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.

Review: Bucephalus minimus, a deleterious trematode parasite of cockles Cerastoderma spp.

“…Parasites can seriously interfere with host population performance (Curtis 1995;de Montaudouin et al 2014;Jonsson and André 1992), although their precise contribution often remains neglected. Trematodes are the most abundant and common macroparasites in coastal waters (Lauckner 1983;Schmidt and Roberts 2000).…”

The Effect of Season on the Metabolic Profile of the European Clam Ruditapes decussatus as Studied by 1H-NMR Spectroscopy

“…Infection by this parasite has already been reported for several commercial seafoods from the Santa Gilla lagoon including the fish Atherina boyeri (Risso, 1810) and the clams Venerupis aurea (Gmelin, 1791) and Ruditapes decussatus [ 19 ]. Since infection by this parasite has been shown to affect the health of clams [ 20 ], all samples showing any sign of parasitosis were excluded from any further metabolomic analysis.…”

Seasonal variation of transcriptomic and biochemical parameters of Donax trunculus related to its infection by Bacciger bacciger (trematode parasite)

“…Besides fishing exploitation, there are many other factors that can control these population densities, including environmental pollution (Fishelson et al 1999, Neuberger-Cywiak et al 2003, seawater acidification (Pereira et al 2016), temperature (Botelho et al 2018), sediment grain-size (de la Huz et al 2002, La Valle et al 2011 and parasitism. Concerning parasitism, among trematode species infecting the wedge clams, Bacciger bacciger (Rudolphi, 1819) Nicoll, 1914 is the most prevalent in European waters (Ramón et al 1999, de Montaudouin et al 2014. This parasite has a complex life cycle using three different host species (Palombi 1934).…”

“…Despite its already studied detrimental effects on wedge clams condition index (de Montaudouin et al 2014) and reproduction (Ramón et al 1999), little is known about how this pathogen can affect the health of D. trunculus populations and its contribution for the population decline.…”