Southern Spotted Opah, Lampris australensis Underkoffler, Luers, Hyde & Craig 2018

Other Names: Arokura, Kingfish, Mariposa, Moon Fish, Moonfish, Opah, Opal Fish, Spotted Moonfish

A Southern Spotted Opah, Lampris australensis, washed ashore at Lake Tyers, Victoria, July 2016. Source: Jenny Allitt. License: All rights reserved


A steel-blue opah with numerous, mostly circular, white to silver spots that may extend to the red dorsal, anal and caudal fins, and a yellow tinge on the margins of the dorsal, anal and caudal fins. The dorsal profile of the head is distinctly arched (convex).

These rare oceanic fishes are regularly taken as bycatch in tuna longline fisheries. Opahs are "warm-blooded" and regularly dive to depths below 200 metres where they feed on mesopelagic fishes, squids and crustaceans - and where water temperatures are below 4°C.

In Australia, this species was previously known as Lampris guttatus, which occurs in the Eastern North Atlantic including the Irish Sea, the North Sea and the Mediterranean Sea.

Meet Opah - The First Fully Warm-Blooded Fish

Cite this page as:
Bray, D.J. 2018, Lampris australensis in Fishes of Australia, accessed 16 Oct 2018,

Southern Spotted Opah, Lampris australensis Underkoffler, Luers, Hyde & Craig 2018

More Info


Known only from the Southern hemisphere: Australia, Chile, South Africa and Tasmania. In Australia, the species has been recorded from Scotts Head (New South Wales) to just north of Perth (Western Australia), and around Tasmania.

Like it's relative Lampris guttatus, this rare epi- to mesopelagic fish can presumably regularly dive to deep mesopelagic waters to feed during the day.


Dorsal fin I, 50-52; Anal fin 40-42; Pectoral fin 22-23; Pelvic fin 13-15.

Body laterally compressed, rounded, greatest depth slightly anterior to pelvic fins, 1.37–1.45 times in standard length; head length 2.7–2.8 times in standard length; dorsal profile of head distinctly convex (arched); eye diameter 5.0–5.2 in head length; pupil large; jaws protractible and lacking teeth; upper jaw shorter than lower jaw; lower jaw protruding slightly forward of upper jaw, tip narrowing to a blunt point; teeth absent from throat and palate. 

Lateral line angled above gill opening, arching above pectoral fins, and extending along mid-height of body through center of caudal peduncle. Scales small, thin, and easily removed over entire body. 

Dorsal fin long, the length of its base 1.6–1.8 times in standard length; Dorsal fin high, its height contained 2.5–2.7 in standard length; origin of pelvic fins below or posterior to middle of elongated portion of dorsal fin.


To about 2.1 metres total length, and a weight of 30 kg.


Carnivores - Opahs have diverse diets, and feed on a range of pelagic animals including fishes, cephalopods, crustaceans, and gelatinous animals.


Very little is known of the biology and ecology. Spawning reportedly occurs year-round near the surface in the tropics. During development, the pelagic larvae increase rapidly in body depth.

Opahs regularly dive to feed at mesopelagic depths below the thermocline where water temperatures are less than 4 degrees Celsius. Wegener et al. (2015) found that Opahs are whole-body endotherms. They produce heat through the constant “flapping” of their wing-like pectoral fins and minimize heat loss through a series of counter-current heat exchangers within the gills. Unlike other fishes that have been studied, Opahs distribute the warmed blood throughout the body, including to the heart, enhancing physiological performance and buffering the function of internal organs while foraging in the cold, nutrient-rich waters below the ocean thermocline. 

Previously, Runcie et al. (2009) found that Opahs have a brain-heater muscle that maintains the temperature of the brain about 2 degrees higher than that of the surrounding water.


Although not targeted directly, Southern Spotted Opahs are often taken pelagic longline tuna and billfish fisheries, including in the Eastern Tuna and Billfish fishery off the coast of Queensland and New South Wales (AFMA 2006). They are marketed fresh, and are reportedly very good eating.

Southern Spotted Opahs are also prized by recreational anglers fishing deep offshore waters.


Previously, molecular studies indicated that Lampris guttatus is complex of five cryptic species (Hyde et al. 2014). Underkoffler et al. (2018) determined that L. guttatus is restricted to the Eastern North Atlantic and Mediterranean Sea, and described the species found in Australia as L. australensis.

Similar Species

Differs from Lampris immaculatus in  having silvery-white spots on the body, a much deeper body, and longer pectoral and pelvic fins.


Lampris is from the Greek "lamprós", meaning radiant, brilliant or shining,in reference to the Opah’s brilliant coloration. The specific name australensis is from the Latin australis meaning “southern” in reference to the known range of the species in the southern hemisphere.

