Aldrovandia gracilis

Common Name

Graceful Halosaur

Year Described

Goode & Bean, 1896


Dorsal Fin: 10-12
Anal Fin:
Pectoral Fin: I, 8-12
Pelvic Fin: I, 8 (rarely 7 or 9)
Lateral Line Scales: 7-10 (to pelvic), 13-19 (to anus)
Branchiostegal Rays: 10-11
Gill Rakers: 14-16 (total on first arch)
Pyloric Caeca: 6-10

Body very elongate and moderately compressed. Mouth relatively large (maximum premaxilla width <2 times in snout length). Snout fairly long and pointed. Scales absent on top of head and opercle. Lateral line scales three times larger than the body scales. Lateral line scales not continuous; with normal sized body scales interrupting the series. Scales above lateral line number 10-12. Scales around belly usually 7. First dorsal ray is very short and vestigial. Dorsal fin origin well behind pelvic fin origin.


Body grayish white with a blue-gray pigment on head. Snout white. A diffuse lateral stripe often present. Fins body colored. Interior of mouth dark with two pale stripes on roof of mouth. The pyloric caeca are dark. Vent black.


Maximum size to 55cm TL.


Continental shelf waters. Benthopelagic over calcareous bottoms from 1,000-2,000m.


Scattered records from Virginia to the Lesser Antilles, including the northern Gulf of Mexico.


McDowell, S.B. In: Cohen, D.M., N.B. Marshall, A.W. Ebeling, D.E. Rosen, T. Iwamoto, P. Sonoda, S.B. McDowell, W.H. Weed III, and L.P. Woods. 1973. Fishes of the Western North Atlantic. Part 6. Hereromi, Cyprinodontoidei, Berycomorphi, Xenoberyces, Anacanthini. Memoir No. 1. Sears Foundation for Marine Research; Yale University, New Haven, CT. 698 pp., 235 plates.