Hennegoides Africanus sp. nov. from Kadey River in Cameroon.

Abstract

Purpose: Fish are susceptible to various parasitic infections, with Myxozoa emerging as a major group. A taxonomic study of Myxozoa is essential for the rapid diagnosis of species potentially responsible for epizootic diseases.

Methods: The studied fish was collected from the Kadey River, a tributary of the Sangha River in the Congo Basin in Cameroon, and parasitologically dissected. Cysts from gill samples were examined morphologically and molecularly to assess myxozoan diversity and phylogenetic relationships were determined based on SSU rDNA.

Results: Infection by Hennegoides africanus sp. nov., found in gill filaments of 60% of C. gibbosus. Infection characterized as intrafilamental-epithelial type. Myxospore body vaulted on one side, measured 13.5 (12.4-14.8) × 2.1 (1.9-2.5) µm. Caudal appendages measured 31.3 (25.4-34.93) µm, made of thick and filamentous segments. Two polar capsules elongated, differing in size and position; smaller capsule near anterior end measured 2.8 (2.18-3.54) × 0.9 (0.7-1.1) µm, while larger, located posteriorly, measured 3.8 (3.21-4.45) × 1.4 (1.2-1.7) µm. The SSU rDNA gene sequence of Hennegoides africanus sp. nov. does not match any sequences in GenBank and is closely associated with two undetermined species of Henneguya and Myxobolus infecting the gills of Characiformes in Africa.

Conclusion: Morpho-molecular evidence indicates that Hennegoides africanus sp. nov. is a new species to science and the first reported member of its genus in Africa.