HomeFish encyclopediaRay-finned fishesFlatfishesSolesAllen?s Sole Allen?s Sole (Leptachirus alleni) Scientific name: Leptachirus alleni Randall, 2007 The Allen?s Sole (Leptachirus alleni) is a freshwater fish of the family Soleidae. Native range: Asia, New Guinea, Indonesia. BiologyDorsal soft rays (total): 65-73; Anal soft rays: 50 - 53; Vertebrae: 37 - 39. This species is distinguished by the following characters: D 65-73; A 50-53; pelvic rays 4; lateral-line scales 82-93; lateral line on ocular side of head with a ventral branch of 4-6 pores, remaining horizontal anterior part with 5-7 pores; vertebrae 37-39; dorsal pterygiophores anterior to fourth neural spine 8-9; body depth 2.7-3.0 in SL; no caudal peduncle; head length 4.35-4.65 in SL; small eyes, eye diameter 7.2-8.4 in HL; interorbital width 8.1-9.8 in HL; longest dorsal ray 1.75-1.95 in HL; caudal-fin length 4.0-4.25 in SL; pelvic fins and genital papilla not joined, their origins adjacent; short pelvic fins, reaching little beyond base of first anal ray, 2.8-3.2 in HL; alcohol-preserved colour of ocular side grey-brown with scattered dark brown spots smaller than eye (most of about pupil size) and 3 longitudinal rows of larger dark brown blotches; pale dorsal and anal fin rays with membraneSource: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameLeptachirus alleniFamilySoleidae (Soles)OrderPleuronectiformes (Flatfishes)ClassActinopterygii (Ray-finned fishes)Maximum length8.6Depth range0–1 m (0–3 ft)EnvironmentFreshwater; benthopelagic; depth range 0 - 1 mClimateTropicalDistributionAsia: New Guinea, Indonesia.Conservation status (IUCN)Not EvaluatedThreat to humansHarmlessResilienceHigh, 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