Maximum adult body length: 8 mm; tail: 27-34 %.
Body slender; transversal musculature absent; head fairly large; hooks not serrated. Fin bridge absent; one pair of short lateral fins both on trunk and tail; posterior fins short, partially rayed, rounded. Collarette absent; gut diverticula absent. Small eyes, with star-shaped pigment spot. Seminal vesicles with knob and trunk; position of seminal vesicles: touching both posterior fins and tail fin. Ovaries of medium length, reaching to region of ventral ganglion; ova very large. Adhesive papillae and adhesive organs absent. Apical glands absent.
Distribution: epi- and mesopelagic; global between 30°N and 30°S.
Remarks: very prominent anterior teeth.
Type locality: North-West Pacific.