Abstract
A description is provided for Pythium porphyrae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASES: Red-rot disease, red-wasting disease. HOSTS: Bangia atropurpurea, Callophyllis adhaerens, Polyopes affinis (syn. Carpopeltis affinis), Gelidium elegans, Gloiosiphonia capillaris, Gracilaria spp., Grateloupia turuturu, Griffithsia subcylindrica, Lomentaria hakodatensis, Polysiphonia morrowii, Porphyra tenera, P. yezoensis, Pterocladiella capillacea, Rhodymenia intricata, Stylonema alsidii, Wrangelia tanegana (Rhodophyta). GEOGRAPHICAL DISTRIBUTION: ASIA: Japan, Korea. TRANSMISSION: Contaminated organic matter (oospores) and water (sporangia).