trease-cox2-sequences-MSAoutput-Saprolegnia-spp.

Saprolegnia, a notable genus within the Saprolegniales, is known for its pathogenic tendencies on a wide range of aquatic organisms, causing infections such as saprolegniasis and Epizootic Ulcerative Syndrome (EUS). From late 1985 to early 1986, accounts of local periodic EUS outbreaks were reported. However, the infection has primarily been associated with Aphanomyces sp., another genus within the same order, rather than Saprolegnia sp. The only species from this genus documented in the country thus far is Saprolegnia diclina, with the last recorded isolation occurring sixty years ago. No member of the genus has been isolated, much less rediscovered, since then. It is speculated that its rarity is due to elevated temperatures in the Philippines, which created unfavorable conditions for its growth. Considering this, the study deliberately targeted a remote highland area with low temperatures, specifically in Kibungan, Benguet, Philippines, in search of cold-dwelling Saprolegnia species in the tropics. Two isolates, collected from muddy water samples baited using sesame seeds, underwent morphological, physiological, and molecular analyses and were identified as Saprolegnia ferax. Further, the findings emphasize the importance of temperature as a key growth and dispersal factor as the isolates thrive within the range of 15 ºC to 30 ºC yet exhibit limited growth at temperatures equal to or beyond 35ºC. This paper describes the second Saprolegnia report for the Philippines.