Results for “melanism”

This uniquely-shaped rainbow is an uncommonly seen species in the hobby, mainly because it hails from such a remote area in Australia. It is currently listed on the IUCN list of threatened species as being at risk, so all attempts at captive spawning are to be encouraged....

One of the more beautifull-coloured rainbowfish available when mature, M. herbertaxelrodi is probably at risk from overfishing, but not enough data is available to consider it an endangered species as yet....

This beautiful rainbow is not often seen in the hobby. It can be identified by the fact that the middle rays in the dorsal and anal fins are longer than the other fin rays. This feature is usually associated with the closely-realated Glossolepis genus of rainbowfish....

Unfortunately the prisitine environment form where this fish comes is being threatened by overfishing (much of it for the aquarium trade) and industry, with an oil development being built at one end of the lake during the 1990s. M. lacustris has therefore been given "vulnerable" status on the IUCN red list. The lake was designated a Wetland of International Importance in 1998, as both it and the Kikori Basin where it lies contain some of the earth's greatest biodiversity in terms ...

There are a few geographical variants of this species available, which differ in colour, patterning and less commonly, size. These should not be mixed in aquaria, as they may hybridise. The differences are so apparent between some of these forms that they may well turn out to be different species in the future....

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M. trifasciata exhibits a wide variation in colour and patterning depending on locality, and it's very important that the different morphs are not mixed in the aquarium, as they will hybridise freely. These different forms are often distinguished by the addition of the name of collection locality being added to the scientific name of the fish. It's thought that several species may in fact be in evidence here, and a reclassification will probably occur at some point As with many othe...

This fish feeds in a similar way to Geophagus species in that it will sift sand through its gills to extract invertebrates and morsels hidden in the substrate. It was until recently classified in the genus Enatiopus and is still named as such in much of the available literature. There are slight geographical variations in colour but these are not major. Interestingly, the shoals in which these fish live in nature appear to be fixed. That is, that an individual will remain in the same group for ...

This species is often confused with the nominal congeners C. marulius (Hamilton, 1822) and C. melanoptera (Bleeker, 1855) with all three presenting taxonomic problems. For example, C. marulioides exhibits a number of variations in colour pattern depending on collection locality with the most common possessing a brownish base colour with a series of dark, chevron-like markings along each flank and some scales margined posteriorly in white.

Unfortunately, precise diagnostic characters cannot currently be provided since we’ve been unable to obtain the type description, and little has been Characters said to separate it from species such as C. ambiacus, C. agassizii, C. brevirostris, C. ephippifer, and C. melanistius include a combination of relatively elongated snout, dark spots on body fading in adults, dark anterior dorsal-fin patch extending to upper extremity of fin, and presence of spots in the caudal-fin.

This species appears superficially similar to a number of congeners including C. ambiacus, C. agassizii, C. brevirostris, C. delphax, and C. melanistius. Among these C. ephippifer seems to be unique in that all fins except the dorsal are transparent and lack markings.

There also exists a sister-group relationship between the Melanotaeniidae and Malagasy family Bedotiidae, which may seem surprising given their respective modern-day distributional patterns. The precise origin and subsequent dispersal of the two families has been the subject of debate, with some palentologists suggesting that Madagascar's freshwater fishes derived froma trans-oceanic dispersal during the Cenozoic Era, but the most compelling arguments currently indicate a freshwater radiation which occurred during the Mezozoic break-up of Gondwana.

Inhabits ephemeral, water-filled depressions, pools and swamps mostly located in lowland floodplains. Water levels in these seasonally-variable habitats typically decrease during the dry season and eventually become completely dessicated for several months each year. Near Bagamoyo it's been collected from pools of a flat, grassy floodplain alongside the congeners N. annectens, N. janpapi and N. melanospilus, while at Soga it occus together with N. janpapi and N. ocellatus. Most habitats appear to be heavily overgrown with terrestrial vegetation.

This is the most commonly-encountered representative of the genus in the aquatic trade though is by no means common. As in other members of the genus body colouration is highly variable, even among individuals collected from a single locality, although a few useful regularities have been observed which can be used to distinguish certain species. This is thought related to the fact that Acrochordonichthys spp. periodically shed their skins and appear paler post-moulting. A. rugosus lends its ...

The type series was derived from a commercial shipment and this species' natural range remains unconfirmed. It may be restricted to the area between the Kwango and Gamba rivers, the latter a tributary of the former, in western Democratic Republic of Congo. The Kwango is itself a tributary of the Kasai, an affluent of the Congo.

This species can be told apart from the similar-looking congener C. baramensis (once considered synonymous with C. melasoma) by absence (vs. presence) of a black spot in the centre of numerous body scales and absence (vs. presence in specimens larger than 120 mm SL) of a barred caudal-fin pattern.

C. brevirostris was described from an aquarium specimen apparently exported from the Río Orinoco drainage in Venezuela, and its wider distribution is somewhat vague, usually being given as the Orinoco system plus unnamed coastal rivers in Suriname. This represents a somewhat disjunct pattern of distribution and if correct the species is also likely to occur in Guyana.

This species is traded under various vernacular names including 'ember barb', 'banded barb' and 'black spot barb', and is perhaps among the more undervalued small cyprinids in the aquarium hobby being peaceful, relatively hardy, colourful, and of interesting behaviour. It exists in a number of colour for...