Dashing Danios

Seemingly imbued with boundless energy. Perpetually inquisitive. Danios are firm favourites with tropical fishkeepers, and have been from the outset of the modern hobby. The Zebra danio (Brachydanio rerio) is too well known to need description. As one of the most prolific egg-laying tropical fish it has been available in large numbers at bargain prices since its introduction to the hobby at the beginning of the century. Endemic to India, Zebra danio stocks are occasionally shipped from there to the world’s aquarium markets. But most supplies will have been commercially bred in Hong Kong, Singapore, Florida, and other established centres of fish breeding.
Long finned varieties and golden forms of Zebra danios enhance the attraction of the species to many fishkeepers. Long finned varieties of Pearl danios (B. albolineatus) and Leopard danios (B. frankei) are also freely available now. One species which sed to be readily available to the UK markets up to some 20 years ago was the aintily marked Spotted danio (B. nigrofasciatus). But it is now something of a rarity to the hobby. Why this pretty little danio disappeared from commercial breeding programmes is not known, but it might be that it was ousted by the Leopard danio when it made its debut to the hobby.
The origins of the Leopard danio are uncertain. It just “appeared” to the hobby in 1963 and is thought to have resulted from crossing other Brachydanio species…probably in Eastern Europe. A first generation cross between Zebra and Pearl danios maybe give a clue to the actual origins of the Leopard danio.
Wherever the strain originated it has become a firm favourite with hobbyists across the world.
Colour variations are producing some very eye-catching danio varieties. The Golden zebra is questionably an “improvement” on the original wild fish. The golden caste masks the stark contrast between the steel-blue body horizontally embellished with silver or brassy stripes. A colourful variety of the Pearl danio has been dubbed the Rainbow danio. This variety has lost the distinct lateral stripe of the regular form, and retains only a shadow of that feature. The shining pearly body has metallic blue and red areas. A Blue danio has resulted from “sports” of Leopard danio breeding. The spotted markings have diminished appreciably, leaving a silvery-blue colouring in prominence. Also the Zebra Danio and Leopard Danio have been developed with long fins.
Long finned varieties and golden forms of Zebra danios enhance the attraction of the species to many fishkeepers. Long finned varieties of Pearl danios (B. albolineatus) and Leopard danios (B. frankei) are also freely available now. One species which sed to be readily available to the UK markets up to some 20 years ago was the aintily marked Spotted danio (B. nigrofasciatus). But it is now something of a rarity to the hobby. Why this pretty little danio disappeared from commercial breeding programmes is not known, but it might be that it was ousted by the Leopard danio when it made its debut to the hobby.

The origins of the Leopard danio are uncertain. It just “appeared” to the hobby in 1963 and is thought to have resulted from crossing other Brachydanio species…probably in Eastern Europe. A first generation cross between Zebra and Pearl danios maybe give a clue to the actual origins of the Leopard danio. Wherever the strain originated it has become a firm favourite with hobbyists across the world.

Colour variations are producing some very eye-catching danio varieties. The Golden zebra is questionably an “improvement” on the original wild fish. The golden caste masks the stark contrast between the steel-blue body horizontally embellished with silver or brassy stripes. A colourful variety of the Pearl danio has been dubbed the Rainbow danio. This variety has lost the distinct lateral stripe of the regular form, and retains only a shadow of that feature. The shining pearly body has metallic blue and red areas. A Blue danio has resulted from “sports” of Leopard danio breeding. The spotted markings have diminished appreciably, leaving a silvery-blue colouring in prominence. Also the Zebra Danio and Leopard Danio have been developed with long fins.

One of the “close cousins” of the little Brachydanio species is the Dadio (Chela dadyburjori). This pretty little fish looks very much like a danio, and certainly comes from the same huge family of Cyprinidae. But its sub-family is Cultrinae, unlike the Brachydanio species which are of the sub-family Rasborinae. However, for the hobbyist such scientific quibbles are not important, and this stylish little fish might well have been given a common name of a “something” danio! The body shape is a little deeper and the finnage more elongated than that of the Brachydanios. The Dadio is also somewhat less robust, although once acclimatised to its surroundings it will flourish without special attention.

The Giant danio (Danio aequipinnatus) from Sri Lanka has become something of a mystery fish through domestic breeding. The wild form has a broken patchwork of yellow markings on the lower part of its flanks and immediately behind the gills. It might also have reddish anal and caudal fins. A similar looking fish is the Queen danio (Danio regina) from S.E. Asia which has quite distinct lines running laterally through the body, and rather richer colouring. Farm bred fish might have some blood from either strain in their stock, as they frequently match up to neither wild form, but seem to combine features from both. Growing to about 10 or 11 cms this is truly a giant amongst the other tiny members of the sub-family Rasborinae.

Metallic blues, greens, and golds are the predominant colours associated with the “danios and cousins”, making a handsome contrast to more gaudily coloured companions in the peaceful community aquarium. Constant busy movement is a common feature, and a propensity to move in shoal formation. Brachydanio species will usefully occupy the upper levels of the aquarium, whilst the other species tend to be mid-water swimmers. Taking a wide variety of foods and mostly proving to be easily bred without undue fuss or preference, the danios are an ideal beginners fish, adding dash and delight to the aquarium.

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