Species Citation

Lampris australensis Underkoffler, Luers, Hyde & Craig 2018, Zootaxa 4413(3): 556, Fig. 4C. Type locality: East of Tasman Island, Tasmania, 43°12'S, 148°18'E.


Bray, D.J. 2018


Australian Faunal Directory

Southern Spotted Opah, Lampris australensis Underkoffler, Luers, Hyde & Craig 2018


Abécassis, M. 2006. Vertical habitat of opah (Lampris guttatus) electronically tagged with pop-up archival satellite tags. Mémoire de Master "Mention sciences de l‟Univers, Enrvironment, Ecologie". 41 pp.

Australian Fisheries Management Authority (AFMA). 2006. Eastern tuna and billfish: Fishery Status Reviews tuna and billfish fisheries. Australian Fisheries Management Authority, Canberra, Australia. 20 pp. (as Lampris guttatus)

Bray, D.J. 2008. Family Lamprididae. pp. 297 in Gomon. M.F., Bray, D.J. & Kuiter, R.H (eds). Fishes of Australia's Southern Coast. Sydney : Reed New Holland 928 pp. (as Lampris guttatus)

Choy C.A. & Drazen, J.C. 2013. Plastic for dinner? Observations of frequent debris ingestion by pelagic predatory fishes from the central North Pacific. Marine Ecology Progress Series 485: 155-163. PDF

Choy, C., Popp, B., Kaneko, J. & Drazen, J. 2009. The influence of depth on mercury levels in pelagic fishes and their prey. Proceedings of the National Academy of Sciences 106(33): 13865-13869. PDF

Choy, C.A., E. Portner, M. Iwane & J.C. Drazen. 2013. The diets of five important predatory mesopelagic fishes of the central North Pacific. Marine Ecology Progress Series 492: 169-184. PDF

Glover, C.J.M. 1994. Families Lampridae, Veliferidae, Lophotidae, Trachipteridae, Regalecidae, Fistulariidae. pp. 427-435 figs 382-387 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 (as Lampris guttatus)

Hawn, D.R. & Collette, B.B. 2012. What are the maximum size and live body coloration of opah (Teleostei: Lampridae: Lampris species)? Ichthyological Research 59(3): 272-275. PDF

Hyde, J. R., K.E. Underkoffler & M.A. Sundberg. 2014. DNA barcoding provides support for a cryptic species complex within the globally distributed and fishery important opah (Lampris guttatus). Molecular Ecology Research 14: 1239–1247. doi: 10.1111/1755-0998.12268 Open access

Olney, J.E. 1999. Families Veliferidae, Lamprididae, Stylephoridae, Lophotidae, Radiicephalidae, Trachipteridae, Regalecidae. pp. 1966-1975 in Carpenter, K.E. & Niem, V.H. (eds). The Living Marine Resources of the Western Central Pacific. FAO Species Identification Guide for Fisheries Purposes. Rome : FAO Vol. 3 1397-2068 pp.

Polovina, J.J., Hawn, D. & Abecassis, M. 2008. Vertical movement and habitat of opah (Lampris guttatus) in the central North Pacific recorded with pop-up archival tags. Marine Biology 153: 257-267.

Rosenblatt, R.H. & G.D. Johnson. 1976. Anatomical considerations of swimming in the Opah, Lampris guttatus. Copeia 1976(2): 367-370.

Runcie, R., Dewar, H., Hawn, D., Frank, L. & Dickson, K. 2009. Evidence for cranial endothermy in the opah (Lampris guttatus). Journal of Experimental Biology 212(4): 461-470. doi: 10.1242/jeb.022814. PDF

Underkoffler, K.E., Luers, M.A., Hyde, J.R. & Craig, M.T. 2018. A taxonomic review of Lampris guttatus (Brünnich 1788) (Lampridiformes; Lampridae) with descriptions of three new species. Zootaxa 4413(3): 551-565 DOI: Abstract

Wegner, N.C., Snodgrass, O.E., Dewar, H. & J.R. Hyde. 2015. Whole-body endothermy in a mesopelagic fish, the opah, Lampris guttatus. Science 348 (6236): 786-789. DOI:10.1126/science.aaa8902 Abstract

Whitley, G.P. 1950. The opah or moonfish in Australasia. Australian Museum Magazine 10(3): 76-78 (as Lampris guttatus)

Whitley, G.P. 1966. Marine Fishes of Australia. Brisbane : Jacaranda Press Vol. 1 pp. 1-142. (as Lampris guttatus)

Quick Facts

CAAB Code:37268001


Depth:10-400 m

Fishing:Commercial, recreational fish

Habitat:Oceanic: epi- & mesopelagic

Max Size:2.1 m; 270+ kg

Species Image Gallery

Species Maps

CAAB distribution map