© Baker, J.L. (2009) Marine Species of Conservation Concern in South Australia Full citation Baker, J.L. (2009) Marine Species of Conservation Concern in South Australia: Volume 1 - Bony and Cartilaginous Fishes. Report for the South Australian Working Group for Marine Species of Conservation Concern. J. Baker (consultant); Science and Conservation Division, and Coast and Marine Conservation branches of S.A. Department for Environment and Heritage (DEH); Marine and Coastal Community Network of S.A. (MCCN), and Threatened Species Network (TSN). Web version published by Reef Watch, South Australia.

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Seven-Bar Weedfish / Ogilby’s Weedfish

Family Name:	Clinidae
Scientific Name:	Heteroclinus heptaeolus (Ogilby, 1885)
Recommended Status in S.A:	Least Concern
Rationale:  Seven-bar Weedfish is included here because (i) the species is strongly site-associated in nearshore habitats, likely occurs over a narrow depth range, and may thus be vulnerable to habitat impacts in some areas (such as degradation of nearshore reefs and seagrass beds), but there are no specific data; (ii) Clinids reproduce at a small, site-associated scale (and have live young), characteristics that may increase the species vulnerability to population decline. The species is listed here as Least Concern, due to its broad geographic distribution across southern Australia, including its presence throughout South Australian coastal waters, and also, because the species may not have specialised habitat requirements (compared with some other members of the family), and occurs in a variety of nearshore marine habitat types.

Page Contents

Current Conservation Status

No listings known

Distribution

Southern Australia

An Indo-Pacific species, widespread along the southern coast, from northern New South Wales, through to the central coast of W.A., including northern Tasmania and Bass Strait islands, southern Tasmania (Edgar, 1984, cited by RPDC Marine, 2002),Victoria and South Australia (Hoese et al., in Gomon et al., 1994; Kuiter, 1996b; Edgar et al., 1999; OZCAM database, 2007).
Many of the museum records of this species come from South Australia, Victoria and New South Wales (Australian Museum data; South Australian Museum data; Museum of Victoria data, cited in OZCAM database, 2005, 2006).
In W.A., the species is has been collected from few localities, such as Geographe Bay and other areas, as far north as Lancelin (B. Hutchins, ex-W.A. Museum, pers. comm., 2007).

South Australia

Examples of locations in South Australia where the species has been recorded include the Ceduna area, Venus Bay, and Flinders Island, all in the eastern Great Australian Bight; northern (e.g. Port Pirie area), central-eastern (e.g. Cape Elizabeth) and south-western Spencer Gulf (the latter including the Sir Joseph Banks Group islands); Marion Bay / Sturt Bay area off southern Yorke Peninsula; the “heel” of Yorke Peninsula (e.g. Wattle Point, and other locations); northern (e.g. Emu Bay), north-eastern (e.g. Penneshaw, Point Morrison), eastern (D’Estrees Bay) and southern Kangaroo Island; Murray Mouth estuary (unverifeid) and the upper South-East of S.A. (e.g. Cape Jaffa area) (Wilson et al., 1983; Kuiter, 1993 and 1996b; S.A. Museum records, 1926-1984 and undated; data by W. Gosline and J. Glover, 1966, cited in Anonymous, 2001a; South Australian Museum data, 2003, cited by T. Bertozzi, SAM, pers. comm., 2005; Museum of Victoria record, South Australian Museum records, cited in OZCAM database, 2007; S.A. Museum data, 2006, cited by R. Foster, pers. comm., 2006; Ye et al., 2007).

