Pop-up bubble in a lobster tank at the Aquamarine Fukishima in Japan. / by Martin

How cool is a lobster? Very cool from close-up.
Look at the photo below. Click on it for a larger version. 

Here is another shot.

At the lobster tank at the aquarium, Aquamarine Fukushima in Japan, you can see these animals from very close, and from just a few inches away their colors and details are spectacular.
Here is a photo that I took from the inside of a pop-up bubble. You can see every little detail on the antennae.  
Again, click on the photo for a larger version.
And another shot.

The lobster tank can be viewed from all sides. Underneath the tank is a crawl through tunnel with a pop-up bubble (acrylic hemisphere).
The photo below shows an overview.

(1) visitors standing in front of the tank.
(2) exit, or entrance, of crawl-through tunnel
Notice the steps in front of the crawl-through tunnel. They lift the eye level of the adult visitors (1) high above the rock cave that surrounds the pop-up bubble, and that is where all the lobsters hang out. Adults, standing on the raised area, need to bend down down if they want to view the lobsters from close up.

The benefit of the raised platform is that kids can view the lobsters from close up without needing to be lifted up, as you can see in the next photo.

Natural rocks (versus artificial ones) are placed around the pop-up bubble, leaving a space of about 10 to 30 centimeters (4 to 12 inches) for the lobster to tuck themselves between the acrylic hemisphere and the rocks.
The rock arrangement opens up towards the main viewing (from where the boy looks and from where I took the photo). If you look from any other side of the tank, you'll see mainly rocks, but here and there lobsters are peeking or hanging out through the gaps - if they're not wandering around anyways.
Below is a photo showing the back of the side of the rock cave. From here you can't see the acrylic dome which is hidden under what appears to be a heap of rocks.

I was wondering how difficult it must be to clean the dome with all the rocks and animals around. However, as with almost all aquariums that I visited in Japan, and the Aquamarine Fukushima in particular, all acrylic screens were spanking clean.

The crawl through tunnel was too low for adults of my size. I couldn't bend or crawl on my knees, but had to slither my way in. The carpet made it somewhat soft and the walls and ceiling were cushioned.
So what if some adults can't or won't make it through the tunnel? All the more fun for the kids!

Below is a view into the tunnel. If you enlarge it you can pick out the round shape of the pop-up in the back. Then the tunnel takes a turn to the right for the exit.

A few more shots from inside the pop up:

There was quite some counter light for the camera. But don't let the photos fool you. The animals were in excellent view, and you could see their tops or underside with all their fascinating spots and markings from very close. Making it even more interesting was the fact that these animals were active, and constantly pushing and shoving around. A fun tank for the visitor.

On the photo below is a woman and a little boy in the acrylic hemisphere. How they both fit in there was a mystery to me. I had no room to spare.

I'm not sure what lobster species they had on display. Because of their long, spiny antennae and the lack of claws I assume that it was from the family of the spiny lobsters Palinuridae, also known as langouste.

They were mixed with Blackbar soldierfish Myripristis jacobus (another assumption). Soldierfish are active at night and like to hang out under dark shelves or in caves. So I am not sure that the exhibit was to their liking, but they seemed fine and they certainly made a pretty sight.

In the video below I'm standing at the back side of the tank and at the end of of this short video I hold the camera down into the crawl through tunnel. "Back side " might be a misleading term: in fact this side is the first view into the tank for the visitors that follow the general circulation flow. All they see is a large tank and a heap of rocks in the center, nicely concealing the acrylic hemisphere. Kids can dive down and disappear in the tunnel where they will be in for a fun surprise (or shock), when they get to the dome and find themselves surrounded by a nest of colorful lobster bodies with their long antennae and legs. And once parents make it along to the other side they have great view of the lobsters and their kids in the midst of them.

Bottom line 
Judging the tank from a visitor's perspective, it is a fantastic display. It offers many excellent viewing opportunities, and the clean and lean decor keeps the focus on the animals. A few more rocks creating more climbing opportunities and overhanging shelves for the animals might have been nice.
The clever layout allows surprise discoveries, and provides activities for the children and bonding opportunities between the generations when they wave at each other from pop-up to main viewing window and vice-versa , or when they both squeeze into the acrylic dome. All in all, I was impressed.