Phylum Chytridiomycotaencompasses most fungi, which at some point in their life cycles exists as flagellatedswimming cells and these fungi are therefore, primarily, found in aquaticenvironments. These fungi reproduce asexually whena zoospore lands on a substrate, followed by formation of a cell wall around it- leading to creation of a fungi body. Long threads, rhizoids, attach to the substrateand through these nutrients are absorbed. After a period of feeding, the fungibody is converted into a sporangium, a structure which contains andsubsequently releases zoospores. Sexual reproduction occurs by fusing zoospores,thus creating a diploid zoospore, which then hardens and creates ameiosporangium.
Later fusing of nuclei create meiospores, which can then swimaway and form a new fungi body. Fungi of this phyla are mostly harmless,saprotrophic fungi, although a few pathogens such as Batrachochytrium dendrobatidis, which causes chytridiomycosis in amphibious animalshave been found. Phylum Zygomycota clusters more than 1100 different species, mostlysaprotrophic soil fungi, who exploits nutrients by decomposing waste products,such as rotten fruit. Their name, refers to their reproductive sexualmechanism, as it forms a structure called zygosporangium, arising from theconjugation between two compatible hyphae, with each hyphae stemming from a separateorganism. After conjugation, a cell wallis formed behind the fusing hyphae, which at this point are called gametangia.Next to this, the wall separating the two hyphae is broken down, leading tofusion of both hyphae’s cell components into one organism, except their nuclei,which are still separate entities.
Following this, their nuclei fuse and thewalls around the zygosporangium grows even harder and thicker than before – thisconverts the sporangium to a zygospore. After a long resting period, meiosis occurs,and the fused nuclei are divided into two separate recombinant nuclei. These are then later integrated and releasedas meiospores. Most Zygomycota are harmless to humans, although a few arepathological causing a disease called mucormycose,which arises when spores are inhaled from dusty environments.