Prevalence of Henneguya infections on cage-reared channel catfish Ictalurus punctatus (Rafinesque) in Mexico

Abstract

The aim of the present study was to determine the type of infection, species, the period and annual spatial prevalence, the effect of site, period and host size on prevalence of Henneguya infections in floating cages-raised channel catfish. Henneguya infections were detected in gills, fin adipose and skin, with mature spores measuring 58 to 66 μm and 16 to 17 μm TL/BL. H. exilis was identified as the causing infection agent based on fresh cyst morphology and spore measurements. In addition, mature spores measuring from 45 to 60 μm in TL and 14 to 19 μm in BL, were observed in the adipose tissue infections; H. adipose was identified as the infective agent in the adipose tissue, whereas the skin infection may be related to H. sutherlandi. Histological changes showed the fusion and displacement of gill lamellae. In regard to Henneguya infections seasonal prevalence, it was shown that the highest (Maria Soto la Marina dam) and lowest (Soto la Marina River) prevalence were during the periods March-April and July-August.