For a number of decades this species was thought to occur throughout much of Madagsacar’s western slope but populations immediately to the north and south of the range described above (see ‘Distribution’) are currently considered to represent unidentified species, while a number of populations from the Mahavavy du Sud and Betsiboka riv…

Described from close to the city of Beira, Mozambique and for many years thought widely-distributed between the Kruger National Park, South Africa to the Kwa-Kwa River north of the Zambezi delta.

Populations from the south and north of this range exhibiting differences in colour pattern and morphology have now been described as N. pienaari and N. krysanovi, respectively, meaning N. rachovii sensu stricto is restricted to the area between the lower Pungwe and Zambezi river basins in eastern Mozambique.

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.

Type locality is ‘Rufiji River near Utete, eastern Tanzania’, and this species is apparently endemic to the lower Rufiji including the Selous Game Reserve and freshwater parts of the Rufiji delta region.

Populations in the aquarium hobby include ‘Rufiji river camp’, ‘Kikongono’, ‘Ruhoi River’, ‘Kanga’, ‘Utete’, ‘Saadani Game Reserve’, ‘Ruvu River’, ‘Bagamoyo’, ‘Makurunge’, ‘Killimani’, ‘Chamakwese’, ‘Nyamwage’, ‘Mohoro’, and ‘Ukuni’.

There exist many different populations of this species in nature, some of which are now threatened or extinct, due to rapid human development in Ghana and the Ivory Coast in recent years. It is not a common fish in the hobby. Interestingly, it appears that F. walkeri occurs as both an annual and non-annual fish. This adaptation allows it to inhabit many different habitats, as it is able to breed in both permananent and temporary bodies of water.
Note that this fish prefers cooler temperatures t…

This species is arguably one of the most misunderstood in the hobby since it's wholly unsuitable for smaller aquaria despite its ubiquitous availability. Most retailers sell it without providing what should be considered essential information regarding long-term care and most specimens undoubtedly fail to reach their potential in captivity. The purchase of a group is also a considerable investment given that if properly cared for typical life span is in excess…

One of the most stunning killifish available, due to the sublime colouration of adult males combined with their impressive maximum size. It was formerly classified as Aphyosemion sjoestedti and much of the available literature still refers to it by this name. There are several colour forms available, including a smaller variety known as "Dwarf Red".

This is not an annual species, occuring only in permanent bodies of water.

Note the cooler temperatures required by this rare species. It is not an annual fish, occuring only in permanent bodies of water.

This species is also known as ‘Gardner’s Killi’ and ‘blue lyretail’ and the commonly-available aquarium forms are perhaps among the best choices for those new to keeping killifishes being relatively hardy, colourful and easy to breed.

A number of ornamental strains have also been line-bred by aquarists including ‘gold’ and ‘albino’.