Classification / Names
Common names | Synonyms | Catalog of Fishes (gen., sp.) | ITIS | CoL | WoRMS | Cloffa
Actinopterygii (ray-finned fishes) > Osteoglossiformes
(Bony tongues) > Osteoglossidae
Etymology: Scleropages: Greek, skleros = hard + Greek, page, -es = knot (Ref. 45335).
Environment / Climate / Range
Freshwater; benthopelagic. Tropical; 24°C - 30°C (Ref. 2060), preferred ?
Asia: Southern Myanmar to Malay Peninsula and Indonesia, eastern Thailand to Cardamon Range. International trade banned (CITES I, since 1.7.75).
Length at first maturity / Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 90.0 cm TL male/unsexed; (Ref. 6398)
With 1 pair of barbels; scales large.
Occurs in tannin stained blackwater streams (Ref. 12693). Found in forest covered streams including peat adjacent areas. Take around three months for free swimming fries (Ref. 57235). Young individuals feed on insects at the water surface, adults take fishes (Ref. 12693, 57235) and smaller vertebrates (Ref. 56749). A mouth brooder, young about 6 cm at birth (Ref. 7050, 57235). Valued as an aquarium fish, its flesh commands a moderate price.
From an observation of a breeding pair in a concrete tank, courtship lasts from several weeks to months. During this stage, the breeding pair swims near the water surface usually at night. "The male chases the female around the perimeter of the tank. Sometimes, the pair circle each other nose-to-tail. About one to two weeks before spawning takes place, the fish swim side by side with their bodies touching. Eventually, the female releases a cluster of orange-red eggs. The male fertilises the eggs and then scoops them into its mouth where it incubates them. After hatching which occurs in about a week, the young larvae continue to live in the male's mouth for 7-8 weeks more until the yolk sac is totally absorbed" (Ref. 57886).
Kottelat, M., 2013. The fishes of the inland waters of Southeast Asia: a catalogue and core bibliography of the fishes known to occur in freshwaters, mangroves and estuaries. The Raffles Bulletin of Zoology 2013 (Suppl. 27):1-663. (Ref. 94476)
IUCN Red List Status (Ref. 109396)
Threat to humans
Fisheries: commercial; aquarium: highly commercial
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 0.5781 [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), based on all LWR estimates for this body shape (Ref. 93245
Trophic Level (Ref. 69278
): 3.9 ±0.63 se; Based on food items.
Resilience (Ref. 69278
): Low, minimum population doubling time 4.5 - 14 years (tm = 3-4; Fec = 50 (in concrete tanks)).
Vulnerability (Ref. 59153
): Moderate to high vulnerability (47 of 100) .