Loma camerounensis sp. nov. (Protozoa:Microsporida) a parasite of Oreochromis niloticus Linnaeus, 1757 (Teleost:Cichlidae) in fish-rearing ponds in Melen, Yaoundé, Cameroon.

A new microsporidian, Loma camerounensis, was found in the Cichlidae Oreochromis niloticus from the Melen fish-rearing station in Yaoundé, Cameroon. Xenomas were located in the gut from the oesophagus to the intestine, but preferentially in the duodenum. Dimensions of the fresh spores were 3.96 x 2.16 microns. The ultrastructural study indicated the following characteristics: parasite stages arranged in a random, unstratified manner in the xenoma; merogony by multiple fission; sporogonic stages isolated within a sporophorous vesicle containing several sporoblasts and polysporoblastic sporogony. Ultimately the spores appeared to be isolated in a single vesicle, but this was a secondary phenomenon induced by the intervention of tubules that resolved in partitions of the initial sporophorous vesicle.