Oil catfish

Something a little less commonly seen in stores (in every sense), but becoming more popular in the hobby, is the commonly named Oil catfish, although Honecycomb catfish is also occasionally used. Even going by a scientific name can be awkward as there’s some confusion to the valid name: Duringlanis or Centromochlus. Some stores may even offer them under the synonym of Tatia.

A relative whopper on this list at a maximum size of around 5-6cm, this highly adaptive fish has probably the widest hardness and pH tolerance of all the species here, and offers a chance for those of us in harder water conditions to explore nano catfish.

Duringlanis enjoys a dimly lit setup and is primarily nocturnal. An od-looking creature, it seems to have been designed by committee, with various parts of multiple different catfish genera tossed into the mixing pot. Even its eating and breeding habits are unusual — though spending the bulk of its time on the substrate, it’s a surface feeder (and absolutely thrilling to watch), and it practices internal fertilisation, but then lays eggs.

One word of warning — give them warm conditions, good flow, and plenty of food, and Duringlanis breeds at a rate that will put most livebearers to shame. Be prepared for a glut of youngsters if you get the equation right!