Phylum Chytridiomycota (chytrids or water molds)
Basic features:
Aquatic , unicellular and coenocytic (multinucleate), hyphae are typically haploid (but some diploid) - typically composed of a microscopic sphere, cell walls are made of chitin. They have Rhizoids to penetrate food source. Many are parasitic on plants and other fungi. Some are saprophytics.
Reproduction:
Asexual reproduction - Sporangium with single nucleus that splits off to produce a flagellate zoospore with one flagellum. Sexual production through the formation of sporophyte.
Phylum Oomycota (water molds & mildews)
Basic features:
Aquatic, extensive nonseptate mycelium (unicellular, coenocytic), hyphae are diploid, cell walls made of cellulose , they are heterotrophic: parasites on fish, plant pathogen, also initial decomposers of dead insects.
Asexual Reproduction:
Hyphae grow, terminal portions of a mycelium pinch off to produce Zoospores , each with two flagella.
Sexual Reproduction
Reproductive cells produced by meiosis several eggs per Oogonium , Antheridium long and skinny (clavate).
Phylum Myxomycota (plasmodial slime molds)
Basic features:
They are terrestrial; contain no cell walls, vegetative structure are called as plasmodium which is diploid (coenocytic), Amoeboid -feed by phagocytosis.
With adverse environmental conditions (ex. drought)-formation of a hardened Sclerotium (multicellular resting structure)
Sexual Reproduction
Sporangium development -- meiosis to form 4 haploid spores, 3 of the 4 spores disintegrate before release. Germination into amoeboid cells, some cells become flagellate, fusion to form a zygote which later develops into a new plasmodium
Phylum Zygomycota (pin and bread molds)
Basic features:
Terrestrial, hyphae haploid, septate, cell walls made of chitin
Saprophytic
Produced complex reproductive structure; zygosporangium with one zygospore
Asexual Reproduction:
Nonmotile spores on aerial sporangia
Spores are air dispersed
Sexual Reproduction
When two hyphae come in contact, they produce Gametangia by the initiation of process of conjugation (fusion), and two haploid nuclei into a common cell and fertilize with a thickened wall; Zygosporangium