Hippopus Clam - How much should it open?

[ahmed.boomer]

So ended up buying a Hippopus clam (~2.5"). Got it sight unseen. Thought the color would be slightly better than it was, but they're pretty dull.

Placed it in the sand bed with my Derasa clam. Derasa is quite happy. However my Hippopus doesn't open up like my derasa does (not talking about the mantle).

It usually gets its widest in the morning, then closes around mid day to reopen in the evening.

How much opening should I expect from these clams? This photo was taken in the evening. Doesn't every get much wider than this!

 

[DSC reef]

Doesn't look bad. It appears to be acclimating to the light/tank. Give it time and the valve should open more. It won't have the same mantle extension as a derasa, squamosa, ect. That's a nice looking hippopus

 

[hart24601]

The hippos I have had all opened up considerably wider than that, however it's very possible this individual just doesn't open up that much or it's getting all the light it needs, closes a bit, then opens up later - which I have seen with many clams when they get enough light they just close a bit.

They only thing I would be concerned about is something nipping that is keeping it closed, however with the other clam around not showing the same signs I wouldn't worry about it.

Just personally I like hippo clams. They don't have the shape or color, but I think they are just as cool.

 

[hart24601]

I should also add that while I have seen articles that both say the hippo needs extreme light and it's low light in my personal experience I have found them not like ultra intense light like maximas.