Habitat

The species (or members of a closely-related species complex) has been recorded from a variety of nearshore habitats.
Generally, Seven-bar Weedfish commonly occurs in shallow weedy areas, in either green or brown macroalgae (Kuiter, 1993, 1996b). The species is associated with large brown macroalgae in shallow, rocky coastal waters, but it is also found in species of the green macroalga Caulerpa (Hoese et al., in Gomon et al., 1994); and in seagrass beds (South Australian Museum records, Museum of Victoria records, cited in OZCAM database, 2004, 2006).
In Victoria, the species has also been found in the shallow water of estuaries (e.g. near mouth of the Fitzroy River, 1m deep; beach near mouth of Betka River, also1m deep); also in seagrass beds (Hindell et al., 2001), and near breakwaters, jetties, and other structures in the shallows of Port Phillip Bay (Museum of Victoria records, cited in OZCAM database, 2005).
Seven-bar Weedfish has also been recorded from estuaries on King Island, in Bass Strait (Edgar et al., 1999), and in the Blackwood River estuary in Western Australia (Lenanton, 1982).
 There are recent records of the species from shallow rock pools in N.S.W. (Griffiths, 2003a; Griffiths et al., 2004).
Examples of habitats in S.A. in which H. heptaeolus has been recorded, include rock pools (intertidal and shallow subtidal), and under rocks (e.g. at 9m depth); in macroalgae beds on shallow reefs, and in Posidonia seagrass beds – e.g. at 3m deep (S.A. Museum records, 1980, 1984, and undated).
Records of Seven-bar Weedfish are commonly taken within the depth range 0m - 10m (OZCAM database, 2005), but there is a record from Three Hummock I. in central Bass Strait, of a specimen taken from 40m deep (Museum of Victoria record A 2294), and others from 22m, in eastern Bass Strait (Museum of Victoria records A 2338 and A 2318, cited in OZCAM database, 2005).

Notes on the Biology

Growth

H. heptaeolus is reported to grow to 10cm (Kuiter, 1996b) or 12cm (Hoese et al., in Gomon et al., 1994).
No estimates of longevity were found for this report; however, it is noted that post-settlement growth is rapid, and a study of 12 weedfish species in south-eastern Australia showed that most of the reproductive populations consist of fishes in the 1 + year-class (Gunn and Thresher, 1991).

Reproduction

Temperate weedfishes are viviparous, many are “super-foetate” (simultaneously developing multiple batches of eggs and/or embryo) and reproduce over several months in spring and summer (Gunn and Thresher, 1991). Maternal investment in the nutrition of the young is high. After parturition, the larvae spend from 3 to 7 weeks in the plankton, primarily in in-shore waters (Gunn and Thresher, 1991).

Vulnerable Characteristics of the Species and Threatening Processes

This member of the Clinidae is strongly site-associated in coastal areas of macroalgae and seagrass, and processes which damage such habitats may adversely affect populations of clinid species.
The estuarine association of some H. heptaeolus could render that portion of the population vulnerable to impacts, such as degradation of estuarine water quality and quantity, including severe reduction in estuarine flows.
Members of the family are viviparous (bear live young), and therefore reproduce at a local, site-associated level, and have low dispersive ability, characteristics that can increase vulnerability to processes causing population decline

Research Requirements

Little is known of the relative abundance of this species across the range (including South Australia). Information is lacking on the biology and population dynamics of this species. Information on the distribution, relative abundance, habitat requirements and biology may help in better determining the susceptibility of weedfishes to threats such as habitat degradation. However, the difficulty of determining distribution and relative abundance of small, cryptic, benthic species such as weedfishes is noted.

Management Requirements

Seven-bar Weedfish is site-associated in nearshore habitats. Habitat protection is required from processes that degrade the quality of nearshore reefs (and associated macroalgae) and seagrass beds (e.g. physical damage; eutrophication; siltation etc).

Other Information

Seven-bar Weedfish is one of a complex of five closely related species that form the Heteroclinus heptaeolus complex (Hoese et al., in Gomon et al., 1994). Heteroclinus equiradiatus (Milward, 1960) from W.A. (Hutchins and Smith, 1991) is closely related to Seven-bar Weedfish / Ogilby’s Weedfish, and shares the same two common names (see CSIRO, 2006; Hoese et al., 2006).
Seven-bar Weedfish occurs in a number of marine parks and sanctuaries in Victoria, such as Bunurong (Ferns et al., 2002; Plummer et al., 2003).
The genetic sequence of DNA in Heteroclinus heptaeolus as been determined by C. Stepien, and published in NCBI GenBank Sequence Data Base.