Ijimaia loppei

Common Name

Loppe's Tadpole Fish

Year Described

Roule, 1922


Dorsal Fin: 9-10
Anal Fin: 80-87
Pectoral Fin: 13-14
Pelvic Fin: 1-3
Caudal Fin: 9-14
Gill Rakers: 8-10 (first arch)

Body shaped like a macrourid, or tadpole shaped, with a thickened trunk. Skin very loose and gelatinous, becoming amorphous when removed from the water. Body depth 14-15% of TL. Snout gelatinous and bulbous in life. Mouth subterminal and reaches middle of orbit. Eye 9.4-12.1% of head length. Tail gradually tapers to a point posterior to the origin of the anal fin. Dorsal fin high and without a strong spine. No second dorsal fin or adipose fin. Pectoral fin about the same size and length as dorsal fin but more rounded. Anal fin quite long; runs from anus to tail tip. Caudal fin continuous with anal fin. Pelvic fin jugular and consists of one filamentous ray and a few buried rays under the skin (characteristic of the genus Ijimaia). Body naked with indistinct lateral line.


Body pale brown with cloudy brown markings and mottling. Fins dusky. Anal fin with a dark margin. Eye silvery-blue.


A large species reaching up to 200cm TL.


Occurs at or near the bottom but habits very poorly known. Brazilian adults taken between 6000-900m by trawlers.


Known from several specimens taken off eastern and southeastern Brazil. Also eastern Atlantic.


Schroeder, R., Schwarz, R., & Schwingel, P.R. 2011. The occurrence of the jellynose fish Ijimaia antillarum in the south-western Atlantic. Marine Biodiversity Records, 4. E59. doi:10.1017/S1755267211000595

Other Notes

The taxonomy of the Ateleopodiformes is very poorly understood and identification of the two known Atlantic species is based on few specimens with little knowledge on the variation present. The genus Ijimaia and Ateleopus share the reduced pelvic fin with a single visible ray but differ only in the relative length of the fin and the size of the fish. Ateleopus may represent different sized individuals of the same species with Ijimaia being consistently quite large in size. The differences in eye size may also be ontogenetic. The differences in rooted caudal fin rays (5 vs 9+ confirmed by radiograph) seem to separate Ijimaia into two groups of Atlantic material but this trait could also be variable. More study is needed to determine if Ijimaia antillarum and I. loppei are considered one or two species (FAO: Moore, 2003).