Actinopteri (ray-finned fishes) > Osteoglossiformes
(Bony tongues) > Mormyridae
Etymology: Petrocephalus: Latin, petra = stone + Greek, kephale = head (Ref. 45335).
More on author: Sauvage.
Environment: milieu / climate zone / depth range / distribution range
Freshwater; demersal. Tropical
Africa: Ogowe River in Gabon (Ref. 3203, 85311) and the Congo River basin in Cameroon (Ref. 46901), Republic of Congo (Ref. 85311) and Democratic Republic of the Congo (Ref. 1879, 4910, 41580, 41590, 44985, 45434, 45441, 93897, 106245).
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 11.0 cm TL male/unsexed; (Ref. 42522)
Morphology | Morphometrics
Petrocephalus balayi is distinguished from all other Petrocephalus species in Central Africa by the following combination of characteristics: dorsal fin with 20-22 branched rays, anal fin with 26 or 27 branched rays, eye small (HL/ED=4,5-4,9), mouth very wide, associated with a very characteristic head shape when viewed from below, 14 teeth or more in the upper jaw, 28 teeth or more in the lower jaw (Ref. 85331). Melanin pattern consisting of the following: (1) a distinct black round mark on each side of the body below dorsal fin origin; (2) an ovoid mark on each side at the base of the caudal peduncle, not extending onto the upper and lower parts of the caudal fin; (3) a black mark, sometimes diffuse but always present, at the base of the pectoral fins (Ref. 85331).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Gosse, J.-P., 1984. Mormyridae. p. 63-122. In J. Daget, J.-P. Gosse and D.F.E. Thys van den Audenaerde (eds.) Check-list of the freshwater fishes of Africa (CLOFFA). ORSTOM, Paris and MRAC, Tervuren. Vol. 1. (Ref. 3203)
IUCN Red List Status (Ref. 125652)
Threat to humans
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=0.01622 (0.00858 - 0.03065), b=2.94 (2.78 - 3.10), in cm total length, based on LWR estimates for species & Genus-BS (Ref. 93245
Trophic level (Ref. 69278
): 3.2 ±0.4 se; based on size and trophs of closest relatives
Resilience (Ref. 120179
): High, minimum population doubling time less than 15 months (Preliminary K or Fecundity.).
Fishing Vulnerability (Ref. 59153
): Low vulnerability (10 of 100) .
Climate Vulnerability (Ref. 125649
): (0 of 100) .