Question about Gigas Scrunching Up Mantle


Hey All,

I have a 4.5" Gigas that has some strange behavior developed. On one corner of its mantle, it scrunches up and so is not extended to the edge of the shell. THe rest of the mantle is extended to the edge of the shell. Its been doing this more and more for the last two weeks. Any thoughts? I'll try to post a picture later.

Could be a pyramidellid snail either near the mantle, or beneath. Could also be a number of other things including water parameters. What are your dKH (alkalinity), pH, specific gravity, temperature, and Ca levels?

It could also be something as simple as some sand in-between the mantle and shell. If this were the case I would never attempt to manually remove it, the clam would be able to do that themselves.
My parameters are fairly normal

Hardness: 4.5 Meq
Calcium: 425
Ph: 8.2
Salinity: 1.025
Temperature: 75

I checked for snails and found none. Not sure if there's sand trapped in there. Its been two weeks that its doing this so i'm not sure if its sand.
here's the picture of the clam

That looks like an injury or something irritating the clam. Is there anything picking on the clam? I had one neon goby (a "yellow line") which I had to remove because it would have killed the clam picking, actually trying to eat the purplish/pink eye spots.

I've found my T. gigas likes more flow then either T. crocea or T. maxima, but perhaps the clam pictured is getting to much circulation in that area. From the picture, it appears the whole clam is under stress, not just the one corner of the mantle because mantle expansion is really not that good IMO/IME for a T. gigas clam.
Are you sure this isn't the mantle-pinching condition that was going around the end of last year and into this year? It is a progressive condition, but can sometimes be cured by 30 minute FW dip. I got 3 cultured clams from a reputable source in March, one developed this pinching condition after about 2-3 weeks, and it spread to another of the clams. There were several threads about this earlier this year. I'm not saying this is what you have, and am not experienced enough to distinguish it from other irritations that may lead to mantle pinching. But if your clam DOES have it, the longer you wait to dip, the harder the dip will be on the clam, IME. The one clam I had showing a lot of pinching barely survived the dip and is still struggling. The slightly pinching clam recovered after about a week. The clam that showed no pinching didn't miss a beat when dipped.

Good luck, I hope you figure it out.
i have that problem too. under the calm there is a bunch of bristil worms, i think thats what they are called. can that be it? they are going in the calm thru the bottom. should i do a dip if is a illness?
As far as I know, the exact cause of the pinching condition I'm speaking of is not known, but it is not caused by bristle worms.

You need to study the threads on this topic before you undertake a dip, IMO. People say that dipping kills weakened clams, and IME, clams showing the condition take dipping harder than clams that don't. I've only been keeping clams a couple of months so please don't take me as an expert.

Here are a couple of threads on the topic: