Pyrsonympha major Powell, 1928 Pyrsonympha vertens Leidy, 1877 Spironympha kofoidi Koidzumi, 1917 Spirotrichonympha flagellata (Grassi, 1892) Trichomitus trypanoides (Duboscq & Grassé, 1924) Trichonympha agilis Leidy, 1877 A 2003 study that focused on oxymonad flagellates found evidence of at least one additional undescribed Dinenympha species. They also found what they believe is an undescribed "second" Pyrsonympha species in addition to P. vertens. The authors question whether P. major, which was first described in Reticulitermes hesperus, is truly found in R. flavipes and consider it a case of mistaken identity. Role in digestion Flagellates are a feature of all termite families except Termitidae, the so-called "higher termites". They are found exclusively in the hindgut, especially the paunch, an enlarged section of the hindgut with an anaerobic interior that serves as a fermenter. In R. flavipes, wood eaten by the termite is first broken up with the mandibles, treated with host endoglucanases from the salivary glands, ground up into small particles in the gizzard, and then treated with additional host cellulases in the midgut, freeing glucose for immediate absorption. It then passes into the paunch, where flagellates take up the partly-digested wood particles through endocytosis. The flagellates break lignocellulose (xylan or cellulose) down into simple sugars, which they ferment for their own energy needs, producing CO2, H2, and short-chain fatty acids such as acetate as waste products. The short-chain fatty acids (which are also produced by homoacetogenic gut bacteria from CO2 and H2) can be directly absorbed by the termite host. The vast majority of digestion takes place in the paunch: almost all xylanase activity, just over one quarter of the endoglucanase activity, and almost two thirds of the exoglucanase activity in the R. flavipes digestive system is localised in the hindgut and attributed to gut flagellates. Although this is an obligate symbiosis, newly hatched larvae do not have gut flagellates. These are acquired when the larvae are fed with flagellate-containing anal fluids from other members of the colony (proctodeal trophallaxis). Proctodeal trophallaxis is also used to replenish flagellates and other gut symbionts after each moult. Bacteria Most bacterial species in the termite gut are difficult or impossible to culture, so methods like 16S ribosomal RNA sequencing are used to identify which groups are present. One such analysis of R. flavipes worker guts uncovered representatives of the Endomicrobia (Elusimicrobiota), Actinomycetota, Pseudomonadota, Bacillota, Bacteroidota, and Spirochaetota. The dominant bacterial taxon in the core gut