portrait

Description:

Lateral view of the mobiline peritrich ciliate, Trichodina pediculus (Ehrenberg,1851). These individuals are ectocommensals on Chlorohydra viridissimus. The bobbin-shaped cell body attaches to the epidermis of the host by an aboral adhesive disc or holdfast organelle that has a complex skeletal ring of denticles. When contracted the cells appear as flattened discs in lateral view. There is a ring of cilia around the aboral end. The peristomal ciliary field makes 1 1/4 turns around the anterior end. The pellicle between the anterior end and aboral end is bare of cilia. The C-shaped macronucleus lies in the transverse plane. There is one contractile vacuole.The cells scurry allong the surface of the host by means of the aboral cilia and adhesive disc. T. pediculus can be an important harmful parasite of freshwater fish. Collected from slow-flowing freshwater stream near Boise, Idaho February 2005. DIC.