Chilatherina fasciata (Weber 1913)

Like many rainbowfishes, Chilatherina fasciata often shows great variation in body color and markings depending on location. Throughout New Guinea there are effective natural barriers that isolate various populations, thus contributing to the number of different color variations.

In Nature, Chilatherina fasciata varieties were collected primarily in clear, slow-flowing rainforest streams, generally in deeper pools exposed to sunlight for most of the day. These streams usually have a substrate consisting mostly of gravel or sand and strewn with leaves and other debris. Natural pH and temperature ranges have been reported as 6.2-8.1 and 27-32°C, respectively.

Heiko Bleher has collected live specimens of the Kalibiru variety for the aquarium trade in 1999 from Kalibiru Lake (Lake Nenggwambu) in West Papua. He collected only males and had to return in 2000 for a second time together with Natasha Khardina in order to collect females.

In the Kalibiru Lake there was a vigorously streaming outflow, but no apparent inlet, indicative of a subterranean connection with neighbouring lakes via the limestone substratum.

Water in the Kalibiru Lake was relatively clear and maximum depth was estimated to be at least 10-15m, pH 7.8, and conductivity 60µS/cm. The lake was surrounded by secondary forest and aquatic plants were abundant, but relatively few species were evident.

Fishes were most strongly congregated around the outlet, where vegetation was very dense Glossolepis dorityi was also collected from this location.

In the natural habitat Chilatherina fasciata are swimming near the edge of the lake not at the surface nor near the bottom but all levels of mid water in 1-1.5m depth. They are relaxed, spread out and swim in loose groups during a normal day, form schools if attacked by predators or when travelling.

Chilatherina fasciata are relatively small fishes, males may reach a maximum size of 12cm, but females are usually less than 10cm. Sexual maturity occurs in most species at a relatively small size, usually about 3.5-4.0cm SL in females and 4.5-5.5cm SL in males.

Males of Chilatherina fasciata var. Kalibiru has a body colour of brown to orange on the upper half, light orange to yellowish on the lower half with a diffuse dark mid-lateral stripe. Scales of this region often bordered with pale orange. Males usually have several diffuse blackish bars on the lower sides, above the front half of the anal-fin base; fins dusky yellowish to deep-orange. This particular variety has a broad orange stripe from the tip of its snout to the first dorsal fin.

Males are generally deeper bodied than females, this feature becoming more obvious with increased growth. In addition, the posterior profile of the dorsal and anal fins is more pointed and elongated in males. In contrast to males, which have longer posterior dorsal rays, females have the longest rays at the anterior part of the fin. Finally, mature males are more colourful than females often exhibiting reddish or yellowish dorsal and anal fins. While spawning the males colour becomes very intense and the top of the head radiates a brilliant bronze to vermilion hue.

Females are basically silver to olive overall with clear fins. Perhaps the most distinguishing feature of Chilatherina fasciata is their deep, laterally compressed body that increases with age, particularly in males.

Their diet includes filamentous algae, small crustaceans, terrestrial insects (particularly ants and tiny beetles), and aquatic insect larvae.

The male Kalibiru rainbowfish reaches sexual maturity when he is roughly 5-6cm long, and the female is even smaller at her fist spawning. The male becomes even more colourful than normal during the breeding period. Keep at least 2-3 females for each Kalibiru rainbowfish male in the aquarium, in order to disperse the aggressive tendencies of several individuals. It is also important to make sure that the females have a lot of good hiding spots in the aquarium, especially during the breeding period.

Give your fishes a suitable spawning medium in the aquarium, e.g. Java moss or spawning mops. When the actual spawning has taken place, move the spawning medium with the eggs to a separate container to avoid predation.

Small flake or pellet, small frozen or live foods.

Rainbowfishes are egg scatterers with eggs and sperm ejected simultaneously requiring both sexes for a successful fertile egg laying. Chilatherina species will produce about 40 to 80 viable eggs a day for several consecutive days in a two week period. This amount of egg production will continue during times of good water quality and abundant foods which would occur for several months before, during and shortly after the wet season.

Males with close areas will sometime circle each other flaring their fins. This rarely causes any damage and as it is mostly stylised display to establish male dominance. Rainbowfishes are peaceful towards each other and other species, with the exception of the previously mentioned male displays.

Hatching time for eggs is about 15 days at 22-24°C. The fry can be fed with infusoria and finely grounded flake food until they are big enough to nibble at whole flakes and devour newly hatched brine shrimp.

The young develop rapidly and sexual maturity is attained before the end of their first year.