Pilobolus crystallinus

Description and significance
Pilobolus crystallinus is a fungus belonging to the mucorales order and according to Wikipedia it is also referred to as the “Dung Cannon” or the “Hat Thrower”. This fungus is found in the feces of herbivorous animals and they grows 2-4 centimeters tall but they have pressure in their vesicle which allows them to shoot their spores 2 meters away reaching speed of about 0-45mph during the first millimeter of travel. This fungus grows under the surface where oxygen concentration is low because oxygen prevents radial growth of its hyphae. McVickar and Ootaki et al. has divided the development of pilobolus crystallinus into six stages. In the first stage there is elongation of the sporangiophore at the apex without rotation which leads to the second stage where a sporangium develops from the sporangiophore. In the third stage no growth occurs and in the fourth stage a subsporangial vesice can be seen expanding under the sporangium. Stage five spore maturation occurs and the hypha region below the subsporangial vesicle elongates. In the last stage, stage six the subsporangial vesicle bursts and the sporangium are releases into the air. This is a time lapse video pilobolus crystallinus development which was documented by Dave Kalb and Kent Loeffler from Cornell University



Cell structure and metabolism
Scanning and transmission electron microscope has been used to study the structure and surface of pilobolus crystallinus. There are two different sizes of calcium oxalate crystals some large and some small which covers the surface of the sporangium. The large crystals surround spines that have a central pore and serves as protection. This species of fungus has a vesicle that has a mucus like substance which allows the spores that stick to vegetation such as grass where it can then eaten by animals. It travels through the digestive systems of animals and begins it growth in their feces.

Ecology
Pilobolus crystallinus is a heterotrophic organism. It produces exoenzymes to digest its food outside its body before it ingest the nutrients. It is dependent on the nitrogen source found in the dung of animals as it food source. It also needs the water found in the feces of animals in order to disperse its spores. Nematodes has a symbiotic relationship with pilobolus crystallinus in that they assist the fungi with decomposition of the animal feces but when the nutrients become depleted the nematodes sits on top of the fungi so that it gets launched towards a new food source.

Pathology
Herbivorous animals such as deer’s, cattle, elk, horses’ etc. can become infected by parasitic organisms called lungworms. The larva of the lungworm is excreted in the feces of these animals. The larva can position themselves on the sporangiophores of philobolus crystillinus and it is launched with the sporangium where they now have the ability to infect a new host.