A trill's most distinct features pertain to the symbiotic nature. The trill people have a small abdominal pouch, which can be used to host a symbiot. Because of their symbiotic nature, some joined trill have adverse effects from using transporters, up until advances in the technology around 2340, yet some host still refuse to use them. Joined trill are also highly allergic to insect bites & have noticeably cold hands and feet.
Symbionts live for thousands of years, but Trills are considerably shorter-lived. So symbionts are often transferred from one host to another when the host dies. The knowledge and experiences of each host is retained by the symbiont, who shares it with a new host.
Trill physiology is somewhat unique from standard Terran. To begin with, there are two distinct forms of Trill humanoid. First there's the typical 'spotted' Trill, but there's also ridged Trill (curiosy they only appear in TNG ;-)).
®Star Trek is a registered trademark of Paramount Pictures registered in the United States Patent and Trademark Office. ©Star Trek: ©Star Trek: The Next Generation, ©Star Trek: Deep Space Nine, and ©Star Trek: Voyager are Trademarks of PARAMOUNT PICTURES. These site is a non-profit fan website and has no affiliation with Paramount Pictures. This site is optmised for Internet Explorer and a resolution of at least 800x600.