Hooks: 6-9; anterior teeth: 6-9; posterior teeth: 9-15.
Maximum adult body length: 30 mm; tail: 20-30 %.
Body slender; transversal musculature absent; head wide; hooks not serrated. Fin bridge absent. Anterior fins of medium length, partially rayed, rounded; posterior fins of medium length, partially rayed, rounded. Collarette absent; gut diverticula present. Large eyes, with T-shaped pigment spot. Seminal vesicles narrow with head and trunk; position of seminal vesicles: separated from posterior fins and close to, or touching, tail fin. Ovaries short, reaching to anterior end of posterior fins; ova small. Adhesive papillae and adhesive organs absent. Apical glands absent.
Distribution: deep-mesopelagic; circumglobal between 40°N and 40°S.
Remarks: was depicted as Sagitta decipeins by Von Ritter-Záhony, 1911 and is confused with this species ever since.
Type locality: Indonesian waters.