Did you know that parrotfishes actually EAT coral? It's true. Well, kind of. Here's what happens: Parrotfishes have fused teeth that form "beaks" which are used to scrape algae from dead coral rock, which is made mostly of calcium carbonate. In the process, large amounts of coral are taken in, ground up by bony teeth plates and the algae is extracted for consumption.

You can see the peas embedded in the block

Our GOT coral is artificial, made of fiberglass and urethane, so the parrotfish can't perform the usual grazing. But also made mostly of calcium carbonate is—you guessed it—Plaster of Paris, so it's perfect for these bricks of peas we put in the GOT for our parrotfishes. It keeps them happy and healthy :-)

A diver places the block on a coral ledge, giving visitors a great view

The block tends to draw a crowd

But it's the parrotfish that really benefit from this particular feeding

The action of scraping their teeth on the plaster can file down their teeth, keeping them healthy and trim

And they get a tasty treat—always eat your vegetables!

The parrotfish, and other fishes, dine on these crafty blocks of Plaster of Paris every week or so. So now if you see a curious white brick nestled amid the colorful corals, you'll know about the specialized feeding that's taking place inside the Giant Ocean Tank.

Learn more about parrotfishes from our researchers and global explorers.

Oh, and we'll be posting a video of this feeding event soon. Stay tuned!

— Chris

With hundreds of little fish in a 200,000 gallon fish tank, it's impossible to know if every single small fish has gotten a morsel of food.

Evie feeds little fishes

But we do our best to make sure they all at least have the ability to eat if they so choose. So some of the feedings are geared towards this: Instead of targeting individual fish, it's a scatter or broadcast feeding. Nothing expresses this better than our twice-a-day zooplankton feed. Our walk-in freezer is filled with a stack of 35# blocks of this zooplankton.


Before it goes into the Giant Ocean Tank, it's cut up into smaller blocks. Twice a day a diver swims it around, spreading as much as they can throughout the water before it melts completely.

Mmmm...tasty, no?

Check out this video to see what I'm talking about.  Notice that some of the bigger fish like the zooplankton too (i.e. cownose ray :-)

We were closed today due to the snow… but just like Christmas and Thanksgiving some of the aquarists head on into work to take care of the animals.  Props to the MBTA for getting us there safely!

We have several different feedings in the Giant Ocean Tank. Some are broadcast feeds (meaning we scatter the food), some target our larger predators and some target the smaller shyer fishes. This squid tentacle feeding is specifically for the boxfishes: cowfishes and trunkfishes... and sometimes for smaller puffers that come looking for a handout.



As you can see, it's not always that easy to only feed the boxfishes. Others come by, knowing they may be able to snag a morsel or two. The biggest culprit? The porkfish (yellow and black fish) are notorious tentacle thieves, and most divers feel accomplished if they can keep them from getting any (don't worry, they have ample opportunity to eat during other feedings).

Our local followers might recognize this boxfish—a honeycomb cowfish, Acanthostracion polygonia. This fish appeared on some of our splashy advertising this summer announcing the reopening of the Giant Ocean Tank.

Smooth trunkfish, Lactophrys triqueter

Scrawled cowfish, Acanthostracion quadricornis

Some of the divers call this the cuteness feeding. Because did you see all those little fish lined up for their snack in the video?! If you want to get a look for yourself, we're usually feeding these fishes around 11:15 each morning (though of course that could always change day-to-day, depending on the animals' needs).

And stay tuned for more about the other feedings inside the Giant Ocean Tank.