i have this calico fantail and she used to have a friend who was a black moor, a little smaller than her, and they were really lively. i had them in this little 2 gallon death-trap for a while but they were definitely lovers. well the black one couldn't handle the move to the 10 gallon, (i'm guessing because of the ammonia levels but the fantail seemed unaffected)

so after the black one died, i noticed a major change in the fish's behavior, when before she swam all over the place she seemed depressed kind of like looking for the other fish, she also became afraid of my hand, when before neither of the fish seemed to mind my moving things around in the tank. I think it is post traumatic stress from having to be in the tank with her dead lover for so long, (i hadn't been in my dorm all day or all night long, and i got back at 6:00am). it's a sad story but, there's more.

by chance i ended up having to babysit 4 comets for a while until i find new homes for them. they are like twice the size of my 1 1/2 inch fantail. they behave totally differently, just sort of staying in one place and looking in one direction in a school. occasionally they dart around for food, but they dont explore and move around and play like my black moor or my fantail. i think it is because the fish have no personality, they were destined to be feeder fish before my friend bought 6 of them on a "whim." (for a gallery opening, one of the pieces involved a bathtub filled with water, so she filled the tub with fish just for kicks)

normally i wouldn't mind this generic boring behavior , but i think my goldfish is trying to blend in with the crowd. she schools with them, and does the same sort of, looking in one direction and treading water type thing. she's even loosing some of the black she had with the other fish and turning more orange to reflect the brighter color of the comets. no longer does she swim around and poke around to keep herself occupied. is this something i should be worried about? or is my fish just afraid to go against the grain.

(i know i shouldn't have 5 fish in a 10 gallon, but this is temporary, i only plan on keeping one)

Gfish are schooling fish, and when faced with a situation where there are other fish who are schooling at the time, they will school. If i fish is by itself, it will form a closer bond with its human friend, and thats why you notice her to be more personable, with other fish acting like fish, shes just following her fishy instincts. The commons were probably just left to be fishes, and not socialised, so they are showing fishy behavior. They arent dumb by any means lol. Some of the common fanciers here are going to find that toungue in cheek! lol

haha! that's a good point. they actually seem to be becoming more independent as time goes on, but they are wreaking havoc on my tank now, it's like 5 times the poop and the tank hadn't been fully cycled before I added them. i'd doing daily 20% H2) changes and added kosher salt

i also noticed that the comets swim really slow, doing the minimum amount of movement needed to take them from place to place... could this be an evolutionary adaptation to deal with the absence of food (lack of calories) in a a non-tank environment? they spend a lot of time with their dorsal fin down, something my old fish never does, unless they get scared or excited at which point the dorsal pops back up. is this a sign of sickness? boredom? submission

i'm a really new fish/pet owner, and they are SO FASCINATING, i watch them for hours every day.

Its a sign of stress actually, among other things. They are probably a bit stressed from not so good water quality and lack of tank space. Acting lathargic with clamped fins indicates this.

They are fasanating though arent they? Wonderful little guys.

It sounds to me like tthey are either stressed or not feeling well. I have a 55 gallon, and always have 1 or 2 commons in there...My biggest were about 6 inches long each, and they always ZOOMED everywhere. We are sort of starting from scratch here, now, and the common we just got is teeny...only about an inch long, but he zooms everywhere too.

do you have test kits to see whats going on with your tank water? if not i'd recommend getting some for ammonia, nitrites, nitrates and pH... water chemistry could be causing some of the symptoms you're describing, especially if the tank is not cycled yet.

i have a wee comet guy and he's very bright and active, zooming about, playing in the bubbles and exploring everything. hopefully you're fishies personalities will come out more over time.

my commons are SUPER active, playing chase... taking turks "bopping" sharky (Sharky has SBD and they "bonk" him with their backs while he's floating aimlessly, which he does NOT upsidedown)

they come to the from when they want to, and peek from behind their house other times. very nibbly at cleaning time though! so i have to disagree with commons having no personality.

i agree with the above, their suffocating in their own waste, and so dont have the energy to play or be interesting...

i was able to give away 2 of the commons, and i now have 2 commons and a fantail in the 10 gallon. the nitrites are still high (2-3 ppm) but i do daily water changes (30-50% now) in order to keep it to a minimum. i also added 1tsp of salt/gallon to help with the toxicity of the nitrites. nitrates are only on the order of 20 or so, and ammonia is at 0.

they are acting very differently now. i think it a lot of it was the shock of being moved around so much at one time, from the petstore, to the bathtub, to little plastic cups, to various tanks...
and also the waste/overcrowding issue.