Maturation of trematode larval stages is expected to be temporally and spatially adapted to maximise the encounter with the adequate downstream host, i.e. the host, which will be infected by this parasite stage. Since studies on intramolluscan parasite maturation are scarce but important in the context of parasite transmission, the larval development inside sporocysts was monitored during upshore residency of the snail host Gibbula adansonii (Trochidae), i.e., from March to May (2011 and 2013), when these snails temporarily reside in the intertidal habitat of a Western Mediterranean lagoon (40° 37' 35″ N, 0° 44' 31″ E, Spain). Data on the relative quantity of different maturation stages of Cainocreadium labracis and Macvicaria obovata (Opecoelidae) parasitising the G. adansonii as well as on snail and sporocyst size were explored using linear models and linear mixed models. The effect of the trematodes on snail growth was shown to be species-specific, with snail and sporocyst size acting as proxies of the reproductive capacity of M. obovata but not that of C. labracis. The number of cercarial embryos and germinal balls did not show monthly variation in either parasite species, but a higher number of mature stages and the highest maturity index was found in April. Hence, during the snail's limited spawning-related presence in the upshore waters of the lagoon, continuous production and output of infectious cercariae was observed, which indicates a link between larval maturation and snail migration. The synchronization of snails, mature parasite transmission stages and downstream hosts in time and space guarantees a successful completion of the life cycle.

Cavanilles Institute for Biodiversity and Evolutionary Biology Science Park University of Valencia PO Box 22 085 46071 Valencia Spain

Institute of Parasitology Biology Centre of the Czech Academy of Sciences Branišovská 31 370 05 České Budějovice Czech Republic

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Parasitology. 2007 Apr;134(Pt 4):599-605 PubMed

Parasitology. 2002;124 Suppl:S137-51 PubMed

J Parasitol. 2003 Jun;89(3):458-63 PubMed

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Z Parasitenkd. 1969;32(4):316-23 PubMed

Parasitology. 2001;123 Suppl:S229-43 PubMed

Exp Parasitol. 1954 Mar;3(2):185-225 PubMed

Parasit Vectors. 2014 May 27;7:243 PubMed

Parasitology. 2008 Apr;135(4):407-26 PubMed

Acta Parasitol. 2013 Jun;58(2):155-66 PubMed

Parasitol Int. 2007 Mar;56(1):19-22 PubMed

J Parasitol. 2002 Oct;88(5):910-8 PubMed

J Parasitol. 2002 Aug;88(4):730-7 PubMed

Parasitol Int. 2012 Sep;61(3):450-60 PubMed

Biom J. 2008 Jun;50(3):346-63 PubMed

J Helminthol. 2010 Dec;84(4):362-8 PubMed

Parassitologia. 2007 Sep;49(3):111-7 PubMed

J Helminthol. 1992 Sep;66(3):159-66 PubMed

Parasitology. 1983 Oct;87 (Pt 2):343-69 PubMed

Parasitol Res. 2006 Sep;99(4):341-5 PubMed

Parasitology. 1986 Apr;92 ( Pt 2):337-41 PubMed

Parasitology. 2004 Jan;128(Pt 1):7-14 PubMed

Science. 1987 Mar 20;235(4795):1509-11 PubMed

Trends Parasitol. 2003 Jul;19(7):293-9 PubMed

C R Acad Sci Hebd Seances Acad Sci D. 1971 Jun 28;272(26):3303-6 PubMed

J Parasitol. 1954 Feb;40(1):1-21 PubMed

J Helminthol. 2010 Dec;84(4):381-9 PubMed

Parasitol Res. 2009 Oct;105(5):1231-8 PubMed

Parazitologiia. 2008 Jan-Feb;42(1):41-52 PubMed

Evolution. 1975 Jun;29(2):335-352 PubMed

Parasitol Res. 1987;74(2):155-60 PubMed

Southeast Asian J Trop Med Public Health. 1997 Jun;28(2):296-302 PubMed