Mollies attack other mollies?

hi, I am new to this forum and I just got a 2.5 gallon tank. I started off with 2 mollies and a platy, I noticed that immediately one of the mollies was extremely aggressive and was attacking the other 2 fish and eventually after 2 days of having the fish, has killed both the fish, or atleast I'm assuming it killed the fish because I saw it attacking them. have any of you ever noticed this activity with any of your fish?

 

2.5 gallons is really too small for two mollies and a platy, firstly. You should have three gallons for each molly and one gallon per adult inch of any other fish (mollies grow to about 3", I don't know about platies). If you get any more fish, please buy a larger tank. A ten gallon isn't expensive, and you can use your 2.5 gallon as an isolation tank or a home for a happy betta fish. If you choose to simply maintain your 2.5; please don't add any more fish.

Can you give any information on whether the fish involved were male or female? Males sometimes get nippy with each other - tho after my more aggressive molly was seperated for a while he stopped bothering the other fish. Females can sometimes get overstressed if there are not enough females per male (same species, 2females per male is a good ratio), and this can lead to them dieing. Was your tank cycled? spikes in the toxic chemicals (ammonia, nitrates, and nitrites) can kill fish. Another option is that your fish were sick when they arrived at your house and the combination of crowded living conditions, an aggressive tankmate, the stress of the move and change in water quality (whether your tank is cycled or not) lead to them dieing.

 

2.5 gallons is really too small for two mollies and a platy, firstly.  You should have three gallons for each molly and one gallon per adult inch of any other fish (mollies grow to about 3", I don't know about platies).  If you get any more fish, please buy a larger tank.  A ten gallon isn't expensive, and you can use your 2.5 gallon as an isolation tank or a home for a happy betta fish.  If you choose to simply maintain your 2.5; please don't add any more fish. 

Can you give any information on whether the fish involved were male or female?  Males sometimes get nippy with each other - tho after my more aggressive molly was seperated for a while he stopped bothering the other fish.  Females can sometimes get overstressed if there are not enough females per male (same species, 2females per male is a good ratio), and this can lead to them dieing.  Was your tank cycled? spikes in the toxic chemicals (ammonia, nitrates, and nitrites) can kill fish.  Another option is that your fish were sick when they arrived at your house and the combination of crowded living conditions, an aggressive tankmate, the stress of the move and change in water quality (whether your tank is cycled or not) lead to them dieing. 

yea, I just got the tank last weekend, I cycled the water with chemicals for 3 days and then took it in to the pet store to get it tested before I got fish and the test came back just fine. the lady that sold me the fish said she has 3 tanks at home and that they would be just fine in that size tank. I do know that the female was the fish attacking the other fish. thanks for your help!I'm new to having tanks and all

 

Wow, the lady in the store told you that she had that many fish in such a small tank? It can be done, but the health of the fish suffers drastically. Fish store people often just want to sell you fish, IMHO. also, just because someone who has kept fish for a long time can maintain such a population in a small tank doesn't mean a beginner can, except by dumb luck. and the lady probably has just dumb luck anyway - maintaining such a population would require tons of filtration and water changes to keep the fish healthy, and you still have stress from overcrowding. Putting that many fish in such a small tank all at once will probably shock the filter and create chemical spikes even in a cycled tank. sorry, I just distrust advice that comes from fish stores unless I know the person myself (my go-to person is a good friend of mine who works at the aquarium specialty store here in town). The one inch of fish per gallon rule can be fudged slightly (not recommending doing so, but for example three inches of fish in two and a half gallons with a good filter isnt' bad), but you should never ever stick eight inches of fish into two and a half gallons. (not blaming you, you were misinformed). The problem is that it is advertised that you CAN do so, and even people who have had aquariums for a while (or perhaps especially those people) don't know or think that because they've done it before, that's the best way to do it. Consider the small cups bettas are sold in - with a note that they live in that much water in their natural habitat (just because they CAN doesn't mean they should be subjected to it all the time) - or goldfish bowls: goldfish need large surface area in order to breath (even in a really big bowl, the round shape decreases surface area in relationship to volume), and have a large bioload and so need 20gallons for one fish, 30 for 2, 40 for 3 and so on as a general rule. I know a woman who has kept large aquariums for years, and just bought two bettas in one of those divided "tanks" that has about three cups of total water... it makes me sick to see them but she blew me off when I said something about it, and I don't know what else to say to her about how horrible it is. (I guess if one of them gets sick, she might come ask for my help - I have six and she's never had them before).

