Hippocampus breviceps 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Actinopterygii Syngnathiformes Syngnathidae

Scientific Name: Hippocampus breviceps Peters, 1869
Common Name(s):
English Knobby Seahorse, Short-headed Seahorse, Short-snouted Seahorse
Hippocampus tuberculatus Castelnau, 1875
Taxonomic Source(s): Peters, W.C.H. 1869. Über neue oder weniger bekannte Fische des Berliner Zoologischen Museums. Monatsberichte der Königlichen Preussischen Akademie der Wissenschaften zu Berlin 1869: 703-711.

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2017
Date Assessed: 2016-08-23
Assessor(s): Pollom, R.
Reviewer(s): Ralph, G.
Hippocampus breviceps is a coastal seahorse species that inhabits waters in southwestern and southeastern Australia. The species may be threatened locally by coastal development, but this is not prevalent across its range. They are habitat generalists and are protected throughout their range by multiple legislation. Therefore this species is listed as Least Concern.
Previously published Red List assessments:

Geographic Range [top]

Range Description:Hippocampus breviceps inhabits temperate southern Australian waters from Gregory to Bremer Bay, Western Australia, and from Denial Bay, South Australia to Newcastle, New South Wales. Further research is needed to determine whether these are disjunct subpopulations, or if the species is distributed along the entire southern Australia coast. The species is also found off the coasts of Tasmania (Lourie et al. 2016).
Countries occurrence:
Australia (New South Wales, South Australia, Tasmania, Victoria, Western Australia)
FAO Marine Fishing Areas:
Indian Ocean – eastern; Pacific – southwest
Additional data:
Continuing decline in area of occupancy (AOO):Unknown
Extreme fluctuations in area of occupancy (AOO):UnknownEstimated extent of occurrence (EOO) - km2:
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):15
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:To date there have been no dedicated surveys or population estimates for Hippocampus breviceps. Further research is needed in order to determine population size and trends in abundance for this species.
Current Population Trend:Unknown
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:Hippocampus breviceps occurs in sheltered coastal reefs in macroalgal beds (Sargassum spp.) and seagrass (Moreau and Vincent 2004, Kuiter 2000). Individuals have also been found on floating macroalgae (Gomon et al. 1994), associated with rock reef and jetty habitats (Coleman 1980) and observed on sponge reefs at depths below 15 m (Kuiter 2000). Hippocampus breviceps are more normally found at depths of approximately 5 m, although may be difficult to see because of good camouflage (Edgar 1997).  Hippocampus breviceps feeds close to the sand or rubble during the day and is carnivorous, targeting mysids, harpacticoid copepods, and gammarid and caprellid amphipods (Kuiter 2000, Kendrick and Hyndes 2005).

In Port Philip Bay animals occur in small to large aggregations (Kuiter 1993) with male:female sex ratios of 1:1 (Moreau and Vincent 2004). Group (2–5 individuals) occurrence coincides with particular seaweed areas that are the site of early morning social encounters (Moreau and Vincent 2004). Kuiter (2000) suggests that small groups congregate in safe places at night, often high in macroalgae to keep away from crabs on the substrate. Adults exhibit variable site fidelity, with 12 of 38 individuals remaining within a focal study area for five weeks of observation (Moreau and Vincent 2004). Females use significantly larger area than males (Moreau and Vincent 2004).

H. breviceps is thought to breed on an approximately monthly cycle throughout the Austral summer, producing 50–100 young per brood (Kuiter 2000). Males have large pouches that they inflate when courting females. In situ observations indicate that adult seahorses display and interact with potential partners, although not every day, and not necessarily with the same partner at each encounter (Moreau and Vincent 2004). Females transfer batches of eggs (1.6 mm diameter (Vincent 1990) to males during copulation which can take from a matter of minutes to 2.5 days, in ex situ conditions (Kuiter 1993). Kuiter (1993) reports that in captivity, males may accept eggs from more than one female, although this has yet to be observed in natural wild pairs. Larvae have been observed swimming to the surface upon release, where they grasp small bits of weed or debris in surface waters (Kuiter 2000). Kuiter (2000) reports size at settlement to be 25 mm.

Longevity in aquaria is at least 3–5 years (P. Quong, pers. comm. in Pogonoski et al. 2002), but lifespan in the wild is unknown.
Movement patterns:Unknown

Use and Trade [top]

Use and Trade: Hippocampus breviceps is wild-caught and traded live in Australia and as an export, but levels of offtake are thought to be low (Martin-Smith and Vincent 2006). There may also be captive-bred sources.

Threats [top]

Major Threat(s): Hippocampus breviceps may be threatened locally by coastal development.

Conservation Actions [top]

Conservation Actions: There are no species specific conservation measures in place for Hippocampus breviceps. The species is listed internationally along with all other seahorses on CITES Appendix II. It is also protected throughout its range along with all other syngnathids by Australia's Environment Protection and Biodiversity Conservation Act (1999) as well as state restrictions. It occurs in several protected areas.

Citation: Pollom, R. 2017. Hippocampus breviceps. The IUCN Red List of Threatened Species 2017: e.T10063A54904334. . Downloaded on 24 September 2018.
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