Pachyjoenia howa, a new symbiotic parabasalid joeniid flagellate of the termite Postelectrotermes howa

The Joenia-like lophomonad of Postelectrotermes howa is identified by light and electron microscopy as a new genus and species Pachyjoenia howa. Its flagellar area of about 1800 flagella is dome shaped. Basal bodies bear a composite root oriented counterclockwise in addition to the clockwise hook-shaped lamina present in other joeniids. There are four parallel privileged basal bodies. The main parabasal fibre is twisted around the axostyle and splits into several branches bearing Golgi bodies. The axostyle trunk is conspicuous and composed of a bundle of ∼90 small axostyles. There are sausage-shaped bacterial endosymbionts mixed with hydrogenosomes in the cytoplasm and coccoid bacterial endobionts in the nucleus. The characters of this new joeniid genus are compared with those of other joeniid genera.