help weird mark showed up in 2 hr on tsn

[dpmac10]

hey whats up i have a 2 tsn's and there about 12 inches long well tonight i cleaned the tank and the filter broke so i took the impeler off and glued it with some tank safe glue and i had the filter not working for about 2hours and then when brought it back from letting it dry one of my tsn's have a grayish looking patch on its back, i've never seen anything like this well it kill my fish. the filter is working now and everthing. he seems to be acting fine the mark kinda looks like a bruise thanks for the info and holpfully u guys and identify it and tell me what to do with it thanks.

[OrionGirl]

Could be a stress reaction. Cats (and most fish) can change color to reflact their mood and health. The time without the filter might have included a dip in O2, or a slight spike in ammonia, and the fish would react to that. I'd watch and see if it changes. Fish typically don't bruise the way mammals do, but they can damage scales and skin in a collision. If this happened, it's possible the area could become infected, so you'll want to watch it closely and treat if needed.