Rainbow Shiner (Notropis chrosomus)

Rainbow Shiners are peaceful shoaling fish that are best kept in groups of six or more individuals. It would be more beneficial if you try and get a mixture of both females and males to assure that the males have potential mates to display to and rival males to show off to. These fish are Unfussy and adaptable cold water fish suitable for a variety of different water temperatures.

The aquarium needs to be spacious, established and well filtered with a decent current from additional powerheads. You will also need to provide your fish with plenty of hiding places using things like rocks, bogwood and robust planting.

Rainbow Shiners mix well with other fish of a similar temperament and size that also enjoy the same fast-flowing conditions as they do. Ideal tankmates could include the torpedo-shaped Nemacheilid loaches such as Nemacheilus, Schistura and Mesonoemacheilus, which will occupy the lower levels of the aquarium, as well as subtropical Botiid Loaches.

Weather Loaches would also be suitable, providing your tank is large enough to accommodate these inquisitive bottom dwellers. Rhinogobius sp. Gobies also make excellent companions. Although Rainbow Shiners are generally peaceful species, it would be better if you avoided long-finned tankmates.

Rainbow Shiners have elongated streamlined bodies. Their bodies are an iridescent pinkish colour that displays a bright golden band along the midline of the flank from behind the operculum to the base of the tail fin. The anal, dorsal and pelvic fins are marked with orange or red blotches.

Habitat

Rainbow Shiners are a North American species that has been recorded from several states in the southeast of the United States of America, including Alabama, Tennessee and Georgia. This species was formerly endemic to the Mobile River drainage, including the Cahaba, Coosa and Alabama river drainages but has since spread elsewhere. They inhabit fast-flowing waters in small rivers, creeks, springs, streams, pools and riffles with gravel or sandy substrates.

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Diet & Feeding

Some describe the Rainbow Shiner as a drift feeder in the wild because it feeds on small aquatic objects such as invertebrates and plant matter drifting past in the current. In the aquarium, these fish will readily accept good quality dried food such as flakes and micro granules as well as small frozen and love foods such as daphnia, mosquito larvae and vitamin-enriched brine shrimp.

Sexual Dimorphism

It is relatively straightforward to distinguish male from female Rainbow Shiners. Males are typically slimmer and more brightly coloured than females. During the breeding season, both sexes develop tubercules on their heads and bodies. Another interesting fact is that females live longer than males.

Breeding

In their natural habitats, Rainbow Shiners spawn during the late spring to early summer. Rainbow Shiners reach sexual maturity around 12 months of age. They increase their food intake during the late winter and spring months before spawning to meet the increased energy needs for gamete production and sexual reproduction. These fish breed pretty readily in the home aquarium and may be triggered into spawning by slightly raising the water temperature.

When in breeding condition, the males will experience a dramatic colour change. The back, head and fin bases will turn a metallic purplish-blue colour, and they will display a silver stripe that will run along each side of the body. The males will build nests in the substrate or available rocks, become very territorial, and defend their nests.

Both parents will predate on the eggs, so it is advised that you remove them to another aquarium once spawning has ceased.

Although largely temperature-dependent, the eggs should hatch within a week and become free-swimming around a week later. You can feed the fry on infusoria type foods until they are big enough to accept crushed flake food and baby brine shrimp.

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