Effects of temperature and host density on the snail-finding capacity of cercariae of Echinostoma caproni (Digenea: Echinostomatidae)

Abstract

The effect of temperature (19-36 degrees C) and snail host density (0.014-10 snails/l) on the snail-finding capacity of Echinostoma caproni cercariae is described. The initial swimming speed increased whereas the length of the infective period decreased with increasing temperature. The combined effect resulted in the E. caproni cercarial snail-finding capacity being temperature independent in the range 19 to 36 degrees C at a snail density of 0.014 snails/l. A moderate temperature dependency was, however, seen at a lower snail density. The cercarial snail-finding capacity was snail-host density dependent in the density range 0.014 to 1 snail/l. The findings from this study show that a relatively low and biologically realistic snail host density must be used in experimental studies if realistic estimates of the dynamics of cercarial transmission are to be obtained.

Patterns of parasite transmission in polar seas: Daily rhythms of cercarial emergence from intertidal snails

“…For this reason, cercarial emergence at the time when the water temperature has reached its daily maximum may increase the probability of the encounter and a successful infection of the downstream host. However, trade-offs between cercarial activity and infectivity on the one hand and longevity on the other hand should be taken into account, as the longevity of cercariae decreases with the increasing temperature (Evans, 1985; A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT Lawson and Wilson, 1980;Lo and Lee, 1996;Meyrowitsch et al, 1991;Mouritsen, 2002a;Prokofiev, 1999Prokofiev, , 2001Rea andIrwin, 1992 Thieltges andRick, 2006;Studer and Poulin, 2014).…”

Effect of temperature on survival and infectivity of Echinostoma trivolvis cercariae: a test of the energy limitation hypothesis

“…Among trematodes in general, the time between emergence and death of cercariae is temperature dependent and species specific; at about 20 °C, cercariae rarely survive more than 24-48 h (Anderson & Whitfield, 1975;Lawson & Wilson, 1980;Evans, 1985;Ginetsinskaya, 1988;Meyrowitsch, Christensen & Hindsbo, 1991;Rea & Irwin, 1992). Death probably reflects depletion of energy reserves, with tail glycogen serving as the primary energy source for cercarial metabolism (Anderson & Whitfield, 1975;Lawson & Wilson, 1980;Ginetsinskaya, 1988).…”

Infection success of Echinoparyphium aconiatum (Trematoda) in its snail host under high temperature: role of host resistance

“…First, temperature could directly affect parasite cercariae by altering their mobility, survival, and infectivity [10,13,31,32]. For instance, an effect on the activity of cercariae can alter the contact probability between the parasite and the host leading to changed transmission efficiency [10,13,32]. Similarly, altered efficiency in the use of energy reserves can change infectivity of cercariae [10,12].…”

“…For instance, temperature can directly affect parasite infective stages (e.g. survival, mobility) thus modifying their infection success [10-13]. Similarly, in ectothermic species, temperature affects host metabolism and could modify their physiological traits (see [14] for review).…”