Violet Roughy, Optivus agastos Gomon 2004


Other Names: Slender Roughy

A Violet Roughy, Optivus agastos, at Bare Island, Botany Bay, New South Wales, 16 April 2016. Source: John Turnbull / Flickr. License: CC by Attribution-NonCommercial-ShareAlike

Summary:
A greenish to greyish-brown roughy, with a silvery belly, pink fins, and a reddish-brown stripe along the upper and lower lobes of the caudal fin. The Violet Roughy has a series of scutes along the belly.

Cite this page as:
Bray, D.J. 2018, Optivus agastos in Fishes of Australia, accessed 18 Nov 2018, http://fishesofaustralia.net.au/home/species/1739

Violet Roughy, Optivus agastos Gomon 2004

More Info


Distribution

Endemic to eastern and southeastern Australia from Noosa, Queensland, to Port Phillip, Victoria, and Freycinet, Tasmania. Also at Lord Howe Island in the Tasman Sea.
Shelters beneath rocky ledges during the day.

Features

Dorsal fin IV-V, 10-11; Anal fin III, 9-10; Vertebrae: 26; Gill rakers 22-25 (modally 23).
Lateral profile of nape and head nearly straight, distinctly angled downward in front of dorsal fin; snout tip rounded, often projecting slightly in front of upper jaw; depth of head at vertical through upper end of gill opening 2.9-3.2 times in SL; snout length 1.6-2.7 times in eye diameter; inner row of teeth on premaxilla is noticeably longer than others; caudal peduncle relatively short and deep, its depth 0.9-1.3 times in length. 
Dorsal and anal fins are relatively low, third segmented dorsal-fin ray 3.5-4.2 times in SL, first anal-fin ray 5.2-6.3 times in SL.

Similar Species

The Violet Roughy has long been confused with the New Zealand Slender Roughy, Optivus elongatus, which differs in having more gill rakers on the first gill arch (24-27, vs. 22-25), a slightly larger eye, shorter snout, and shorter teeth along the inner margin of the jaws.
The Western Rought, Optivus agrammus, differs from the Violet Roughy in lacking the brown stripe along each caudal fin lobe 

Etymology

The specific name agastos is from the Greek word meaning 'near kinsman', in reference to the similarity and presumed close relationship of the Violet Roughy to Trachichthys elongatus.

Species Citation

Optivus agastos Gomon, 2004, Rec. Aust. Mus. 56: 174, figs 1-2. Type locality: Cape Wellington, Wilsons Promontory, Victoria (39°04.1'S, 146°28.6'E). 

Author

Bray, D.J. 2018

Resources

Australian Faunal Directory

Violet Roughy, Optivus agastos Gomon 2004

References


Allen, G.R., Hoese, D.F., Paxton, J.R., Randall, J.E., Russell, B.C., Starck, W.A., Talbot, F.H. & Whitley, G.P. 1976. Annotated checklist of the fishes of Lord Howe Island. Records of the Australian Museum 30(15): 365-454 figs 1-2 (Hoplostethus elongatus)

Francis, M. 1993. Checklist of the coastal fishes of Lord Howe, Norfolk, and Kermadec Islands, southwest Pacific Ocean. Pacific Science 47(2): 136-170 figs 1-2 (as Optivus elongatus)

Gomon, M.F. 1994. Family Trachichthyidae. In Gomon, M.F., Glover, C.J.M. & R.H. Kuiter (eds). The Fishes of Australia's South Coast. State Print, Adelaide. 992 pp. (as Optivus sp. 1)

Gomon, M.F. 2004. Two new species of roughy (Trachichthyidae: Optivus) from coastal waters of southern Australia. Records of the Australian Museum 56: 173-178 DOI:10.3853/j.0067-1975.56.2004.1419 See ref online, open access

Gomon, M.F. 2008. Family Trachichthyidae. pp. 420-430 in Gomon, M.F., Bray, D.J. & Kuiter, R.H. (eds). Fishes of Australia's Southern Coast. Sydney : Reed New Holland 928 pp. 

Hutchins, B. & Swainston, R. 1986. Sea Fishes of Southern Australia. Complete Field Guide for Anglers and Divers. Swainston Publishing. 180 pp. (as Optivus elongatus)

Johnson, J.W., 1999. Annotated checklist of the fishes of Moreton Bay, Queensland, Australia. Memoirs of the Queensland Museum 43(2):709-762. (as Optivus elongatus)

Johnson, J.W. 2010. Fishes of the Moreton Bay Marine Park and adjacent continental shelf waters, Queensland, Australia. pp. 299-353 in Davie, P.J.F. & Phillips, J.A. Proceedings of the Thirteenth International Marine Biological Workshop, The Marine Fauna and Flora of Moreton Bay. Memoirs of the Queensland Museum 54(3)

Kuiter, R.H. 1993. Coastal Fishes of South-eastern Australia. Bathurst : Crawford House Press 437 pp. (as Optivus elongatus)

Kuiter, R.H. 1996. Guide to Sea Fishes of Australia. A comprehensive reference for divers and fishermen. Sydney, NSW, Australia : New Holland Publishers xvii, 434 pp. (as Optivus elongatus)

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

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. (as Optivus sp. 1)

McCulloch, A.R. 1923. Notes on fishes from Australia and Lord Howe Island. Records of the Australian Museum 14(1): 1-17 pls 1-3 (as Hoplostethus elongatus)


Quick Facts


CAAB Code:37255007

Feeding:1–146 m

Habitat:Reef associated

Max Size:9.5 cm SL

Native:Endemic

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