HomeFish encyclopediaRay-finned fishesNeedle fishesNeedlefishesStout longtom Stout longtom (Tylosurus gavialoides) Scientific name: Tylosurus gavialoides Castelnau, 1873 The Stout longtom (Tylosurus gavialoides) is a marine fish of the family Belonidae. Native range: Indo-West Pacific, endemic to Australia. BiologyCoastal species. Inhabit coral reefs. Oviparous. Eggs may be found attached to objects in the water by tendrils on the egg's surface.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameTylosurus gavialoidesFamilyBelonidae (Needlefishes)OrderBeloniformes (Needle fishes)ClassActinopterygii (Ray-finned fishes)Maximum length75.0Common length80.0EnvironmentMarine; reef-associatedClimateTropicalDistributionIndo-West Pacific: endemic to Australia.Conservation status (IUCN)Not EvaluatedThreat to humansHarmlessResilienceMedium, minimum population doubling time 1.4 - 4.4 years (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