Oily Halosaur, Aldrovandia oleosa Sulak 1977

Other Names: Bathyal Halosaur

Illustration of an Oily Halosaur, Aldrovandia oleosa. Source: Fig. in Smith (2016) in Carpenter & De Angelis (eds). The living marine resources of the Eastern Central Atlantic. Volume 3 / FAO. License: CC by Attribution-NonCommercial-ShareAlike

A brown halosaur with a black head, a white anus surrounded by a ring of darkly pigmented tissue, and a black stomach, pyloric caeca, and peritoneum. Males have black tubular anterior nostrils and enlarged posterior nostrils when approaching breeding condition. The species has large lateral-line scales and oily skin.

Cite this page as:
Bray, D.J. 2022, Aldrovandia oleosa in Fishes of Australia, accessed 22 Jun 2024, https://fishesofaustralia.net.au/Home/species/5683

Oily Halosaur, Aldrovandia oleosa Sulak 1977

More Info


Balthazar seamount, SW of Christmas Island, eastern Indian Ocean. Elsewhere the species is circumglobal on the outer Continental Slope.


Dorsal fin 10-11; Pectoral fin rays 9-11; Pelvic fin I,8-9;  Gill rakers 19-23; Lateral line scales before anus 16-24; Gill Rakers 19-23 (total first arch); Branchiostegal rays: 9-11; Pyloric caecae 5-8.
Body very elongate, moderately compressed; skin loose, oily; preoral portion of snout short, approx. one-third total snout length; mouth relatively small; palatine tooth patch well separated medially, widely separated from pterygoid tooth patch by a distance 1-4 times its length. Scales absent on top of head and opercle; lateral line scales two times larger than body scales, continuous with each other. Dorsal fin origin posterior to pelvic fin origin; first dorsal ray very short, vestigial.


Maximum  size: 52.0 cm TL; 16 cm preanal length.


Feeds on polychaete worms


The specific name is from the Greek oleosa (= oily), in reference to the yellowish oil in the flesh of this species.

Species Citation

Aldrovandia oleosa Sulak 1977, Copeia 1977(1): 12, Figs. 1, 2 left, 3 upper, 4 (A-C). Type locality: Tongue-of-the-Ocean, Bahamas, 23°38.5'-23°40.3'N, 76°47.75'-76°45.1'W, depth 1324-1307 m.


Bray, D.J. 2022


Atlas of Living Australia

Oily Halosaur, Aldrovandia oleosa Sulak 1977


Kamikawa, D. & Stevenson, D. 2010. New records of Aldrovandia oleosa (notacanthiformes: Halosauridae) from the Eastern North Pacific Ocean. California Fish and Game 96: 216-220. 

Smith, D.G. 2016. Halosauridae, Halosaurs pp. 1594-1600 in Carpenter, K.E. & De Angelis, N. (eds). The living marine resources of the Eastern Central Atlantic. Volume 3. Bony fishes part 1 (Elopiformes to Scorpaeniformes). FAO Species Identification Guide for Fishery Purposes. Rome, FAO. i-xiv + 1511-2350.

Sulak, K.J. 1977. Aldrovandia oleosa, a new species of the Halosauridae, with observations on several other species of the family. Copeia 1977(1): 11-20. https://doi.org/10.2307/1443498

Sulak, K.J. 1990. Halosauridae. pp. 126-132 in Quéro, J.-C., Hureau, J.-C., Karrer, C., Post, A. & Saldanha, L. (eds). Check-list of the Fishes of the Eastern Tropical Atlantic. Paris : UNESCO 1492 pp., 3 vols.

Tighe, K. 2015. Aldrovandia oleosa. The IUCN Red List of Threatened Species 2015: e.T190312A1947402. https://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T190312A1947402.en. Accessed on 13 September 2022.

Quick Facts

CAAB Code:37081008

Conservation:IUCN Least Concern

Depth:1200-1900 m


Max Size:52 cm TL

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