Effects of Euhaplorchis californiensis (Trematoda) infection on metallic ions in the host snail Cerithidea californica (Gastropoda).

Graphite furnace atomic absorption spectrometry and ion chromatography were used to study the metallic ions in the digestive gland-gonad complex (DGG) of Cerithidea californica snails infected with the daughter rediae and cercariae of Euhaplorchis californiensis and in uninfected DGGs. Seven metals (calcium, copper, iron, magnesium, potassium, sodium, zinc) were found to be present in infected and uninfected DGGs at concentrations above the minimum levels required for detection. Of these, calcium was present in significantly higher amounts (Student's t-test, confidence level of 95%) in the infected versus uninfected DGGs; magnesium occurred in significantly lower amounts in the infected DGGs. Our results were compared with a previous study that analyzed metallic ions in the DGG of Helisoma trivolvis naturally infected with Echinostoma trivolvis. That study reported a significant elevation of sodium but a reduction of magnesium and manganese in the DGG of infected snails. Variations in the results of the two studies reflect intrinsic differences in the larval trematode-snail systems used.