Effects of environmental change on helminth infections in amphibians: exploring the emergence of Ribeiroia and Echinostoma infections in North America.

摘要: Amphibians have long served as model organisms for studying animal physiology, vertebrate anatomy, and host–parasite interactions. Recently, however, the occurrence of precipitous declines in many amphibian populations severe limb malformations others has catalyzed renewed efforts to understand effects parasites on amphibians. In this brief review, we examine importance two groups trematodes that utilize amphibians intermediate hosts: species genus Ribeiroia broader “echinostome” group which collectively includes genera Echinostoma Echinoparyphium. For each, specifically explore pathology resulting from infection, whether parasite recently increased abundance or geographic range, biotic abiotic factors likely influence infection. Both can induce significant hosts. Exposure cercariae causes substantial increases mortality larval These malformations, include missing, malformed extra limbs, may further reduce survival amphibians; are extremely rare adult frogs, even following years they abundant (>50%) among juvenile frogs. Similarly, echinostomes, colonize kidneys amphibians, increase incidence edema renal failure, particularly laboratory experiments. Recent surveys National Wildlife Refuges across USA suggest both widespread sometimes (~1,000 metacercariae per frog). Infections appear be most common along major rivers bird flyways northern half country. While limited evidence suggests a recent paucity available historical data precludes definitive assessment either emerged. We discuss future approaches question contemporary ecological changes known hypothesized patterns including land use, nutrient pesticide runoff, decreases community diversity shifts climate. Considering documented pathologies each group, their often infection patterns, ongoing observed populations, emphasize urgent need study echinostome infections