Little Dragonfish, Eurypegasus draconis (Linnaeus 1766)
A Little Dragonfish, Eurypegasus draconis, at Lembeh Strait, North Sulawesi, Indonesia . Source: Dave Harasti / http://www.daveharasti.com/. License: All rights reserved
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.
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 |
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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 |
Little Dragonfish, Eurypegasus draconis (Linnaeus 1766)
References
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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
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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)
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