Elephantnose fish

The elephantnose fish is one of the most fascinating oddball species available to the aquarium hobby, thanks to its unique proboscis-like lower lip, weak electric field generation, and relatively large brain. It has a vast distribution across West and Central Africa, recorded from Mali to Zambia, inhabiting the dark, muddy beds and heavily-vegetated areas of slow-moving rivers. Adults reach approximately 22.5 cm (9 inches) in standard length.

This is a nocturnal, quiet but territorial species. It is peaceful towards other species but should not be kept with very active or aggressive fish, as it will be out-competed at feeding time. It also does not mix well with other mormyrids. If keeping more than one, purchase at least five specimens to disperse aggression within the group. A tank of at least 255 litres (120cm x 45cm x 45cm) is required, with dim lighting, plenty of cover, and critically, a soft sand substrate — the fish uses its trunk-like lip to probe for food in the substrate and sharp-edged gravel will damage its mouthparts.

Water conditions should be 23-28°C, pH 6.0-7.5, with moderate hardness. Diet is unfussy and includes a range of dried, frozen, and live foods, with worms being a particular favourite. The elephantnose is very sensitive to deteriorating water conditions and to many aquarium medications (being scaleless). It uses a weak electric field for navigation, prey detection, and communication with conspecifics in total darkness — one of the most remarkable adaptations in the freshwater aquarium world.