Fowler's Pearlfish, Onuxodon fowleri (Smith 1955)

Fowler's Pearlfish, Onuxodon fowleri, at Bali, Indonesia. Source: John E. Randall / FishBase. License: CC by Attribution-NonCommercial

A small slender eel-like fish with a translucent pinkish body, a dusky underside and dusky rear part of the tail. Fowler's Pearlfish is commensal with bivalve molluscs - clams, oysters and pearl shells, and produces sounds using its modified swim bladder.

Cite this page as:
Dianne J. Bray, Onuxodon fowleri in Fishes of Australia, accessed 26 Sep 2023,

Fowler's Pearlfish, Onuxodon fowleri (Smith 1955)

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Recorded from Eastern Australia - Queensland and New South Wales. Elsewhere, widespread in the Indo-west-central Pacific. Individuals are nocturnal, usually sheltering in pearl oysters and other bivalves during the day, and foraging at night.


Meristic features: Dorsal fin 43-50; Anal fin 46-51; Vertebrae 90; Precaudal vertebrae 19-22; . 
Body eel-like, slender to moderate in depth, trunk compressed; 1 to several large symphyseal fangs on premaxilla and dentary; anterior swim bladder modified into 'rockerbone'; predorsal bone present; pectoral fin rays supported by numerous small distal radials.


Carnivore - feeds on crustaceans, polychaete worms and bivalve molluscs.

Species Citation

Jordanicus fowleri Smith, 1955, Ann. Mag. Nat. Hist. 12 8(90): 403 [based on Jordanicus caninus of Fowler, H.W. 1927]. Type locality: Lectotype  - Kiritimati (as Christmas Island), Line Islands. 


Dianne J. Bray

Fowler's Pearlfish, Onuxodon fowleri (Smith 1955)


Allen, G.R. & Erdmann. M.V. 2012. Reef fishes of the East Indies. Perth : Tropical Reef Research 3 vols, 1260 pp.

Amaoka K. & Yoseda Y. 2005. Two species of pearl fi shes, Onuxodon parvibrachium & O. fowleri (Ophidiiformes, Carapidae) from the honeycomb oyster (Hyotissa hyotis), from Ishigaki Island, Okinawa Prefecture. Bulletin of the Biogeographical Society of Japan 60: 5-12.

Francis, M.P., 1993. Checklist of the coastal fishes of Lord Howe, Norfolk, and Kermadec Islands, Southwest Pacific Ocean. Pacific Science 47(2): 136-170.

Kéver, L., Colleye, O., Lugli, M., Lecchini, D., Lerouvreur, F., Herrel, A. & Parmentier, E. 2014. Sound production in Onuxodon fowleri (Carapidae) and its amplification by the host shell. J. Exp. Biol. 217: 4283-4294.

Markle D.F. & Olney J.E. 1990. Systematics of the Pearlfi sh (Pisces: Carapidae). Bulletin of Marine Science 47: 269-410.

Nielsen J.G., Cohen D.M., Markle D.F. & Robins C.R. 1999. FAO species catalogue. Volume 18. 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 Fisheries Synopsis, 125. FAO, Rome.

Parmentier, E., G. Castillo, M. Chardon & P. Vandewalle. 2000. Phylogenetic analysis of the pearlfish tribe Carapini (Pisces: Carapidae). Acta Zool. 81:293-306.

Parmentier E., Castro-Aguirre J.L. & Vandewalle P. 2000. Morphological comparison of the buccal apparatus in two bivalve commensal Teleostei: Encheliophis dubius and Onuxodon fowleri (Carapidae, Ophidiiformes). Zoomorphology 120: 29-37.

Randall, J.E., Allen, G.R. & Steene, R. 1990. Fishes of the Great Barrier Reef and Coral Sea. Bathurst : Crawford House Press 507 pp. figs. 

Smith, J.L.B. 1955. The fishes of the family Carapidae in the western Indian Ocean. Annals and Magazine of Natural History 12 8(90): 401-416 figs 1-8

Quick Facts

CAAB Code:37229013

Behaviour:Commensal with bivalve molluscs

Depth:1-30 m

Habitat:Reef associated

Max Size:10 cm TL

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