Common Goldfish Harrassing Black Moor

[Equinophobe]

These fish have been in a 30gal talk with a pleco for almost a year now. The black moor I've had for two years. They are both fairly large now. The common goldfish seems to be acting more and more aggressive toward the moor, who is always trying to escape him(probably). They are frequently close together, probably (I'm now noticing) because the goldfish refuses to leave the moor alone for more then a few seconds. He's much stronger and faster and is constantly biting at the moors butt, pinning him/her against the gravel and the tank's walls and biting at the moor's eyes.

one eye has a reddish mark in it now, though this may have been the result of an older injury. the moor pathetically tries to escape the common and keeps trying to swim through gaps that he is much too large, now, to fit through and im afraid he's going to hurt himself (assuming that the goldfish's nips arent already hurting her/him.)

my guess is that the common goldfish is male and is either a) asserting dominance over the male moor or b) attempting to subdue and copulate with the female moor. ive been observing them all day and i am appalled. the black moor seems miserable. i guess i will scoop out the common for now, but i really wish they could go back to getting along. dont have any other place to put these too since my other tank is filled with tiny fish.

any advice?

[Equinophobe]

and before someone points it out, I know these guys are probably gonna need a bigger tank at some point, but they are gonna have to wait till I can afford one. At this time, 3 medium sized fish ought to be ok in a 30gal tank, right?

[Flaringshutter]

Mmmmm... I would say they would do alright as long as you've got at least a 10x filter turnover, you're underfeeding, doing huge water changes very often and you have something like a strong powerhead or a bunch of bubble wands to add tons of dissolved oxygen to the water.... (you see the problems with keeping large goldfish in a small tank) but now that youre having aggression problems I think the cause is too little room and the solution is a larger tank.
You probably should find another tank, and house the two separately. The moor will be alright in the 30g for a while, and I'd find at least a 30 for the common. Goldfish, being peaceful, don't really "assert their dominance" in the way that a betta might try to do, so I think you probably have a male common and a female moor. You'll want to look for tubercles on the male common's gill covers as a clue. While the male's advances would be totally normal for a female common (my two court like this constantly, chasing and rubbing) the same advances toward a black moor could be dangerous, as you've seen.
The moor can't move fast enough respond properly to the male's advances, and therefore he's going to injure her. I think you should separate them as soon as you possibly can because moors have telescoped eyes, and so she has a huge risk of injuring her eye, which could be fatal.

Try the classifieds for a new tank, or craigslist is a GREAT place to find something big for not too much cash. I found an old 60 for $50.

[fishcatch22]

and before someone points it out, I know these guys are probably gonna need a bigger tank at some point, but they are gonna have to wait till I can afford one. At this time, 3 medium sized fish ought to be ok in a 30gal tank, right?if you have enough fitration, yes.

as she said before, i'd separate the moor and the common.

when you upgrade, get at LEAST a 75G.

[Equinophobe]

thanks. {sigh} well, I guess I'll get 'em a big **** tank then. any suggestions for tankmates I can get without breaking the bank for a common that's already this big? (about 5"-6" from nose to tail-tip)

[fishcatch22]

thanks. {sigh} well, I guess I'll get 'em a big **** tank then. any suggestions for tankmates I can get without breaking the bank for a common that's already this big? (about 5"-6" from nose to tail-tip)I probably wouldn't add anything more at all. your common (both pleco and goldfish) will easily get over a foot as adults, and your moor may get about 8".

[InR reason]

You will see this between diffreing species of goldfish. Because a common is a more agile swimmer than the Moor you will see a kind of "status" in your tank. the Moor will seem to be picked on. You could easily keep two fancies in a 30g with proper filtration, but as stated above the Common needs 30g alone. That's why they've suggested such a large tank. Fancies need about 20g for the first and then 10g for each additional fish. Commons and Commets needat least a good 20-30g each because they often get double the size of Fancies.

[fishcatch22]

You will see this between diffreing species of goldfish. Because a common is a more agile swimmer than the Moor you will see a kind of "status" in your tank. the Moor will seem to be picked on. You could easily keep two fancies in a 30g with proper filtration, but as stated above the Common needs 30g alone. That's why they've suggested such a large tank. Fancies need about 20g for the first and then 10g for each additional fish. Commons and Commets needat least a good 20-30g each because they often get double the size of Fancies.actually, I would say commons should be given at least 55Gs for one with 20 gallons for each additonal one, and fancies should have 30Gs to start with 10 gallons for each additonal one.

[Equinophobe]

arg! anything larger then a 30gal tank with a single goldfish is going to look ridiculous until it gets to be 8"+ and probably, even then. any suggestions for tank mates? could i get some snails, crayfish, etc? any small fish that could escape the goldfish?

arg! ive tried ebay, CL, and all the local stores. Can't seem to find anything 40gal+ that is under $100. grrr.

[Equinophobe]

ok. got a 40gal for $40. That oughta tide be over till this summer. Suggestions for tankmates? (non-fish even?) I just can't conceive of a big ol tank for just a single goldfish.

[InR reason]

actually, I would say commons should be given at least 55Gs for one with 20 gallons for each additonal one, and fancies should have 30Gs to start with 10 gallons for each additonal one.

I'm talking about the bare minimum. You can have 75g for the first and then 30g for each additional fish if you like. I'm giving the bare minimum to healthily sustain these fish.

[Flaringshutter]

Definitely agreed, reason. This is the minimum. I think fishcatch, your estimate may be the happiest choice for the goldfish, certainly, but if you're on a budget right now you could go with something a bit smaller, say a 40 gallon, and be alright in the short term.

I have apple snails (Pomacea bridgesii and Pomacea Canaliculata) with my goldfish, and they get along very well. Snails, you say, gross and boring. Not so! I am totally in love with my snails. They're interesting, and they have such personality! They jump off the side of the tanks and surf in the bubble wand, they interact with each other, they clean the tank... Mine are all about the size of a golf ball and the goldfish don't bother them at all. Check out applesnail.net. Bridgesii species are usually sold as your standard "mystery snail" in most stores. I have six in a 60 gallon. The maximum stocking recommended is about 3 gallons per snail, but fewer snails will be fine.

[daniellehaagen]

arg! anything larger then a 30gal tank with a single goldfish is going to look ridiculous until it gets to be 8"+ and probably, even then. any suggestions for tank mates? could i get some snails, crayfish, etc? any small fish that could escape the goldfish?

arg! ive tried ebay, CL, and all the local stores. Can't seem to find anything 40gal+ that is under $100. grrr.

I have two fancies in a 55 gallon and I think it looks great. Just knowing that they have enough room to grow properly and swim freely, puts a smile on face everytime I look at them. I know where you are coming from though, it would be hard to have just one fish in a tank that you spend so much money on. Hopefully you can find a big tank for a great price. Good luck!

[Jessu]

I have 3 fancys in a 55g. When I first put them in there everyone kept asking me if I was going to get more fish. Once they are full grown it wont look strange.

[fishcatch22]

you could easily keep some coldwater inverts with them, crayfish come to mind. I think amano and ghost shrimp can live in CW too, and most mystery snails can tolerate water in the mid 60s. if you can find them, japanese trapdoor snails, which are CW snails, would be perfect. but I seriously wouldn't add any more fish.

also, the common pleco is not a true CW fish, and may not be as happy in an unheated tank, plus i've seen common
plecos over 2 feet long. I think it would be wise to get rid of the common pleco.

there's an old saying here at AC, "If your tank looks bare, it's just right."