麻豆传媒AV

Citation

Tinsley RC, York JE, Everard ALE, Stott LC, Chapple SJ & Tinsley MC (2011) Environmental constraints influencing survival of an African parasite in a north temperate habitat: effects of temperature on egg development. Parasitology, 138 (8), pp. 1029-1038. https://doi.org/10.1017/S0031182011000461

Abstract
SUMMARYFactors affecting survival of parasites introduced to new geographical regions include changes in environmental temperature. Protopolystoma xenopodis is a monogenean introduced with the amphibian Xenopus laevis from South Africa to Wales (probably in the 1960s) where low water temperatures impose major constraints on life-cycle processes. Effects were quantified by maintenance of eggs from infections in Wales under controlled conditions at 10, 12, 15, 18, 20 and 25°C. The threshold for egg viability/ development was 15°C. Mean times to hatching were 22 days at 25°C, 32 days at 20°C, extending to 66 days at 15°C. Field temperature records provided calibration of transmission schedules. Although egg production continues year-round, all eggs produced during >8 months/ year die without hatching. Output contributing significantly to transmission is restricted to 10 weeks (May-mid-July). Host infection, beginning after a time lag of 8 weeks for egg development, is also restricted to 10 weeks (July-September). Habitat temperatures (mean 15·5°C in summer 2008) allow only a narrow margin for life-cycle progress: even small temperature increases, predicted with 'global warming', enhance infection. This system provides empirical data on the metrics of transmission permitting long-term persistence of isolated parasite populations in limiting environments.

Keywords
Xenopus; Protopolystoma; alien species introductions; Monogenea; temperature; development; global warming; Host-parasite relationships.; Xenopus

Journal
Parasitology: Volume 138, Issue 8

• Proto Egg Devt.doc
• Proto Egg Devt.pdf