Australia

This species is not traded for aquaria but is occasionally exported as bycatch among shipments of other species. It differs from congeners in that the outermost row of teeth are not enlarged plus the interorbital space and cheek below eye are not scaled. Butis spp. are largely nocturnal ambush predators with cryptic...

Butis spp. are largely nocturnal ambush predators with cryptic patterning to help them blend in with their surroundings. They can also lighten and darken their body colouration to an extent, have a habit of aligning themselves with solid surfaces whether horizontal, vertical, or inverted, and often swim in an upside-down position. The genus is usually included in the family Eleotridae of which members are often referred to...

Lake Eyre is a vast endorheic basin within which lies the lowest point in Australia at some 15 m BMSL. It only fills with water occasionally and when it does so forms the country's largest salt lake. C. eremius does not occur in the lake itself since no fishes are able to survive there, rather it inhabits isolated freshwater springs, flowing artesian bores (wells), and ephemeral waterholes where it tends to be associated with rocks and other submerged cover.

Occurs in northern and eastern Australia and southern New Guinea. In the former its range extends from the Pilbara and Kimberley regions of Western Australia state around the northern and eastern coastlines of the continent as far as the Towamba river system in New South Wales state.

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.

Type locality is ‘Nicol Bay, Cape York, Queensland, Australia’, and this species is restricted to the tips of northern Australia and southern Papua New Guinea. In Australia records exist only from the Jardine and Jackson river systems on the Cape York Peninsula, while in Papua New Guinea it’s known from the Fly River plus some other drainages.

Euryhaline and thus capable of withstanding significant fluctuations in salinity and other water conditions. It's been recorded in full marine conditions as well as pure freshwater environments, and commonly inhabits coastal mangrove creeks and swamps. Such changes may occur on a daily or seasonal basis depending on locality, with some habitats influenced by daily tides whereas others become hypersal...

Described from 'Rivulet in sago forest at Ngaiguli, Terangan, Aru Island, Aru Islands, Maluku, Indonesia', corresponding to the island now normally referred to as 'Trangan' in the Aru Islands group, eastern Indonesia. The islands are located in the Arafura Sea, with western New Guinea to the north and the Arnhem Land Region of Australia's Northern Territory to the south, and though they lie within Maluku province of eastern Indonesia, are part of the Australian continent in a geological sense.

Generally found within 15-20 km of the sea but habitat-type is extremely variable. It's been recorded in full marine conditions as well as pure freshwater environments, and commonly inhabits coastal mangrove creeks, swamps, and salt marshes. Freshwater habitats tend to comprise lowland swamps or forest streams with clear water but some populations inhabit acidic, tannin-stained, black waters. It's also abundant in the artificial canals typical of residential zones in the Gold Coast, southern Queensland.

Euryhaline and mostly inhabits coastal floodplains where it's found in both fresh and brackish habitats, including tidal estuaries and salt marshes. It's particularly common in swamps, billabongs, and slow-moving streams where aquatic vegetation grows densely, but some populations have colonised upper sections of freshwater streams. Larger individuals may also move into main river channels. Tappin (2010) gives the following ranges of parameters based on those taken from various localities: temperature 27 - 38 °C, pH 5...

Wild swordtails are a fairly basic green colur. However the vast majority of swordtails available in the hobby today are hybrids of X.helleri with X.maculatus or X.variatus. There are a huge number of selectively-bred varieties available, including wagtail, lyretail, tuxedo, albino, neon, red, green and hi-fin. Swordtails may undergo what appears to be a change in sex. In young fish this may simply be late development. However some adult females develop male characteristics which is thought ...

Occurs naturally in Brazil, Paraguay, Uruguay and Argentina with feral populations in Australia, New Zealand, Ethiopia and Malawi which were purportedly introduced for purposes of mosquito control but are now considered invasive. Following Lucinda (2008) its natural range comprises the Lagoa dos Patos system, lower rio Uruguai, rio Tramandaí, and rio Mampituba in Rio Grande do Sul st...