While we have identified the fungal microbiota within the GI tract, the type of symbiotic relationship that this partnership takes with bacteria and host is unknown. It is conceivable that during the breakdown of lignocellulose, microbes produce volatile fatty acids and amino acids, which are absorbed by the fish and provide a source of energy. Bacteria facilitate fungal decomposition of lignin , by altering wood chemistry, structure, and permeability . They may also provide nutritional benefits to wood degrading fungi via nitrogen fixation, allowing fungi to decompose nitrogen-sparse wood . An active nitrogen-fixing community has been identified in the GI tract of P. nigrolioneatus , suggesting that a mutualistic symbiosis between fungi and bacteria is possible within the fish GI tract. Confirmation of such a relationship will require further studies.