When you look at the flowery yellow and blue things in the photo, would you guess that they’re worms? They are worms, nicknamed “Christmas tree worm,” since they look a bit like a leafy fir tree. The Christmas tree worm lives on the Great Barrier Reef, a giant stretch of underwater coral off the coast of Australia. It hangs onto that coral but doesn’t eat it: it’s a filter feeder, using those fluffy tentacles to suck tiny creatures from the water and stuff them in its mouth. It doesn’t wave those around just to look pretty.
Wee ones: If this worm has 6 layers of spiraling tentacles and its friend has 8, which one has more?
Little kids: If you scuba dive to photograph this worm at 300 feet deep, and so far you’ve swum 100 feet down, how much deeper do you have to swim? Bonus: The Great Barrier Reef covers 133,000 square miles, while the state of California covers 164,000 square miles. Which one is bigger?
Big kids: If you scuba dive and swim 200 feet down, then 90 feet up, and then 10 feet back down to take an underwater photo, how deep are you? Bonus: The Great Barrier Reef is home to 125 species, or types, of sharks and rays. If there are 4 times as many types of sharks as rays, how many shark species are there?
Answers:
Wee ones: The neighbor, with 8 layers.
Little kids: 200 more feet. Bonus: California is bigger, but not by much!
Big kids: 120 feet down. Bonus: 100 shark species (and 25 rays).
