© 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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Longfin Handfish / Long-finned Handfish

Family Name:	Brachionichthyidae
Scientific Name:	Pezichthys macropinnis Last and Gledhill, 2009
Recommended Status in S.A:	Data Deficient
Rationale:  Longfin Handfish is included here because (i) it is a slow-moving, benthic fish (and therefore has a strong site association and limited mobility), and, like other members of the genus, possibly has low reproductive potential and restricted larval dispersal. These characteristics increase the vulnerability of handfishes to localised impacts, and population decline; (ii) the species is known from a single specimen, in a region that is trawled as part of a Commonwealth-managed multi-species fishery; (iii) Longfin Handfish may be part of the discarded bycatch in trawls operating in deeper shelf waters of the Great Australian Bight, but there is no information to date; and (iv) nothing is known of the specific habitat requirements, nor of the full distribution of this species, nor is there any information on the relative abundance (likely to be low), biology, population dynamics and ecology. The recommended status in S.A. is Data Deficient, due to the paucity of specimens and data. .

Page Contents

Current Conservation Status

Pogonoski et al. (2002) suggested Data Deficient, on an Australia-wide basis.
Australian Society of Fish Biology 2001 list: Data Deficient

Distribution

Pezichthys macropinnis is known to date from a single specimen, collected 300 km south-west of Ceduna, Great Australian Bight, South Australia (33° 16'S, 130° 37'E) (Last and Gledhill, 2009).

This is the only handfish species known solely from west of Bass Strait (Last and Gledhill, 2009).

Habitat

the holotype (and only recorded specimen) of Pezichthys macropinnis was collected at 145m depth (Last and Gledhill, 2009), but habitat details were not recorded.

Notes on the Biology and Behaviour

Growth

The total length of the only specimen known to date is 28.8mm, and this is reported to be a juvenile (Last and Gledhill, 2009).

Fisheries Information

Given the depth and location in which the holotype was recorded, Longfin Handfish is likely to be an infrequent part of the bycatch in the Great Australian Bight trawl sector of the Commonwealth-managed Southern and Eastern Scalefish and Shark Fisheries (SESSF), but there are no data available.

Vulnerable Characteristics of the Species

Generally, adult and juvenile handfishes are largely sedentary; these shallow-water species are known to have small, distinct and measurable populations over small ranges; they have low fecundity; they rely upon benthic structures for nesting, and have a high degree of parental care of the eggs, fully formed young at hatching (i.e. no larval phase), and poor dispersal capability. Handfishes are slow to expand their range and colonise new areas. The shallow-water species found in estuaries and associated channels are particularly vulnerable to site-specific impacts.

The strong site association, low reproductive potential and restricted larval dispersal, are characteristics that increase the vulnerability of these fishes to population decline (Pogonoski et al., 2002).

Given the paucity of specimens known to date in an area that is regularly trawled, it is possible that this species exists in low abundance.

Threatening Processes

Although no critical habitats have been identified, it is likely that sandy and shelly soft-bottom substrates are important to this benthic, site-associated species. It is currently believed that all handfishes require benthic structures around which to lay their eggs (Commonwealth of Australia, 2004). Therefore, any processes (such as trawling and dredging) that degrade the quality of critical habitat for this species may impact on existing populations, and also threaten future generations of handfish, by reducing reproductive success. Bottom trawling and other commercial fishing activities may pose a threat to this species, but more information is required.

Research Recommendations

Data should be collated for all specimens of handfish collected or photographed in South Australia, and the specimens should be examined and identified by experts (e.g. CSIRO, Hobart).

All dead handfish specimens recorded as bycatch in the Great Australian Trawl sector of the SESSF should be collected, and the specimens should be forwarded to the South Australian Museum or CSIRO in Hobart.

All prawn trawl fisheries in South Australia (Gulf St Vincent, Spencer Gulf and eastern Great Australian Bight) should record the presence of any handfish species (with location and depth data) when specimens appear in bycatch. Similarly, all benthic fish trawls across the geographic range should record the presence of this, and any other handfish species.

More information is required on the distribution and habitat of this species, across the range.

The biology, behaviour and diet of this species are unknown, because only one specimen has been recorded (Last and Gledhill, 2009). Further research on the biology and ecology of this species is required to fill data gaps. In particular, there is little information on growth, longevity and reproduction.

Management Recommendations

Measures to reduce the bycatch of this species in benthic trawls and dredges should be encouraged.

Dredging operations should be conscious of the potential presence of handfish species, and the possible population impacts on these strongly site-associated benthic species.

Other Information

The species is known to date from a single specimen (Last and Gledhill, 2009).

This species differs from all other living handfishes. The fine, dark, linear body markings and extremely long illicium (and fin rays and spines), are not found in any other living member of the family (Last and Gledhill, 2009). This species most closely resembles in general morphology a fossil handfish known as Histionotophorus bassanii (BMNH P 19060) from the middle Eocene in Italy, figured by Rosen and Patterson (1969). However, although the fossil and the living species have very long fins, they differ markedly in most meristic characters (Last and Gledhill, 2009).