Classification / Names
Common names | Synonyms | Catalog of Fishes (gen., sp.) | ITIS | CoL | WoRMS | Cloffa
Actinopterygii (ray-finned fishes) > Atheriniformes
(Silversides) > Bedotiidae
Etymology: Rheocles: Greek, rheos = stream + Greek, kles, kleis = straits; vatosoa: Named for its jewel-like coloration (vatosoa a Malagasy word for crystal or gemstone); noun in apposition.
Environment: milieu / climate zone / depth range / distribution range
Freshwater; pelagic. Tropical
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 7.9 cm SL male/unsexed; (Ref. 42716)
(total): 5 - 7;
soft rays: 14 - 18;
Vertebrae: 35 - 38. Different from other congeners by possessing a single interdorsal pterygiophore (versus 3). Distinguished from R. sikorae and R. wrightae by having a shorter upper jaw (32.3-43.7%HL vs. 46.2-59), and the absence of black pigmentation of genital papilla; from R. pellegrini and R. derhami by the full squamation of the nape and chest (vs. naked or partially scaled); from R. lateralis by a shorter caudal peduncle (49-79.8 %SL vs. 84.6-96); and, from R. alaotrensis by predorsal scale row implantation (irregular vs. single row), and longer anal fin base (24.1-30.4 %SL vs. 17.2-21.7 %SL) (Ref. 42716).
Collected in the upper and middle reaches of the Lokoho river in the general vicinity of the town of Andapa. Found predominantly in clear streams over gravel or coarse sand bottoms. This streams are characterized by soft, slightly acidic to moderately alkaline water; total and carbonate hardness values < 1°DH and pH 6.8-7.5. Collected from both rapidly flowing rivers and small brooks. Stomach contents almost exclusively of macerated insect remains, most of terrestrial origin. A few remains of aquatic insect larvae suggesting a somewhat opportunistic feeding (Ref. 42716).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Stiassny, M.L.J., D.M. Rodriguez and P.V. Loiselle, 2002. Rheocles vatosoa, a new species of freshwater rainbowfish (Atherinomorpha: Bedotiidae) from the Lokoho River basin in Northeastern Madagascar. Cybium 26(1):71-77. (Ref. 42716)
IUCN Red List Status (Ref. 119314)
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
= 0.5078 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00389 (0.00180 - 0.00842), b=3.12 (2.94 - 3.30), in cm Total Length, based on all LWR estimates for this body shape (Ref. 93245
Trophic Level (Ref. 69278
): 2.6 ±0.28 se; Based on food items.
Resilience (Ref. 69278
): High, minimum population doubling time less than 15 months ().
Vulnerability (Ref. 59153
): Low vulnerability (10 of 100) .