The Spraguea Parasitism in Anglerfishes of the Genus Lophius

To follow the development of the microsporidian Spraguea americanus within the nervous tissue of Lophius. An attempt to determine when and how the infection begins.

Acquiring different age groups of Lophius and recovering the infected sites, particularly the supramedullary neuron fibers and preparing them for microscopy.

The youngest juvenile Lophius recovered were 140 mm long with established infections. These infections consisted of meronts and sporoblasts but no spores. The evidence indicates these infections began a month or so earlier.

Early stages of S. americanus development occur only in juvenile Lophius and not present in older fish. The prediction is infections of all Spraguea species begin early in the life of benthic juvenile Lophius. The high incidence of infection among these fish is an indicator that the location where the infection begins is likely rich in infective spores.