title: Multiple infection of Hydrobia stagnorum (Gmelin) with larval Trematodes.
abstract: Analysis of double infections of Hydrobia stagnorum (Gmelin) with larval trematodes leads to the following conclusions: 1.--negative interaction occurs when both species have the same precercarial stage (rediae or sporocysts); 2.--negative interaction is generally absent when these precercarial stages are different (redia + sporocyst); 3.--the few exceptions on 2. could be a result of predation by the redia on the sporocyst; 4.--the negative interactions are most likely the result of competition for the same type of food.
mesh_terms: D000818:Animals; D006790:Host-Parasite Interactions; D007814:Larva; D012908:Snails / Q000469:parasitology*; D014200:Trematoda / Q000302:isolation & purification* / Q000502:physiology