PlanetCatfish.com

Hello,

I've recently purchased a new Ancistrus Dolichopterus, a black female with small white/blue spots.
I already owned a male Ancistrus Temininckii(brown) and I was told that they were able to live together in a fishtank.
The two fish immediatly searched for eachother and showed some signs of agressive behaviour (swimming towards eachother and making themselves appear larger etc.)
The next morning I saw that my new female ancistrus had severely damaged fins. All her fins seem to be ripped apart. She does still seem healthy but she does appear to be stressed.
I seperated them, not knowing what would be the best option.
I really hope my new fish will heal but I'm not sure what to do or why they show this behaviour. The male is showing this agressive behaviour.

My fish tank isn't very large but it does have some hiding spots (plant pots, plants, a statue and a piece of driftwood).
I hope somebody could tell me what options there are .
(In the attachment you can find a picture of the tail of my fish. The wounds are worse than they look, though. Also, the backfin and other fins are badly injured, but I could't take a better picture, unfortunately)

Kind regards,
Femke

Though hiding spots are needed they do not solve all aggression because a tank is still a closed enviroment. I would keep them apart and get the new fish healthy and try and reintroduce.

If you do decide to remove the battered pleco, let it heal, and then you want to reintroduce it to the same tank, I advise you do it in this way:

1. Remove wounded fish to a different tank and allow it time to heal its fins. Based on what I've seen in other injured fish, I see no reason here why you shouldn't expect a full recovery.
2. Before reintroducing the fish to its original tank (with the other pleco), first REMOVE the other pleco from its home tank to a temporary bucket or other holding pot, then
3. Rearrange the decorations in the tank so that the tank does NOT look at all like it did before.
4. Finally, introduce BOTH plecos at the same time back into the tank.

By removing the other pleco and rearranging the furniture, you will confuse the dominant pleco so that when the two plecos are reintroduced to the tank with a new décor lay-out, neither of them will think they are back on their "home turf" and they will both have a fair chance to establish their own safe places/territories. That way, neither fish is perceived as an "intruder" on the home turf of the other.

Good luck,
Eric

What size is the tank? I've found a pair of adults of the same species (Common BN) really need a minimum of 24x12x12

When you mix species the tank needs to be a bit bigger - good advice above from bekateen which should work but the restricted space may be a problem & any changes may result in a temporary truce & aggression resurfaces later on

Richard B wrote: [The advice] should work but the restricted space may be a problem & any changes may result in a temporary truce & aggression resurfaces later on

I fully agree. I meant my words not as a guaranteed solution but a possibility to try, with the fallback being rehome one or the other (or get a bigger tank, which is effectively rehoming both ).

In parallel with this thread, there is another, very similar thread describing conflicts between Ancistrus and corys. You can read it here: Corydoras Panda swimming up and down glass

Cheers, Eric

My fishtank is about 42x25x27 cm.
I´ve put my injured fish in a smaller tank (27x17x18) for recovery.
Thank you for all the tips, I'll try to redecorate my fishtank when my fish is healed and try to put them back together. I might also buy a larger tank soon.
I was also told that an Ancistrus Dolichopterus and an Ancistrus Temminincki are able to live and breed together, is this true?

In my experience smaller plecs like a substrate area at least a foot square (30cm x 30cm) each, with one or two hiding places in that area.
Ideally they would have more space but I'd be surprised if it works with less.

Mol_PMB, is correct there about the 30×30cm per fish recommendations for small plecos, if you look in the clog pages, where there's info held for different species, this is suggested for many of the smaller plecos.

Richard B wrote:What size is the tank? I've found a pair of adults of the same species (Common BN) really need a minimum of 24x12x12

When you mix species the tank needs to be a bit bigger - good advice above from bekateen which should work but the restricted space may be a problem & any changes may result in a temporary truce & aggression resurfaces later on

I would agree for other species, however I keep all of my bristlenose trios in 10g tanks (20x10x12 inches) and I have never had an issue with fighting. Lots of driftwood and plants always seem to do the trick for me.

Forester wrote:

Richard B wrote:What size is the tank? I've found a pair of adults of the same species (Common BN) really need a minimum of 24x12x12

When you mix species the tank needs to be a bit bigger - good advice above from bekateen which should work but the restricted space may be a problem & any changes may result in a temporary truce & aggression resurfaces later on

I would agree for other species, however I keep all of my bristlenose trios in 10g tanks (20x10x12 inches) and I have never had an issue with fighting. Lots of driftwood and plants always seem to do the trick for me.

