Research Article

Metazoan parasite community as a potential biological indicator in juveniles of the starry smooth-hound Mustelus asterias Cloquet, 1819 (Carcharhiniformes Triakidae)

¹ CNRS, ECOBIO (Ecosystèmes, biodiversité, évolution) – UMR 6553, Université de Rennes, 35000 Rennes, France
² IGEPP, INRAE, Institut Agro, Université de Rennes, 35000 Rennes, France
³ Muséum National d'Histoire Naturelle, Service des Stations Marines, Station Marine de Dinard (CRESCO), 38 rue du port Blanc, 35800 Dinard, France
⁴ French Agency for Food, Environmental and Occupational Health and Safety (Anses), Laboratory for Food Safety, 62200 Boulogne-sur-Mer, France

^* Corresponding author: claudia.gerard@univ-rennes1.fr

Handling Editor: Ryan Carnegie

Received: 29 October 2021
Accepted: 15 February 2022

Abstract

The starry smooth-hound Mustelus asterias is a near-threatened coastal shark in Europe, whose parasitofauna is largely unknown. We studied metazoan parasites of 20 immature sharks (13 males and seven females) from the English Channel and we examined their relationships with host condition and their use as host bioindicators. All the sharks were parasitized by one to six metazoan taxa among the twelve recorded in the whole sampling (one trematode, six cestodes and two nematodes trophically-transmitted; one monogenean, one copepod and one myxosporean on gills), with a mean abundance of 30.5 ± 21.4 parasites per fish (myxosporeans not included). The three major taxa were in decreasing order: the nematode Acanthocheilus rotundatus (prevalence: 75%, Confidence Interval 53–89%), the cestode Eutetrarhynchus sp. (70%, CI 48–85%), and the monogenean Erpocotyle laevis (60%, CI 39–78%). The gill copepod Kroyeria lineata and the gut nematode Proleptus obtusus were identified as significant pathogens. Parasite community differed between males and females despite their immature stage, suggesting early spatial sex-segregation, with E. laevis, Eutetrarhynchus sp. and Anthobothrium sp. proposed as tags. We discuss results in terms of host fitness loss and information given by parasites on diet ecology and stock discrimination. We recommend incorporating parasitology in further research to improve shark conservation and management.