Just wondering - are you certain the fish is a female? The past two times I've bought mollies, I've requested males and had the employee give me a female. I now check before they bag the fish. If the lady at the store said "this is a female" based on something like "she's fatter than the others" or thinking that males are the ones with the fanned out analfins, or any other misinformation... you may have an aggressive male and not know it. I've never heard of a female being overly aggressive but its possible.

OK now that I've once again gone off and written a whole page of info... feel free to ask any questions you have, everyone here is glad to help

 

Wow, the lady in the store told you that she had that many fish in such a small tank?  It can be done, but the health of the fish suffers drastically.  Fish store people often just want to sell you fish, IMHO.  also, just because someone who has kept fish for a long time can maintain such a population in a small tank doesn't mean a beginner can, except by dumb luck.  and the lady probably has just dumb luck anyway - maintaining such a population would require tons of filtration and water changes to keep the fish healthy, and you still have stress from overcrowding. Putting that many fish in such a small tank all at once will probably shock the filter and create chemical spikes even in a cycled tank.  sorry, I just distrust advice that comes from fish stores unless I know the person myself (my go-to person is a good friend of mine who works at the aquarium specialty store here in town).  The one inch of fish per gallon rule can be fudged slightly (not recommending doing so, but for example three inches of fish in two and a half gallons with a good filter isnt' bad), but you should never ever stick eight inches of fish into two and a half gallons.  (not blaming you, you were misinformed).  The problem is that it is advertised that you CAN do so, and even people who have had aquariums for a while (or perhaps especially those people) don't know or think that because they've done it before, that's the best way to do it.  Consider the small cups bettas are sold in - with a note that they live in that much water in their natural habitat (just because they CAN doesn't mean they should be subjected to it all the time) - or goldfish bowls: goldfish need large surface area in order to breath (even in a really big bowl, the round shape decreases surface area in relationship to volume), and have a large bioload and so need 20gallons for one fish, 30 for 2, 40 for 3 and so on as a general rule.  I know a woman who has kept large aquariums for years, and just bought two bettas in one of those divided "tanks" that has about three cups of total water... it makes me sick to see them but she blew me off when I said something about it, and I don't know what else to say to her about how horrible it is.  (I guess if one of them gets sick, she might come ask for my help - I have six and she's never had them before).

Just wondering - are you certain the fish is a female?  The past two times I've bought mollies, I've requested males and had the employee give me a female.  I now check before they bag the fish.  If the lady at the store said "this is a female" based on something like "she's fatter than the others" or thinking that males are the ones with the fanned out analfins, or any other misinformation... you may have an aggressive male and not know it.  I've never heard of a female being overly aggressive but its possible. 

OK now that I've once again gone off and written a whole page of info... feel free to ask any questions you have, everyone here is glad to help

thanks for the help, I just got 2 new mollies today after I let the water cycle with chemicals for a week and the water is much clearner now. I am not sure if I have a male and female, but if I do, will they get pregnant if they are different colors

 

Yes they will still get pregnant if they are different colors.

 

I have two female mollies and one male molly and they constantly chase each other but haven't noticed them bothering my other fish. One thing to try when you get a larger tank is increasing the number in your school to something like 6 so they have more than one person to chase around. A larger area for them should also help lessen aggression.