My adult pair were fine in a 24x12x12 but when moved into an 18x12x15, with more caves, driftwood the male nearly killed the female - it's somewhere around these sizes that's the limit - better be safe than sorry although every fish & set-up is a unique circumstance

My ABN pair are in a 30×12×12 spwaned for the first time recently in a community tank, i moved them to this tank, still in spawning mode, the male continously chases the female, I'd like to think she has a place to rest, and eat! As whenever the male spots her he's chasing her again i wouldn't put them in a smaller tank.

bekateen wrote:If you do decide to remove the battered pleco, let it heal, and then you want to reintroduce it to the same tank, I advise you do it in this way:

1. Remove wounded fish to a different tank and allow it time to heal its fins. Based on what I've seen in other injured fish, I see no reason here why you shouldn't expect a full recovery.
   Eric

My fish started to show some signs of improvement after a few ays, but now she seems to have no strength anymore. She doesn´t stick to objects anymore and sometimes she just lies on her side. I have absolutely no idea what the problem might be. Since the tank is small and doesn´t have a filter or pump, I clean the water once in a few days. The water gets quite filthy because of her food pills (which she doesn't eat...). I don't remove all the water and the temperature is around 22*C, which should be fine. There are enough hiding spots, which she used just a few days ago, now she just lies on places, since she can't stick to objects and has trouble with swimming.
What should I do? Put her back in the original tank with the other pleco ( since the water might be the problem) or should I just wait and see what happens?

It might be worth checking all the parameters, especially Ammonia, Nitrites and Nitrates, though with no filter, the first Ammonia is most likely to be the problem and changing the water every few days will most likely not remove enough of it. It would have built up here. Nitrites and subsequently Nitrates is the end product of the nitrogen cycle and are dealt with by filter bacteria. Sometimes an LFS will take a measurement if you take in a sample of tank water. If there's uneaten food, this will contribute to ammonia, and thus its possibly ammonia may be what's stopping her eating. As she's in a smaller tank ammonia levels would have become very high, how mature is the tank with the male in, if the tanks been running for some time, get a filter ASAP for the female's tank. Then take some media, not all of it though, sponge or whatever it is you are using, and put it in the new filter in the females tank. It's the only option i can think of for you, going by what you've described her condition to be i can't promise this will work, but its the best option i can think of as I think putting her back in with the male in her condition, may do more harm than good.

I agree that water quality might now be a bigger problem than the original aggression. You'd be surprised at how fast a decent sized fish like your pleco can foul the water. If you can't control water quality in the new tank, you might be better off putting the fish back in the original tank, if that is your only other option for housing.

If you do have to put her back with the male, if getting a filter quickly is difficult for you, then this is your only option, she's better in a filtered tank than one that isn't, break up the decor as much as possible, as Eric described seems good, to provide her with several places to hide from the male BN she will need to be able to have space from him, where she can recover.
Edit. Where I am in the UK, it would be impossible for me to get a filter straight away, this late on a Friday night, as you're in Europe also i guess it would be just as difficult for you to.

bekateen wrote:I agree that water quality might now be a bigger problem than the original aggression. You'd be surprised at how fast a decent sized fish like your pleco can foul the water. If you can't control water quality in the new tank, you might be better off putting the fish back in the original tank, if that is your only other option for housing.

Unfortunately, the fish already died short after I put her in the original tank. I honestly don't think the water quality was the issue, since I checked it and it was fine. I think the fish might already have been sick when I bought her because the new guppies I bought at that shop also died quickly and short after that my old guppies also died (the new ancistrus also didn't foul the water, only the pills did, which is also a little odd). I've never had any issues with diseases before this.
I just hope my other ancistrus doesn't get sick so I've put some medicines in the tank to prevent further issues.

Sorry to have heard this. Some advice, this may help you for the future when you get more fish, what i do in all of my tanks is run a second filter. Either a sponge or internal (some of my tanks have more than 2, I tend to overfilter them), this means if I need to set up an isolation/hospital/fry tank I have a filter to hand i can use that is already mature.

[/quote]My adult pair were fine in a 24x12x12 but when moved into an 18x12x15, with more caves, driftwood the male nearly killed the female - it's somewhere around these sizes that's the limit - better be safe than sorry although every fish & set-up is a unique circumstance[/quote]

Part of it may be having a trio instead of a pair. With a two females the males aggression is spread out. This must be why 20x10x12 works for me, cause I have never really had any issues with the males beating up the females.

I'd possibly keep a trio in a smaller tank, like a two ft, my male does chase my female, as i mentioned the bigger tank i have gives her some space from him when she wants it. But I didn't want two females. Be way too many babies to cope with

pleconut wrote:I'd possibly keep a trio in a smaller tank, like a two ft, my male does chase my female, as i mentioned the bigger tank i have gives her some space from him when she wants it. But I didn't want two females. Be way too many babies to cope with

Makes sense. Yeah I just pulled close to 100 babies from one of my longfin super red caves, though i cant really complain because aquabid loves em