Other monogenean skin parasites

Species of Entobdella are not the only monopisthocotylean monogeneans living on the skin of fishes. Many are large enough to be seen with the naked eye. Capsala martinieri (Figure 4.1A), a relative of E. soleae, and in the same family (Capsalidae), is one of the largest monogeneans, exceeding E. hippoglossi in size. Members of the Acanthocotylidae, Microbothriidae and Udonellidae, although smaller than Capsala are not difficult to see. At the other end of the spectrum are the tiny members of the Gyrodactylidae. These are especially diverse and abundant on freshwater fishes, but also occur on marine hosts. The gyrodactylids appear to have ‘broken the mould’ as far as monogeneans are concerned, having a reproductive pattern entirely different from that of the rest of the monogeneans, and, as a consequence of this, some unique biological features.