Actinopteri (ray-finned fishes) > Synbranchiformes
(Spiny eels) > Mastacembelidae
Etymology: Macrognathus: Greek, makros = great + Greek, gnathos = jaw (Ref. 45335). More on author: Day.
Environment: milieu / climate zone / depth range / distribution range
Freshwater; benthopelagic. Tropical
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 29.9 cm SL male/unsexed; (Ref. 97143); common length : 20.0 cm TL male/unsexed; (Ref. 4833)
Morphology | Morphometrics
soft rays: 62 - 75. Macrognathus guentheri can be distinguished from Macrognathus albus by the following characters: body with distinct bars or marblings (vs. absent in M. albus), head shorter (14.1-6.3 % SL vs. 16.6- 17.4) and less deep (39.5-42.2 % HL vs.43.0- 48.6), body wider (7.0-7.5 % SL vs. 5.7- 7.1), pre dorsal (21.1-24.0 % SL vs. 26.9-28.4) and pre anal (56.0-61.6 % SL vs. 61.5-67.4) distances shorter, eyes are widely set (inter orbital width 10.5- 12.0 % HL vs. 6.3- 6.8), snout shorter (37.2- 41.1 % HL vs. 42.8- 48.4) and anal fin with 62-75 soft rays (vs. 56-62); irregular blotches absent on the mid dorsal side and extending a little to upper lateral side stretching from the opercle to caudal base (vs. present); dorsal spines comparatively longer and prominent (vs. short and partly hidden under skin); spinous part of dorsal fin originating just behind the end of pectoral fin (vs. originating considerably behind the end of pectoral fin); and preorbital spine present (vs. absent) (Ref. 97143).
Found in pools and running waters.
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Talwar, P.K. and A.G. Jhingran, 1991. Inland fishes of India and adjacent countries. Volume 2. A.A. Balkema, Rotterdam. (Ref. 4833)
IUCN Red List Status (Ref. 123251)
CITES (Ref. 123416)
Threat to humans
Fisheries: minor commercial; aquarium: commercial
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingNutrientsMass conversion
Estimates based on models
Phylogenetic diversity index (Ref. 82805
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00355 (0.00153 - 0.00825), b=2.92 (2.74 - 3.10), in cm total length, based on LWR estimates for this Genus-body shape (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.).
Vulnerability (Ref. 59153
): Low to moderate vulnerability (34 of 100) .