Do mollies and/or platies eat other fish (like tetras)?

[jersey355]

I'm a very green beginner as far as aquariums go...

Anyway, I set up a 15 gallon tank recently and started off with 2 platies and 2 dalmatian mollies (with the longer fancy tails)... a week later or so, I added 5 neon tetras and 2 black mollies (also with the longer fancy tails).

A couple of days later, I noticed that one of the black mollies kept nipping at all other fish, and especially terrorizing the little tetras.

The next day I came home to find one of the tetras had comitted suicide by jumping out of the back of the tank and another was just floating around dead in the tank.

I immediately suspected the bully black molly so I went out and got a small 2 gallon tank to separate him/her from the other fish. I also went out and got 5 more neon tetras and a small algae bottom feeder that just keeps to himself a few days ago.

A couple of days ago, I came home from work to find only 3 neon tetras (down from eight, and there is no trace of the missing 5... and I've looked everywhere inside and outside the tank)!!!

I think when I get home today, I'm actually going to separate the remaining tetras and return the bully molly to the main tank, but... I was told a the pet shop that mollies and platys are great community fish and get along with most fish! Did they lie to me?

Any advice?

 

[Vircomore]

I didn't notice you mention gender, can you reply with that please? Mollies and Platys are usually nice community fish, but if they're kept in a "Male:Female" ratio of less than 1:2, the males will become extremely aggressive (usually toward other males, but they could take it out on the tetras). Females on the other hand tend to remain relative peaceful if they're kept in an all-female group.

You can tell a female molly from a male molly like this:

Look at the anal fin (the single fin on the bottom rear of the fish)
-- A female's anal fin will look just like a regular fin.
-- A male's anal fin will be curled up into something called a "gonopodium", it's what they use to fertilize the females.

As far as deliberately trying to eat the Neons - I find that highly unlikely unless you're feeding them nothing but vegetables. Mollies are algae-eaters in nature and vegetarians in the aquarium, but they do need a little protein every so often.

 

[jersey355]

Thanks. To tell you the truth, I'm not even sure what I have, but will check when I get home (based on your fin description) and reply back w/those details.

 

[jersey355]

Based on your description it looks like I have 1:1 male:female ratio with the mollies. I have a pair of dalmatian mollies and a pair of black mollies...

 

[HN1]

Did you cycle your tank? Neons are notoriously weak and the most susceptible to ammonia. The "algae" eater is most likely not a good choice for a tank that size as the commonly available ones get huge when given a chance.

The original question... I doubt they attacked or ate them. They will eat their fry when allowed, but I've never seen any of the normal livebearers prey on other fish.

 

[RaptorBro]

My platys do that to every fish because they are curious... I havent had any problems with that

 

[i3k]

x2 on cycling. your fish most likely jumped out because of ammonia burns.