Salinity and temperature affect growth rate of Alphamyces chaetifer and Gorgonomyces haynaldii (Chytridiomycota) isolated from coastal habitats of Taiwan

Salinity and temperature are two of the key environmental variables influencing the distribution of fungi. Results from the limited research available on the effects of salinity and temperature on growth and reproduction of chytrids were inconclusive. This study investigated the combined effects of salinity (0, 1, 2, 4, 8, 16, 32) and temperature (17, 24, 30 °C) on the growth rate of Alphamyces chaetifer (isolates IMB230, IMB231, IMB232) and Gorgonomyces haynaldii (IMB233, IMB237, IMB239) cultured from low-salinity water samples collected from coastal wetlands/ponds of eastern Taiwan. All isolates grew well at salinity 4 or below, irrespective of the incubation temperatures, although some grew significantly faster at 30 °C. No growth was observed at salinity 16 or 32. At or below 4, A. chaetifer IMB230 and IMB231, isolated from the same collection site where salinity was 2, produced the fastest growth rate at these salinities while G. haynaldii IMB237 and IMB239, isolated from water samples of zero salinity, had the slowest growth rate. These results agree with previous research that chytrids are sensitive to salinity, and may explain why only 27 culturable Chytridiomycota species and allied taxa have been documented from the marine environment. © 2023 the author(s), published by De Gruyter.