I have 4 female guppys and 2 are pregnant an 1 male they all seemed fine I have been leaving the light on cause i have yet to get a heater but i am going today i came home from work decided to turn the light off an usually the temperature is always at 75 degrees no less but foun my male guppy dead on my filter so 1 do females get aggresive when pregant and might have attacked and killed him or 2 the tempature went down to about 72 when the light was off so could the change been the cause or 3 could my filter have sucked him on the tube and killed him? like I said I am going to get a heater asap but I just wanna know peoples opinions thanks alot