Combined influence of hydroperiod and parasitism on larval amphibian development

Abstract

Hydroperiod strongly influences the breeding period and development time of many amphibians, and larvae of various species display developmental plasticity in response to habitat drying. Hydrologic alterations associated with anthropogenic activities potentially can influence host-parasite interactions in humans and wildlife, but few investigators have examined this possibility. Pathogens can delay amphibian development, so infections could constrain the ability of parasitized larvae to respond to a shortened hydroperiod under drying conditions. We examined the individual and joint effects of hydroperiod and infection with a pathogenic trematode parasite (Ribeiroia ondatrae) on larval development of Pacific chorus frogs (Pseudacris regilla) in mesocosms. Tadpoles subjected to accelerated drying were twice as likely to emerge early. However, this tendency was most pronounced among uninfected individuals (96% of early-emerging individuals) and may have arisen from differences in competitive ability between infected and uninfected conspecifics in mesocosms. Our findings indicate the importance of investigating hydrologic variables associated with environmental perturbations, such as climate change, particularly as they relate to the ability of organisms to respond to multiple stressors that include diseases.

Percepção Dos Problemas Ambientais Em Uma Comunidade Ribeirinha Da Região Amazônica Brasileira

“…Nos corpos d'água 2, 3, 4, 5 e 6 os girinos aceleravam sua metamorfose em resposta a rápida diminuição da água dessas poças. Estudos mostram que a diminuição do volume da água no corpo d´água é a principal variável que induz a aceleração da metamorfose dos girinos, assim como consequência o tamanho corporal menor ao completar a metamorfose (LOMAN, 2002;THELY, 2008;KEHR et al, 2014;KOPRIVNIKAR;PAULL;JOHNSON, 2014;) fatores evidenciados neste estudo.…”

How Temperature, Pond-Drying, and Nutrients Influence Parasite Infection and Pathology

“…Third, we recognized the potential for high rates of pond-drying to have conflicting effects on infection. If reduced water levels concentrated hosts and parasites closer together, transmission would likely increase and lead to greater infection and pathology (Kiesecker and Skelly 2001); however, if reduced water levels caused greater mortality of parasites (O’Connor et al 2008; Martinaud et al 2009) or snails (Thomas and McClintock 1996; Sandland and Minchella 2004) and/or accelerated amphibian larval development (Doughty and Roberts 2003; Koprivnikar et al 2014), infection loads in emerging frogs could decrease. Fourth and finally, we expected nutrients to alter the virulence of parasites (Aalto et al 2015), or to affect infection indirectly by increasing algal growth, which can promote snail densities or their production of cercariae (Johnson et al 2007), thereby increasing amphibian infections.…”

Influence of desiccation on the survival of Bulinus globosus under laboratory conditions

“…On day 8 after acclimatization, water was gradually drained from the aquaria of the experimental groups only. Three times a week (every after 2 days), 30 mL (cumulatively, 90 mL a week) of water was drained from each experimental aquarium using a graduated pipette (Koprivnikar et al 2014;Pozna nska et al 2017). This process was done for a period of 3 weeks.…”