Fungal diseases are a serious threat to most of Earth’s ecosystems. Already I have explained the ecology and destructive nature of two fungal parasites that are interacting with a number of species on a global scale. Chytrid fungi are the main reason for much of the recent frog and salamander extinctions, while Pseudogymnoascus destructans is killing off an unprecedented number of bats in North America. A lesser known fungal parasite is well established in North America and recent surveys show its spread to Europe. Ophidiomyces ophiodiicola causes snake fungal disease (SFD) and has serious potential to change the way ecosystems function. These Fungi Fridays are meant to inspire and captivate the everyday reader and show them the mystical side of the forest floor. Sometimes, these articles must be used to communicate the overwhelming threats our planet is facing during this critical period in Earth’s history.
The known distribution of O. ophiodiicola back in 2014. It has since spread to more states. Allender et al. 2015.
Quite astonoundingly O. ophiodiicola is very new to science. It was first observed in 2006 as infected pitvipers were popping out throughout America’s East Coast. Some of these snakes had minor skin lesions and swelling while other dead snakes had more severe skin infections. 2006 was only 12 years ago! For a fungal parasite that has most likely been around for several millions of years, this recent detection astounds me. The reason for its recent discovery is due to the presence of another widely known fungal parasite that infects a diverse array of reptiles. This other fungus is called Chrysosporium anamorph of Nannizziopsis vriesii or CANV. Before figuring out that O. ophiodiicola was different, pretty much every reptile with a fungal skin infection was described as a CANV or CANV-like infection. So it makes sense that it was first described as Chrysosporium ophiodiicola by Josef Guarro back in 2009. Though, after genetic analysis, researchers saw too many incongruencies with the Chrysosporium genus, so the novel genus Ophidiomyces was erected in 2013. To this day, O. ophiodiicola is still the only species present in the newly synthesized genus.
Its appearance and saprophytic nature, breaking down the keratin in a multitude of organisms. Allender et al. 2015.
O. ophiodiicola wouldn’t be such a scary threat if it specialized in just a few snake species. Instead, like other globally destructive fungal diseases, the species is a generalist, infecting a huge diversity of snakes. With its general ecology, it has become more present, spreading faster than it would if it only infected a few species of snakes. With all of its potential vectors, occurrences of SFD are becoming more present on the Eastern seaboard where some of our countries most endangered snakes inhabit. A key adaptation that really aids the species spread is its ability to use different carbon resources.
Just like species of chytrid and the bat specific parasites, O. ophiodiicola too doesn’t require living or dead tissue from its preferred host to stay alive. All of these parasites can break down a number of carbon rich resources saprophytically, which allows each of these species to persist in ecosystems for years without encountering its preferred host. O. ophiodiicola is a keratinophilic fungus, which is why it persists in ecosystems. Keratin is a protein that is found throughout the animal kingdom, so there is never a shortage of the species preferred carbon resource. Matthew Allender and his team back in 2015 successfully grew cultures of O. ophiodiicola on a series of keratin rich substrates, including carp species, locus species, shrimp shells and even shiitake mushrooms.
A cottonmouth (Agkistrodon piscivorous) with the snake fungal disease spreading under its eye. Allender et al. 2015.
A recent 2017 survey has revealed that the parasite has spread to parts of Europe. By sampling 33 snake carcasses and 303 molted skins, Lydia Franklinos and her team detected 8.6% of their samples had O. ophiodiicola infections. Compared to O. ophiodiicola isolated from North America, the European isolates differed genetically, confirming that there are multiple strains occurring throughout the world. Additionally, these European isolates had phenotypic differences, growing slower than the North American varieties.
O. ophiodiicola is not at the same threating level that chytrid and Pseudogymnoascus destructans is at, but the species is definitely under the eye of several ecologists around the world. It shares many ecological similarities with other general fungal parasites, which show that it is not taken lightly. We know with the current state of species extinctions how imperative it is to stay proactive, protecting Earth’s species as best as we can. This newly described species has the potential to annihilate snake species around the world. Many predatory snake species provide top down control in a variety of ecosystems in the United States and Europe, and ultimately permit more species diversity and ecological functioning. A threat to snakes is a threat to natural communities. A threat to natural communities is a threat to us.