Influence of Anguillicola crassus (Nematoda) and Ichthyophthirius multifiliis (Ciliophora) on swimming activity of European eel Anguilla anguilla

Diseases of Aquatic Organisms

B. Sures¹  H. Taraschewski¹  M. Münderle¹ 

关键词: Swimming activity;    European eel;    Anguilla anguilla;    Anguillicola crassus;    Ichthyophthirius multifiliis;    Pathology;    Pathogenicity;    Behaviour;    Sexual mate choice;   

DOI  :  10.3354/dao060133

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: We investigated the swimming activity of 70 European eels Anguilla anguilla in relation to natural infection with 2 parasite species: the eel-specific swimbladder nematode Anguillicola crassus and the non-specific skin and gillprotozoan Ichthyophthirius multifiliis. We measured how long individual eels exposed to a water current in a swimming channel with a steady-stream profile could withstand the water current. The parasites affected the swimming behaviour of eels indifferent ways. The maximum period of time the fish were able to swim against the current was not correlated with infection by A. crassus. In contrast, infection with I. multifiliis reduced the swimming time. The protozoan has a higherpathogenicity than the swimbladder nematode, at least in closed systems, where I. multifiliis is able to spread within a few days. Reduction in swimming capacity after infection with the ciliate averaged 47 % compared to capacity prior toinfection. Thus, our results do not support the previously suggested strong negative relation between swimming activity of eels and intensity of A. crassus infection, at least in the short-term. However, there are indications in the literature thatthe pathological effects of A. crassus on the eel swimmbladder may involve a higher energy demand, possibly manifested in a prolonged spawning migration. As a result, eels heavily infected with this parasite may arrive too late at the spawning siteto participate in mating. This could ensure a selection of ‘good genes’.

【 授权许可】

Unknown