A manatee: Imagine eating lettuce under water | Helen Sullivan

Manatees don't have incisors or canines, only cheek teeth'. No hair, only whiskers. Algae growing on their backs. Everything is gentle

A manatee looks like every animal I have ever tried to make with play-dough: roll a big piece into a sausage, flatten a bit on either side with your forefingers and a bit at the end with your thumb. Hey presto. A manatee also happens to be the grey of all play-dough colours mixed together.

Imagine eating lettuce underwater: the crunch, the squelch. Reading about manatees, I finally give in and look up what the word prehensile" actually means, as in a giraffe's prehensile tongue, a monkey's prehensile tail, a manatee's prehensile lips. What could these things have in common, you wonder, for 25 years. Then it is time to find out.