neon and guppies dying because of zebra?

Question
QUESTION: Hi everyone.
I am new here and I have an urgent problem.
I have been keeping a crew of guppies and neon tetra for many years and everything was going fine.
Then a few weeks ago someone gave me a zebra (yes only one). I didn't know what to do with it, but since after checking the net it sounded safe to put it with the other fish that's just what I did.
During the first two weeks everything was fine although it kinds of chases the others regularly. I thought this fish was much faster and more agressive that the others, but so far none of them died.
Then someone else gave me two of these fish who clean the bottom of the tank. I don't know their name but they are small and don't move much, so I doubt they can do any harm.
And this morning when I woke up, which is about one week after I got the cleening fishes  and 2 and a half week after I guess the rather more agressive zebra, all my neon were dead (at least 5) plus one guppy. The neons were very old but still, 5 one one day it's crazy!
SO my question is : what do you think is the reason for those deaths and what would be the solution????
HELP!

ANSWER: Hi Jerry,
 If by zebra you mean zebra cichlid, also called a convict cichlid, then that is your problem.  There is very little chance of keeping neon tetras and/or guppies alive in a tank with even one convict cichlid.  Convicts eat them.

-- Ron
  rcoleman@cichlidresearch.com
  Cichlid Research Home Page <http://cichlidresearch.com>


---------- FOLLOW-UP ----------

QUESTION: Thanks a lot for your answer
I did some extra research (because when I got the fish it was only written "zebra"), and the fish is a Zebra Danio, or Danio rerio. And it doesn't eat the dead fish...
I was thinking, maybe the heat? The temperature suddenly rose above 35 a few days ago, that may have affected the tank. WOuld neon be weaker to heat than other species?
Thank you again

Answer
Hi Jerry,
  You are correct in that a zebra danio is no threat to the other fish.  
Temperature above 35 in the water would be close to lethal for most fish. Did the water actually hit 35?   The key to dealing with warm water is to ensure that there is LOTS of oxygen in the tank.  Many fish can survive higher than normal temperatures if they have LOTS of oxygen.

-- Ron
   rcoleman@cichlidresearch.com
   Cichlid Research Home Page <http://cichlidresearch.com>