title: Bacciger bacciger (Trematoda: Fellodistomidae) infection effects on wedge clam Donax trunculus condition.
abstract: Wedge clams Donax trunculus inhabit high-energy environments along sandy coasts of the northeastern Atlantic Ocean and the Mediterranean Sea. Two sites were sampled monthly, one in Morocco (Mehdia), where the density was normal, and one in France (Biscarosse), where the density was very low. We tested the hypothesis that the difference in density between the sites was related to infection by the trematode parasite Bacciger bacciger. Identity of both the parasite and the host were verified using anatomical and molecular criteria. Parasite prevalence (i.e. the percentage of parasitized clams) was almost 3 times higher at Biscarosse. At this site, overall prevalence reached 32% in July and was correlated with the migration of several individuals (with a prevalence of 88%) to the sediment surface. After this peak, prevalence decreased rapidly, suggesting death of parasitized clams. The deleterious effect of B. bacciger on wedge clams was also supported by our calculations indicating that the weight of the parasite made up to 56% of the total weight of the parasitized clams. However, condition indices of trematode-free clams were also lower in Biscarosse than in Mehdia or other sites, suggesting that other factors such as pollutants or microparasites (Microcytos sp.) may alter wedge clam population fitness in Biscarosse.
authors.affiliation: Université de Bordeaux, CNRS, UMR 5805 EPOC, Marine Station, 2 rue du Pr Jolyet, 33120 Arcachon, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: de Montaudouin
authors.forename: Hocein
authors.initials: H
authors.lastname: Bazairi
authors.forename: Karima Ait
authors.initials: KA
authors.lastname: Mlik
authors.forename: Patrice
authors.initials: P
authors.lastname: Gonzalez
mesh_terms: D063147:Animal Distribution; D000818:Animals; D049872:Bivalvia / Q000469:parasitology*; D005602:France; D006790:Host-Parasite Interactions; D009018:Morocco; D010802:Phylogeny; D011156:Population Density; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D014200:Trematoda / Q000235:genetics / Q000502:physiology*
chemical_list: D012337:RNA, Ribosomal, 18S