Classification / Names
Common names | Synonyms | Catalog of Fishes (gen., sp.) | ITIS | CoL | WoRMS | Cloffa
Actinopterygii (ray-finned fishes) > Characiformes
(Characins) > Crenuchidae
(South American darters) > Characidiinae
Etymology: Characidium: Diminutive of Charax, -akos = a fish without identification (Ref. 45335); summus: From the Latin summus, which means high, elevated, alluding to the high altitude where the species occurs, near Pico Tracoá, higher than 1100 m above sea level in the Serra dos Pacaás Novos (Ref. 104900).
Environment: milieu / climate zone / depth range / distribution range
Freshwater; benthopelagic; pH range: ? - 3.6. Tropical; ? - 22°C
South America: only known from upper rio Pacaás Novos, a tributary of rio Mamoré, rio Madeira basin, Rondônia State, Brazil (Ref. 104900).
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 4.2 cm SL male/unsexed; (Ref. 104900)
Morphology | Morphometrics
soft rays: 8 - 9;
Vertebrae: 36. Diagnosis: Characidium summus is a unique species among congeners by lacking an adipose fin and having a complete lateral line; can be further distinguished from congeners, including C. vestigipinne, that have complete lateral line and adipose fin absent, vestigial or reduced by the absence of dark bars or spots on head, body or fins, except for a dark blotch immediately on the rear of opercle, a narrow midlateral dark stripe (less than half scale deep), and a dark basicaudal spot (Ref. 104900).
The rio Pacaás Novos is a black water river, with moderate water current and predominantly rocky bottom; specimens of C. summus were sampled in small puddles (1-4 m wide and 1.5 m deep) and laterally in the river backwaters (Ref. 104900).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Zanata, A.M., L.M. Sarmento-Soares and R.F. Martins-Pinheiro, 2015. A new species of Characidium Reinhardt (Ostariophysi: Characiformes: Crenuchidae) from coastal rivers in the extreme south of Bahia, Brazil. Zootaxa 4040(3):371-383. (Ref. 104900)
IUCN Red List Status (Ref. 120744)
CITES (Ref. 115941)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg 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=0.01023 (0.00328 - 0.03191), b=3.06 (2.81 - 3.31), in cm Total Length, based on LWR estimates for this (Sub)family-body shape (Ref. 93245
Trophic Level (Ref. 69278
): 3.3 ±0.3 se; Based on size and trophs of closest relatives
Resilience (Ref. 69278
Vulnerability (Ref. 59153
): Low vulnerability (10 of 100) .