LAUSR

Members of the Torpedinidae (torpedoes) and Hypnidae (coffin ray) use electric organ discharges (EOD) to stun or kill their prey before consumption. We investigated whether EOD could also negatively affect the helminth larvae infecting these preys through a surrogate model: we applied electric discharges to individuals of blue whiting, Micromesistius poutassou that harboured live larvae of Anisakis. Larval mortality throughout a 6-h period was significantly higher in the treatment group, suggesting that EODs could significantly hamper helminth recruitment. We then tested whether torpedinids and hypnids ('strong-EOD' families) harboured species-poor helminth (cestode) assemblages compared with 'weak-EOD' torpediniforms (Narcidae and Narkidae) and other Batoidea. Based on comparisons on estimated species diversity and mean species richness of tapeworms at host individual level we found that (1) Torpediniformes had the lowest tapeworm diversity of all Batoidea orders; (2) Torpedo spp. consistently had the lowest mean cestode richness at host individual level, and this could not be related to other host factors influencing cestode diversity in chondrichthyans, i.e., body size, trophic level or dietary breath. However, a preliminary comparison between 'strong-EOD' and 'weak-EOD' torpediniforms did not detect clear differences of cestode richness. Thus, evidence supporting an unambiguous contribution of EODs to depauperate cestode assemblages requires further research. This article is protected by copyright. All rights reserved.