Clam Issue. Help!

[MyOwnGrowOp]

i have a crocea clam that has been in my 120 for about 3 years now and has about trippled in size and has been doing great. today for no apparent reason, when i got home from work, he was gaping and spitting white stuff into the tank... i have watched a few videos of clams spawning and it looks just like that, but its gaping big time and the ones in the videos i watched are not.... is he dying? all perams are good and the fish are the same fish that have been with him for years. HELP

 

[moliken]

my first thought was spawning. gaping does not involve just the siphon. " shell fully open, mantle poorly extended, and inhalant siphon widely stretched. The mantle will begin to pull inwards, shriveling and tearing between the siphons. A healthy clam's inhalant siphon can open wide sometimes, but gaping leaves a very wide opening."
btw, spitting is coming from which opening? other inhabitants. if it is spawning, u need to do water changing

 

[MyOwnGrowOp]

the "spitting" is coming from siphon (small hole)... the siphon looks normal or a little on the open side. and the big hole is gapping huge.. yes the mantel is pulling inwards, and it spits white into the water about every minute