Morphotaxonomy and histopathology of three species of Myxobolus Bütschli, 1882 parasites of Enteromius martorelli Roman, 1971 from the Anga River in Cameroon

Abstract

Myxosporea are almost exclusively fish parasites and have been recognized as a key limiting factor in the development of aquaculture. For this, we aimed at studying myxosporean, parasites of Enteromius martorelli so as to facilitate their future comparative identification and provide histopathological data. The morphological and metric characteristics of myxospores harvested fit together with those of Myxobolus nyongana; Myxobolus oloi and Myxobolus njinei. Histological funding revealed that M nyongana form plasmodia in the lumen of vascular network directly at the base of the secondary gill lamellae and result in deformation of adjacent gill lamellae. Plasmodia of M. oloi were implanted between the muscle fibers and exert a mechanical pressure on the adjacent cells. M. njinei affected the fins and gill. Plasmodia of M. njinei on fins occur in three typical locations: between the finrays; inside the lumen of the finrays; and the outer surface of the hemisegments under the basal lamina. Parasites species harvested exhibited two type of specificity: euryxenous and mesostenoxenous. Given the lack of knowledge on pathogens that affect E. martorelli, data from the present study could be of considerable importance in the handling of the species under cultivation.

Keywords: Myxobolus nyongana; Myxobolus oloi; Myxobolus njinei; Cyprinid fish