Scientists aren’t even exactly sure how this remarkable creature can withstand such extreme temperatures. They’re studying the symbiotic relationship-based bacteria that form a “fleece-like” covering on their backs. A symbiotic is one in which both animals benefit. In this case, the worms secrete mucus from tiny glands on their backs to feed the bacteria, and in return they are protected by some degree of insulation.
The Pompeii worm is the most heat-tolerant complex animal known to science after the tardigrades (or water bears that have previously been featured), which are able to survive temperatures over 150 °C.
…and no, those aren’t really its nipples. No idea what they are – assuming gills!
Edit: the “nipple-eye” photos are of a different but similar species of bristle worm in the same class (Polychaeta) as the Pompeii Worm.