Deceased Fish - Please Help

[Melissa716]

Hello all, Need some advice. I have a 100 gallon aquarium and current inhabitants include:

Rock Amenone
Torch Coral
Mushrooms
Brain Coral
Frogspawnx2
Birdsnest
Sun Coral
Emerald Crab
Pistol Shrimp

Fish-
Percula Clown x2
Randall's Shrimp Goby
Six Line Wrasse
Pajama Cardinal
Lawnmower Blenny (now deceased)
Firefish (just added yesterday)

Water Parameters-
Ammonia-0
Nitrite-0
PH-8.2
Nitrate-0-5 cant tell
SG-between 1.024-1.025

I had puchased the lawnmower last Saturday 5/14 from a lfs I had never been too before. He seemed fine, fat and active. He has been reclusive since Ive added him to the tank but seemed normal, nipping at the diatoms on the glass (thats the only time I'd see him) and spending the rest of his time resting on and around the back of the tank in the lr, not very active.
I had bought him algae sheets and placed them near his hiding places, but have never observed him eating them although they are usually gone when I check a few hours later.
Today got home to see him in his death throes, twitching, breathing quickly but after he passed,I observed him closely and did not see any spots, mucus or lacerations.
Is it likely that either the torch or the nem got him?I thought maybe the sixline but he is very small and the blenny was about 3 1/2" long.
Im realtively new to this and although Ive done a lot of reserach it doesnt even feel like Ive skimmed the surface so any suggestions would be appreciated!

 

[Melissa716]

*Update*
Calcium - 480-500ppm
Carbonate - 10 d KH
Phosphate- 0-.25

 

[Melissa716]

Anyone?

 

[Bonz]

Could of been something internal. I had a golden tiger blenny (algae eater) and did the same thing after two weeks. I purchased another one and its been doing fine for 3 months. Sometimes you will never know. If you started to lose multiple fish, then you should be in panic mode

 

[adeian]

Anyone?

Some times that last move from the lfs to home is the last bit of stress the fish can take. Other times it's just that it was sick when you got it.

I'm lucky that the lfs I use puts the date the fish arrived with them on the tank. I only buy the ones that have been around at least a couple weeks. That way it's had a bit of time to rest up from being shipped all over the world.

I've missed being able to get some fish I wanted but I've had really good luck with the ones I've got.

Adeian

 

[Melissa716]

It's really been driving me crazy that there's no logical reason why he would have freaked out like that. Poor little guy, named him Pancho (maybe not politically correct seeing as how he was a lawnmower but what the heck...)
On a better note all the other fish are fine, thriving in fact. Still wonder if he got stung or if the sixline got nippy? Just gotta quit worrying I guess.