Chytrid in the context of "Apicomplexa"

Chytridiomycosis (/kaɪˌtrɪdiəmaɪˈkoʊsɪs/ ky-TRID-ee-ə-my-KOH-sis) is an infectious disease in amphibians, caused by the chytrid fungi Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans. Chytridiomycosis has been linked to dramatic population declines or extinctions of amphibian species in western North America, Central America, South America, eastern Australia, east Africa (Tanzania), and Dominica and Montserrat in the Caribbean. Much of the New World is also at risk of the disease arriving within the coming years. The fungus is capable of causing sporadic deaths in some amphibian populations and 100% mortality in others. No effective measure is known for control of the disease in wild populations. Various clinical signs are seen by individuals affected by the disease. A number of options are possible for controlling this disease-causing fungus, though none has proved to be feasible on a large scale. The disease has been proposed as a contributing factor to a global decline in amphibian populations that apparently has affected about 30% of the amphibian species of the world. Some research found evidence insufficient for linking chytrid fungi and chytridiomycosis to global amphibian declines, but more recent research establishes a connection and attributes the spread of the disease to its transmission through international trade routes into native ecosystems.

Batrachochytrium salamandrivorans (Bsal) is a pathogenic chytrid fungus that infects amphibian species. Although salamanders and newts seem to be the most susceptible, some anuran species are also affected. Bsal has emerged recently and poses a major threat to species in Europe and North America.

It was described in 2013 based on a strain collected from skin tissue of fire salamanders Salamandra salamandra. The pathogen, unidentified up to then, had devastated fire salamander populations in the Netherlands. Molecular phylogenetics confirmed it as related to the well known chytrid B. dendrobatidis. Like this species, it causes chytridiomycosis, which is manifested in skin lesions and is lethal for the salamanders. Damage to the epidermal layer can be extensive and may result in osmoregulatory issues or sepsis.

Atelopus varius, the Costa Rican variable harlequin toad or clown frog, is a small Neotropical true toad from the family Bufonidae. Once ranging from Costa Rica to Panama, A. varius is now listed as critically endangered and has been reduced to a single remnant population near Quepos, Costa Rica (rediscovered in 2003), and has only relict populations in western Panama. Recent variation in air temperature, precipitation, stream flow patterns, and the subsequent spread of a pathogenic chytrid fungus (Batrachochytrium dendrobatidis) linked to global climate change have been the leading cause of decline for A. varius. A. zeteki has been considered a subspecies of A. varius, but is now generally considered a separate species.