Actinopteri (ray-finned fishes) > Osteoglossiformes
(Bony tongues) > Mormyridae
Etymology: Petrocephalus: Latin, petra = stone + Greek, kephale = head (Ref. 45335); similis: The specific epithet similis is given in reference to the resemblance between this new species and P. sullivani (Ref. 87308).
Environment: milieu / climate zone / depth range / distribution range
Freshwater; benthopelagic. Tropical; 7°N - 6°N, 12°E - 13°E
Africa: Djerem River, upper Sanaga basin in Cameroon (Ref. 87308).
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 11.9 cm SL male/unsexed; (Ref. 87308)
Morphology | Morphometrics
Diagnosis: Petrocephalus similis is distinguished from all other Petrocephalus species of Central Africa by the following combination of characteristics: body coloration gold/silver-white without melanin mark; 22–24 branched rays in the dorsal fin and 28-29 branched rays in the anal fin (Ref. 87308). Petrocephalus similis can be further distinguished from P. simus by its mouth opening under the posterior half of the eye vs. the anterior half of the eye in P. simus); its relatively deep caudal peduncle, the ratio caudal peduncle length and caudal peduncle depth between 2.2 and 2.6 vs. 2.8 in P. simus; and its greater number of scale rows between the anterior base of the anal fin and the lateral line, 16 or 17 vs. 12 in P. simus (Ref. 87308). Petrocephalus similis can be further distinguished from P. sullivani, by its proportionally larger mouth, the ratio head length and mouth width between 3.9 and 4.5 vs. 4.8 in P. sullivani; wider head, the ratio head length and head width between 1.6 and 1.9 vs. 2.0 in P. sullivani; and its shorter caudal peduncle, the ratio standard length and caudal peduncle length between 6.3 and 7.5 vs. 6.3 in P. sullivani (Ref. 87308). From the six Nilo-Sudanian species occurring in the Niger and Chad basins bordering the upper Sanaga, P. similis is easily distinguished from Petrocephalus pallidomaculatus, Petrocephalus soudanensis and Petrocephalus ansorgii by its complete absence of large melanin sub-dorsal spot; from Petrocephalus bane and Petrocephalus sauvagii, by its smaller mouth and fewer branched rays in the dorsal and anal fins; and from Petrocephalus bovei, by its fewer branched rays in the dorsal and anal fins and its larger maximum standard length (Ref. 87308).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Lavoué, S., 2011. A new species of Petrocephalus Marcusen 1854 (Osteoglossomorpha: Mormyridae) from the Sanaga River basin, Cameroon. Zootaxa 2934:20-28. (Ref. 87308)
IUCN Red List Status (Ref. 123251)
CITES (Ref. 123416)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass 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 (0.00704 - 0.03738), b=2.83 (2.65 - 3.01), 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
): High, minimum population doubling time less than 15 months (Preliminary K or Fecundity.).
Vulnerability (Ref. 59153
): Low vulnerability (14 of 100) .