Sciadonus jonassoni

Common Name

Jonasson's Blindfish

Year Described

Nybelin, 1957


Dorsal Fin: 68-80
Anal Fin: 38-49
Pectoral Fin: 9-10
Pelvic Fin: absent
Caudal Fin: 6
Gill Rakers: 11-13 short rakers on first arch
Vertebrae: 65-75 (35-43 precaudal)

Body elongate and slender. Head large and broader than body. The mouth is slightly oblique and the lower jaw projects beyond the upper. Premaxillary and dentary with teeth. Vomer with 2-10 fangs. Eyes are tiny black dots. The pectoral fin base is extended as a limb-like pedicel. Dorsal fin short; origin around mid-body. The dorsal and anal fins are continuous with the caudal fin, which is relatively long. Penis small.


Body pale translucent with black speckles along the dorsal fin base, anal fin base, lateral midline, and on the head. Peritoneum and eye dark.


Ranges from 35-51mm SL.


Benthic at abyssal depths (1464-5610m).


Known from 2 specimens in the area: off the Bahamas and off Trinidad. Also known in the central and eastern Atlantic.


Nielsen, J.G. 1969. Systematics and biology of the Aphyonidae (Pisces, Ophidioidea). Galathea Report v. 10: 7-90, Pls. 1-4.

Nielsen, J.G., D.M. Cohen, D.F. Markle, and C.R. Robins. 1999. Ophidiiform fishes of the world (Order Ophidiiformes). An annotated and illustrated catalogue of pearlfishes, cusk-eels, brotulas and other ophidiiform fishes known to date. FAO Fish. Synop. 125(18): 178p.

Nielsen, J.G. 2018. Revision of the cosmopolitan deep-sea genus Sciadonus (Teleostei, Bythitidae) with two new species. Cybium, 42(2), 177-187.

Other Notes

Distinguished from other Sciadonus in the area by having black spots on the body and much fewer pectoral fin rays.