'Pasteurised' Tilapia: Drastic Mortality of Gyrodactylus cichlidarum During the Spring 2024 Heat Wave.

During spring 2024, a heat wave induced sustained water temperatures of 34°C during a week in Veracruz, Mexico. Serendipitously, we monitored Gyrodactylus cichlidarum infecting farmed tilapia fry during this pulse warming event and recorded a drastic decline of parasite populations over the following days. We subsequently established that parasites incubated in vitro at ca.

Microhabitat use, not temperature, regulates intensity of Gyrodactylus cichlidarum long-term infection on farmed tilapia--are parasites evading competition or immunity?

Gyrodactylids (Monogenea) are ectoparasites of fish, some of which negatively affect commercially valuable fishes. Temperature strongly regulates population dynamics of these viviparous flatworms in farmed and wild fish populations, with most gyrodactylid species showing positive temperature-abundance associations. In agreement with epidemiological theory, numerous laboratory studies demonstrate that these parasites cannot persist in confined fish populations without periodic introduction of susceptible hosts.