© 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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Warty Prowfish

Family Name:	Pataecidae
Scientific Name:	Aetapcus maculatus (Günther, 1861)
Recommended Status in S.A:	Data Deficient
Rationale:  Although the Warty Prowfish has a broad geographic range across southern Australia (and within South Australia), it is included here because (i) the species is benthic, sedentary / slow-moving, and strongly site-associated, and (like other prowfishes) probably exists at low densities per area; all of these characteristics can increase the vulnerability of populations to localised impacts; (ii) A. maculatus is found inshore over a narrow depth range (~2m – 25m), in the vicinity of macroalgae-covered reefs and sponges, and any processes that degrade such nearshore habitats may adversely affect populations; (iii) the species is a minor bycatch in nearshore fisheries such as rock lobster, but there are no data for South Australia; (iv) in Tasmania, it is part of a developing aquarium trade in unusual, temperate marine fish species; (iv) very little is known of the biology (particularly growth, longevity, and reproduction), and population dynamics of this species. Although there is a considerable number of records of this species from nearshore waters across South Australia, the recommended status is Data Deficient, because it is not known to what extent potentially threatening processes may impact on populations in South Australia.

Page Contents

Current Conservation Status

No listings known

Distribution

Southern Australia

A. maculatus ranges across southern Australia, from Victoria to W.A. (Hutchins and Swainston, 1986, 2001; Gomon, in Gomon et al., 1994), including Tasmania and Bass Strait islands (Edgar, 1984; Australian Museum, 2005o).

South Australia

There are numerous records from South Australia, particularly in the gulfs region, and most sightings are of single specimens.
Examples of locations in S.A. from where the species has been recorded include islands in the eastern Great Australian Bight (Nuyts Archipelago / St Francis Isles); northern Spencer Gulf (e.g. Jarrold Point / Port Davis area); central coast of Spencer Gulf (e.g. Port Broughton, Port Hughes, Moonta Bay); south-western Spencer Gulf (e.g. Port Lincoln area); south-eastern Spencer Gulf (e.g. Point Turton); northern Gulf St Vincent (GSV) (e.g. Port Wakefield); metropolitan coast of GSV (e.g. Semaphore, Outer Harbour, Henley Beach, Glenelg, Marino Rocks); south-western GSV (e.g. Edithburgh); the Fleurieu Peninsula / southern GSV (e.g. Port Noarlunga, Christies Beach, Rapid Head, Haycock Point, Carrickalinga, Second Valley, Cape Jervis and other locations); Encounter Bay (e.g. The Bluff; also West Island, seaward of Encounter Bay); northern Kangaroo I. (e.g. Cape Dutton, Stokes Bay and other locations); north-eastern Kangaroo Island (e.g. Kingscote, Hog Bay area and other locations) and the upper South East (e.g. Kingston area) (Glover, 1979; Hureau, 1991; MLSSA, undated; D. Muirhead, unpubl. data, 2001; photographs by J. Lewis, 2004, 2005; J. Brook, pers. comm., 2006; S. Shepherd, SARDI, pers. comm., 2006; Edgar et al., 2006; S.A. Museum records, Australian Museum records, cited in OZCAM database, 2007).

Habitat

A. maculatus is usually found in sheltered / protected waters, on various parts of reefs, including inside reef crevices, or near sponges or macroalgae (Hutchins and Swainston, 1986, 2001; Gomon, in Gomon et al., 1994; Hutchins, 2005).
At West Island in S.A., Warty Prowfish have been recorded under Ecklonia kelp near boulder reef habitat (S. Shepherd, SARDI, pers. comm., 2006).
The recorded depth range is about 2m – 25m (Gomon, in Gomon et al., 1994; Museum of Victoria data, Australian Museum data, cited in CSIRO, 2007 and OZCAM database, 2007).

Notes on the Biology

Growth

Warty Prowfish grows to around 22cm (Hutchins and Swainston, 1986; Gomon, in Gomon et al., 1994).
One of the maximum sizes recorded is 0.454kg (Hutchins and Swainston, 1986).

