Order Cyprinodontiformes
Superfamily Cyprinodontoidae
Family Nothobranchiidae
Continued…
Genus Nothobranchius. N.
— Nothobranchius guentheri [Pfeffer, 1893] — Nothobranchius guentheri. Code: GUE. Synonym: Adiniops, Fundulus guentheri. (Eng. Bluefin Redtail Notho). Eastern Africa, from Kenya to Tanzania, in fresh and brackish waters. 7 cm, females 5 cm. Body elongated. Anal and dorsal fins large, rounded, set far back. Males are richly colored.
The main body color of the male is bluish-green, brown, scales with a burgundy-red edge forming a reticulated pattern on the body. Some individuals also have a vertical or darker chevron-like pattern on the rear part of the body, extending towards the posterior end. The chin is deeply yellow. There are convoluted bright red lines on the gill covers. This coloration extends to the bases of the pectoral fins, which additionally have a light blue stripe.
The dorsal fin is yellow-green with numerous randomly scattered small red dots, and the edge is darker with a light blue stripe. The anal fin is also yellowish with red dots and short strokes. The caudal fin and its base are deeply dark red, the outer edge of the fin ends with a black marginal band. Ventral and pectoral fins are bluish. Females have fins of the same shape and size as males, but unlike them, they are uncolored. They are greenish, pale brown, or bluish with a silvery sheen, and all fins are colorless to transparent without any pattern. There is a golden morph.
The most aggressive species of this genus. A particular issue is the aggression of males towards females when kept together. When keeping only males, they are less aggressive, although they constantly display to each other. They also show some territorial behavior if the aquarium is large enough. A ratio of 3 males to 5-6 spawning-ready females seems to be a quite a compromise for breeding in a spacious aquarium.
If several males are present, the aggressiveness of the dominant male is distributed among several individuals and divided in space and time. In a community aquarium, they chase other fish and can bite the fins of slow ones. They require numerous shelters from dense thickets. Kept in aquariums well overgrown with rootless plants, with a soft bottom (peat layer) and only in the company of related species. Old, peat-filtered water, aeration, weekly water changes.
Food should be varied and necessarily live; the fish often refuse non-living food. Prone to diseases caused by protozoa. For disease prevention, 1 teaspoon of salt per 5 liters of water is added to the aquarium water. In nature, Nothobranchius guentheri lives for one season (several months), then the fish die. In aquariums, life can be extended up to 2 years by keeping the fish at a low temperature of 18-20°C. They mature in 1.5-2 months. Spawns in a peat substrate or soft sand. Spawns for a long time, and numerous spawnings can be observed every day. dH 2-12°; pH 6.5-8; T 20-24°C.
Identification: Nothobranchius guentheri.
— Nothobranchius janpapi [Wildekamp, 1977] — Nothobranchius janpapi. Code: JAN. Subgenus Aphyobranchius. Synonym: Nothobranchius papi. Tanzania. 5 cm. In the male, the main body color is violet-blue, brownish on the back, whitish on the belly, throat yellow. The scales have a thin reddish-brown border. The dorsal fin is yellow-green with a few brown flecks, turning grey-blue at the base, with a thin whitish-blue border.
The caudal fin is yellowish-green, with red strokes on the top and bottom in the proximal part. At the base, the anal fin is yellow, turning into bright orange. Pectoral fins are colorless with a small light blue border. Females are grey-brown, belly and iris are silvery, all fins are colorless. There is an orange-red morph. In males, the extended dorsal fin reaches far beyond the beginning of the caudal peduncle, in females it reaches only the beginning of the peduncle.
They inhabit the upper water layers rather than the lower ones. The aquarium for keeping should be densely planted with water ferns to provide females and weak males with hiding places. Frequent water changes are also necessary for the well-being of these fish. Males are not aggressive towards each other. Stronger males still displace weaker ones to brighter areas of the aquarium.
If the aquarium is spacious enough, torn fins and beaten fish are rarely observed. In a spacious aquarium, several males can be kept simultaneously if there are 10-15 liters of water per each. Putting 2 males in one small aquarium should be avoided; in this case, the stronger male will constantly chase the weaker one or even kill it.
At too high a temperature, lifespan is significantly reduced. Adding salt (1 tsp per 10 l of water) as a preventative measure against velvet disease (oodiniasis). Peculiar to this species is the fact that breeders do not go down to the bottom to lay eggs. Spawning can take place anywhere in the aquarium, preferably in open areas in middle water layers. Thus, this species does not need a layer of peat. In about 3-4 months, males begin to color up, and become sexually mature at 5-6 months. pH 6.8-7.0; dH 9-16°; T 23-25°C.
