Kingdom: Stramenopila
Phylum: Oomycota
Class: Oomycetes
Order: Saprolegniales
Family: Saprolegniaceae

Hyphae are coarse in appearance. Often very distinguishable because if the hyphal profuse branching that is coenocytic and easily visible. It often surrounds decaying plant or animal tissue in water. It also colonizes on living frogs. The septa is formed immediately below the reproductive organs separating the fertile and somatic hyphae. The reproductive organs are usually aseptate.

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. This species produce oogonia and antheridia, have 2 flagella—one tinsel and one whiplash. The genera is diploid dominant and has mitochondria of the tubular cristae type. Cell walls are composed of beta 1,3 and 1,6-glucans, cellulose, and hydroxyproline (chitin is present, but not abundantly). Mycolaminarins (beta 1,3 glucan) is the carbohydrate storage type. A distinctive feature of this species is that it produces steroid pheromones such as antheridiol and oogonial. The hyphae is coenocytic with few cross walls and nuclear division is intranuclear with centrioles.

Unknown

Live in aquatic environments. It often colonizes around decaying plant or animal tissue in the water. 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 Saprolegnia, Dictyuchus, 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.

C. J. Alexopoulos, C. W. Mims, M. Blackwell. Introductory Mycology. 4th ed. USA: John Wiley & Sons, 1996.

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, http://www.ncbi.nlm.nih.gov/sites/entrez?db=taxonomy

Mycobank, http://www.mycobank.org/MycoTaxo.aspx