Gemfish, Rexea solandri (Cuvier 1832)


Other Names: Barraconda, Common Gemfish, Deepsea Kingfish, Eastern Gemfish, Hake, King Barracouta, King Couta, Kingfish, Silver Gemfish, Silver Kingfish, Southern Kingfish

A Gemfish, Rexea solandri, from the Tasman Sea. Source: NORFANZ Founding Parties. License: CC By Attribution-NonCommercial-ShareAlike

Summary:

A somewhat elongate, compressed gempylid with an iridescent bluish back becoming silver below, with a large black blotch near the outer margin between the first three dorsal-fin spines, and orange second dorsal, anal and caudal fins. Gemfish have a forked lateral line, with the upper branch running along the back to below the second dorsal fin, and the lower branch diverging downward below the first dorsal fin and running in a wavy line along the side to the tail base.


Cite this page as:
Bray, D.J. & Schultz, S. 2018, Rexea solandri in Fishes of Australia, accessed 12 Dec 2018, http://fishesofaustralia.net.au/home/species/710

Gemfish, Rexea solandri (Cuvier 1832)

More Info


Distribution

Off southern Queensland, to off Point Cloates, Western Australia, and Tasmania; absent from Bass Strait. Elsewhere the species occurs in New Zealand. An oceanic benthopelagic schooling species in depths of 100 to 800 m. Juveniles are pelagic.

Features

Dorsal fin XVII-XVIII, 0, I, 16-19; Anal fin II, 13-16; Pectoral fin 13-15; Pelvic fin I, 5.

Body long, slender, compressed, depth 5-6 times in standard length. Head length 3.1-3.9 times in standard length. Lower jaw protruding, dermal processes absent from jaws. Upper jaw with 3-4 pairs of rigid teeth, and 0-3 pairs of depressible fang-like teeth; lower jaw with a single pair of fang-like teeth; palatine teeth present. 

Lateral line in two parts, bifurcating below the 5th to 6th spine of the first dorsal fin; upper lateral line extending beyond the second dorsal-fin origin and terminating below 8th to 12th soft ray; the lower lateral line is midlateral, undulating above the anal fin base, terminating at the caudal peduncle. the second dorsal and anal fins are followed by two finlets. Scales present in specimens over 25 cm in length.

Size

To at least 110 cm and 10 kg. A 13 year old fish is around 104 cm in length.

Colour

Body blue dorsally

Feeding

Carnivore: feeds mostly on fishes such as macrourids (whiptails or grenadiers) and Deepwater Cardinalfish (Apogonops anomalus), as well as on squid and Royal Red prawns.

Biology

Males and females in the eastern Gemfish population mature at different ages. Males attain maturity at 3-5 years of age, reach a length of about 106 cm and can live for 13 years. Females mature between 4 and 6 years of age, grow to about 116 cm and can live up to 17 years of age.

In southeastern Australia spawning schools migrate each winter from Tasmanian waters to off the NSW and southern Qld coasts.

Both eggs and larvae are pelagic, with the larvae being around 2.9 mm in length at hatching.

Fisheries

 In Australian waters, the eastern and western populations of this species are genetically distinct. During the late 1970s and 1980s, this excellent food fish was the target of an important commercially fishery in south-eastern Australia. The eastern Gemfish population was heavily overfished, leading to substantial and rapid decline in catch rates and a decline in size at maturity of eastern gemfish since the 1970's. This fishery was closed in 1993, although eastern Gemfish by-catch can be retained. This genetically distinct population was listed as conservation dependent under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act).

In the 1970's and 1980's, the small recreational fishery and the large commercial fishery targeted the annual pre-spawning migration of eastern gemfish along the NSW coast in winter. After peaking at 5,000 tonnes in 1980, the commercial rates significantly and rapidly declined. Along with the decline in catch rates, this heavy targeting of the breeding stock also resulted in a steady decline in size at maturity individuals within this population. The fishery is now a by-catch fishery of juveniles and sub-adults in the trawl sector and mature fish in the dropline sector and is tightly regulated. The majority of the catch is taken north of 40°S latitude.

Conservation

Australian Government Legislation: The eastern Gemfish population is listed as conservation dependent under the EPBC Act 1999. http://www.environment.gov.au/biodiversity/threatened/species/pubs/76339-listing-advice.pdf

State Government Legislation: In January 2008, the NSW Government Fisheries Scientific Committee determined that Rexea solandri - Gemfish is not facing a very high or high risk of extinction in New South Wales in the near future, and was therefore not eligible to be listed as an endangered species. http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0005/213827/FD30-gemfish.pdf

Remarks

Although the New Zealand population is genetically similar to that found in eastern Australia, there is limited migration across the Tasman Sea. As a result, there is little gene flow between the New Zealand and Australian populations.

Species Citation

Gempylus solandri Cuvier 1832, Historie naturelle des poissons 8: 215. Type locality: Bay of Islands, New Zealand.

Author

Bray, D.J. & Schultz, S. 2018

Resources

Australian Faunal Directory

Gemfish, Rexea solandri (Cuvier 1832)

References


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Department of the Environment, Water, Heritage and the Arts (2009). Rexea solandri (eastern Australian population) in Species Profile and Threats Database, Department of the Environment, Water, Heritage and the Arts, Canberra. Available from: http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=76339 Accessed 2009-04-02@17:44:54.

