The body surface ofBranchiobdella pentodonta whit. (annelida, oligochaeta) examined by scanning microscopy

Abstract
The body of Branchiobdella pentodonta is uniformly covered with cuticular microvilli and abounds in sensory receptors. Muscle attachments are clearly visible both on the prostomium and trunk (11 segments). The mouth opening, oriented dorsally with respect to the adhesive sucker disk, possesses papillae with apical notches. On all trunk segments except the last three, which form the posterior sucker, mucous gland pores are evident. The nephridia open on the 3rd and 8th segments. On the more turgid sexual segments (5th, 6th, 7th) the spermathecal, atrial, and oviductal openings are seen. The 6th and 7th also contain the clitellum gland pores. The posterior sucker is delimited by a thick ring and the adhesive disk, and like the anterior disk is completely covered with the gland complex pores. The anal opening is on the 9th segment dorsal to the sucker. Based on these studies, we believe that the family Branchiobdellidae should be removed from the Oligochaeta and raised in rank to form a separate group.