New morphological data on Cheilospirura hamulosa (Nematoda, Acuarioidea) by means of bright-field and scanning electron microscopy.

This study reports on the morphology and morphometry of the nematode Cheilospirura hamulosa on the basis of bright-field and scanning electron microscopy. Specimens were recovered after necropsies of 28 Brazilian ring-necked pheasants ( Phasianus colchicus) and 30 domestic chickens ( Gallus g. domesticus) from backyard flocks. Measurements relate to the buccal capsule in the males and the distance of the excretory pore from the anterior end in both sexes, while the vulva and ovijector are studied for the first time. The most important taxonomic characters for the diagnosis of this nematode are the four long, longitudinal cordons which are neither anastomosed nor recurrent. They are composed of a groove with margins formed by cuticular specializations that change in appearance and width backward along the body and which run backward from the cephalic region ending near the posterior end as a cuticular depression. According to their morphology, these cordons could probably have nutritional, attachment and/or sensory functions.