Aquarium cleaning staff

Are you good at cleaning? I'm terrible at it.

Even after cleaning and tidying up my room, I often find that some dirt remains, or that it starts to get messy again the next day even after I've made it sparkling clean. I often end up spending my days off cleaning... Unlike me, who's terrible at cleaning, there are plenty of creatures at Tokyo Sea Life Park that are "good at cleaning."

For example, when you observe the long-fingered hermit crabs in an aquarium, you'll see them using both of their claws alternately to bring something to their mouths.

The long-fingered hermit crab feeds on algae and other food left behind by other creatures. In particular, the "Taberu no Majika" exhibit within the special display area is recommended as it is easy to observe them picking up and eating algae growing on the surface of oyster shells.

Next up is the sea cucumber. Many species of sea cucumbers feed on organic matter mixed in with the sand.

They eat leftover food scraps from other creatures, including the sand, and then excrete only the sand as feces. For this reason, they are sometimes kept in aquariums to clean the bottom substrate. If you see something that looks like udon noodles made of sand at the bottom of a display tank, it might be sea cucumber feces.

The tank in the tide pool area where the sea cucumbers are kept is shallow, so you can observe not only the sea cucumbers but also their droppings up close. If you're lucky, you might even see them defecating!

There are other fish that are good at cleaning. Bluestreak Cleaner Wrasse eat parasites that are attached to the surface of other fish's bodies and gills. If you keep them in an aquarium, you should be able to observe them pecking at the bodies of other fish.

Especially in the "South China Sea" tank in the "World's Oceans" area, it's common to see them inside the mouths of giant groupers that are tens or even hundreds of times larger than themselves. You might be worried that they'll get eaten, but other fish seem to know that Bluestreak Cleaner Wrasse cleans their bodies, so they are almost never eaten.

How did you like our introduction to the aquarium's cleaning crew? We've shown you three species this time, but there are many other creatures that "clean" as well.

Please try to find the "aquarium cleaners." My immediate goal is to learn to keep my room clean by following the example of these skilled cleaning creatures.

[Tokyo Sea Life Park]

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(March 20, 2026)