Actinopteri (ray-finned fishes) > Cyprinodontiformes
(Rivulines, killifishes and live bearers) > Nothobranchiidae
Etymology: Nothobranchius: Greek, nothos = false + Greek, brangchia = gill (Ref. 45335); rachovii: Named in honour of Arthur Rachow (Ref. 97289). More on author: Ahl.
Environment: milieu / climate zone / depth range / distribution range
Freshwater; benthopelagic; pH range: 6.0 - 7.0; dH range: 4 - 6; non-migratory. Tropical; 20°C - 24°C (Ref. 1672); 19°S - 20°S
Africa: temporary pools and swamps or water-filled depressions in the lowland floodplains of the lower Pungwe River and lower Zambezi River (Ref. 85866), probably also in floodplains of other rivers between Pungwe and Zambezi River (Ref. 85866).
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 6.0 cm TL male/unsexed; (Ref. 27139)
soft rays: 15 - 18. Diagnosis: Nothobranchius rachovii is distinguished from other species of the genus by the following combination of characters: in males, a bright colouration consisting of alternating light blue and orange-red bars on the body and fins, orange-red head, and orange subterminal and black terminal bands in the caudal fin (Ref. 85866). It can be distinguished from the other species of the subgenus Nothobranchius as follows: from N. furzeri by male colouration, higher number of dorsal fin rays, 15-17 vs. 14-15, and a lower number of scales on the mid-longitudinal series, 26-28 vs. 28-30; from N. orthonotus by male colouration, lower number of scales on the mid-longitudinal series, 26-28 vs. 28-33, and shape of the dorsal profile, convex vs. flat; and from N. kadleci by male colouration and shape of the frontal region, higher number of dorsal and anal fin rays, 15-17 vs. 13-14 and 15-17 vs. 13-14 (Ref. 85866). Females can be distinguished by the presence of a reflective light blue spot on all scales of the flanks, vs. few, irregularly dispersed light blue-green spots in N. furzeri and N. kadleci or frequent presence of brown spots on body and fins in N. orthonotus (Ref. 85866). Nothobranchius rachovii can also be distinguished from all other species of the genus by its low number of diploid chromosomes, 2n=16 (Ref. 85866).
Found in water-filled depressions in the floodplains of rivers; water depth is variable and decreases as the dry season progresses, eventually drying out completely (Ref. 85866). Littoral vegetation usually consists of grasses; aquatic vegetation may consis of Nymphea, Ottelia, Lagarosiphon and Utricularia species; occasionally, the swamps are used by local inhabitants to cultivate rice (Ref. 85866). Very difficult to maintain in aquarium (Ref. 27139).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Annual fish. Matures after 12 weeks. This updates previous information from Ref. 1672.
Shidlovskiy, K.M., B.R. Watters and R.H. Wildekamp, 2010. Notes on the annual killifish species Nothobranchius rachovii (Cyprinodontiformes; Nothobranchiidae) with the description of two new species. Zootaxa 2724:37-57. (Ref. 85866)
IUCN Red List Status (Ref. 123251)
CITES (Ref. 123416)
Threat to humans
Fisheries: ; aquarium: commercial
Estimates based on models
Phylogenetic diversity index (Ref. 82805
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01072 (0.00442 - 0.02595), b=2.92 (2.71 - 3.13), 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 ().
Vulnerability (Ref. 59153
): Low vulnerability (10 of 100) .