Classification / Names
Common names | Synonyms | Catalog of Fishes(genus, species) | ITIS | CoL | WoRMS | Cloffa
Teleostei (teleosts) > Osteoglossiformes
(Bony tongues) > Arapaimidae
Etymology: Arapaima: From tupí-guaraní, arapaima (Ref. 45335); leptosoma: Derived from the Greek leptos, meaning slender, and soma, meaning body. This in reference to the relatively slender body form of this species..
Environment: milieu / climate zone / depth range / distribution range
Freshwater; benthopelagic. Tropical
South America: Solimões River in Brazil.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 77.6 cm SL male/unsexed; (Ref. 94273)
Morphology | Morphometrics
soft rays: 38;
Vertebrae: 83. Diagnosed from all congeners by having the following characters: extremely slender dorsal most lateralis sensory cavity on preopercle, strongly angled ventrolateral margin of head where third infraorbital meets anterior limb of preopercle such that ventral surface of head is almost flat, and enlarged thickened sheath on anterior third of dorsal-fin base that hides anterior dorsal-fin rays when adpressed. Differs also from all other Arapaima except A. agassizii by having extremely long fourth infraorbital. Distinguished from A. arapaima and all other examined non-type specimens by having notably slender body; from A. mapae and A. agassizii by having relatively deep caudal peduncle (6.0% SL, vs. ,4.0 in both of latter two taxa); from A. gigas by having dentary teeth in a single row (vs. dentary teeth in 2-2.5 irregular rows); and from A. agassizii by having 28 teeth on maxilla (vs. 43) and on single ramus of dentary (30-32, vs. 44) (Ref. 94273).
Obligate air-breathing (Ref. 126274)
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Stewart, D.J., 2013. A new species of Arapaima (Osteoglossomorpha: Osteoglossidae) from the Solimões River, Amazonas State, Brazil. Copeia 2013(3):470-476. (Ref. 94273)
IUCN Red List Status (Ref. 126983)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingNutrientsMass conversion
Estimates based on models
Phylogenetic diversity index (Ref. 82804
= 0.5938 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00389 (0.00180 - 0.00842), b=3.12 (2.94 - 3.30), in cm total length, based on all LWR estimates for this BS (Ref. 93245
Trophic level (Ref. 69278
): 3.3 ±0.4 se; based on size and trophs of closest relatives
Resilience (Ref. 120179
): Medium, minimum population doubling time 1.4 - 4.4 years (Preliminary K or Fecundity.).
Fishing Vulnerability (Ref. 59153
): High vulnerability (58 of 100).