Adenodidymocystis Yamaguti, 1970 (additional source)
Allodidymocodium Yamaguti, 1970 (additional source)
Allodidymocodium euthynni Pozdnyakov, 1996 (original description)
Allometanematobothrioides Yamaguti, 1965 (additional source)
Allonematobothrioides Yamaguti, 1970 (additional source)
Allonematobothrioides hirosaba Pozdnyakov, 1988 (redescription)
Allonematobothrium Yamaguti, 1965 (additional source)
Allonematobothrium apharei Yamaguti, 1970 (redescription)
Allonematobothrium epinepheli Yamaguti, 1965 (redescription)
Allonematobothrium megalaspi Pozdnyakov, 1996 (original description)
Allopseudocolocyntotrema Yamaguti, 1970 (additional source)
Allopseudocolocyntotrema alioshkini Pozdnyakov, 1994 (redescription)
Angionematobothrium Yamaguti, 1970 (additional source)
Annulocystis Yamaguti, 1970 (additional source)
Annulocystis auxis Yamaguti, 1970 (redescription)
Annulocystis katsuwoni (Yamaguti, 1970) Pozdnyakov, 1996 (new combination reference)
Atalostrophion MacCallum, 1915 (additional source)
Brasicystis Thatcher, 1979 (additional source)
Coeliotrema Yamaguti, 1938 (additional source)
Coeliotrema thynni Yamaguti, 1938 (redescription)
Colocyntotrema Yamaguti, 1951 (additional source)
Colocyntotrema auxis Yamaguti, 1951 (redescription)
Dermatodidymocystis indicus Nikolaeva & Dubina, 1978 accepted as Platocystis viviparoides (Yamaguti, 1970) Pozdnyakov, 1987 (source of synonymy)
Didymocodium Yamaguti, 1970 (additional source)
Didymocodium euthynni Yamaguti, 1970 (redescription)
Didymocylindrus Ishii, 1935 (additional source)
Didymocylindrus apharyngi (Job, 1961) Pozdnyakov, 1996 (new combination reference)
Didymocylindrus filiformis Ishii, 1935 (redescription)
Didymocylindrus fusiformis (Ishii, 1935) Pozdnyakov, 1966 (redescription)
Didymocylindrus fusiformis (Ishii, 1935) Pozdnyakov, 1966 (new combination reference)
Didymocylindrus gasteralis (Abdul-Salam & Sreelatha, 1995) Pozdnyakov, 1996 (new combination reference)
Didymocylindrus opercularis (Madhavi, 1982) Pozdnyakov, 1996 (new combination reference)
Didymocylindrus simplex (Ishii, 1935) Yamaguti, 1970 (redescription)
Didymocylindrus singularis (Job, 1966) Pozdnyakov, 1996 (new combination reference)
Didymocylindrus sphyraenae (Yamaguti, 1959) Pozdnyakov, 1996 (new combination reference)
Didymocystis Ariola, 1902 (additional source)
Didymocystis abdominalis Yamaguti, 1938 (redescription)
Didymocystis acanthocybii Yamaguti, 1938 (redescription)
Didymocystis albacari Pozdnyakov, 1996 (original description)
Didymocystis buccalis (Yamaguti, 1970) Pozdnyakov, 1990 (redescription)
Didymocystis chorinemi Pozdnyakov, 1996 (original description)
Didymocystis exigua (Yamaguti, 1970) Podznyakov, 1990 (redescription)
Didymocystis kamegaii (Yamaguti, 1970) Pozdnyakov, 1996 (new combination reference)
Didymocystis kamegaii (Yamaguti, 1970) Pozdnyakov, 1996 (redescription)
Didymocystis katsuwoni (Yamaguti, 1970) Pozdnyakov, 1996 (new combination reference)
Didymocystis komoroensis (Nikolaeva & Dubina, 1978) Kamegai & Araki, 1995 (additional source)
Didymocystis lingualis (Nikolaeva & Dubina, 1985) Pozdnyakov, 1996 (new combination reference)
Didymocystis lingualis (Nikolaeva & Dubina, 1985) Pozdnyakov, 1996 (redescription)
Didymocystis neothunni (Yamaguti, 1970) Pozdnyakov, 1996 (new combination reference)
Didymocystis oesophagicola (Yamaguti, 1970) Podznyakov, 1990 (redescription)
Didymocystis ovata Ishii, 1935 (status source)
Didymocystis pectoralis (Yamaguti, 1970) Podznyakov, 1990 (redescription)
