The cuticle of T. tessulatum is transparent, olive green or brownish in colour, with larger individuals often exhibiting six longitudinal rows of small yellow spots.

[3] It is common in the coastal flat parts of Holland which are visited by the waterfowl that act as its hosts.

[2] When the young are ready to emerge, the adult uses its sensilla organs to detect vibrations in the water and will move towards any disturbance that might be caused by a potential host.

Although generally nocturnal and negatively phototactic (avoiding light), when the brooding adult is ready to release its young, it may swim in open water in the middle of the day.

[3] If it finds a suitable host, it attaches itself with its sucker to the nasal passages, the respiratory tract or inside the mouth.