Alligator Garrrrrr!! [Possible Giveaway]

Hi everyone..

I want to ask something not related to games, I hope you wont mind..
I dont know any good active fish forums so Steamgift is where I go back to =P

I bought some Predator fishes yesterday, planning to combine it with my Bigger Alligator Gar..

Bought: (They are around the same size, except the Albino Bichir)

• 1 Spatula Gar
• 2 Alligator Gar
• 2 Armored Bichir
• 1 Iridescent shark
• 1 Albino Iridescent shark
• 2 Albino Bichir (around half of the Spatula's size and Spatula was chasing it, trying to eat em)

I tried putting one Iridescent shark yesterday (Not a shark, more like a catfish.. Just the name), in the morning I found it already injured (fins, etc gone. still alive and swimming well though) now I moved it to the pond with my turtle and other feeder fishes..

Today I mixed the The Big Alligator Gar with the Smaller Alligator Gar.. The big one was chasing the small one around, idk if its trying to eat it or just a friendly gesture (like dogs sniffing one another).. After a while I think the big one "Attacked" the small one, maybe.. Not injury at all I think but I did saw some aggressive movements there..

The fish seller told me that mixing the same species is fine, especially with the Alligator Gar since it isn't as aggressive as the other Gar..

Rough Size Comparison: Big Gar and Small Gar

Please help me.. I'm sure there are some Fish Enthusiast somewhere here.. Thanks ><

Note: I dont know some of the fishes name until I searched the net today, so I am not a pro with this stuff at all..