Little Dragonfish, Eurypegasus draconis (Linnaeus 1766)


Other Names: Common Seamoth, Short Dragonfish, Short Dragon-fish, Short Seamoth

A Little Dragonfish, Eurypegasus draconis, at Lembeh Strait, North Sulawesi, Indonesia . Source: Dave Harasti / http://www.daveharasti.com/. License: All rights reserved

Summary:

The Little Dragonfish is encased in bony armour, has a long, flattened snout and wing-like pectoral fins. They are highly variable in colour pattern and extremely well-camouflaged to resemble pieces of shell or rubble. The pectoral fins of males have broad pale blue and white margins that they sometimes 'flash' when disturbed.

Great video of Little Dragonfish and a Slender Seamoth.

Video of Little Dragonfishes at Guam

Little Dragonfish up-close in Lembeh Straits, Indonesia.


Cite this page as:
Bray, D.J. & Thompson, V.J. 2018, Eurypegasus draconis in Fishes of Australia, accessed 20 Nov 2018, http://fishesofaustralia.net.au/home/species/3201

Little Dragonfish, Eurypegasus draconis (Linnaeus 1766)

More Info


Distribution

Off Onslo to north of Bedout Island, Western Australia, and north of Wessel Islands, Northern Territory, to Tathra, New Spouth Wales, also reefs in the Coral Sea, and Lord Howe Island in the Tasman Sea. Elsewhere the species is widespread in the tropical Indo-West-Central Pacific, from the Red Sea and East Africa, to the Marquesas and Society Islands, southern Japan, southwards New Caledonia and Australia.

Bottom-dwelling fishes inhabiting sheltered bays and estuaries at 3-90 m, commonly in 35-90 m, usually living on rubble, shelly or sandy substrates amongst the seagrass Halophila and on isolated coral patches.

Features

Dorsal fin 5; Anal fin 5; Pectoral fin 9-12; Caudal fin 8; Pelvic fin I, 2; Vertebrae 19-22; Tail rings 8-9.

Body depth 19.2-34.4% SL. Body short, depressed, completely encased in fused, dermal plates; 3 pairs of dorsolateral body plates; 4 pairs of ventrolateral body plates; tail rings 8 (rarely 9), mobile; pair of deep pits posterior to orbit; suborbital shelf concave; ventral ridges of rostrum greatly expanded than dorsal ridges, each with laterally directed denticles; anal papilla absent.

Pectoral fins large, wing-like, orientated horizontally; pelvic fins thoracic, fin spine and 1st ray forming an elongate, tentacular structure to aid ‘walking’.

Size

Grows to a total length of about 10 cm.

Colour

Little Dragonfish are highly variable in colour, with well-camouflaged individuals mimicking pieces of shell or rubble. They are often brownish with dark reticulations on the top and sides of the body, often with lighter markings on the carapace. Males may have broad, bluish-white margins on the pectorals fins, which they often 'flash' when disturbed.

Feeding

Seamoths are opportunistic feeders, crawling over the seafloor on their finger-like pelvic fins in search of small crustaceans, worms and molluscs.

Biology

The sexes are separate and males and females are sexually dimorphic, with the larger females having a broader carapace. Seamoths form monogamous pairs, and fertilisation is external. Mating occurs at dusk, with individuals rapidly rising up from the bottom to release their pelagic eggs and sperm into the water column. The eggs are pelagic and spherical, and about 1 mm in diameter.

Larvae are pelagic and hatch at 2.2mm, settling to the bottom at about 9mm. Small larvae have the body enclosed by a dermal sac. Larvae have a depressed body, a compressed tail and large, fan-shaped horizontally-oriented pectoral fins.

Fisheries

Taken as bycatch in trawl and seine fisheries and traded by several Southeast Asian countries for the Traditional Chinese Medicine (TCM) trade. Live specimens are also collected for sale in the aquarium industry, although not as frequently as other sea moth species.

Conservation

  • IUCN Red List : Least Concern
  • New South Wales: Listed as a protected species under the NSW Fisheries Management Act 1994.
  • Remarks

    Seamoths frequently shed their outer skin layer to remove algae and tiny invertebrates which growing on these slow-moving fishes.

    Similar Species

    Little Seamoths differ from Pegasus volitans, the other seamoth in Australian waters, in having a shorter snout, a stouter body and reaching a smaller size.

    Etymology

    Eurypegasus is from the Greek eurys, meaning wide or broad, in reference to the body shape, and pegasos, a winged horse. The specific name draconis is from the Latin draco meaning a fabulous, lizard-like animal.

    Species Citation

    Pegasus draconis Linnaeus 1766. Systema Naturae. 12th Ed. 1(1): 418. Type locality: India.

    Author

    Bray, D.J. & Thompson, V.J. 2018

    Resources

    Australian Faunal Directory

    Little Dragonfish, Eurypegasus draconis (Linnaeus 1766)

    References


    Allen, G.R. 1997. Marine Fishes of Tropical Australia and South-east Asia. Perth : Western Australian Museum 292 pp. 106 pls.