Other Information

Like other members of the family, the Warty Prowfish is known to periodically shed its skin, which rids the fish of encrusting biota, thus improving its camouflage.
The compressed body shape and resemblance of Warty Prowfish to erect benthic biota, indicates that it is bentho-pelagic in habit (i.e. free swimming near the bottom) (Drabsch, 1996).

Fisheries Information

Commercial

Warty Prowfish are discarded bycatch in rock lobster pots (Hutchins and Thompson, 1983, 2001). It is noted that A. maculatus was not recorded in two bycatch sampling programs for the rock lobster fishery in South Australia, during the 1990s (Prescott and Xiao, 2001), and early 2000s (Brock et al., 2004).
In Tasmania, under the Tasmanian Fisheries (Scalefish) Rules 2004, Regulation 100, there is a commercial fishing possession limitation of a maximum of 3 Red Velvetfish per licence holder per day, due to the development of a separate aquarium trade (see below).
Warty Prowfish A. maculatus is taken under permit in Tasmania for the international aquarium market. In 2005, the export price was available on application (e.g. Ryan and Clarke, 2005).

Recreational

The species is not known to be targeted by recreational fishers, but is occasionally taken by anglers (Wheeler, 1977, cited in Froese and Pauly, 2006).
Warty Prowfish is taken by some spear fishers, and one of the record-sized specimens (0.454kg) was taken by spearfishing (Hutchins and Swainston, 1986, 2001; Australian Underwater Federation Inc., 2003).

Vulnerable Characteristics of the Species and Threatening Processes

The inshore distribution, narrow depth range (~ 2m – 25m), benthic nature, and strong habitat association (on reefs, with macroalgae and sponges) may make Warty Prowfish populations susceptible to decline from habitat impacts in some areas. There are no data specific to this species, but examples of degradation of nearshore reef habitats in some parts of the South Australia (where this species occurs) are documented in Cheshire et al. (1998); Cheshire and Westphalen (2000), Fairhead et al. (2002a, 2002b), and Turner et al. (2007). Baker (2004) provided a detailed summary of some nearshore habitat impacts in southern Gulf St Vincent, Spencer Gulf, northern Kangaroo Island and other S.A. regions.
Warty Prowfish, like other prow-fishes, are sedentary, slow-moving and live in low densities, which can make populations vulnerable to localised exploitation.
There is no knowledge of reproduction in this species. If dispersal is low, and recruitment of the next generation is localised, then that mode of reproduction may increase the vulnerability of populations to site-specific impacts.
The species is reported to be part of the discarded bycatch from rock lobster pots (Hutchins and Thompson, 1983, 2001), but it is not known to what extent this practice threatens populations in any area.
The extent to which populations of Warty Prowfish are affected by fishing mortality is not known. Collection for the aquarium trade (in Tasmania) and fishing mortality (as target or bycatch) may potentially threaten local populations in some areas, but no data are available.

Research Requirements

There is very little information known about the biology (including growth, longevity and reproduction), diet, and population dynamics of this species.
Bycatch data from rock lobster fisheries (and any other fisheries in which the species occurs) are required.

Management Requirements

The annual take of this species for the aquarium trade should be documented over space and time, and sustainability assessments should be undertaken. The potential for illegal collecting of this species should also be monitored and prevented.
Measures to reduce bycatch of benthic fish species in rock lobster pots should be encouraged.
The capture of this non-edible species by recreational anglers and spear-fishers should be prohibited.

Other Information

The species occurs in a number of Marine National Parks (MNPs) and sanctuaries in Victoria, such as the Wilsons Promontory MNP, Port Phillip Heads MNP, and Phillip Island MNP (Plummer et al., 2003; Edmunds et al., 2003), and a sanctuary in Port Phillip Bay (Hart et al., 2003). The species has also been recorded at the Maria Island National Park in Tasmania (G. Edgar, University of Tasmania, pers. comm., 2006).
Warty Prowfish is one of the fish species monitored in the Reef Watch program in Victoria.
Due to its unusual appearance, Warty Prowfish is of interest to some divers, including marine photographers.