Salinity affects growth of selected true chytrids isolated from coastal habitats of Taiwan

Few Chytridiomycota and allied taxa have been cultured from the marine milieu, and their growth may be susceptible to changes in salinity. The limited research on the influence of salinity on growth and reproduction of chytrids is inconclusive. This study examined the combined effects of salinity (0, 1, 2, 4, 8, 16, 32) and temperature (17, 24, 30 °C) on growth of Alphamyces chaetifer (isolates IMB230, IMB231, IMB232) and Gorgonomyces haynaldii (isolates IMB233, IMB237, IMB239), which were isolated from low-salinity water samples collected in wetlands/estuaries of eastern Taiwan. Salinity had a more pronounced effect on the growth of these isolates compared to temperature. All the isolates exhibited significantly strong growth at salinities of 4 PSU or below, regardless of the incubation temperatures. Isolates 230 and 231 displayed consistently superior growth and were obtained from the same location where the water salinity was 2 PSU. Conversely, isolates 237 and 239 exhibited the weakest growth which was cultured from water with a salinity of 0 PSU. These findings agree with previous studies, confirming the sensitivity of chytrids to salinity changes. This salinity sensitivity might explain why only 27 species of Chytridiomycota and related taxa have been documented in the marine environments.