This fascinating species is the one that is most commonly sold as elephant nose fish. The Elephant Nose(Gnathonemus Petersii) is an exciting fish that originates from the Niger River and its tributaries in Western Africa.
The Gnathonemus petersii is a flat-bodied fish developed in length. Its color is black with dark blue or dark brown trends. At the level of its dorsal and anal fins, far behind the body, they have a sort of clearer design in the form of brackets. The caudal fin is “V” shaped. The round mouth, one millimeter in diameter, is located above the mouth’s rostrum, extending the lower jaw. Their tail is home to an electrical organ that allows them to move around and find their prey. The rostrum is a tactile appendage that will enable them to search for the soil. In nature, the Gnathonemus petersii can grow very well up to 35 cm in adulthood, but in the aquarium, their length averages around 25 cm, a length that is, however, worthy of note.
The Elephant nose uses its trunk-like extension to forage for food, communicate, move through the water, and self-defense. It possesses a weak electrical organ at the caudal peduncles, which is used to locate food.
Care Level: Moderate
Water Conditions: 25 ° -29 °C, 73-80° F, KH 0-10, pH 6.5-7.0
Minimum Tank Size: 50 gallons
It requires a minimum of a 50-gallon aquarium with good water conditions. It is generally timid and reclusive, preferring a fine-gravel-bottom aquarium with plenty of plants and rocks for hiding places where it can find refuge from the light. Many hobbyists will purchase a “ghost tube,” a clear plastic tube that facilitates viewing during the day to appreciate this fish better. Once accustomed to its surroundings, the Elephant Nose can become incredibly tame and trusting to the point of being hand-held. It does well with other, larger species of a peaceful nature, but may be aggressive towards those of similar or smaller size.
In its natural habitat, it feeds on worms, crustaceans, insects, and larvae.
In the aquarium, you can provide:
- Live Artemia
- Mussel pulp
- Frozen feed.
The Elephant Nose is carnivorous and will eat many types of meaty foods, including; blood worms, chopped earthworms, brine shrimp, flake and pellet foods, and an array of frozen meaty foods. They apparently have poor eyesight and locate food very slowly; it often takes between 20 and 30 minutes. Therefore, it is essential always to ensure that they are not disturbed during their meal. They also agree to replace live food with frozen (previously thawed worms). Provided they are placed in a cup (5 cm in diameter) upside down in the ground (because these fish do not feed on the surface and the dried food floats). Finally, it is best to feed them in the dark because they tend to be nocturnal fish.
These fish do not reproduce in the aquarium, some Mormyridae could be reproduced, but it is always very difficult to do so.
The Electrical organ of the Elephant Nose
The electrical organ of the Gnathonemus petersii is found in its caudal peduncle. The receptors are close to the fish’s head. This electrical organ is of great interest to many researchers worldwide and even finds applications in military and medical fields. This electric organ’s primary function is not for attack ( the Gnathonemus petersii is a low current electric fish ) but a further sense that allows it to find its way in the dark and muddy waters and identify its prey. The electrical discharges they emit are also a means of communication among others, Gnathonemus petersii.
The electrical impulses generated by Elephant Nose fish play the role of “sonar. ” The general principle is simple to establish: any object (which has a resistance and a capacitance) found in the electric field generated by the pulse distorts this field. The fish has sensors to evaluate this distortion. The position of the object is considered in orientation and distance.
The receivers give Their orientation: the side that records the most significant distortion indicates whether the object is to the right or left of the basking fish. The precise orientation of the item is found by an assessment of the direction of the disturbance. Finally, the distance to the object is given by evaluating the strength and focus of the distortion.
The three-dimensional world around the fish is perceived as a two-dimensional “projection” of this world onto its body. Therefore, it would seem that the position of an object is perceived as a more or less intense and vague point on the fish’s body. The perceived image is not unambiguous. This is partly resolved because the side opposite to the place where the object is still stimulated (weakly) and therefore provides additional information, but still insufficient to restore a three-dimensional position.
As for binocular vision, the second source of information is needed to locate objects – this is the goal of the fish’s tail’s permanent movement. The various angles it adopts offer a multitude of additional images (even in two dimensions). By cutting out all this information, the fish can form a three-dimensional image of its environment.
Similarly, the fish can determine which moves are fixed by comparing two successive” images. ” The passive perception of the weak electric field produced by other fish (and prey) is exciting information.
Elephant Nose Fish, a particular fish, also for the search of food.
The food search involves the use of the many senses of the Gnathonemus petersii. The use of electrical impulses is that they live most of their time in the dark or a complex and unknown environment. But when they manage to use it, sight becomes the dominant sense.
In a dark environment where electrical impulses can be ineffective, the Gnathonemus petersii relies on the prey’s movements. These movements are perceived by sensors located along the lateral line of the fish. It can also evaluate the electrical characteristics of the prey (i.e., their resistance and their capacity). So it easily distinguishes inanimate objects from others and identifies the type of prey. Gnathonemus petersii also uses the touch of its podium and chemical analysis to determine the nature of its prey. Of course, when possible, the elephant fish can also use all its senses to find its prey quickly. But each model has its strategy that favors a certain sense according to the environment and its experience.
Communication between fish
When two fish emitting similar frequencies enter the same zone, each fish adapts its frequency, thus avoiding annoying interference. One fish increases its frequency while the other lowers it. The nature of the electrical emission depends on the sex of the animal. Thus, a fish, analyzing the emission of another, knows its sex and its species and perhaps also the identity of the latter. Each fish can tell others about its mood (aggression, good attitude, etc.) by changing its impulses’ characteristics.