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 Norway lobsters (Nephrops norvegicus) and compared to animals at different stages of infection by a parasitic dinoflagellate (Hematodinium sp.). Animals showed a progressive decline in overall swimming performance as infection severity increased, with reductions in the number of tail-flips performed, the number of swimming bouts and the total distance travelled by swimming. The velocity of the first (giant-fibre mediated) tail flip and average velocity over the swimming bout were also significantly reduced in infected lobsters. Possible reasons for this decreased swimming performance are suggested and the implications of this for predator avoidance of infected lobsters in the benthic habitat, and for capture of Nephrops by trawl rigs are discussed.