Classification / Names
Common names | Synonyms | Catalog of Fishes(genus, species) | ITIS | CoL | WoRMS | Cloffa
Teleostei (teleosts) >
Siluriformes (Catfishes) >
Ariidae (Sea catfishes) > Ariinae
Etymology: Potamarius: Greek, potamos = river (Ref. 45335); usumacintae: The specific name refers to the Río Usumacinta basin, where this species occurs.
Environment: milieu / climate zone / depth range / distribution range
Ecology
Freshwater; demersal. Tropical
Central America: endemic to the Río Usumacinta basin in Guatemala and Mexico.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 59.5 cm SL male/unsexed; (Ref. 75770)
Short description
Identification keys | Morphology | Morphometrics
Dorsal spines (total): 1; Dorsal soft rays (total): 7; Anal soft rays: 19 - 23. Distinguished from other freshwater ariids occurring in Mesoamerica by the following combination of characters: presence of accessory tooth patches on palate; premaxillary tooth band length 2.4-2.9 in its width; ; snout length 1.4-1.8 in postorbital length; lateral gill rakers on first gill arch 17-20 (mode 19); mesial gill rakers on first two gill arches well developed; accessory palatal patches with numerous pointed-conical teeth; premaxillary maxillary barbel not extending behind gill membrane; and dorsomedian fleshy groove on head absent (Ref. 75770).
Adults occur only in freshwater, preferring the main channel of medium to large rivers (Ref. 75770). Migratory behaviour is undetermined (Ref. 126106).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Betancur-R., R. and P.W. Willink, 2007. A new freshwater ariid (Otophysi: Siluriformes) from the Río Usumacinta Basin. Copeia 2007(4):818-828. (Ref. 75770)
IUCN Red List Status (Ref. 130435: Version 2025-2 (Global))
Threat to humans
Traumatogenic (Ref. 58010)
Human uses
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Estimates based on models
Phylogenetic diversity index (Ref.
82804): PD
50 = 0.6250 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00468 (0.00245 - 0.00892), b=3.13 (2.96 - 3.30), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref.
93245).
Trophic level (Ref.
69278): 3.7 ±0.4 se; based on size and trophs of closest relatives
Resilience (Ref.
120179): Medium, minimum population doubling time 1.4 - 4.4 years (Preliminary K or Fecundity.).
Fishing Vulnerability (Ref.
59153): Moderate to high vulnerability (49 of 100).
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