Devine, J.A., Baker, K.D. & R.L. Haedrich. 2006. Deep-sea fishes qualify as endangered. Nature 439: 29.

Cuvier, G.L. in Cuvier, G.L. & Valenciennes, A. 1832. Histoire Naturelle des Poissons. Paris : Levrault Vol. 8 509 pp. pls 209-245. 

Gomon, M.F. 1994. Family Gempylidae. pp. 813-816, figs 718-720 in Gomon, M.F., Glover, C.J.M. & Kuiter, R.H. (eds). The Fishes of Australia's South Coast. Adelaide : State Printer 992 pp. 810 figs. 

Gomon, M.F. 2008. Families Sphyraenidae to Centrolophidae. pp. 774-800 in Gomon, M.F., Bray, D.J. & Kuiter, R.H. (eds). Fishes of Australia's Southern Coast. Sydney : Reed New Holland 928 pp.

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Last, P.R., Scott, E.O.G. & Talbot, F.H. 1983. Fishes of Tasmania. Hobart : Tasmanian Fisheries Development Authority 563 pp. figs.

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May, J.L. & Maxwell, J.G.H. 1986. Field Guide to Trawl Fish from Temperate Waters of Australia. Hobart : CSIRO Division of Marine Research 492 pp. 

McCoy, F. 1873. On a new Australian species of Thyrsites. Annals and Magazine of Natural History 4 11(4): 338-339 (as Thyrsites micropus)

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Nakamura, I. & Parin, N.V. 1993. FAO Species Catalogue. Snake mackerels and cutlassfishes of the world (families Gempylidae and Trichiuridae). An annotated and illustrated catalogue of the Snake Mackerels, Snoeks, Escolars, Gemfishes, Sackfishes, Domine, Oilfish, Cutlassfishes, Scabbardfishes, Hairtails, and Frostfishes known to date. Fisheries Synopsis No. 125, Vol. 15. Rome : FAO 136 pp. 200 figs. 

Nakamura, I. & Parin, N.V. 2001. Gempylidae, Trichiuridae. pp. 3698-3720 in Carpenter, K.E. & Niem, T.H. (eds). The Living Marine Resources of the Western Central Pacific. FAO Species Identification Guide for Fisheries Purposes. Rome : FAO Vol. 6 pp. 3381-4218.

Neira, F.J., A.G. Miskiewicz & T. Trnski. 1998. Larvae of temperate Australian fishes: laboratory guide for larval fish identification. University of Western Australia Press. Nedlands, Western Australia, 474 pp.

NSW Fisheries Scientific Committee. 2008. Final determination, Rexea solandri - Gemfish. http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0005/213827/FD30-gemfish.pdf

Parin, N.V. & Paxton, J.R. 1990. Australia's east coast gemfish. Australian Fisheries 49(5): 115

Pogonoski JJ, Pollard DA & Paxton JR. 2002. Conservation Overview and Action Plan for Australian Threatened and Potentially Threatened Marine and Estuarine Fishes. Environment Australia, Canberra.

Prince, J.D. & Griffin, D.A. 2001. Spawning dynamics of the eastern gemfish (Rexea solandri) in relation to regional oceanography in south-eastern Australia. Marine and Freshwater Research 52: 611-622.

Rowling, K.R. 1990. Changes in the stock composition and abundance of spawning Gemfish Rexea solandri (Cuvier), Gempylidae, in South-eastern Australian waters. Australian Journal of Marine and Freshwater Research 41(1): 145-163.

Rowling, K.R. 1994. Gemfish, Rexea solandri, pp. 115-123. In R.D.J. Tilzey (ed.) The South East Fishery: a scientific review with reference to quota management. Bureau of Resource Sciences, Australian Government Print Service, Canberra. 360 pp.

Rowling, K. 1995. Eastern gemfish: will they come back? Australian Fisheries (May): 8-9.

Rowling, K.R. & Reid, D.D. 1992. Effect of temporal changes in size composition on estimates of von Bertalanffy growth parameters for gemfish, Rexea solandri (Cuvier), Gempylidae. Australian Journal of Marine and Freshwater Research 43(5): 1229-1239.

Tilzey, R.D.J., Zann-Schuster, M., Klaer, N.L. & Williams, M.J. 1990. The South East Trawl Fishery: biological synopses and catch distributions for seven major commercial fish species. Bureau of Rural Resources Bulletin 8. 80 pp.

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Withell, A.F. & Wankowksi, J.W.J. 1989. Age and growth estimates for pink ling, Genypterus blacodes (Schneider), and gemfish, Rexea solandri (Cuvier), from eastern Bass Strait, Australia. Australian Journal of Marine and Freshwater Research 40(2): 215-226.

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Quick Facts


CAAB Code:37439002

Conservation:ASFB Vulnerable

Conservation:EPBC Act Conservation Dependent (eastern Population)

Depth:100-800 m

Fishing:Commercial fish

Max Size:120 cm

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