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: milieu / climate zone / depth range / distribution range
Freshwater; benthopelagic. Tropical
Asia: Mekong, Chao Phraya (Ref. 43281), Maeklong, Peninsular and Southeast Thailand river systems (Ref. 26336).
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 30.0 cm SL male/unsexed; (Ref. 30857)
(total): 13 - 19;
soft rays: 49;
Vertebrae: 75. Distinguishable by its dorsal spine count of 13-19 and a series of 3-6 conspicuous ocelli along the base of the soft dorsal fin (Ref. 27732). The ocelli along the base of the dorsal fin are much larger than those in M. aral and the dorsal and caudal fins lack the fine striations seen in M. aral and M. meklongensis (Ref. 39392). Dorsal, caudal and anal fins not fused (Ref. 43281).
Found at bottom depths in slow-moving or standing waters. Often lies buried in the silt, sand, or fine gravel with only a portion of its head protruding from the bottom (Ref. 12693). Enters flooded forest (Ref. 9497). Emerges at dusk to forage for food. Feeds on benthic insect larvae, crustaceans, and worms (Ref. 12693). Marketed fresh and often seen in the aquarium trade (Ref. 12693).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Kottelat, M., 1998. Fishes of the Nam Theun and Xe Bangfai basins, Laos, with diagnoses of twenty-two new species (Teleostei: Cyprinidae, Balitoridae, Cobitidae, Coiidae and Odontobutidae). Ichthyol. Explor. Freshwat. 9(1):1-128. (Ref. 27732)
IUCN Red List Status (Ref. 119314)
CITES (Ref. 115941)
Threat to humans
Fisheries: commercial; aquarium: commercial
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
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=0.00380 (0.00162 - 0.00892), b=2.91 (2.73 - 3.09), in cm Total Length, based on LWR estimates for this Genus-body shape (Ref. 93245
Trophic Level (Ref. 69278
): 3.3 ±0.40 se; Based on food items.
Resilience (Ref. 69278
): Medium, minimum population doubling time 1.4 - 4.4 years (Preliminary K or Fecundity.).
Vulnerability (Ref. 59153
): Low to moderate vulnerability (34 of 100) .