Factors influencing the distribution of trematode larvae in blue mussels Mytilus edulis in the North Atlantic and Arctic Oceans

Abstract

abundance of avian final hosts) on trematode infection was examined. Infection levels correlated with the interaction between local bird abundance and mussel age and density. They increased with mussel age but their dependence on mussel density and bird abundance varied among parasite genera. Prevalence and intensity increased with SSTmax for Renicola spp., but no relationship was found for Gymnophallus and Himasthla spp. The ambiguous effect of SSTmax is likely explained by the broad range of optimal temperatures for the normal functioning of trematode larvae (cercariae) infective for mussels and by the high dependence of the level of mussel infection on a combination of local ecological factors. High infection levels were observed even in localities with a low SSTmax. No mussels were infected in the most northeastern population, probably due to extreme conditions in the Arctic intertidal preventing trematode transmission. Abstract Blue mussels, Mytilus edulis, serve as second intermediate hosts for several trematode species, but little is known about the mechanisms underlying parasite infections in mussels. To reveal these mechanisms, the prevalence and intensity of trematode larvae (metacercariae in species of Gymnophallus, Himasthla and Renicola) were examined in blue mussels at 19 intertidal sites from the North Atlantic (Ireland, Iceland, Norway) to the Arctic Ocean (north-western Russia). Mussel samples were taken in [2005][2006][2007][2008]. The impact of a number of environmental (maximal sea surface temperature, SSTmax) and biological factors (mussel age and density and the Communicated by J. Grassle. Electronic supplementary materialThe online version of this article (

Association of helminth infections and food consumption in common eiders Somateria mollissima in Iceland

“…However, the longevity of the metacercaria and of the adult trematode are unknown. Recent studies have confirmed abundant and prevalent metacercariae infections (on average eight metacercariae per mussel; infection prevalence 83.8%) in M. edulis close to the study area (Galaktionov et al, 2015).…”

How invasive oysters can affect parasite infection patterns in native mussels on a large spatial scale

“…While such effects have been studied experimentally (e.g., Kopp and Jokela 2007;Thieltges et al 2009, Goedknegt et al 2015, surprisingly few studies have attempted to study the effects of invasive species on infection patterns in native hosts in the field (but see Paterson et al 2011Paterson et al , 2013 who used a combined approach). Parasite infection levels in native hosts are not only potentially affected by invasive species but also influenced by many other factors which have been shown to underlie the generally high spatial heterogeneities in infection levels observed in the field (Thieltges and Reise 2007;Byers et al 2008;Wilson et al 2011;Galaktionov et al 2015;Stringer and Linklater 2015). For example, the population density of native hosts often affects infection patterns across many parasite and host taxa (Arneberg 1998;Galaktionov et al 2015;Stringer and Linklater 2015;Searle et al 2016).…”

“…Parasite infection levels in native hosts are not only potentially affected by invasive species but also influenced by many other factors which have been shown to underlie the generally high spatial heterogeneities in infection levels observed in the field (Thieltges and Reise 2007;Byers et al 2008;Wilson et al 2011;Galaktionov et al 2015;Stringer and Linklater 2015). For example, the population density of native hosts often affects infection patterns across many parasite and host taxa (Arneberg 1998;Galaktionov et al 2015;Stringer and Linklater 2015;Searle et al 2016). Other factors known to affect infection patterns include host size (Mouritsen et al 2003;Thieltges and Reise 2007), the supply of free-living infective stages (often approximated via preceding intermediate host densities for parasites with complex life cycles; Byers et al 2008;Wilson et al 2011;Galaktionov et al 2015) and environmental variables such as temperature, pH and salinity (Pietrock and Marcogliese 2003;Poulin 2006).…”

“…For example, the population density of native hosts often affects infection patterns across many parasite and host taxa (Arneberg 1998;Galaktionov et al 2015;Stringer and Linklater 2015;Searle et al 2016). Other factors known to affect infection patterns include host size (Mouritsen et al 2003;Thieltges and Reise 2007), the supply of free-living infective stages (often approximated via preceding intermediate host densities for parasites with complex life cycles; Byers et al 2008;Wilson et al 2011;Galaktionov et al 2015) and environmental variables such as temperature, pH and salinity (Pietrock and Marcogliese 2003;Poulin 2006). The existence of a multitude of biological and environmental factors driving infection levels, questions the relative contribution of invasive hosts, or in other words, whether invader presence and abundance matter for infections in native hosts.…”

Reprint of ‘Association of helminth infections and food consumption in common eiders Somateria mollissima in Iceland’

“…However, the longevity of the metacercaria and of the adult trematode is unknown. Recent studies have confirmed abundant and prevalent metacercariae infections (on average eight metacercariae per mussel; infection prevalence 83.8%) in M. edulis close to the study area (Galaktionov et al, 2015).…”