Pythium porphyrae
Pythium porphyrae, is a parasitic species of oomycete in the family Pythiaceae. It is the cause of red rot disease or red wasting disease, also called akagusare (赤ぐされ) in Japanese. The specific epithet porphyrae (πορφυρα) stems from the genus of one of its common hosts, Porphyra, and the purple-red color of the lesions on the thallus of the host. However, many of its hosts have been moved from the genus Porphyra to Pyropia.
From the article Pythium porphyrae on Wikipedia (CC BY-SA), quoted section by section
Description
Pythium porphyrae has a mycelial thallus that is eucarpic, meaning only part of the thallus turns into sporangia. It is primarily a facultative parasite of algae, but can also be saprobic. Its hyphae can grow up to 4.5 μm wide, and are not septate. On algae, the hyphae will extend through the cell wall. It does not have haustoria not chlamydospores. The appressoria are club-shaped. It has sporangia that are unbranched, filamentous, and non-inflated, typically forming 6–17 zoospores per vesicle. Encysted zoospores are 8–12 μm in diameter. Hyphal swellings are intercalary and globose, from 12–28 μm in diameter. Oogonia average 17 μm in diameter and are also intercalary and globose, but rarely are terminal. In each oogonium are 1–2 diclinous antheridia coming out far away from the oogonial stalk. The antheridia's cells are clavate (club shaped) or globose. The antheridia will be apical to the oogonial wall. Sometimes there will be two antheridial cells on one stalk. The yellowish oospores average 15 μm in diameter, have thick (~2 μm) walls, and are plerotic (fill the whole oogonium). Conidia are spherical at 8.8–30.8 μm diameter, but rarely produced. Pythium porphyrae shares many physical traits with P. marinum and P. monospermum, and appears to be most closely related to P. adhaerens. …
What it does
Pythium porphyrae has been found in Japan, Netherlands, New Zealand, and Korea, but this range is likely underreported. It has a parasitic relationship with the following hosts. Though some species of Pyropia and Porphyra are susceptible to infection in their gametophytic phase, they are resistant in their Conchocelis (sporophytic) phase.
Bangia atropurpurea Callophyllis adhaerens Chondrus crispus Gelidium elegans Gloiosiphonia capillaris Gracilaria spp. Grateloupia turuturu Griffithsia subcylindrica Lomentaria hakodatensis Mastocarpus papillatus Polyopes affinis (Carpopeltis affinis) Polysiphonia morrowii Pterocladiella capillacea Pyropia cinnamomea Pyropia plicata Pyropia suborbiculata Pyropia tenera Pyropia virididentata Pyropia yezoensis Rhodymenia intricata Stylonema alsidii Wrangelia tanegana
Wikipedia: “Ecology”
Where it lives
Recorded sightings
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geo-referenced records in GBIF, from museums, herbaria and field observers.
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In the stacks
Searching the stacks…
Every page naming Pythium porphyrae in the Biodiversity Heritage Library →
This page is assembled live from iNaturalist, GBIF, Wikipedia, the Source Library and the Internet Archive. It is not yet part of the hand-edited codex. iNaturalist taxon 556412.