Classification / Names
Common names | Synonyms | Catalog of Fishes(genus, species) | ITIS | CoL | WoRMS | Cloffa
Teleostei (teleosts) >
Cyprinodontiformes (Rivulines, killifishes and live bearers) >
Rivulidae (Rivulines) > Rivulinae
Etymology: Rivulus: Latin, rivus = stream (Ref. 45335); formosensis: The specific name formosensis alludes to the occurrence of the species in the Formoso river floodplains.
More on author: Costa.
Environment: milieu / climate zone / depth range / distribution range
Ecology
Freshwater; benthopelagic; pH range: 5.6 - ?. Tropical
South America: Formoso river floodplains, upper Corrente river drainage of the upper Paraná river basin in Brazil.
Size / Weight / Age
Maturity: Lm ? range ? - ? cm
Max length : 3.3 cm SL male/unsexed; (Ref. 75995); 3.5 cm SL (female)
Short description
Identification keys | Morphology | Morphometrics
Dorsal soft rays (total): 10 - 11; Anal soft rays: 13 - 15; Vertebrae: 30. Diagnosed from all congeners by the presence of red marks on flank arranged in chevron-like pattern with a branching on the upper portion forming Y-shaped red marks in males. Additional characters not unique but useful to distinguish from all congeners when combined include: flank intense greenish blue, to purplish blue above anal-fin base in males; red marks on flank arranged in chevron-like pattern; sub-basal red stripe on the dorsal fin absent in males; absence of black reticulation on head in females; absence of orange pigmentation on caudal fin in females; 29-31 scales in the longitudinal series; frontal squamation E-patterned; 31-33 caudal-fin rays; pre-dorsal length 75.1-79.5% SL in males; and anal-fin base 20.6-23.0% SL in males; 18.2-20.0% SL in females (Ref. 75995).
Inhabits open areas highly exposed to sunlight (Ref. 75995).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Costa, W.J.E.M., 2008. Rivulus formosensis, a new aplocheiloid killifish from the upper Corrente River drainage, upper Paraná River basin, central Brazil (Cyprinodontiformes: Rivulidae). Ichthyol. Explor. Freshwat. 19(1):85-90. (Ref. 75995)
IUCN Red List Status (Ref. 130435: Version 2024-1)
Threat to humans
Harmless
Human uses
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Internet sources
Estimates based on models
Phylogenetic diversity index (Ref.
82804): PD
50 = 0.5010 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00661 (0.00305 - 0.01429), b=3.10 (2.91 - 3.29), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref.
93245).
Trophic level (Ref.
69278): 3.2 ±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.).
Fishing Vulnerability (Ref.
59153): Low vulnerability (10 of 100).
