Are my killifish killer fish?

[tukituki]

About a year ago i bought a trio of australe gold and a trio of nigerianus gold. initially they were put in my community tank but didn't do so well so put them in their own small tank with lots of java moss.

one female died but i never knew which breed she was.

over xmas my male australe gold died, we found him when we got back from holiday but there was a young killifish who turned out to be a male nigerianus gold.

these 5 killifish have been living fine together, or so i thought. i haven't been paying too much attention to the killifish tank over the past few weeks as i've been very busy. they've been getting their regular flake food every other day and blood worms 1-2 times per week. you'd see the fish at feeding times but i found they tended to hide a bit so haven't thought much about them.

we decided to do a big clean up of the tank yesterday as there was algae growing on the sides, only 2 of my killfish remained - the young male nigerianus gold and a female (not sure what type). i have moved these two to the community tank and they are swimming around happily.

there were no bodies of the 3 missing fish. there is no way they could have jumped out as it is a tight fitting aqua one tank and the lid never gets left open as i know they are good jumpers. there were no fish remains of any kind.

do you think the remaining 2 ate the others? it could only have been over the last 2-3 weeks at the most, probably less as i used to count and i'd compare my little killi to his dad (who i swear i've seen recently but most of my attention went to the baby killi).