Dalmation Mollys Attacking Platy

[mull3t]

The other day I posted about my Male platy constantly chasing the female around, and biting her.

Today/last night I noticed that my Dalmation mollys were doing the same, chasing her, biting, and also the mollys were chasing the male platy too.

I have had all these fish together for over a month now and I have never seen this behaviour, what could be causing it?

It appears the female black tail platy as swam her last stroke as she has not got the strength to swim. All her fins look closed, and they is no sign of disease on the platy. I have seperated her from the the rest.

I have lost 3 platys now (including this one) and they all seem to go the same way (bar the aggression this time).

I have had my water checked out by the store and they say everything is normal, temperture is normal, water changes weekly. etc.

Thanks

 

[nosoup4you]

What size is the tank? How many fish? You should really ask the fish store for the exact water test results. Many times what is normal to pet store/fish store employees is deadly to your fish. Does the female Platy appear to be pregnant? Often, if a fish is heavily pregnant, the other fish will actually harass a female to death waiting for her babies to pop out...it's like a fishy vending machine. I'd do a 50% water change just to be on the safe side.

 

[mull3t]

What size is the tank? How many fish? You should really ask the fish store for the exact water test results. Many times what is normal to pet store/fish store employees is deadly to your fish. Does the female Platy appear to be pregnant? Often, if a fish is heavily pregnant, the other fish will actually harass a female to death waiting for her babies to pop out...it's like a fishy vending machine. I'd do a 50% water change just to be on the safe side.

Its a 3ft long by 1ft wide, and Id say about 1.5 ft drop. Im a little unsure how many 'GL' it is though.. sorry.

Fish I have are 15 Neon Tetras, 1 Albino cat fish, 2 Female Dalmation Mollys, 1 Male Dalation molly & now 1 male red platy (female just died).

I have only had problems with the platys, all other fish look healthy, and seem well. She didnt look pregnant, and I did not notice any change in size.


I will go get a home test kit tomorrow, what sort of results should I be looking out for?

 

[nosoup4you]

It sounds like you have a roughly 30-35 gallon tank. Your stocking seems okay provided the tank was cycled before the fish were added. How long has the tank been up and running? Did you add all of the fish at once? Ammonia should be 0, nitrite should be 0, and nitrates should be no more than30 ppm (preferably less).

 

[mull3t]

It sounds like you have a roughly 30-35 gallon tank. Your stocking seems okay provided the tank was cycled before the fish were added. How long has the tank been up and running? Did you add all of the fish at once? Ammonia should be 0, nitrite should be 0, and nitrates should be no more than 40 ppm (preferably less).

I established it first, adding the gravel, water heater, filter etc for about a week and a half, then I introduced some plants, after for about a week or 2. The by week 3/4 I added some fish, all introduced to the tank on the same day. Left each bag floating on the water for 30-45mins or so, and cut one every 20 mins or so, until they was all in.

It just seems strange that all the platys are getting ill and dieing and I have had no problems with the others. even though platys are one of the easiest fish (supposidly) to keep.

I'd understand if I had different fish dieing, but its always been the platys, and they always look the same and go the same way before dieing.

Thanks for your reply, will get a home test kit and see what my results say.

 

[nosoup4you]

If there was no fish waste (ammonia) for the bacteria necessary for biological filtration to feed on, then I'm going to guess that this is what is killing your fish. Your tank may very well be cycled now (which may be why your water is testing okay), but the damage from toxic ammonia/nitrite levels has probably taken its toll on the fish. Clamped fins is almost always a sign of poor water conditions/stress. Typically, even in cycled tanks, fish are added gradually to allow the bacterial colony enough time to grow to compensate for the increased bio-load. Here is a good link to resources on cycling:

http/www.fishforums.net/index.php?showtopic=141944