Feeding, Growth, and Parasites of Trout Salmo Trutta L. From Mulroy Bay, an Irish Sea Lough

Abstract

The feeding and gut parasite burden of 354 trout collected between May 1980 and April 1981 from Mulroy Bay on the north coast of Ireland are described and compared with a collection of trout from the Irish Sea. The sea ages of the fish ranged between 0 and 2 sea winters, more than 90% being post-smalt. Males and females were equally represented in the younger, females predominated in the older. The food web was larger than in the Irish Sea, insects and crustaceans being its most numerous constituents but fish making up the greatest volume. Shoal fishes were relatively unimportant. Parasites comprised five species of Digenea, one cestode and a nematode. All occurred at a relatively low incidence and burden. Weights of the Mulroy fish were lower than for trout of equivalent length from the Irish Sea.