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).
Environment: milieu / climate zone / depth range / distribution range
Ecology
Freshwater; benthopelagic. Tropical
South America: Columbia and possibly in Brazil and Venezuela.
Size / Weight / Age
Maturity: Lm ? range ? - ? cm
Max length : 2.8 cm SL male/unsexed; (Ref. 130065); 2.5 cm SL (female)
Short description
Identification keys | Morphology | Morphometrics
Males of Rivulus carolinae n. spec., differ from other minute species in the subgenus
Owiyeye, also known as the “rectocaudatus species group”, by the following combination Thus of characters. Body slender and small, dorsal pointed with a small basis, reaching beyond the caudal-fin base; anal fin long but not pointed; pelvic fins exceptional long, reaching from ray 8 to 11 (occasionally to the end of the anal fin base ending) of the anal fin; caudal truncated with straight but “frayed” yellow-white posterior border and reticulated pattern in the central portion; dark stripe starting posterior to the eyes, fading posteriorly on a bright blue background; orange dots on the sides surrounded with fine dark borders; males never express a "Rivulus spot."
Females differ by having all fins rounded; a brown nearly black zone, starting posterior of the caudal peduncle covering one-third of the caudal; the dark zone is divided in two by a thin white line reaching from the dorsal- to the ventral border. Females also differ from those of all known congeners by evincing a rust-color on ventral fins and all unpaired fins as well, and a body with red spots surrounded by a thin black margin on a blueish background. A somewhat similar caudal fin pattern is seen on females of Rivulus uakti from the middle Rio Negro. However, in that species the caudal pattern only covers twothirds of the dorsoposterior portion of the caudal. It differs from R. carolinae n. spec., by evincing different body colors and shorter ventral fins and a dark margin at the anal of females caudal fin. The image to the right shows a variation seen in few wild males only and is likely the result of fighting and in the process of regeneration. (Ref. 130065).
The type locality, a black water creek was located in primary forest under a thick canopy and where water depth was only a few cms, likely due to the flat terrain. The creek is divided into several smaller streams and covered a wide stretch of the forest floor. Rivulus carolinae was taken in leaf litter in the shallowest parts of the stream (Ref. 130065).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Vermeulen, F.B.M. and D.A. Mejia-Vargas, 2020. Two new sympatric species of the aplocheiloid killifish genus Rivulus (s.l.) (Cyprinodontiformes: Rivulidae) from the Alto Rio Negro, Guainía Dpt., Colombia. Killi-Data Series 2020:22-35. (Ref. 130065)
IUCN Red List Status (Ref. 130435: Version 2024-1)
Threat to humans
Harmless
Human uses
Fisheries: of no interest
Tools
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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=0.00661 (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): 3.1 ±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.).
Fishing Vulnerability (Ref.
59153): Low vulnerability (10 of 100).
