Classification / Names
Common names | Synonyms | Catalog of Fishes(genus, species) | ITIS | CoL | WoRMS | Cloffa
Teleostei (teleosts) >
Characiformes (Characins) >
Alestidae (African tetras)
Etymology: Alestion: Alestion is from Alestes Müller & Troschel 1844 (origin unknown), and the Greek diminutive suffix -ion. Gender masculine. While names ended in -ion classically are of neuter gender, for purposes of zoological nomenclature they may be regarded as masculine, as also with Thrattidion Roberts 1972 and Leptophilypnion Roberts 2013.; rapax: The species epithet rapax is from Greek rapax, an adjective meaning voracious, rapacious, or predatory (Ref. 123194).
Environment: milieu / climate zone / depth range / distribution range
Ecology
Freshwater; benthopelagic; depth range 0 - 1 m (Ref. 123194). Tropical
Africa: Kwilu River, Lower Congo River basin, in Democratic Republic of the Congo (Ref. 123194).
Size / Weight / Age
Maturity: Lm ? range ? - ? cm
Max length : 1.7 cm SL male/unsexed; (Ref. 123194)
Short description
Identification keys | Morphology | Morphometrics
Dorsal spines (total): 0; Dorsal soft rays (total): 10; Anal spines: 0; Anal soft rays: 14; Vertebrae: 39 - 40. Diagnosis: This species differs from all other alestid and all other characiform species in having supposed adults with greatly enlarged conical teeth in two rows on the premaxillary and on the dentary (Ref. 123194). Mouth slightly upturned; jaws short, entirely anterior to eyes; teeth with large round base and sharp slightly recurved tip, evidently specialized for puncturing (Ref. 123194). Head and body laterally compressed, slender; circumorbital bones absent; scales absent; postcephalic laterosensory system absent (Ref. 123194).
Found in river with maximum depth about one meter, width of river 40m; water turbid; bottom sand and gravel; with dense cover provided by Vossia and other aquatic plants on one side of channel (Ref. 123194). Stomach contents appear to be exclusively insect remains (Ref. 123194).
Life cycle and mating behavior
Maturities | Reproduction | Spawnings | Egg(s) | Fecundities | Larvae
Roberts, T.R., 2019. Alestion rapax, a new genus and species of miniature paedomorphic characiform fish with large conical teeth from the Lower Congo basin (Ostariophysi, Alestidae). Aqua, Int. J. Ichthyol., 25(3):85-102. (Ref. 123194)
IUCN Red List Status (Ref. 130435)
Threat to humans
Harmless
Human uses
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Estimates based on models
Phylogenetic diversity index (Ref.
82804): PD
50 = No PD50 data [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01000 (0.00244 - 0.04107), b=3.04 (2.81 - 3.27), in cm total length, based on all LWR estimates for this body shape (Ref.
93245).
Trophic level (Ref.
69278): 3.0 ±0.3 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).
