Phycodurus eques 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Actinopterygii Syngnathiformes Syngnathidae

Scientific Name: Phycodurus eques (Günther, 1865)
Common Name(s):
English Leafy Seadragon, Glauerts Seadragon
Phycodurus glauerti Whitley, 1939
Phyllopteryx eques Günther, 1865
Taxonomic Source(s): Dawson, C.E. 1985. Indo-Pacific Pipefishes (Red Sea to the Americas). The Gulf Coast Research Laboratory Ocean Springs, Mississippi, USA.
Taxonomic Notes: Synonym = Phycodurus glauerti Whitley, 1939.

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2017
Date Assessed: 2016-05-12
Assessor(s): Pollom, R.
Reviewer(s): Ralph, G.
Contributor(s): Connolly, R.
Phycodurus eques is a coastal marine seadragon that inhabits macroalgae and seagrass to depths of 30 m. The species is threatened by habitat degradation and loss that is resulting from coastal development and pollution, especially around urban centers. However, these reductions have not been measured and probably represent a small proportion of totals of fish abundances and habitat extent. Threats from bycatch and aquarium collection are present but are not thought to be causing substantial declines. There are no other known threats. Therefore this species is listed as Least Concern.
Previously published Red List assessments:

Geographic Range [top]

Range Description:Phycodurus eques is a coastal species that occurs from Western Australia (Abrolhos Islands) to western Victoria (Kuiter 2000a, Baker 2002, Stiller et al. 2015). Unconfirmed reports of sightings come from the Bass Strait Islands (King Island, Kent Group) of northwestern Tasmania (K. Martin-Smith, pers. comm. 2006).

This species been recorded down to 30 m (Kuiter 2000b).
Countries occurrence:
Australia (South Australia, Victoria, Western Australia)
FAO Marine Fishing Areas:
Indian Ocean – eastern
Additional data:
Estimated area of occupancy (AOO) - km2:112355Continuing decline in area of occupancy (AOO):Unknown
Extreme fluctuations in area of occupancy (AOO):UnknownEstimated extent of occurrence (EOO) - km2:400000
Continuing decline in extent of occurrence (EOO):UnknownExtreme fluctuations in extent of occurrence (EOO):Unknown
Continuing decline in number of locations:Unknown
Extreme fluctuations in the number of locations:Unknown
Lower depth limit (metres):30
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:To date there have been few dedicated surveys and no population estimates for Phycodurus eques.  Just one estimate of density exists for this species, from a single location at one time. Connolly et al. (2002a) estimated the density of Leafy Seadragons around West Island, in Encounter Bay, to be 57 fish per ha (small juveniles (less than 100 mm) were not included in the study).  Further research is needed in order to determine population size across the species' range, and monitoring should be undertaken to determine trends in abundance. The species is likely declining as a result of ongoing coastal development and pollution in the region, but this has not been quantified.
Current Population Trend:Decreasing
Additional data:
Continuing decline of mature individuals:Unknown
Extreme fluctuations:UnknownPopulation severely fragmented:Unknown
Continuing decline in subpopulations:Unknown
Extreme fluctuations in subpopulations:UnknownAll individuals in one subpopulation:No

Habitat and Ecology [top]

Habitat and Ecology:Phycodurus eques occurs near rocky reefs supporting stands of kelp or other macroalgae, where they have been observed feeding on mysids and other crustaceans (Kuiter 2000a). Telemetry using ultrasonic transmitters has shown, however, that this species is just as prevalent over shallow (5–15 m depth) Posidonia seagrass meadows and patches of sand amongst seagrass (Connolly et al. 2002b).

Leafy Seadragons tracked over periods of up to 10 days typically remained within well-defined home ranges of up to 5 ha (Connolly et al. 2002b). Patterns of movement are characterized by short bursts (at average velocities of 2–17 m/h) punctuating long periods (up to 68 h) without movement. No diel pattern of movement is apparent (Connolly et al. 2002b).

This species can survive for at least two to three years in aquaria if supplied with its specific live food requirements (P. Quong, pers. comm. in Pogonoski et al. 2002). Longevity in situ is not known. Phycodurus eques attains a maximum length of about 35 cm (Kuiter 1993).Mating occurs during summer months (Kuiter 2000b). As with other syngnathids, male seadragons carry the fertilized embryos. For Leafy Seadragons, the male broods about 200 embryos on the exposed surface of the underside of its tail (there is no pouch).

Phycodurus eques is particularly well camouflaged, with a number of frond-like appendages that resemble kelp. The species also rocks back and forth with wave action, increasing its resemblance to algae swept by coastal surge (Gomon et al. 1994).

Leafy Seadragons lack a caudal fin and are weak swimmers; in conjunction with a lack of a dispersive egg phase, this potentially makes them vulnerable to habitat loss and degradation as well as to incidental harvesting during commercial fishing (Connolly et al. 2002b).

Populations in South Australia and Western Austalia show molecular evidence of demographic independence (Stiller et al. 2016).
Continuing decline in area, extent and/or quality of habitat:Yes
Movement patterns:Not a Migrant

Use and Trade [top]

Use and Trade: Phycodurus eques is not traded for use in traditional medicines as other syngnathid fishes are. The species has been noted in the aquarium trade, but levels of offtake are thought to be low (Martin-Smith and Vincent 2006).

Threats [top]

Major Threat(s): Phycodurus eques is threatened by coastal habitat loss and degradation and by being caught as bycatch in fisheries.

Leafy Seadragons are associated with seagrass beds and reefs supporting macroalgae (Connolly et al. 2002b). These habitats have been adversely affected by human activities and loss in quality and quantity has been documented and is ongoing (Baker 2003, Marzinelli et al. 2015). The loss of habitat is most severe near major urban centres (e.g., Perth, Adelaide, Melbourne), where discharge of storm water and treated sewage leads to eutrophication and increased sedimentation. Losses of seagrass have been particularly severe along the metropolitan coasts and are well documented (Short and Wyllie-Echeverria 1996).

Connolly et al. (2002b) report anecdotal evidence that Leafy Seadragons are killed as incidental bycatch in the trawling industry in South Australia. Fishers have indicated that on occasions they catch “large numbers” of Leafy Seadragons. This information remains at the level of anecdote however, and neither the rate nor distribution of incidental catch have been substantiated.
The species is collected for the aquarium trade but levels of offtake are thought to be low (Martin-Smith and Vincent 2006).

This species is a major attraction for the dive industry in southern Australia, and it has been made the official fish emblem in the state of South Australia. Recreational divers often harass or disturb individuals (Kuiter 2000a). Suitable protocols for divers should be encouraged to protect local populations, but the disturbance probably does not harm the long-term prospects for regional populations.

Conservation Actions [top]

Conservation Actions: Phycodurus eques occurs in several protected areas throughout its range, and is fully protected along with all other syngnathids by the Australian Environment Protection and Biodiversity Conservation Act (1999). There are no species-specific conservation measures in place, and this species is not mentioned in any international legislation or trade regulations.

Citation: Pollom, R. 2017. Phycodurus eques. The IUCN Red List of Threatened Species 2017: e.T17096A67622420. . Downloaded on 24 September 2018.
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