Classification / Names
Common names | Synonyms | Catalog of Fishes (gen., sp.) | ITIS | CoL | WoRMS | Cloffa
Actinopterygii (ray-finned fishes) > Perciformes
(Perch-likes) > Cichlidae
(Cichlids) > Pseudocrenilabrinae
Etymology: Haplochromis: Greek, Haploos = single + Greek, chromis = a fish, perhaps a perch (Ref. 45335); argens: In reference to the silver male colouration, H. argens was given the nickname "argens" under the false assumption it was Latinized Greek for silver; since this species is well known under its cheironym, the authors thought it was best to upgrade the nickname to the species' epitheton (Ref. 92860).
Environment / Climate / Range
Freshwater; pelagic. Tropical
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 7.6 cm SL male/unsexed; (Ref. 92860)
Morphology | Morphometrics
Vertebrae: 30 - 32. Diagnosis: Small sized, slender (body depth less than 31% of standard length), micrognathic zooplanktivorous Haplochromis species with slightly curved to straight dorsal head profile. Relatively long and slender, mainly bicuspid, teeth in oral jaws. Premaxillary dentigerous area extending almost to caudal end of dentigerous arm. Both males and females silvery with conspicuously ivory-white lips. Three to five, generally faint vertical stripes on flank; faint traces of a dark mid-lateral band occasionally present. Males with yellow to greenish sheen on flank (Ref. 92860).
Africa: Tanzanian part of Lake Victoria (Ref. 92860).
Haplochromis argens is a pelagic species from the littoral and sub-littoral zone (Ref. 92860). At night the species is virtually restricted to the two upper metres of the water column; by day, the highest densities were found at two to three metres from the surface, but individuals of this species were also caught with bottom trawls over sand and mud bottoms, and in gill nets and traps near rocks (Ref. 92860).
Before the ecological changes in Lake Victoria, the diet of H. argens comprised mainly zooplankton during the day; Chaoborus larvae were important at night (Ref. 92860). The current diet is unknown, but all the studied resurgent species in the Mwanza Gulf changed their diet (Ref. 92860).
Haplochromis argens is a female mouth brooder (Ref. 92860). Spawning sites are located at depths less than 9 metres (Ref. 92860).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Haplochromis argens is a female mouth brooder (Ref. 92860).
de Zeeuw, M.P., M.J.P. van Oijen and F. Witte, 2013. Two new species of zooplanktivorous haplochromine cichlids from Lake Victoria, Tanzania. ZooKeys 256:1-34. (Ref. 92860)
IUCN Red List Status (Ref. 96402)
CITES (Ref. 94142)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningFecundityEggsEgg 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=0.01514 (0.00709 - 0.03231), b=2.97 (2.80 - 3.14), based on LWR estimates for this Subfamily-body shape (Ref. 93245
Trophic Level (Ref. 69278
): 3.3 ±0.4 se; Based on size and trophs of closest relatives
Resilience (Ref. 69278
): High, minimum population doubling time less than 15 months ().
Vulnerability (Ref. 59153
): Low vulnerability (11 of 100) .