Some Parasites of Plaice 'Pleuronectes platessa L.'in Three Different Farm Environments.

摘要

Over a period of fifteen months,young plaice (Pleuronectes platessa L.) were held in three different experimental farm environments and periodically examined for parasites. These environments were: Onshore tanks with heated chlorinated water (Hunterston);floating cages in a marine pond (Ardtoe);and floating cages in a sea loch (Loch Moidart). The parasite fauna of the Hunterston farm fish showed a different pattern from the others,notably in the complete absence of Gyrodactylus unicopula. Several digenean metacercariae which are common in wild plaice were absent from farm fish,although one, Cryptocotyle lingua,was more common in farm stock than in wild fish. Concurrent infestations of Trichodina borealis and Gyrodactylus unicopula appear to be more detrimental to farm plaice stocks than either species alone. Rearing benthic flatfish in floating cages avoids some common infestations involving parasites with benthic intermediate stages.