Effects of temperature, salinity, and pH on the survival and activity of marine cercariae

Abstract

Alterations of abiotic factors due to global climate change are predicted to impact disease dynamics, particularly for pathogens with complex life cycles involving free-living infectious stages, such as the cercariae of trematode parasites. Previous investigations of cercarial output, longevity, and infectivity suggest an overall increase in trematode transmission in response to elevated temperature. However, while increased temperature will likely be accompanied by changes in salinity and pH in marine ecosystems, little is known regarding their influence on cercariae. We investigated the response of trematode cercariae of the intertidal horn snail Cerithidea californica to altered temperature, salinity, and pH. The survival and activity of one trematode species, Euhaplorchis californiensis (Heterophydae), appears to be largely unaffected by increased temperature, while that of a second species, Acanthoparyphium spinulosum (Echinostomatidae), decreased at the warmer temperature (25 degrees C). Cercariae of E. californiensis generally fared best at the highest salinity (40 ppt), whereas A. spinulosum showed the opposite effect. Neither species was affected by pH alone although there were interactions with salinity and time. These results may reflect different emergence patterns of the two species and demonstrate that trematode parasitism in intertidal zones may be impacted by alterations of the marine environment resulting from climate change.

The metazoan parasite communities of the shoal flounder ( Syacium gunteri ) as bioindicators of chemical contamination in the southern Gulf of Mexico

“…In further support of this hypothesis, pH values between 7.7 and 7.9 increased the mortality of larval brittlestar Ophiothrix fragilis in comparison with the control pH value of 8.1 [69]. For parasites, Koprivnikar et al [70] reported an interaction between pH (range = 7.8 to 8.2), salinity and time affecting the survival of the larval stages of the digenean Acanthoparyphium spinulosum. Thus, the potential interaction between pH and the decrease in the number of parasites cannot be disregarded without experimental evidence.…”

Parasite fauna of the grey mulletMugil cephalusL. 1758, and its relationship with some ecological factors in Lower Kızılırmak Delta located by the Black Sea, Turkey

“…In the ordination, this parasite group is distributed at the bottom, indicating that they are more common in autumn and winter. Koprivnikar et al (2010) indicated 18 A. Özer and D.Y. Kırca that some hydrological conditions such as temperature and salinity influence the abundance and distribution of the free-living stages of the parasites.…”

“…Koprivnikar et al (2010) indicated that some hydrological conditions such as temperature and salinity influence the abundance and distribution of free-living stages of the parasites, representing in our context the completion of the digenean life cycle.…”

Impacts of ocean acidification on multiplication and caste organisation of parasitic trematodes in their gastropod host

“…In some trematode species, however, there is no second intermediate host; cercariae encyst on various substrates and become metacercariae, awaiting ingestion by a definitive host (Galaktionov and Dobrovolskij 2003). Multiple studies have documented how sensitive cercariae and metacercariae attached to external substrates are to abiotic conditions, such as temperature (Studer et al 2010;Morley and Lewis 2013), salinity (Lei and Poulin 2011) and pH (Koprivnikar et al 2010;MacLeod and Poulin 2015).…”