Classification / Names
Common names | Synonyms | Catalog of Fishes (gen., sp.) | ITIS | CoL | WoRMS | Cloffa
Actinopterygii (ray-finned fishes) > Cyprinodontiformes
(Rivulines, killifishes and live bearers) > Rivulidae
Etymology: Rivulus: Latin, rivus = stream (Ref. 45335); tomasi: Named for the German aquarist, adventurer and fish collector Joachim Tomas, co-collector of the species during a survey in 2010.
Environment: milieu / climate zone / depth range / distribution range
Freshwater; benthopelagic. Tropical
South America: Venezuela.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 3.7 cm SL male/unsexed; (Ref. 94444); 3.2 cm SL (female)
Morphology | Morphometrics
soft rays: 13 - 14. This species is distinguished by the following characters: males with red longitudinal stripes between the rays of the caudal fin, yellow stripe near dorsal and ventral fin margin; females possess brown spots between caudal fin rays; pelvic fins in males moderately long, reaching between 4th and 5th anal fin ray; fin rays, dorsal 8-9, anal 13-14; caudal 30-32; lateral scale rows 39-42 (Ref. 94444).
Collected alongside a fast running part of a creek that flows down a boulder-strewn area, with a fall of approximately one in every five meters, a place where people find leisure and can slide down the rocky face. This rocky open area is surrounded by a primary forest. This species lives between tree roots and fallen leaves attached to boulders at the edges of the stream, and between boulders. It was also collected a in places where the water ran slower, but was not found in still water surrounding the rocky waterslide. At the time of collection (September 2006), the water at the collecting site was clear, pH 7, 27.6°C, conductivity was <1 ?S/cm. (Ref. 94444).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Vermeulen, F.B.M., S. Valdesalici and J.R. Garcia-Gil, 2013. Rivulus tomasi (Teleostei: Cyprinodontiformes: Rivulidae), a new killifish from Tobogán de la Selva, middle Orinoco river drainage in the Amazonas Territory, southwest Venezuela. Aqua Int. J. Ichthyol. 19(4):187-192. (Ref. 94444)
IUCN Red List Status (Ref. 120744)
CITES (Ref. 118484)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates based on models
Phylogenetic diversity index (Ref. 82805
= 0.5010 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00479 (0.00199 - 0.01154), b=3.14 (2.93 - 3.35), in cm Total Length, based on LWR estimates for this (Sub)family-body shape (Ref. 93245
Trophic Level (Ref. 69278
): 3.1 ±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.).
Vulnerability (Ref. 59153
): Low vulnerability (10 of 100) .