Leidyopsis Kofoid & Swezy, 1919 Trichonympha is a genus of single-celled, anaerobic parabasalids of the order Hypermastigia that is found exclusively in the hindgut of lower termites and wood roaches.
[2] Trichonympha’s bell shape and thousands of flagella make it an easily recognizable cell.
Trichonympha also has a variety of bacterial symbionts that are involved in sugar metabolism and nitrogen fixation.
In the 1930s to 1960s Lemuel Cleveland dedicated a large part of his career to studying the inhabitants of wood roach and lower termite hindguts, including Trichonympha.
He focused mainly on what happens to hindgut symbionts when their host molts, which directly impacts the lifecycle of Trichonympha.
In 2008 the SSU rRNA of many termite hindgut symbionts was sequenced, including that of Trichonympha, allowing the phylogenetic relationship between many genera to be determined.
Trichonympha lives in a very specific habitat: the hindgut of lower termites and wood roaches.
Trichonympha is found as an endosymbiont in four families of lower termites (Archotermopsidae, Rhinotermitidae, Kalotermitidae, and Hodotermitidae) and in the wood roach, Cryptocercus.
[12] It is thought that the common ancestor of lower termites and wood roaches, Isoptera, acquired Trichonympha.
Trichonympha and other endosymbionts in the hindgut of these organisms help with the digestion of wood related particles.
These flagellate protists, including Trichonympha, convert cellulose into sugar using glycoside hydrolases.
[6][13] Acetate is the main energy source for lower termites and wood roaches,[13] so without the activity of Trichonympha, its host would not be able to survive.
Higher termites likely do not have flagellates, such as Trichonympha, in their hindgut because they have diversified their diet to include food sources other than wood.
[6] The large quantities of hydrogen produced while sugar is converted into the energy for the host's use causes the hindgut of lower termites and wood roaches to be highly anoxic.
During the molting process, lower termites and wood roaches replace their chitinous exoskeleton as well as the cuticle that lines their gut.
This is accomplished by proctodeal trophallaxis, where nestmates eat each other's hindgut fluid to acquire endosymbionts.
[5] This is vital to the success of Trichonympha, as the diet of lower termites and wood roaches lack readily usable nitrogen.
One hypothesis suggests that Endomicrobia were present in the common ancestor of all Trichonympha and then lost in some lineages.
[18] They are thought to be involved in a variety of processes including nitrogen fixation, acetogenesis and the degradation of lignin.
[3] The centrioles are located in the rostral tube, which is an internal component of the cell, that leads to the rostrum.
[21] Each cell has two centrioles, one long and one short, located beneath the inner cap, in the anterior end of the rostral tube.
[22] This large Golgi complex is often referred to as the parabasal body and originates anterior to the single nucleus, which it extends around.
[24] Trichonympha live exclusively in lower termite or wood roach guts throughout all stages of their life cycle.
[3] A common misconception about the molting process is that the Trichonympha cells die when they are shed with the hindgut of the lower termite or wood roach.
[3] Sexual reproduction in Trichonympha occurs in three distinct phases: gametogenesis, fertilization and meiosis.
[14] Gametogenesis occurs when gametes are produced by the division of a haploid cell that has encysted in response to the wood roach host molting.
[14] Inside the ring is a fertilization cone, which provides an entry point for the other gamete, referred to by Cleveland as the “sperm”.