© 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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Striped Rainbow Wrasse / Striped Trawl Wrasse

Family Name:	Labridae
Scientific Name:	Suezichthys bifurcatus Russell, 1986
Recommended Status in S.A:	Data Deficient
Rationale:  Included here because (i) the Striped Rainbow Wrasse apparently has a limited geographic range and depth distribution, being known to date mainly from the Great Australian Bight in W.A. and S.A., in waters between 50m and 100m, plus isolated records from the shallows; (ii) the species is known from very few specimens; (iii) the Striped Trawl Wrasse is a member of a genus of cleaner wrasses, but lives in deeper water than other members of the genus, and there is almost no information on the full distribution, relative abundance, habitat preferences, biology (including feeding habits) and populations dynamics of this species; and (iv) the species may be part of the bycatch in trawl fisheries in the Great Australian Bight, but data are lacking.

Page Contents

Current Conservation Status

No listings known

Distribution

There are very few published records of this species. The Striped Trawl Wrasse is known to occur in the Great Australian Bight in Western Australia and South Australia (Gomon and Russell, in Gomon et al., 1994; Parenti and Randall, 2000).
In W.A., there are several records from the western Great Australian Bight, such as waters south of Point Dover and Point Culver (CSIRO Marine Research records). The holotype and paratype (South Australian Museum records F 05037 and F 05038) are also from waters in the vicinity (Recherche Archipelago). The species has also been recorded near Perth (West Australian Museum record).
There are only two museum records from South Australia, these being two specimens collected by CSIRO in the deeper waters of the eastern Great Australian Bight, west of Anxious Bay (CSIRO Marine Research records CA 3443 and B 3290).

Habitat

The species is known to date from a limited depth range (Gomon and Russell, in Gomon et al., 1994), with specimens mostly known from within the range 50m – 100m (South Australian Museum records, CSIRO Marine Research records), but there are also specimens from shallow waters (e.g. 1m – 2m) (B. Hutchins, W.A. Museum, pers. comm., 2006).

Notes on the Biology

The Striped Trawl Wrasse is known to grow to at least 9cm (Gomon and Russell, in Gomon et al., 1994); however this estimate is based on very few known records of the species.
There is no published information on the diet or feeding behaviour of this species; however it is noted that S. bifurcatus is a member of the genus of Cleaner Wrasses. Generally, cleaner wrasses are considered to be “facultative cleaner symbionts”, removing parasites and damaged scales and skin from other fishes. Cleaner wrasses also feed on small crustaceans from the bottom (Russell, 1985, cited in Froese and Pauly, 2004). It is noted that the Striped Trawl Wrasse is found in deeper waters than are other members of the genus; hence its feeding behaviour may differ.

Fisheries Information

Given the recorded distribution and depth range of specimens collected to date, Striped Trawl Wrasse is likely to be part of the bycatch in the Great Australian Bight Trawl Fishery; however it was not recorded during recent bycatch sampling (e.g. Brown and Knuckey, 2002).
Striped Trawl wrasse may be part of the bycatch in the West Coast Prawn Trawl fishery in South Australia; however bycatch data are not collected in this fishery.

Vulnerable Characteristics of the Species, and Threatening Processes

The species apparently occurs in a relatively small geographic area (i.e. known to date only from the Great Australian Bight), within a limited depth range (recorded to date mainly between 50m and 100m, with isolated records from the shallow subtidal).
Members of the Labridae are usually strongly site-associated, which increases their vulnerability to site-specific / localised impacts.
There is no information on the relative abundance of this species within the known range (Great Australian Bight); however, given that trawl fisheries operate in that range, trawling may pose a threat to Striped Trawl wrasse populations. It is noted that, in an Australian study of the susceptibility of trawl-caught fishes to population impacts (Stobutski et al., 2000, 2001), fishes in the Labridae were amongst those whose populations were considered to have a low recovery time when trawled, and overall, were considered least likely to be sustainable if trawled (Stobutski et al., 2001).

Research Requirements

There is a distinct lack of information on the full geographic range and depth distribution of this species, as well as its habitat, biology, ecology, and population dynamics.
In both State (e.g. prawn) and Commonwealth-managed fisheries in the Great Australian Bight, bycatch data from trawl fisheries should be monitored for the presence of this species.

Management Requirements

Given the limited known geographic distribution and depth range of this species in mid continental shelf water, where possible methods should be introduced to reduce the bycatch of Striped Trawl Wrasse in prawn and fish trawl fisheries in the Great Australian Bight.

Other Information

The Striped Trawl Wrasses is related to the group of Suezichthys cleaner wrasses, such as Blue-throated Suez Wrasse S. cyanolaemus, known only from W.A. (Albany to Point Quobba) (Hutchins and Thompson, 2001); Crimson Cleaner Wrasse S. aylingi, known from isolated populations in south-eastern Australia and New Zealand, and S. gracilis, from the Western Pacific, including eastern Australia. Generally, Cleaner Wrasses occur in sand patches adjacent to reef areas in shallow waters (Russell, 1985, cited in Froese and Pauly, 2005); however, unlike other members of the genus, the Striped Trawl Wrasse has not been recorded in shallow waters.