Nutrition and Habitats Fungi are heterotrophs that acquire nutrients by absorption . They secrete hydrolytic enzymes and acids to decompose complex molecules into simpler ones that can be absorbed. Parasitic fungi , which absorb nutrients from body fluids of living hosts. Some are pathogenic. Mutualistic fungi , which absorb nutrients from a host but reciprocate to benefit the host.
Fungi exist in diverse habitats and form symbioses with many organisms.
Except for yeasts, fungal bodies are diffuse, intertwining mats of hyphae that are organized around and within their food source. Provide enormous surface area for the absorptive mode of nutrition. Parasitic fungi have modified hyphae called haustoria - nutrient absorbing hyphae that penetrate host tissue, but remain outside the host cell membrane. Fungal hyphae may be aseptate or septate . Hyphae of aseptate fungi lack cross-walls and are coenocytic , formed from repeated nuclear division without cytokinesis.