© 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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Alison’s Blue Devil

Family Name:	Plesiopidae
Scientific Name:	Paraplesiops alisonae Hoese & Kuiter, 1984
Recommended Status in S.A:	Data Deficient, possibly Rare E(i) in S.A.
Rationale:  Included here because (i) Alison’s Blue Devil apparently has a limited distribution in S.A. (south-east); (ii) the species appears to be uncommon over the range; (iii) Paraplesiops fishes are solitary (or form pair bonds), territorial, slow-moving, inquisitive, strongly site-associated with reefs in shallow nearshore waters, and have site-specific reproduction, and these characteristics can make populations vulnerable to localised impacts; (iv) concern has been expressed that populations may be vulnerable to decline due to site-specific habitat impacts;  and (v) little information exists about the biology and population dynamics of this species, and no surveys have been undertaken to estimate abundance over its range.

Page Contents

Current Conservation Status

No listings known

Distribution

South-Eastern Australia

The species is endemic to south-eastern Australia (e.g. Port Phillip Bay and Portsea area in Victoria, to Kangaroo Island in S.A.) and Tasmania (e.g. Tamar River mouth, and Bass Strait and islands) (Paxton et al., 1989, cited in Froese and Pauly, 2006; Hutchins and Swainston, 2001).
In “The Rip” area of outer Port Phillip Bay, there is a major population of adult P. alisonae (Fyfe, 2004, citing R. Kuiter, pers. comm.).

South Australia

There are museum records from Cape Cassini on northern Kangaroo Island (Smithsonian National Museum of Natural History record, cited in Anonymous, 2001a; Australian Museum record, cited in OZCAM database, 2006), and from the Encounter Bay area. The species is likely to also occur in parts of the lower South-East of S.A., given its distribution in biogeographically similar areas such as northern Tasmania, western Victoria and southern Victoria.

Habitat

Alison’s Blue Devil is found in inshore benthic habitats from 3m to around 30m (Kuiter, 1993), including rocky reefs, and shallow protected bays (Kuiter, in Gomon et al., 1994; Kuiter, 1996a).
Juveniles are found mainly under rocks and in crevices, in shallow protected bays. Pairs of adults are usually found together at the back of long caves, and “deep walls with rich invertebrate growth” (Kuiter, 1996a).
The species is also associated with structures such as piers / jetties and breakwaters (Museum of Victoria records, cited in OZCAM database, 2006).
In outer Port Phillip Bay (e.g. “The Rip”), Alison’s Blue Devil occurs in clear waters, in the vicinity of current-exposed ledges, covered with sponges, corals and other sessile fauna (Fyfe, 2004, citing R. Kuiter, pers. comm.).

Notes on the Biology and Behaviour

Growth

Alison’s Blue Devil grows to around 15cm (Kuiter, in Gomon et al., 1994; Kuiter, 1996a).

Behaviour

The species is nocturnal, and usually remains hidden during the day, beneath narrow ledges (Kuiter, in Gomon et al., 1994) or at the back of caves (Kuiter, 1996a).
Adults are usually found in pairs, and the species is not often observed due to its cryptic nature (Kuiter, 1996a).

Reproduction

Members of Paraplesiops lay benthic eggs which have anchor-shaped hooks (Mooi, 1990). 
The eggs of P. alisonae are tightly bound together and deposited onto the substratum, and guarded by the male. Males are probably responsible for guarding eggs and rearing juveniles (uncited reference, in N.S.W. Department of Primary Industries, 2004).

Fisheries and Trade Information

Commercial

Alison's Blue Devil has some importance in the aquarium trade (Froese and Pauly, 2006); however the source of specimens could not be found for this report.

Vulnerable Characteristics of the Species

Alison’s Blue Devil is a slow-moving, strongly site-associated, territorial species found on nearshore reefs, over a relatively narrow depth range, and these characteristics can increase the vulnerability of populations to localised impacts.
The species reproduces at localised scales, and has benthic eggs, a life history characteristic that increases its vulnerability to site-specific impacts.
South Australia is at the edge of the species range, and this south-eastern Australian species appears to have a limited geographic distribution in S.A, and may also be uncommon within that distribution.

Threatening Processes

Recreational fishing (both spear-fishing and line fishing) may be a threatening process, but more information is required. It is noted that no data on recreational fishing of this species in Victoria, northern Tasmania, or south-eastern South Australia, could be found for this report.
In some inshore areas, habitat degradation (e.g. from dredging and channel development, sedimentation, and land-based discharges) might be a threatening process, but more information is required. It is noted that concern has been expressed that sedimentation may adversely affect the clear-water habitat in which P. alisonae populations thrive, and thus reduce the feeding ability of resident P. alisonae populations in such areas. A recent example is an impending channel-deepening project in outer Port Phillip Bay, for which concern has been expressed about the potential effects of dredge-induced sedimentation on the community of sessile fauna with which a ledge-dwelling population of Alison’s Blue Devil is associated. Fish researcher R. Kuiter (pers. comm., in Fyfe, 2004) considered that it may take a long time for the Alison’s Blue Devil population in that area to recover if it is reduced, and that the extent of damage would depend upon the duration of the dredging.
Alison's Blue Devil has some importance in the aquarium trade, but it is noted that the species is not included in various published lists of permitted species taken for this trade. Given the popularity of the related species, Southern Blue Devil, in the specialist aquarium trade, collection (legal and/or illegal) of Alison’s Blue Devil could pose a threat to some populations.
Given the strong site-association and territoriality of individuals and pairs, indirect harassment by divers might occur, particularly in the few areas where populations of Alison’s Blue Devils are well known and sought for viewing / photography etc.

Research Requirements

More information is required on the distribution and relative abundance of this species, particularly in South Australia, which is at the edge of the species range.
Very little is known of the biology and population dynamics (especially diet, longevity, reproduction) and ecology of this species.

Management Requirements

Recreational fishing for this species should be prohibited, under State legislation.
Given the likely uncommonness and limited distribution of this site-associated reef fish species in South Australia, efforts should be made to ensure that nearshore reef areas off Kangaroo Island, Encounter Bay, and the South East of S.A. are protected from physical damage (e.g. from dredging and channel development), sedimentation, and land-based discharges, all of which may reduce habitat quality for this species.
There are no publicly available statistics on the take of this species for the aquarium trade. All reef fish species taken for that 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.
Given the strong reef-association and limited geographic distribution of this species in S.A., an increase in the number and spatial extent of protected reefs in south-eastern S.A. is likely to assist the conservation of Alison’s Blue Devil.

Other Information

Given its distribution and habitat, it is likely that Alison’s Blue Devil occurs in some of the marine parks and sanctuaries in Victoria, such as Port Phillip Heads.

Support for S.A. Listing:

Barry Hutchins (ex-W.A. Museum); Graham Edgar (University of Tasmania), the latter recommending Data Deficient category.