The Life Cycle of a Chytrid

Chytrid is one of the oldest and most primitive forms of fungus. It has been found in every continent except Antarctica and can affect both plants and amphibious animals. Although there are close to 600 forms of chytrid, the most well-known form causes batrachochytrium dendrobatidis--a disease that has led to the extinction, or near-extinction, of frog species worldwide.

  1. Description

    • Chytrids are single-celled organisms. One of four groups of fungi in the Kingdom Protista, they are classified as protests, the scientific term for one-cell fungi. However, unlike other protests, they are not light-sensitive and have gametes (sex cells) with whip-like flagellated spores that allow them to asexually reproduce.

    Location

    • Chytrids feed by absorbing nutrients found in terrestrial plants, moist soil, decomposing organic matter and on the skin of fresh-water amphibians. Thus, they are generally found in areas where fresh water has accumulated, such as ponds, lakes, streams, ditches, fields and even in waterlogged wood.

    Life Cycle

    • The chytrid life cycle lasts roughly two weeks. Like most other fungi, chytrids thrive best in warm, moist conditions. Their ideal temperature for reproduction is about 73 degrees Fahrenheit. After feeding off an organism for several days and developing maturity, chytrids asexually produce, then release, a single-cell zoospore. Propelled by its flagella, the zoospore swims or moves through moisture until it finds a food source. Once attached to this organic matter as either a parasite, feeding off a live organism, or a saprophyte, feeding off nutrient-rich dead matter, the life cycle begins again.

    Significance

    • While chytrid fungus does not affect humans, it has caused an infectious disease that scientists believe is responsible for the extinction of more than 100 species of frogs throughout the world. Experts are searching for a cure but face many challenges, including the fact that it is nearly impossible to control the movement of frogs--and thus the spread of the fungus and disease--in the wild. A frog can be contagious for as many as 21 days before it dies, spreading the fungus as it swims and hops.

    Expert Insight

    • Humans concerned about the affect of chytrid fungus on frogs can help stop its spread by not moving frogs out of their natural habitats. Many frogs have built up defenses against the chytrid fungi in their natural habitats. Brought to a new habitat, though, with slightly different forms of chytrid, the frog will often become infected and go on to spread the disease. An infected frog purchased as a pet from a unregulated business, then set free, can also be a carrier. Experts believe that many researches, fishers and campers might also be inadvertently spreading the disease via wet or muddy boots or equipment moving from one fresh water source to another.