Differential tolerances to ocean acidification by parasites that share the same host

• Published in: International journal for parasitology Vol. 45; no. 7; pp. 485 - 493
• Main Authors: MacLeod, C.D., Poulin, R.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.06.2015
• Subjects: Animals; Cercariae; Gastropod; Host-Parasite Interactions; Hydrogen-Ion Concentration; Metacercariae; Ocean acidification; Oceans and Seas; Seawater - chemistry; Snails - parasitology; Species Specificity; Trematoda - physiology; Trematodes; Metacercariae; Trematodes; Cercariae; Gastropod; Ocean acidification; Host–parasite interactions
• ISSN: 0020-7519; 1879-0135
• DOI: 10.1016/j.ijpara.2015.02.007

[Display omitted] •Simulated ocean acidification (OA) conditions reduce cercarial activity.•Simulated OA conditions reduce metacercarial survival.•Species-specific tolerance to low pH exists in parasites that share the same host.•Abiotic stressors experienced during transmission predict cercarial response to OA.•Confamilial parasites exhibit differential tolerance to reduced pH. Ocean acidification is predicted to cause major changes in marine ecosystem structure and function over the next century, as species-specific tolerances to acidified seawater may alter previously stable relationships between coexisting organisms. Such differential tolerances could affect marine host–parasite associations, as either host or parasite may prove more susceptible to the stressors associated with ocean acidification. Despite their important role in many ecological processes, parasites have not been studied in the context of ocean acidification. We tested the effects of low pH seawater on the cercariae and, where possible, the metacercariae of four species of marine trematode parasite. Acidified seawater (pH 7.6 and 7.4, 12.5°C) caused a 40–60% reduction in cercarial longevity and a 0–78% reduction in metacercarial survival. However, the reduction in longevity and survival varied distinctly between parasite taxa, indicating that the effects of reduced pH may be species-specific. These results suggest that ocean acidification has the potential to reduce the transmission success of many trematode species, decrease parasite abundance and alter the fundamental regulatory role of multi-host parasites in marine ecosystems.