HomeFish encyclopediaRay-finned fishesLightfishes and DragonfishesBarbeled dragonfishesSouthern stoplight loosejaw Southern stoplight loosejaw (Malacosteus australis) Scientific name: Malacosteus australis Kenaley, 2007 The Southern stoplight loosejaw (Malacosteus australis) is a marine fish of the family Stomiidae. Native range: Circumglobal, subtropical and temperate waters of the southern hemisphere, 25?-45?S and equatorial Indian Ocean and Indo-Australasian Archipelago. BiologyDorsal soft rays (total): 16-21; Anal soft rays: 18 - 23; Vertebrae: 45 - 51. This species possess the following characters: in male, postorbital photophore (PO) 3.7-6.4% upper jaw length (UJL), 0.9-1.7% SL; female PO 2.5-4.4% UJL, 0.6-1.2% SL; IP photophores 5-7 in 3-7 clusters.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameMalacosteus australisFamilyStomiidae (Barbeled dragonfishes)OrderStomiiformes (Lightfishes and Dragonfishes)ClassActinopterygii (Ray-finned fishes)Maximum length16.6Depth range500–2000 m (1640–6562 ft)EnvironmentMarine; demersal; depth range 500 - 2000 mClimateSubtropicalDistributionCircumglobal: subtropical and temperate waters of the southern hemisphere, 25?-45?S and equatorial Indian Ocean and Indo-Australasian Archipelago.Conservation status (IUCN)Not EvaluatedThreat to humansHarmlessUsesFisheries:ResilienceHigh, minimum population doubling time less than 15 months (Preliminary K or Fecundity.) SourcesTaxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0.Last updated 27 September 2026