Offshore Pipefish, Micrognathus natans Dawson 1982

Other Names: None

Most specimens of the Offshore Pipefish have been collected from near the surface or in midwater trawls and plankton nets in upper layers of the water column.

Cite this page as:
Dianne J. Bray & Vanessa J. Thompson, Micrognathus natans in Fishes of Australia, accessed 14 Jun 2024,

Offshore Pipefish, Micrognathus natans Dawson 1982

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Tropical Western Pacific, from Indonesia, Australia, New Caledonia, the Philippines, Fiji; in Australian waters, recorded from northern Queensland – off Bligh Reef, Cape York and the Lizard Island area, Great Barrier Reef. Most known specimens have been collected from open water, and the very few benthic individuals to be seen inhabit deeper, sheltered muddy or silty areas in 15-25m.


Meristics: D 16–18; A 3–4; P 12–15; Trunk rings 14–15; Tail rings 27–31; Total subdorsal rings 3.75–5.0.

Head and body: Body slender, elongate, head length in SL 6.9–7.8, snout length in head length 2.2–2.5; median dorsal snout ridge low, entire, somewhat concave in lateral profile; longitudinal opercular ridge complete in young, incomplete to obsolete in subadults-adults; superior trunk and tail ridges discontinuous; inferior trunk ridge ends on anal ring; lateral trunk ridge continuous with inferior tail ridge; head and body rings without spines, denticles or serrations; scutella not keeled; larger individuals tend to have some head or body flaps, which are usually absent from those smaller than 35 mm SL.

Fins: Dorsal fin origin often on tail.


Maximum recorded length 60 mm.


Overall tan to dark brownish-red with tiny light speckles; dorsal surface, upper half of side of trunk and tail with irregular, diffuse pale bars. Pectoral and caudal fins largely clear.


Unknown – likely to feed on small crustaceans.


Reproduction: Reproductive mode – ovoviviparous (gives birth to live young) with eggs brooded by males in a pouch under the tail. The brood pouch has pouch plates and pouch folds, with an everted pouch closure. The only male examined with a developing brood pouch was 36mm SL, and was collected from the water column.

Eggs: Not described

Larvae and juveniles: As most known specimens have been collected in plankton nets or midwater trawls, the Offshore Pipefish presumably has an extended pelagic juvenile stage.


Of no interest to fisheries or aquaculture.


CITES: not listed.

IUCN Red List Status: not evaluated.

Australian Commonwealth legislation: Marine listed under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act).


Very few specimens are known from benthic habitats – most were collected in the open ocean.

Similar Species

Micrognathus natans can be distinguished from all other species in the genus Micrognathus in having fhe fewer trunk rings (usually 14), a longer and more slender snout, more pectoral fin rays (12–15 vs 9–13) and essentially straight tail ridges.


Micrognathus is from the Greek micro meaning small and gnathus meaning jaw. The specific name natans is from Latin meaning swimming or floating, in reference to the fact that all the type specimens were collected in the upper region of the water column.

Species Citation

Micrognathus natans Dawson.1982, Proc. Biol. Soc. Wash. 94(3): 682, Beqa Island, Fiji Islands.


Dianne J. Bray & Vanessa J. Thompson

Offshore Pipefish, Micrognathus natans Dawson 1982


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Dawson, C.E. 1982. Review of the genus Micrognathus Duncker (Pisces: Syngnathidae) with description of M. natans, n. sp. Proc. Biol. Soc. Wash. 94(3): 657–687.

Dawson, C.E. 1985. Indo-Pacific Pipefishes (Red Sea to the Americas). Gulf Coast Research Laboratory, Ocean Springs, Mississippi. 230 pp.

Dunning, M., M. Lightowler & P. Jones. 2001. Syngnathid (pipefish) harvest from the Queensland east coast trawl fishery. Statement of Management Arrangements, 16 pp., Brisbane (Queensland Fisheries Service).

Fricke, R. 2004. Review of the pipefishes and seahorses (Teleostei: Syngnathidae) of New Caledonia, with descriptions of five new species. Stuttgarter Beiträge zur Naturkunde. Serie A (Biologie). 66S: 1–66.

Hoese, D.F., D.J. Bray, J.R. Paxton & G.R. Allen. 2006. Fishes. In Beesley, P.L. & A. Wells (eds). Zoological catalogue of Australia. Volume 35. ABRS & CSIRO Publishing: Australia. 2178 pp.

Kuiter, R.H. 2009. Seahorses and their relatives. Aquatic Photographics, Seaford, Australia. Pp. 1–333.

Kuiter, R.H. & T. Tonozuka. 2001. Pictorial guide to Indonesian reef fishes. Part 1. Eels- Snappers, Muraenidae - Lutjanidae. Zoonetics, Australia. 302 pp.

Paulus, T. 1999. Family Syngnathidae. pp 2264–2276, In Carpenter K.E. & V.H. Niem (Eds.) The Living Marine Resources of the Western Central Pacific. FAO Species Identification Guide For Fisheries Purposes. FAO Vol. 4.

Paxton, J.R., J.E. Gates, D.F. Hoese & D.J. Bray. 2006. Syngnathidae (Pp. 810–846). In  Beesley, P.L. & Wells, A. (Eds) Zoological Catalogue of Australia. Volume 35. Fishes. ABRS & CSIRO Publishing, Australia., 3 vols.

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Quick Facts

CAAB Code:37282089

Species Maps

CAAB distribution map