Classification / Names
Common names | Synonyms | Catalog of Fishes (gen., sp.) | ITIS | CoL | WoRMS | Cloffa
Actinopteri (ray-finned fishes) > Cypriniformes
(Carps) > Danionidae
() > Danioninae
Etymology: Danio: Vernacular name fron India and Sri Lanka ; annulosus: The species name, annulosus, is a Neolatin adjective meaning ringed, inspired by the color pattern on the side, which resembles series of dark rings.
Environment: milieu / climate zone / depth range / distribution range
Freshwater; benthopelagic. Tropical
Asia: Shuvolong Falls in the Kaptai Lake system in Bangladesh.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 7.2 cm SL male/unsexed; (Ref. 104133)
Morphology | Morphometrics
soft rays: 16 - 18;
Vertebrae: 36. Danio annulosus can be diagnosed from other congeners, except D. assamila, D. dangila, D. catenatus, D. concatenatus, and D. sysphigmatus, by produced first ray in pectoral and pelvic fins, large cleithral spot, and pattern of dark rings enclosing light interspaces on the side. It differs from these species by slightly horizontally extended cleithral spot (vs. vertically extended in D. dangila, round in the other species), anterior interstripe Ia usually present (vs. absent in D. dangila and D. catenatus), rings in series along side elongate, width of each dark ring of about same as diameter of light centre or wider (vs. elongate, with narrower dark ring in D. sysphigmatus, round or slightly elongate and with dark ring about as wide as light centre in other species), ring pattern usually not extending onto caudal peduncle (vs. present on part of caudal peduncle in D. dangila, D. catenatus and D. concatenatus), 34- 35 lateral-line scales (vs. 35-38 in D. sysphigmatus), pectoral fin barely or not reaching to base of pelvic fin, unbranched leading ray only slightly longer than remaining rays (vs. leading ray prominently elongated, reaching to base of unbranched pelvic-fin ray or beyond), pelvic fin without produced unbranched ray, not reaching to vent (vs. with unbranched ray distinctly longer than the rest, and reaching to vent or bases of anterior anal-fin rays) (Ref. 104133).
Found at the foot of a waterfall draining into the Kaptai Lake, a reservoir formed by the damming of the Karnafuli River, completed in 1962. During the wet season, the fall has a height of about 100 m and falls directly into the lake. At the time of collection, the lake level was low: the waterfall had almost ceased and only some dripple moistened the rock. Water was retained in a small pool at the foot of the fall, at most about 40 cm deep, holding some pieces of rock but devoid of vegetation. Specimens were collected using seine from the deeper shadowed area of the pool along with numerous specimens of shrimp, snails, and a small species of Garra. The pool drained to the lake by a small stream, only about 1 cm deep. The following species were caught in the lake at the mouth of the stream using seine: Esomus danrica (Hamilton), Rasbora daniconius (Hamilton) (Cyprinidae), Dermogenys burmanica Mukerji (Zenarchopteridae), Aplocheilus panchax (Hamilton) (Aplocheilidae), and Trichogaster lalius (Hamilton) (Osphronemidae), which are considered ubiquitous species in Bangladeshi freshwaters (Ref. 104133).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Kullander, S.O., M.M. Rahman, M. Norén and A.R. Mollah, 2015. Danio annulosus, a new species of chain Danio from Shuvolong falls in Bangladesh (Teleostei: Cyprinidae: Danioninae). Zootaxa 3994(1):53-68. (Ref. 104133)
IUCN Red List Status (Ref. 123251)
CITES (Ref. 123416)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates based on models
Phylogenetic diversity index (Ref. 82805
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00871 (0.00371 - 0.02044), b=3.05 (2.85 - 3.25), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref. 93245
Trophic level (Ref. 69278
): 3.0 ±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 (16 of 100) .