    Allen, G.R. 2000. Fishes of the Montebello Islands. Records of the Western Australian Museum, Supplement 59: 47-57 

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

    Allen, G.R., Hoese, D.F., Paxton, J.R., Randall, J.E., Russell, B.C., Starck, W.A., Talbot, F.H. & Whitley, G.P. 1976. Annotated checklist of the fishes of Lord Howe Island. Records of the Australian Museum 30(15): 365-454 figs 1-2 

    Francis, M. 1993. Checklist of the coastal fishes of Lord Howe, Norfolk, and Kermadec Islands, southwest Pacific Ocean. Pacific Science 47(2): 136-170 figs 1-2

    Fricke, R., Kulbicki, M. & Wantiez, L. 2011. Checklist of the fishes of New Caledonia, and their distribution in the Southwest Pacific Ocean (Pisces). Stuttgarter Beiträge zur Naturkunde. Serie A (Biologie) Neue Serie 4: 341-463 

    Grant, E.M. 1975. Guide to Fishes. Brisbane : Queensland Government, Co-ordinator General’s Department 640 pp. 

    Grant, E.M. 2002. Guide to Fishes. Redcliffe : EM Grant Pty Ltd 880 pp.

    Herold, D. & E. Clark. 1993. Monogamy, spawning and skin-shedding of the sea moth, Eurypegasus draconis (Pisces: Pegasidae). Environmental Biology of Fishes 37: 219-236.

    Kuiter, R.H. 1985. The remarkable seamoths. The Scuba Diver 3: 16-18

    Kuiter, R.H. 1993. Coastal Fishes of South-eastern Australia. Bathurst : Crawford House Press 437 pp.

    Kuiter, R.H. 1996. Guide to sea fishes of Australia. A comprehensive reference for divers and fishermen. Sydney, NSW, Australia : New Holland Publishers xvii, 434 pp.

    Kuiter, R.H. 2000. Seahorses, Pipefishes and Their Relatives. Chorleywood, UK : TMC Publishing 240 pp.

    Kuiter, R.H. 2009. Seahorses and their relatives. Seaford, Australia : Aquatic Photographics 331 pp.

    Larson, H.K., Williams, R.S. & Hammer, M.P. 2013. An annotated checklist of the fishes of the Northern Territory, Australia. Zootaxa 3696(1): 1-293 

    Lawson, J M., Foster, S.J. & Vincent, A.C.J. 2017. Low bycatch rates add up to big numbers for a genus of small fishes. Fisheries 42(1): 19-33.

    Linnaeus, C. 1766. Systema Naturae per Regna Tria Naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Holmiae [=Stockholm] : Laurentii Salvii, Tomus I. Regnum Animale(1) Editio duodecima, reformata, 532 pp.

    Ogilby, J.D. 1886. Catalogue of the Fishes of New South Wales, with their principal synonyms. Sydney : Government Printer 67 pp. (as Pegasus pauciradiatus)

    Pajaro, M.G., Meeuwig, J.J., Giles, B.J. & Vincent, A.C.J. 2004. Biology, fishery and trade of sea moths (Pisces: Pegasidae) in the central Philippines. Oryx 38: 432-438.

    Palsson, W.A. & T.W. Pietsch. 1989. Revision of the acanthopterygian fish family Pegasidae (order Gasterosteiformes). Indo-Pacific Fishes 18: 1–38.

    Pietsch, T.W. & Palsson, W.A. 1999. Family Pegasidae. 2262 in Carpenter, K.E. & Niem, T.H. (eds). The Living Marine Resources of the Western Central Pacific. FAO Species Identification Guide for Fisheries Purposes. Rome : FAO Vol. 4 pp. 2069-2790.

    Pollom, R. 2017. Eurypegasus draconis. The IUCN Red List of Threatened Species 2017: e.T8407A67625953. http://dx.doi.org/10.2305/IUCN.UK.2017-3.RLTS.T8407A67625953.en. Downloaded on 30 January 2018.

    Randall, J.E., Allen, G.R. & Steene, R. 1997. Fishes of the Great Barrier Reef and Coral Sea. Bathurst : Crawford House Press 557 pp. figs.

    Reader, S.E., Leis, J.M. & Rennis, D.S. 2000. Pegasidae (Sea Moths). pp. 210-212 in Leis, J.M. & Carson-Ewart, B.M. The larvae of Indo-Pacific coastal fishes. An identification guide to marine fish larvae. Fauna Malesiana Handbooks Leiden : Brill Vol. 2 870 pp.

    Reader, S.E. & Neira, F.J. 1998. Pegasidae: Seamoths. pp. 117-121. in Neira, F.J., Miskiewicz, A.G. & Trnski, T. Larvae of temperate Australian fishes: laboratory guide for larval fish identification. Nedlands, Western Australia : University of Western Australia press 474 pp.

    Stobutzki, I., Miller, M. & Brewer, D. 2001. Sustainability of fishery bycatch: a process for assessing highly diverse and numerous bycatch. Environmental Conservation 28: 167-181.

    Vincent, A.C.J. 1997. Trade in pegasid fishes (sea moths), primarily for traditional Chinese medicine. Oryx 31: 199–208

    Quick Facts


    CAAB Code:37309001

    Conservation:IUCN Least Concern

    Depth:3-90 metres

    Fishing:Aquarium fish (rare)

    Habitat:Reef associated, sandy & rubble areas

    Max Size:10 cm TL

    Species Maps

    CAAB distribution map