Effects of heavy metal pollution on swimming and longevity in cercariae of Cryptocotyle lingua (Digenea: Heterophyidae)

• Published in: Parasitology 2001-11, Vol.123 (5), p.499-507
• Main Authors: CROSS, M. A., IRWIN, S. W. B., FITZPATRICK, S. M.
• Format: Article
• Language: English
• Subjects: Absorption; Animal, plant and microbial ecology; Animals; Applied ecology; Artificial seawater; behaviour; Biological and medical sciences; cercariae; Crustacea - parasitology; Cryptocotyle lingua; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on protozoa and invertebrates; Fundamental and applied biological sciences. Psychology; Heavy metals; Indicator species; Ireland; Longevity; Manganese; Metals, Heavy - metabolism; Metals, Heavy - toxicity; Parasites; Pollution control; Seawater; Survival Analysis; Swimming; Trematoda - drug effects; Trematoda - growth & development; Trematoda - metabolism; Trematoda - physiology; Water Pollutants, Chemical - metabolism; Water Pollutants, Chemical - toxicity
• ISSN: 0031-1820; 1469-8161
• DOI: 10.1017/S0031182001008708

Effects of heavy metal pollution on the cercariae of the marine trematode Cryptocotyle lingua (Creplin) were studied by measuring horizontal swimming rate (HSR) and longevity. These factors are important for transmission to the next host, a fish. Cercariae released by Littorina littorea (L.) collected from polluted and unpolluted sites were compared. Both HSR and longevity were significantly reduced in cercariae from the polluted environment. Cercarial quality was therefore reduced, directly or indirectly, by development within a metal-accumulating host. Cercariae released by hosts from a clean environment were subjected to nominal concentrations of 2 and 3 mg/l copper, 1 and 2 mg/l zinc, 2 and 5 mg/l iron and 2 and 4 mg/l manganese in artificial seawater. In all cases the HSRs and longevity were reduced. The effect was more pronounced in the higher concentrations. The significant HSR tests indicate that the absorption and effect of metals occurred within 1 min. The cercarial tegument, specialized for absorption in endoparasitic environments, is possibly responsible. Cercariae may therefore be excellent indicator organisms for pollution. The pollution-induced reductions in cercarial quality seem capable of producing transmission failure. Heavy metal pollution could therefore alter parasite populations and communities.