— Nothobranchius jubbi [Wildekamp & Berkenkamp, 1979] — Nothobranchius jubbi. Code: JUB, CYA. Synonym: Nothobranchius cyaneus. During studies of various populations of N. jubbi and N. cyaneus in 1986, Wildekamp came to the conclusion that these two species should be considered identical. Kenya, Somalia. 8 cm, females smaller. In N. cyaneus males, the caudal fin is blue, while females have a dark V-shaped pattern pointing towards the tail on the distal part of the body. Unlike N. jubbi, N. cyaneus males have a uniform light bluish-green body coloration, brownish on the back.
Unpaired fins are colored in a uniform dark grey color with light grey strokes, creating the impression of a more or less distinct pattern. The caudal fin is surrounded by a thin white border, slightly thicker on the upper edge. A white marginal band can also be seen on the dorsal fin, the tips of the anal rays are also white. Ventral fins are dark grey, pectoral fins are transparent, often with a white marginal band.
A wide, dark grey-blue band on the caudal fin is characteristic. In older males, this zone is often followed by a thin white marginal band. In all sexually mature and active males, the proximal part (adjacent to the body) of the caudal fin has a red coloration, extending onto the caudal peduncle. The intensity of blue coloration may vary depending on the population.
In southern populations, the lower part of the head is mostly light blue, while in lower populations it is light yellowish. The chin area is yellow. The caudal fin is also grey-blue with an indistinct dark pattern forming dark dots, partially forming concentric stripes. The edge is always colored light blue to white. Red dots can be seen around its base in northern populations, which can merge into a single stripe.
Females of N. cyaneus have a light grey-brown to grey-yellow body coloration, more whitish towards the belly and reddish-brown towards the back. Also, scales are bordered by a reddish-brown stripe. On the rear part of the body, females have dark V-shaped body-surrounding lines, the apex of the V-shaped pattern points backward and lies on the middle longitudinal line of the body. Unpaired and ventral fins are grey-brown, reddish near the base, then colorless. Pectoral fins are completely colorless.
In N. jubbi males, blue, red, or intermediate coloration is observed. The body color of males is grey-blue, darker on the back and lighter to whitish on the belly. Scales are bordered by a thin dark border, forming a reticulated pattern over the entire body. The dorsal fin is grey-blue with numerous dark dots, sometimes merging into irregular strokes. The anal fin is light grey-blue with a small number of dark specks on the outer part. The caudal peduncle and the front part of the caudal fin are red (grey-blue in young individuals), followed by a wide dark grey-blue border (disappearing or strongly reduced with age in males).
Ventral fins are light bluish, pectoral fins are colorless with a light blue edge. Pectoral and anal fins are colorless with a light bluish to white border. There is a dark marginal band on the ventral fins running along the base of the fin. A similar dark stripe can be found at the base of the dorsal fin. These lines first go in fragments, then in groups of small dots from the base to the outer edge of the fin. There is a whitish marginal band on the caudal fin, and two dark to deep red circular bands at the base.
Scale edges are dark red or darker. In populations with intermediate characteristics relative to N. jubbi, red dots can also be found in the central part of the caudal fin. The dorsal and anal fins are colored the same as the caudal fin, but intermediate populations never show a red pattern. The white border on the caudal and dorsal fins is also present.
Females of N. jubbi are colored light blue to light brown. At the mid-body level on the lower side, there are small dark specks. A thin dark vertical stroke runs in the rear part of the body. A thin grey border, sometimes appearing as a spot, is present on the scale edges. Several shiny scales are located behind the gill covers. All fins are colorless, except for the caudal fin, which may have dark specks. Fin rays in the anal and caudal fins are often slightly golden.
Several pairs of fish can be kept in a medium-sized aquarium, providing shelters for females and weak males. Dense vegetation and a few pieces of fibrous peat are sufficient for this. Juveniles grow very quickly, and with frequent water changes and heavy feeding, they can reach sexual maturity at the age of 4-6 weeks. They are very active and constantly looking for food or a partner. They require heavy feeding consisting of various mosquito larvae and worms. When startled, they jump out of the water. This behavior is unique among Nothobranchius, as almost all species swim towards the bottom and even hide in the substrate when suddenly startled.
For normal growth and good health, it is recommended to use clean, fresh water. These fish grow quite fast and are very active, which implies mandatory regular partial water changes. Adding salt (1 tsp of salt per 5-10 liters of water) as a preventative measure against ooliniasis is also recommended. Water hardness plays only a secondary role when keeping, as hardness values from 5 to 40° dH are observed in nature. pH 6.5-8.0, temperature 24-26°C.
Nothobranchius kafuensis, korthausae, kiyawensis, luekei.
Nothobranchius foerschi, Nothobranchius furzeri, Nothobranchius fuscotaeniatus. 
