An analysis of swimming performance in the Norway lobster, Nephrops norvegicus L. infected by a parasitic dinoflagellate of the genus Hematodinium

Various components of swimming performance were measured in uninfected Norw ay lobsters (Nephrops norvegicus) and compared to animals at different stag es of infection by a parasitic dinoflagellate (Hematodinium sp.). Animals s howed a progressive decline in overall swimming performance as infection se verity increased, with reductions in the number of tail-flips performed, th e number of swimming bouts and the total distance travelled by swimming. Th e velocity of the first (giant-fibre mediated) tail flip and average veloci ty over the swimming bout were also significantly reduced in infected lobst ers. Possible reasons for this decreased swimming performance are suggested and the implications of this for predator avoidance of infected lobsters i n the benthic habitat, and for capture of Nephrops by trawl rigs are discus sed. (C) 2000 Elsevier Science B.V. All rights reserved.