|Synonyms||Gnathonemus brevicaudatus, G. histrio, Mormyrus petersii|
|Distribution||Angola, Cameroon, Central African Republic, Chad, Congo, Democratic Republic of the Congo, Nigeria, and Zambia.|
|Maximum Size||25cm (9.8")|
|Temperature||22-28 deg C (72-82 deg F)|
|Water Parameters||pH: 6.0-7.5, dH: up to 15 degrees.|
|Compatibility||Community of medium-sized peaceful fish only.|
The Long-nosed Elephant Fish has a widespread distribution across the Congo and Niger River basins, where it is most commonly found in dark, slow-flowing, heavily vegetated waters with sandy or silty substrates. This unusual nocturnal fish has a long, highly sensitive trunk-like extension on the chin, which it uses to probe for food items in the substrate, with the small round mouth located just above it. For this reason, it absolutely must be provided with a soft sand substrate in the home aquarium - gravel is simply not suitable and will cause unnecessary stress and possibly damage. Like other Mormyrids, the Long-nosed Elephant Fish is capable of producing a weak electrical field. The specialised electric organ which discharges the pulses is located in the caudal peduncle, with cutaneous electro receptors distributed over much of the body (including the 'trunk'). This ability to generate an electric field allows the fish to navigate in darkness or in turbid waters, sense the tiniest of movements around it in order to find food and avoid predators, and also to communicate and find a suitable mate. This electrosensory system is relatively weak as far as electric fish go, so poses no risk to the aquarist. This is an endearing fish which does have some specialist care requirements, in addition to the aforementioned sandy substrate. Firstly, it attains a large size, so a spacious aquarium (at least 5ft long and a minimum 2ft wide) is a must. Secondly, it must be provided with a choice of shady hiding spots e.g. PVC tubes, rocky caves/overhangs (do ensure such structures are stable), and large tangles of driftwood. The lighting should not be too bright as these nocturnal fish are sensitive to intense illumination; if the tank must be brightly lit in some areas, provide plenty of broad leaved aquatic plants and floating species to help diffuse the light. Nonetheless, there absolutely must be areas of darkness within the tank that the fish can retreat to during the day as necessary. Filtration should be efficient, but water movement fairly gentle, and there should be a consistent maintenance regime in place encompassing regular partial water changes, as these fish are sensitive to elevated nitrate and sudden changes in water chemistry. Long-nosed Elephant Fish are somewhat timid and generally peaceful with other fish, but they are rather territorial with their own kind and closely related species. It is best to keep just one to a tank and not with any other elephantnose species, unless the aquarium is extremely voluminous. In such aquaria, a group of 6 or more could be maintained together, but there must be ample swimming room and a plethora of visual barriers. It is not a good idea to try and maintain a smaller group than this, as the dominant fish will pick on the weaker individuals, often with disastrous consequences. This way, no one fish will bear the continual brunt of any territorial aggression. Also worth bearing in mind, is that in the confines of the home aquarium, electrogenic fish can sometimes become stressed by the presence of other such species due to their electrical fields overlapping, so abundant space is absolutely essential to their long-term wellbeing. Tankmates should be medium-sized and of a peaceful nature, and good companions could include African Butterfly Fish, Angelfish, bichirs, Ctenopoma spp., Geophagus spp., gouramis, large deep bodied tetras such as Phenacogrammus spp., Synodontis catfish etc. Avoid housing with any aggressive or boisterous species, as otherwise the elephantnoses will be outcompeted at feeding time. Blue moon lighting, timed to come on just before the main lights switch off in the evening, is useful in observing your fish for a few hours under the preferred subdued lighting. Hopefully, if the tank is maintained appropriately and new fish are quarantined carefully before adding the main aquarium, the need for medications should not arise. However, if treatment is required, take much care as these fish are classed as 'scaleless' and are particularly sensitive to medications (always check with the manufacturer before using - some treatments are not safe, and others may need half dosing). Many aquarists also find that running a UV steriliser on the tank helps to eliminate pathogens and safeguards against the need for putting treatment in the water. Fish in the subfamily Mormyrinae have a high brain to body mass ratio, due to an expanded cerebellum used in their electroperception. The brain size to body weight ratio is even higher than that of humans; although unlike humans, the cerebellum is larger than the cerebrum (front brain). Related to this, they also hold the zoological record as having the brains that consume the most energy as a percentage of the body's metabolic rate of any animal (at around 60%). May also be seen on sale as the Elephantnose Fish or Peters' Elephantnose Fish.
The Long-nosed Elephant Fish is a micro-predator and should be offered a variety of small, meaty foods. Frozen fare could include bloodworm, white mosquito larvae, black mosquito larvae, daphnia, vitamin-enriched brineshrimp etc. Some specimens will also take dried foods. Be sure to offer at least one feed a day after lights out.
This species has not been bred in the home aquarium. In the wild, these fish can detect members of the opposite sex via their electrical impulse frequency. It is thought that these signals become somewhat confused in the confines of even the largest home aquarium, which may account for the lack of breeding success.