Clownfish acting weird

[Tank14]

I have two clownfish in my 55 gallon, a small black one and a larger orange one. Both have been in the tank for a month or so. Both have been acting great( eating well, active). All of a sudden my orange seems to be moving less and less. She seems to hang out towards the bottom (where they sleep at night) She still likes to eat but I am unsure if something is wrong with her. She does not seem to be struggling to breathe, but is just less active than before. The black still seem sto be doing great. Parameters are all normal (ammonia - 0, nitrite - 0, nitrate 5-10, calcium 400, alk 8.6dKH, phosphate - .002) Any ideas?

 

[Trademark]

Whats her belly look like, If you have some moon lights try them for a couple of nights for a couple of hours after lights out,, clowns spawn under full moon,,,, Is it a reef tank and are they hosting anything

 

[Tank14]

Belly looks normal (no bloating or enlarging). She looks the same as when I got her. It is a reef tank ( kenya tree, zoos, mushrooms, Frogspawn, Blasto, Monti caps). It doesnt look like they have hosted anything. I was going to get them an anemone eventually, I was waiting to see if they would host in the frogspawn.