We frequently receive this interesting mormyrid from Nigeria. The systematics of Mormyrus is confused; according to recent findings, there are five species in Nigeria, including M. rume; the shape of the snout is the best way to distinguish the species from each other; the species presented here used to be called M. longirostris (which is how it is listed in our stock list for administrative reasons), but this is a different species from Mozambique.
Although there do exist reports of up to 100 cm long Mormyrus rume catches of specimens longer than 30 cm are extremely rare. The size of the species is quite well known, for M. rume is a common food fish in its natural range.
In 2002 Fawole published a paper on the natural history of M. rume in Lekki Lagoon in Nigeria. He collected during the study (december 1999 until november 2000) in monthly catches a total of 225 specimens which were studied for development of the gonads, the size, gut content etc. The largest specimen in his study was 23 cm long, the smallest 13 cm. He found sexually ripe females from 13.5 cm standard length on, the whole year through females with ripe gonads were found so the species obviously reproduces the whole year through. The gut content was a bit astonishing for all specimens contained inter alia plant material.
In the aquarium, mormyrids are usually fed with food for carnivorous fishes, especially bloodworms are a very good food for them.
Nobody will keep Mormyrus rume for its brillant colours. Nevertheless they are are very interesting animals. Like all mormyrids they have a „language“ basing on electric impulses and the brain of Mormyrus is – compared with the body mass – very big. The tank should be heavily furnished and as large as possible. These fish should be kept solitary or in larger groups. Two or three specimens usually are very quarrelsome against each other in a long time sight. Many people who watch Mormyrus rume are reminded on the most popular mammal of the seas, the dolphin. And in fact, if one looks at M. rume from face to face the similarity is astonishing!
For our customers: the animals have code 152005 on our stocklist. Please note that we exclusively supply the wholesale trade.
Literature:
Fawole, O. O. (2002): Morphometry and diet of Mormyrus rume in the Lekki lagoon, Nigeria. Revista de biología tropical, 50 (2): 689-694
