MY GUESS (I was not at home)...this day, I've feed them with some carps, after this, I get out of my home...some hours later, arriving at home, I looked to the tank and the surprise...my TSN was full of bite marks(just like scraches) - the guess here is died due to injuries - RTC GUILTY. The RTC and Dorado is clear...The Dorado was RTC's mouth, and the RTC were floating with the head down. =/
I just can't understand WHY the RTC tryed to eat him, If she have already eat some hours ago ! (2 carps - 6 cm)