Environment: milieu / climate zone / depth range / distribution range
Freshwater; demersal; pH range: 6.0 - 6.5; dH range: 10 - ?. Tropical; 25°C - 29°C (Ref. 2060); 5°N - 11°S
South America: Amazon River basin. International trade restricted (CITES II, since 1.7.75). The active fishing of this fish has reduced both the population size, and occurrence of large individuals, especially around the populated regions of the Amazon (Ref. 50891).
Length at first maturity / Size / Weight / Age
Maturity: Lm 149.5, range 145 - 154 cm
Max length : 450 cm TL male/unsexed; (Ref. 6398); common length : 200 cm TL male/unsexed; (Ref. 557); max. published weight: 200.0 kg (Ref. 557)
Often referred to as the largest freshwater fish. Builds a nest of about 15 cm depth and 50 cm width in sandy bottoms. Spawns in April and May and guards the eggs and the young. Obligate air breather. The fish rises to the surface of the water and inspires air in a noisy, distinctive gulp, which is reported to carry for long distances (Ref. 50891). Migrates into higher floodplain habitats with rising water and moves back eventually to lacustrine habitats during low water level (Ref. 116898). Threatened due to over harvesting (Ref. 58490).
Ferraris, C.J. Jr., 2003. Arapaimatidae (Bonytongues). p. 31. In R.E. Reis, S.O. Kullander and C.J. Ferraris, Jr. (eds.) Checklist of the Freshwater Fishes of South and Central America. Porto Alegre: EDIPUCRS, Brasil. (Ref. 50891)
IUCN Red List Status (Ref. 125652)
Threat to humans
Fisheries: commercial; aquaculture: commercial; gamefish: yes; aquarium: public aquariums
Estimates based on models
Phylogenetic diversity index (Ref. 82805
= 0.5938 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01096 (0.00596 - 0.02017), b=2.94 (2.77 - 3.11), in cm total length, based on LWR estimates for species & Subfamily-BS (Ref. 93245
Trophic level (Ref. 69278
): 4.5 ±0.0 se; based on diet studies.
Generation time: 11.1 ( na - na) years. Estimated as median ln(3)/K based on 2 growth studies.
Resilience (Ref. 120179
): Low, minimum population doubling time 4.5 - 14 years (tm=4-6; Fec=47,000).
Fishing Vulnerability (Ref. 59153
): Moderate to high vulnerability (54 of 100) .
Climate Vulnerability (Ref. 125649
): (0 of 100) .
Nutrients (Ref. 124155
): Calcium = 38.2 [18.5, 92.8] mg/100g ; Iron = 0.808 [0.489, 1.530] mg/100g ; Protein = 16.6 [14.1, 19.0] % ; Omega3 = 0.294 [0.131, 0.684] g/100g ; Selenium = 125 [44, 359] μg/100g ; VitaminA = 18.4 [5.4, 69.6] μg/100g ; Zinc = 0.643 [0.378, 1.031] mg/100g (wet weight); based on nutrient studies.