (1922), Price (1937), Bychowsky (1957), Yamaguti (1963), and Oliver (1987).
Morphology.
Diplectanids are diagnosed by the combination of these three characters:
Genera.
The genera recognized in WoRMS are: