1. Polyclad flatworms use vibrant colors to deter predators; however, one was found to also use high levels of deadly tetrodotoxins to kill its prey.

2. A parasitic tapeworm as long as a Boeing 737-200 airplane was once found living inside a sperm whale’s gut.

3. The deep-sea marine worm, Escarpia laminata, is one of the longest-lived animals on Earth. Some may still be alive from the time of Machu Picchu’s construction in the 1450s. Say what?

4. Some marine leeches carry blood-borne parasites from fish to fish, much like mosquitoes carry malaria between humans.

5. The colorful bristles, or crowns, of Christmas tree worms are feeding structures that double as gills (pictured); the rest of the worm is safely protected inside the hard-coral structure.

6. The Pompeii marine worm is the world’s most heat-tolerant complex organism. With one end in 72 ̊F water, the other can sit in 176 ̊F, which is hot enough to boil water at the summit of Mount Kilimanjaro.

7. The bobbit worm is the ultimate predatory worm; at 10 feet long and with mouth parts on hair-trigger release, it can catch and devour fishes usually too fast for a worm.

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8. The polychaetes, or bristle worms, are one of the largest and most ancient groups, containing more than 8,000 species. Their fossil record dates back to more than 500 million years ago.

9. The bootlace marine worm is one of the longest organisms on Earth; one washed ashore in Scotland in 1864 measuring 180 feet.

10. The giant tubeworm inhabits hydrothermal vents of the Eastern Pacific more than a mile deep. In two years it can colonize a new site and reach almost 5 feet in length.

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11. The smallest marine worms are a kind of nematode that measures as long as a piece of paper is thick.

Can't get enough? Check out the 50 best small marine animals, and facts about the hammerhead shark!

Follow Richard Smith’s underwater adventures at oceanrealmimages.com.