© 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.

---

TRIGLIDAE: GURNARDS and SEA ROBINS

© John Lewis

The Triglidae is a family of benthic marine fishes known as Gurnards and Sea Robins, distributed throughout all tropical and temperate seas. Currently, there are at least 120 named species recognised in the family (e.g. Froese and Pauly, 2007, plus species listed in Richards et al., 2003). More than 40 species occur along the southern coastline of Australia, including several unnamed species (CSIRO, 2007).
Fishes in the family have prominent, bone-encased, casque-like heads. Most species also have prominent, wing-like pectoral fins, with the lower 2 or 3 fin rays enlarged and free (i.e. unconnected by membranes), for food detection and “walking” along the sea floor (Gomon, in Gomon et al., 1994; Nelson, 1994, cited in Froese and Pauly, 2007; Edgar, 2000).  The strongly contrasting fins of gurnards can be hidden or raised, to signal competitors and mates (Edgar, 2001).
Some of the most widely distributed and commonly known species in southern Australian States (including South Australia) are as follows:
Red Gurnard or Flying Gurnard Chelidonichthys kumu: an edible, fished species with a broad geographic range, found in continental shelf waters. The species is discussed in a synopsis below, due to its common capture in trawl fisheries in southern Australia (both Commonwealth- and State-managed waters), and potential susceptibility to population impacts due to trawl capture;
Butterfly Gurnard Lepidotrigla vanessa: A fairly common species, found in continental shelf waters from New South Wales through to Tasmania and across southern Australia to southern Western Australia. The Butterfly Gurnard is discussed below due to its susceptibility to capture in trawl fisheries.
Deepwater Gurnard / Round-snouted Gurnard Lepidotrigla mulhalli: The Deepwater Gurnard is a common (and commonly caught) south-eastern Australian species, distributed from Port Stephens in N.S.W. through to the western edge of Bass Strait, at depths between 20m and 100m (Gomon, in Gomon et al., 1994). The species is part of the discarded bycatch in the Commonwealth-managed Southern and Eastern Scalefish and Shark Fisheries (SESSF) (AFMA, 2002a). The Deepwater Gurnard is discarded in very large quantities in the South East Trawl Fishery. In the otter trawl sub-fishery of the SETF, an Integrated Scientific Monitoring Program (ISMP) reported that in 282 trawl shots, about 18.24 tonnes of L. mulhalli (as “Gurnard”) were discarded (Wayte et al., 2004), which averages 65kg per trawl shot. During the same monitoring program, L mulhalli was listed again, as “Round-snouted Gurnard”, with 17.5 tonnes discarded in 484 trawl shots (average 36kg per trawl shot) (Wayte et al., 2004).
Painted Latchet / Japanese Gurnard / Spotted Gurnard Pterygotrigla andertoni (previously P. picta): Painted Latchet are known from southern Australia, New Zealand, New Caledonia and Chile, but more than one closely related species may occur across the range. In Australia, P. andertoni is now known from N.S.W. through to Bass Strait (M. Gomon, Museum of Victoria, pers. comm., 2006), and specimens from Great Australian Bight and south-western Australia may represent a different species. Pained Latchet is found on the bottom, at depths between 120m (or 200m) and 450m (or 500m) (May and Maxwell, 1986; Gomon, in Gomon et al., 1994). In the South East Trawl Fishery, paired surveys in 1976/77 and 1996/97 showed that both total catch (kg) and the catch rate (kg / hour) of this species from the Sydney area in the latter period were an order of magnitude lower than 20 years earlier, and the catch rate was also lower (Andrew et al., 1997). Painted Latchet is taken commercially in deeper waters off New Zealand (N.Z. Ministry of Fisheries web site, 2004), and is a bycatch in fisheries in southern Australia, including the Commonwealth-managed SESSF (AFMA, 2002a). It is also taken by recreational fishers in some areas (e.g. N.S.W.), and some fishing clubs and associations keep records of the maximum sizes caught.
Latchet / Sharp-beaked Gurnard Pterygotrigla polyommata: The Latchet ranges from Port Stephens in N.S.W. through to the central coast of W.A., and also occurs in New Zealand (Gomon, in Gomon et al., 1994). Like the Red Gurnard, the Latchet is discussed in a synopsis below, due to its common capture in trawl fisheries in southern Australia (including fisheries in South Australian waters), and previously documented declines in some fisheries in south-eastern Australia.
Gurnards are taken by both commercial and recreational fishers, and species-specific examples from commercial fisheries are listed below. Triglid fishes are also part of the discarded bycatch in a number of fisheries across southern Australia. For example, in the otter trawl sub-fishery of the Commonwealth-managed South East Trawl Fishery (SETF), an Integrated Scientific Monitoring Program (ISMP) reported that in 63 trawl shots, only 2kg of specimens in the Triglidae were retained, but about 1 tonne was discarded (Wayte et al., 2004). Catches of particular gurnard species in that fishery are discussed in the synopses below.
Coastal marine gurnard species are commonly taken by recreational fishers. For example, the recent National Recreational and Indigenous Fishing Survey (Henry and Lyle, 2003) reported that 68,650 Gurnards (species unspecified) were caught and kept by recreational fishers during the survey time period (May 2000 to April 2001), comprising the following State catches (number of fish): N.S.W.: 20,076;  VIC: 6,243;   SA: 3,424;  WA: 2,625;  and TAS: 36,282.
Although the aforementioned species have a wide distribution across southern Australia, and most are commonly recorded, it is noted that some of them are regularly taken as bycatch in southern Australian fisheries (including some in South Australia), as indicated in the above paragraphs, and some are taken by recreational fishers. There is no recent and verifiable information on the relative abundance of these species in State waters, or on the potential impacts of bycatch mortality on populations of Triglid fishes. A number of measures have been undertaken in the South Australian prawn trawl fisheries to reduce bycatch (see PIRSA, 2003), and any additional measures to reduce the bycatch mortality of commonly caught benthic fishes such as triglids, should be undertaken.
Discussed below are the Latchet Pterygotrigla polyommata, the Red Gurnard Chelidonichthys kumu, the Minor Gurnard Lepidotrigla modesta, the Butterfly Gurnard Lepidotrigla vanessa and the Spiny Gurnard L. papilio, all of which are commonly taken in trawl fisheries, and the Southern Shortfin Gurnard Lepidotrigla spinosa, due to its limited geographic distribution (compared with many other members of the family in southern Australia), and lack of records. The Painted Latchet P. andertoni is not included, because it is found mainly in Commonwealth-managed waters, but the potential vulnerability of this species to trawl–induced impacts (including trawling in the Great Australian Bight) is noted.

Associated taxa

Southern Shortfin Gurnard / Shortfin Gurnard	Lepidotrigla spinosa Gomon, 1987
Minor Gurnard / Cocky Gurnard / Grooved Gurnard and western relative	Lepidotrigla modesta Waite, 1899 and Lepidotrigla sp. (undescribed western relative)
Spiny Gurnard / Southern Spiny Gurnard	Lepidotrigla papilio (Cuvier, 1829)
Butterfly Gurnard	Lepidotrigla vanessa (Richardson, 1839)
Red Gurnard / Flying Gurnard	Chelidonichthys kumu (Cuvier, 1829)
Latchet / Sharp-beaked Gurnard	Pterygotrigla polyommata (Richardson, 1839)