Guentherus is a genus of jellynose fishes, belonging to the Ateleopodidae family, with two recognized species:
The genus distinguishes itself from others in its family because of discrepancies in morphology. Guentherus has "3 free rays followed by 6âÂÂ9 normal rays with membrane between them in the pelvic fins." Other genera in this family have "a single long filament or 1 relatively developed ray plus 0 to 3 rudimentary rays."
The family Ateleopodidae is made up of four genera and within that thirteen species: Ateleopus, Ijimaia, Parateleopus and Guentherus. Ateleopodids are located primarily near tropical and subtropical waters; with Ateleopus, Parateleopus, and Guentherus located in the Pacific and Ijimaia located in the Atlantic. Ateleopodids are commonly referred to as Jellynose fish or alternatively also called tadpole fish "because of their very soft and gelatinous snout."
The genus Guentherus was created by Balthazar Osorio in 1917 upon his discovery of Guentherus ativela species. The genus Guentherus differentiates from its other Ateleopodids because of their "posterior placement and structure ofÃÂ its pelvic fins-three free rays followed byÃÂ a normal pelvic fin." They are a benthically dwelling ray-finned fish. Guentherus ativela is known to feed on copepods and polychaetas.
Guentherus katoi was named after Tatsuya Kato who collected the specimen. it has been found at depths of . The only specimens of G. katoi have been found off the coast of Southern Japan to the outlying southern Okinawa Islands.
G. katoi is a scaleless Actinopterygii species with jaws, though lacking teeth.
G. katoi can be distinguished from other species in its genus because of its lack of lateral line and scales.
Guentherus altivela Osório, 1917, original description in