[13] Mild winters correlate with higher infestations and lower crop yields,[14] possibly due to decreased temperatures inducing the development of sex organs in the oomycete.

[1] Losses can be combated by destroying diseased fronds and exposing thalli to the air for 3–4 hours daily.

[15] It has sporangia that are unbranched, filamentous,[1][3] and non-inflated,[3] typically forming 6-17 zoospores per vesicle.

[15] Oogonia average 17 μm in diameter and are also intercalary and globose, but rarely are terminal.

[1] Pythium porphyrae shares many physical traits with P. marinum and P. monospermum,[13] and appears to be most closely related to P.

[13] P. monospermum and P. marinum also have oogonia terminally on short branches, yet in P. porphyrae they tent to be intercalary.

[13] Pythium porphyrae has been found in Japan,[1] Netherlands, New Zealand,[2] and Korea, but this range is likely underreported.

[17] In 2004, molecular analysis of Pythium determined that P. porphyrae is in "Clade A" along with P. adhaerens, P. deliense, P. aphanidermatum, and P. monospermum[3] Clade A has two clusters, and P. porphyrae shares one with the species also originating on algae, P.