Colonization and establishment of Pomphorhynchus laevis (Acanthocephala) in an isolated English river

acanthocephala anguila anguille balitoridae cottus cottus gobio eels epidemiologia epidemiologie epidemiology establecimiento de plantas freshwater fishes gammarus pulex intermediate hosts peces de agua dulce plant establishment platichthys platichthys flesus poisson d'eau douce reino unido salmo trutta united kingdom