Classification / Names
Common names | Synonyms | Catalog of Fishes (gen., sp.) | ITIS | CoL | WoRMS | Cloffa
Actinopterygii (ray-finned fishes) > Synbranchiformes
(Spiny eels) > Mastacembelidae
Etymology: Macrognathus: Greek, makros = great + Greek, gnathos = jaw (Ref. 45335).
Environment / Climate / Range
Freshwater; brackish; benthopelagic; pH range: 6.5 - 7.5; dH range: ? - 15; potamodromous (Ref. 51243). Tropical; 23°C - 28°C (Ref. 1672)
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 38.0 cm TL male/unsexed; (Ref. 2073)
(total): 14 - 20;
soft rays: 50 - 54. Body with series of obliquely oriented bars (Ref. 39392). Dorsal and anal fins with a row of isolated spines followed by a long continuous soft portion, both fins extending to but not confluent with caudal fin. Pelvic fins absent. Caudal fin rounded (Ref. 4792).
Asia: Thailand, Malay Peninsula, Borneo and Indonesia. Reported from Bangladesh (Ref. 1479) and Nepal (Ref. 9496); India (Ref. 43634); Viet Nam (Ref. 89724).
Adults occur in medium to large-sized rivers (Ref. 12975). Found in lowland wetlands and peats. Uncommonly seen in aquarium trades (Ref. 57235).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Produces a minimum of 1000 eggs (Ref. 1672).
Roberts, T.R., 1989. The freshwater fishes of Western Borneo (Kalimantan Barat, Indonesia). Mem. Calif. Acad. Sci. 14:210 p. (Ref. 2091)
IUCN Red List Status (Ref. 96402)
CITES (Ref. 94142)
Threat to humans
Fisheries: minor commercial; aquarium: commercial
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00363 (0.00193 - 0.00683), b=2.97 (2.80 - 3.14), based on LWR estimates for species & (Sub)family-body shape (Ref. 93245
Trophic Level (Ref. 69278
): 3.3 ±0.4 se; Based on size and trophs of closest relatives
Resilience (Ref. 69278
): Medium, minimum population doubling time 1.4 - 4.4 years (Fec>1000).
Vulnerability (Ref. 59153
): Low vulnerability (24 of 100) .