This is in the kingdom Stramenopila/Heteroknots. The phylum is Oomycota. The class is Oomycetes. Order is Saprolegniales. Family is Saprolegniaceae. This genus looks very distinguishable by its profuse branching, coenocytic mycelium that is easily visable. It often coloinizes around decaying plant or animal tissue in the water. Septa is formed immediately below the reproductive organs separating the fertile and somatic hyphae. The reproductive organs are usually aseptate. The hyphae is coarse in appearance. It produces long cylindrical sporangia that has an opening at its tip that realeases zoospores.

Coenocytic (non septate) diploid mycelium.It has elongate sporangia and has antheridia and oogonia that is hormonally regulated. Meiosis occurs in the gametangia. The hyphae vary considerably in diameter. In some species it is very wide and in others it is characteristically fine. Hyphae give rise to the long cyclindrical and terminal zoosporangia. Usually these sporangia are larger in diameter than the hyphae that produce them. Young sporangia are full of dense, granular protoplasm that gives them a somewhat brownish appearance by transmitted light under the microscope.

Unknown

They are in the class Oomycetes so they are water molds and live in aquatic environments. Some are virulent parasites of fish and other aquatic vertebrates in aquaria, hatcheries, rivers, and even some marine habitats. Most are confined to fresh, clear waters, although some species are able to withstand a certain degree of salinity and live in brackish waters of estuaries. A few species occur abundantly in moist soils.

Looks similar to other Oomycota in the order Saprolegniales such as Dictyuchus, Saprolegnia, and Thraustotheca. But it is easily distinguishable by the zoosporangia development. Saprolegnia forms a terminal sporangia that release zoospores through a terminal pore. Dictyuchus branches laterally from the old sporangia. Achlya forms a terminal cluster at the end of the sporangia. Thraustotheca forms a dense cluster of sporangia that eventually ruptures.

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Kupper FC, Maier I, Muller DG, Goer SLD, Guillou L. 2006. Phylogenetic affinities of two eukaryotic pathogens of marine macroalgae, Eurychasma dicksonii (Wright) Magnus and Chytridium polysiphoniae Cohn. Crytogamie Algologie 27:165-184.

Kupper FC, Muller DG. 1999. Massive occurrence of the heteroknot and fungal parasites Anisolpidium, Eurychasma and Chytridium in Pylaiella littoralis (Ectocarpales, Phaeophyceae). Nova Hedwigia 69:381-389.

Moriya, M., T. Nakayama, and I. Inouye. 2000. Ultrastructure and 18S rDNA sequence analysis of Wobblia lunata gen. et an. nov., heterotrophic flagellate (Stramenopiles, Incertaesedis). Protist, 151(1): p. 41-55.

Petersen, A.B. and S. Rosendahl. 2000. Phylogeny of the Peronosporomycetes (Oomycota) based on partial sequences of the large ribosomal subunit (LSU rDNA). Mycological Research, 104(11): p. 1295-1303.

Warner, S.A., G.W. Sovocool, and A.J. Domnas. 1983. Sterols of Selected Species of Oomycetes and Hyphochytridiomycetes. Mycologia, 75(2): p. 285-291.

“NCBI”

“Mycobank”