Impact of two parasitic trematodes, Meiogymnophallus minutus and Himasthla spp., on the growth of the cockle, Cerastoderma edule

The impact of two principal parasitic digenetic trematodes, Meiogymnophallus minutus and Himasthla spp., on the growth (weight and length) of the cockle, Cerastoderma edule, in Arcachon Bay (France) was studied. The experiment was conducted in the land-based mesocosms. The velocity of infestation with both trematodes was far more rapid during summer in the cockles already parasitized with these trematodes (۰.۳۵ to ۰.۴۵ metacercariae day-۱) than those of healthy ones (approximately ۰.۰۱ metacercariae day-۱). The parasitism had also an effect on the growth rates of cockles. During ۱۹۰ days of the experiment, the daily growth speed varied from ۰.۰۰۱mm.da/ to ۰.۰۲۱mm.day-۱. On average, the growth was slightly more important in healthy cockles after the start of experiments (۰.۰۱۴mm.day-۱) than those initially infested cockles (۰.۰۱۱ mm.day-۱). The experiment also showed that infestation of hosts with trematodes could perhaps disturb their immunity system, as the intensification with trematode parasites had been favored by already infested cockles.

Keywords:

Mesocosm , Cerastoderma edule , Parasitism , Digenea , Growth , Host parasite interactions