 

no trying to be rude osuftball12...but after what emileia just told you why would you get two more mollies for your 2.5 gallon tank. I know it looks pretty having more fish in a tiny space but why are you doing it? Most likely they're all going to die in the next few days. Its dangerous for the fish to be even having two in there...so you get three again. If your not listening to what we are saying then why are you coming on here. No matter what other little problems it could have been also, its definetly because of the size of tank you got.. Though if you still don't listen I would at least give one mollie back so you'll only have two..also to keep them alive for the rest of their life your going to have to do daily water changes..have fun :-\

I just really really think you should reconsider putting three mollies in a 2.5 gallon tank! :-[

 

I just really really think you should reconsider putting three mollies in a 2.5 gallon tank! :-[

sorry, I haven't been on here for awhile, ive been busy with school and on spring break. but I have had 2 mollies the last few weeks and they have been really good. I have been testing the water with the testing strips and it has been really nice as well. sorry to seem like I was being rude before, hope there's no bad blood

 

o no I meant.. not trying to be rude..lol
I'm glad you only have two now. I hope they do well. I had a 2.5 gallon with one mollie which seemed to do fine..buit I wanted another one..and after coming on here...I knew I should get a bigger tank.. so I did got one more mollie...and the irst one I had died..so now I'm back to one mollie. I really do like the 2.5 gallon tanks..is it a 2.5 g haxagon one? I just wanted more fish..but now l8ly ive heard a lot of ppl keeping two livebearer fish in a 2 gallon... so I kinda regret getting the 5 gallon...but I'm getting another fish soon so... I wish you luck keep me updated

 

So in my case, why were my females fighting? I have a 55 gal with 1 molly male orange dalmation, 2 female black and white dalmations, and a red/dark orange female. There are also 3 Mickey Mouse platys (1 male, 2 females), a pleco, and 3 guppies (all male). for a few days, the male molly and the one lighter-colored black female would chase the darker-colored female dalmation around and have nipped at her tail until she looks more like a barb. they seem to have stopped now. would that have been caused just by teh stress of moving tanks? I had my little community in a 10-gal for a little more than 2 weeks before getting the 55 gal, letting it normalize for a few days, then moving them over. When I moved them I moved all the stuff from the 10-gal with them. Was it just stress making them do it? Why this molly in particular? No one else got picked on.

 

I bought two molly's for my 70 litre tank tree days ago. Within two I had about 3 babies and a dead molly. Today I replaced the stiff but I've noticed that the surviver has become very aggressive and attacks everything but the pleco. Which died, male or female?

 

Hi. I have a 10 g tank that currently contains 3 female balloon mollies (and a small gold spot pleco that will be rehomed once he gets a bit bigger.) I've had the mollies for 6~7 weeks now. One yellow, one black, one white.

At the beginning the white one would chase the others a lot, especially the yellow one. I put her in a fry net for an hour and she calmed down. Unfortunately she started doing it again recently- and the white one has been chasing the others too, and my mom told me that while I was at work the black one has been doing it as well!

I haven't seen them biting or nipping at each other, but is this normal? I read somewhere that adding more fish of the same breed might make them stop... is this true?

 

Fish will often show aggression in a small tank.

 

I wouldnt add any more mollies to your tank. Itd get too over crowded. Try adding lots of live plants so they have more hiding spots.
What are your ammonia, nirtite and nitrate at?

 

I wouldnt add any more mollies to your tank. Itd get too over crowded. Try adding lots of live plants so they have more hiding spots.
What are your ammonia, nirtite and nitrate at?

Also, you need to upgrade your tank to at least a 29. Petco still has the dollar-per-gallon sale.

 

I don't live in the USA, tanks are very expensive where I live :/ a 4 gallon costs ~60$....

 

I don't live in the USA, tanks are very expensive where I live :/ a 4 gallon costs ~60$....

Can you perhaps find any friends or family members that has a large, unused aquarium? If not, you can try finding aquariums on Craigslist or any other sites in the internet.

 

I was looking for second hand tanks, but the ones that are actually in good condition and cost less than the store price are so far away from me... and I don't have a way to transport the tanks... also none of my friends have unused tanks (except fishbowls) and all our relatives line abroad

 

I was looking for second hand tanks, but the ones that are actually in good condition and cost less than the store price are so far away from me... and I don't have a way to transport the tanks... also none of my friends have unused tanks (except fishbowls) and all our relatives line abroad

Could you ask your lfs to order a specific size tank for you?

 

What's lfs?

 

What's lfs?

Local fish store.

 

I agree the tank you have them in is kinda small. For 3 mollies to be bumbling into each other all the time you might want to upgrade. Also what you heard about more fish of the same breed doesn't really apply to what you have, it's more true for fish like tetras or other schooling types.