New derasa clam pinched mantle?

[scheel78]

I got a new derasa clam two weeks ago. This is my first clam. My parameters are salanity 1.026, temp 78, ca 420, mg 1500, kh 10, ph 8.1. I've searched tons of photos on pinched mantle but I cannot tell if this is it. What do you think.

 

[MondoBongo]

from what i understand derasa aren't typically susceptible to pinched mantle.

i've actually seen mine do this at a few points in the past, and it usually appears to be from some sort of trauma. i suspect a yellow tang or blenny occasionally nipping at the mantle, or perhaps some other kind of injury.

in all cases, so far, mine has gotten better with some time.

 

[Stevenliu9]

The last time I bought a Derasa from LiveAquaria DD, it came in with a slightly "pinched" mantle. I did a 10 minute freshwater dip and it turns out to be a small crustacean looking bug that fell out of that spot. The clam mantle then began to extend fully the next day. So while derasa don't typically get the infection for pinched mantle, it won't hurt to do a gentle FWD and hopefully eliminate whatever is bugging it (literally) at an early stage.