Hexamita

The Diplomonadida, which includes the human pathogen, Giardia lamblia, is particularly interesting as it contains one genus, Hexamita, with both free-living and parasitic species,.

Four synapomorphies support the inclusion of Trepomonas, Hexamita, Spironucleus, Octomitus and Giardia in the suborder Diplomonadina (Fig.

& haddock Melanogrammus aeglefinus (L.) and Hexamita salmonis Moore from brook trout Salvelinus fontinalis (Mitchill).

The following infectious agents were observed on slides: viruses (Viral gametocyte hypertrophy), Rickettsia/Chlamydia/Mycoplasma (rickettsia-like organisms, RLOs), ciliates (Ancistrocomidae) on the gills and in the stomach/intestine, xenomas (Sphenophrya-like ciliates), Sprague's Gregarines, Haplosporidium nelsoni (MSX), Nematopsis ostrearum, Turbellaria and Hexamita nelsoni, the average prevalences of each at each site are presented in Table 1.

Often considered an opportunistic, secondary invader, Hexamita nelsoni (Ford & Tripp 1996) was also present in the oysters of the present study which included several specimens of well-preserved gapers.