A study of tomite structure and metamorphosis in Dendrocometes paradoxus stein (suctoria, ciliophora) using silver...

The organisation of the ciliary bands in the tomite of Dendrocometes paradoxus has been examined using silver staining and scanning electron microscopy (SEM). Stages in the metamorphosis of the tomite have also been examined using SEM. The tomite has a flattened ventral surface and a convex dorsal surface. The posterior end of the tomite is always marked by a small papilla, the remnant of the last point of attachment to either the trophont, or the residual body when the whole trophont transforms into a tomite. The ciliary bands around the tomite have an uneven distribution. On the right hand side of the body and posteriorly there are three bands of cilia. On the left hand side of the body and anteriorly there are four bands of cilia. The number of cilia in the rows that make up the bands also varies. Posteriorly and to the right hand, side the bands are much wider than elsewhere on the body. The ciliary bands are located around the base of the dorsal convex surface. A series of pore-like structures is seen on the right hand side of the flattened ventral surface. During metamorphosis the positions of the ciliary bands are clearly seen even when the feeding tentacles start to emerge.