Fungi play a significant role in the diets and nutrition of diverse vertebrates. Many fungi, particularly truffle-like species, have evolved close associations with animals that help to disperse their spores. These animal-fungus associations are frequently overlooked, but they are an important part of functional ecosystems and imperative for the dispersal of fungi through these systems. An international team of researchers has found that wild bonobos (Pan paniscus) in the rainforests of the Kokolopori Bonobo Reserve in the Democratic Republic of Congo forage and feed on a previously undescribed species of crystal-encrusted truffle.
“Bonobos likely locate the newly-described species, Hysterangium bonobo, by catching its smell wafting through the air or by digging in the soil and sniffing their hands,” said senior author Dr. Matthew Smith, a researcher in the Department of Plant Pathology at the University of Florida.
“The truffles are small enough to be swallowed whole, and their microscopic spores are kept intact by thick cell walls as they journey through a bonobo’s digestive tract.”
“Why they eat these, I’m not sure,” added co-author Dr. Alexander Georgiev, a primatologist at Bangor University.
“Perhaps they like the taste of them. I personally love mushrooms and have never considered what I get out of them nutritionally. They just taste amazing.”
Edible mushrooms widely prized for their aromas, truffles are often ecosystem linchpins, and Hysterangium bonobo is no exception.
Although it looks like a homely potato, it plays a key role in enabling trees to absorb nutrients from the soil and supports the diets of animals. Its irregularly shaped outer layer is also lined with microscopic crystal-encrusted filaments, possibly used for defense or aroma diffusion.
Hysterangium bonobo is known in the local Bantu language (Bongando) as ‘simbokilo,’ a name linked to a longer phrase roughly translated as ‘Don’t let your brother-in-law leave because traps baited with this will bring in plenty of food.’
Local communities use this species for baiting traps to catch several species of small mammals.
“Kokolopori people have celebrated their interdependence with bonobos for generations,” said co-author Albert Lotana Lokasola, a graduate student at the University of Kisangani.
“Our traditional knowledge of the diets of animals such as bonobos, duikers and rodents that includes food items new to science should be valued, preserved and protected.”
Although little is known about Hysterangium bonobo, it shares a number of characteristics with those of high culinary value.
“Even though some truffles are specialized food items, they all evolved in a similar way,” Dr. Smith said.
“They smelled really good, so animals dug them up and spread the spores around.”
“It’s important to realize that even though this paper presents a novel interaction and the description of a new species for the Western scientific community, in reality these are interconnected associations that have been known about for untold generations by the locals in the region,” said first author Todd Elliott, a Ph.D. candidate at the University of New England.
“As foreign scientists, we must take the time to ask and learn from indigenous people and locals in areas where we work because they usually intimately know about the organisms that we think are new.”
The discovery is described in a new paper published in the journal Mycologia.
Todd F. Elliott et al. Hysterangium bonobo: A newly described truffle species that is eaten by bonobos in the Democratic Republic of Congo. Mycologia, published online September 4, 2020; doi: 10.1080/00275514.2020.1790234