This set is made out of parts from the Mermaid series sets 4813, 4814, 4816
The mermaid from 4813 and her accessories is a particularly nice one, one of the best mermaid paints so far.
It also has one of the new mermaid children plus a large seahorse and the white shell.
There isn't a support base for the coral. This is the same as in the 4800 mermaid series. It makes it trickier to do them. You can put them over the pins in the shell, or put one over the pin and connect the other on the top. It's also possible to put them at right angles as shown here. Look for round holes in the coral and try plugging in one of the various pins that stick out. Not as nice as when you have a seafloor base to stand them on, but it works. The fish has a small hole on it's bottom that fits over the smaller pins on the coral, allowing it to "swim"
I just did a new set-up of my undersea scenes and have added these into the mermaid one. Pictures will be in the photos forum in the next couple of days. Just a note about the coral - it is different than the old coral in the plastic used, this is more glossy and it seems to be a tiny bit thicker.
When the coral is in the right orientation it's possible to put the seahorse on over one of the pins. With the set up I used here that wasn't possible, it works best when they are on a proper base and vertical.