The species is related to the seahorses. Unlike seahorses however, the seadragons do not have a pouch for rearing the young. Instead, male seadragons carry the eggs fixed to the underside of the tail.
The standard name of the species in Australia is 'Common Seadragon', but many people know the fish by the name 'Weedy Seadragon'.
The Common Seadragon has a long pipe-like snout with a small terminal mouth. Large females become deep bodied. The name 'Weedy Seadragon' refers to the leaf-like appendages on the body. The species is the only member of the genus occurring in New South Wales, and cannot be confused with any other local member of the family Syngnathidae. It appears to be a frequently encountered member of the coastal fish fauna, especially by divers.
This superbly camouflaged fish usually occurs in kelp-covered rocky reefs at depths from about 3 m to 50 m. It is usually found in areas ranging from shallow estuaries to deep offshore reefs (Pogonoski et.al., 2002). Depths range from 1 m - 50 m (Pogonoski et.al., 2002).
The species is endemic to Australian temperate marine waters. It occurs from the central New South Wales coast around the south coast of Australia to south-western Western Australia.
The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums. Click on the map for detailed information. Source: Atlas of Living Australia.
Feeding and diet
The leaf-shaped appendages and cryptic colouration of this species provide effective camouflage, allowing them to feed on small crustaceans such as mysids.
Other behaviours and adaptations
These fish are poor swimmers, which explains the frequent beach strandings recorded in the Australian Museum database.
The breeding season is early summer, with usually one brood per season. Andrew Trevor-Jones (pers. comm) stated, "At Kurnell [Sydney, New South Wales] the breeding season is late winter through to late summer with up to 3 broods."
Male seadragons carry the eggs fixed to the underside of the tail until they eventually hatch. Incubation time is about 8 weeks with up to 250 young hatching from a single brood (Pogonoski et al., 2002). Some of the young mature in one year, but usuaually will not breed until their second year when fully mature (Pogonoski et al., 2002).
View more information on the Dragon Search page on Preliminary Bioregional Summary of Sighting Data, January 1998 - June 2000.
The video below shows the courtship 'dance'.
The Common Seadragon is protected in New South Wales and Tasmanian waters. It is listed in the 1997 IUCN Red List but only in the DD (Data Deficient) category. As of 2002, there was no evidence for any declines in the Common Seadragon (Pogonoski et al., 2002). However it has been recognised the species would be most threatened by overcollecting of Common Seadragons for the aquarium fish trade (Pogonoski et al., 2002).
The aquarium trade is probably not a threat to this species because its temperate water requirement, diet and size make it difficult for the average aquarist to keep. Australian seadragons are not currently employed in traditional ethnic medicine, although dried and powdered seadragon can sell for up to A$200 per gram (Smith and Pollard, 1996). Fisheries impacts are minimal. The rocky coastal habitat of this species is not under threat from trawling and, owing to their feeding mode, this species is not caught by line fishers.
- Dawson, C.E., 1985. Indo-Pacific Pipefishes (Red Sea to the Americas). Ocean Springs (USA): Gulf Coast Research Laboratory. pp. 1-230. (pp. 158-160).
- Dawson, C.E. in Gomon, M.F, J.C.M. Glover & R.H. Kuiter (Eds). 1994. The Fishes of Australia's South Coast. State Print, Adelaide. Pp. 992.
- Hutchins, B. & R. Swainston. 1986. Sea Fishes of Southern Australia. Complete Field Guide for Anglers and Divers. Swainston Publishing. Pp. 180.
- Kuiter, R.H. 1993. Coastal Fishes of south-eastern Australia. Crawford House Press. Pp. 437.
- Kuiter, R.H. 1996. Guide to Sea Fishes of Australia. New Holland. Pp. 433.
- Kuiter, R.H. 2000. Coastal Fishes of South-eastern Australia. Gary Allen. Pp. 437.
- Kuiter, R.H. 2000. Seahorses, Pipefishes and their Relatives. A Comprehensive Guide to Syngnathiformes. TMC Publishing Pp. 240.
- Paxton, J.R., D.F. Hoese, G.R. Allen & J.E. Hanley. 1989. Zoological Catalogue of Australia Vol.7 Pisces Petromyzontidae to Carangidae. Canberra: Australian Biological Resources Survey. pp. i-xii, 1-665.
- Pogonoski, J.J., Pollard, D.A. & J.R. Paxton. 2002. Conservation Overview and Action Plan for Australian Threatened and Potentially Threatened Marine and Estuarine Fishes. Canberra: Environment Australia. Pp. 199-201.
- Smith, A.K. & Pollard, D.A. 1996, The best available information - some case studies from NSW, Australia, of conservation-related management responses which impact on recreational fishers. Marine Policy, vol.20, no.3, p.261-67.