Didymocystis pseudobranchialis Job, 1964 (status source)
Didymocystis sphyraenae Hussain, Hanumantha Rao & Shyamasundari, 1986 (status source)
Didymodiclinus Pozdnyakov, 1993 (additional source)
Didymodiclinus cypseluri (Yamaguti, 1940) Pozdnyakov, 1994 (redescription)
Didymodiclinus facialis (Baylis, 1938) Pozdnyakov, 1996 (new combination reference)
Didymonaja Pozdnyakov, 1987 (additional source)
Didymonaja branchialis Pozdnyakov, 1987 (redescription)
Didymophaselus Pozdnyakov & Gordeev, 1993 (additional source)
Didymophaselus allothunni Pozdnyakov & Gordeev, 1993 (redescription)
Didymosphaera Mamaev, 1968 nec Linck, 1883 accepted as Opepherotrematoides Yamaguti, 1970 (additional source)
Didymosphaera mirabilis Mamaev, 1968 accepted as Opepherotrematoides mirabilis (Mamaev, 1968) (redescription)
Didymosphaera multitubularis (Yamaguti, 1970) Pozdnyakov, 1996 accepted as Opepherotrematoides multitubularis Yamaguti, 1970 (new combination reference)
Didymosphaera yaito (Yamaguti, 1970) Pozdnyakov, 1996 accepted as Opepherotrematoides yaito (Yamaguti, 1970) Ceccolini & Cianferoni, 2021 (new combination reference)
Didymosulcus Pozdnyakov, 1990 (additional source)
Didymosulcus aahi Pozdnyakov, 1990 (redescription)
Didymosulcus bifurcatus (Yamaguti, 1970) Pozdnyakov, 1990 accepted as Didymocystis bifurcata Yamaguti, 1970 (redescription)
Didymosulcus dimidiatus Pozdnyakov, 1990 (redescription)
Didymosulcus irregularis (Yamaguti, 1970) Pozdnyakov, 1990 (redescription)
Didymosulcus katsuwonicola (Okada, 1926) Pozdnyakov, 1990 (redescription)
Didymosulcus nasalis (Yamaguti, 1970) Pozdnyakov, 1990 (redescription)
Didymosulcus orbitalis (Yamaguti, 1970) Pozdnyakov, 1990 (redescription)
Didymosulcus palati (Yamaguti, 1970) Pozdnyakov, 1990 (redescription)
Didymosulcus philobranchia (Yamaguti, 1970) Pozdnyakov, 1990 (redescription)
Didymosulcus poonui (Yamaguti, 1970) Pozdnyakov, 1990 (redescription)
Didymosulcus rotunditestis (Nikolaeva & Dubina, 1985) Pozdnyakov, 1990 (redescription)
Didymosulcus soleiformis (Ishii, 1935) (status source)
Didymosulcus superpalati (Yamaguti, 1970) Pozdnyakov, 1990 (redescription)
Didymosulcus wedli (Ariola, 1902) (status source)
Didymozoidae Monticelli, 1888 (taxonomy source)
Didymozoon Taschenberg, 1879 (additional source)
Didymozoon diverticulatum Yamaguti, 1970 (redescription)
Didymozoon filicolle Ishii, 1935 (redescription)
Didymozoon gigas Ku & Shen, 1965 (status source)
Didymozoon longicolle Ishii, 1935 (redescription)
Didymozoon molae (Rudolphi, 1819) Dollfus, 1946 (status source)
Didymozoon platycephali Ku & Shen, 1965 accepted as Indodidymozoon platycephali (Ku & Shen, 1965) Anderson & Cribb, 1994 (status source)
Didymozoon serrani Monticelli, 1889 (status source)
Didymozoon taenioides Monticelli, 1883 (status source)
Didymozoon tetragynae Job, 1961 accepted as Didymocylindrus apharyngi (Job, 1961) Pozdnyakov, 1996 (source of synonymy)
Epithelionematobothrium Yamaguti, 1970 (additional source)
Epithelionematobothrium makairi (Nikolaeva & Dubina, 1978) Pozdnyakov, 1996 (new combination reference)
Epithelionematobothrium makairi (Nikolaeva & Dubina, 1978) Pozdnyakov, 1996 (redescription)
Glomeritrema Yamaguti, 1942 (additional source)
Gonapodasmius Ishii, 1935 (additional source)
Gonapodasmius haemuli (MacCallum & MacCallum, 1916) Ishii, 1935 (redescription)
Gonapodasmius hapuki Pozdnyakov, 1994 (redescription)
Halvorsenius Gibson, MacKenzie & Cottle, 1981 (additional source)
Koellikeria Cobbold, 1860 (additional source)