Some hobbyists experience what I call the "kamikaze" fish. You know, the fish that you found dried up on the floor after it flew out of your tank and dive-bombed to it's death!  Of coarse this usually happens at night when we're not able to rescue it.  Why does this happen?  Why do some fish have more of a reputation for displaying this behavior?  Are tank covers really the answer in preventing this?

I've had the pleasure of working with just about every fish offered in this hobby & in every size tank imaginable and I have found that fish DO NOT jump for NO reason. I have identified that there is always a cause & most often it's a case of being chased by a bully tankmate, spooked or attacked, especially by bad crabs (including hermits) while sleeping at night.

Consider this...AquaCorals has lots of people through the facility daily, including children who sometimes tap the tanks in excitement (note for parents....this is not good ;).  You'd think under the circumstances I'd have fish lying on the floor all over the place!  Sorry, doesn't happen (Thank God!)  What I have identified is that fish, when feeling safe & secure usually stay in the tank quite willingly.  But, let another fish, crab, starfish etc. invade the house/hole of another & the poor evicted fish is now homeless, nervous for lack of a safe place & this is where things can get hairy.  Another scenario is a fish being chased/bullied (whether established or newcomer).  More commonly it happens with new fish introduced to your tank, it's scared to death having just been caught, bagged, transported & now facing a new world (your tank) & fretting that someone is going to eat him (big fish eat little fish in the ocean, right) so until the new guy finds his own safe place he's a prime candidate for kamikaze behavior.  Especially if anyone in the tank is bullying/chasing him.  Fish that are "nervous nellies" to begin with like Pearly Jawfish etc. are more prone to this condition until they have established their "house" in your tank.  So, should we cover our tanks to prevent the kamikaze experience?  No.  Covers restrict the gas/air exchange as well as blocks important light from entering the tank and rarely keeps a fish in unless 100% sealed.  What we DO need to do is:

    Be sure your new fish is compatible with those you already have.

    Acclimate & release in the dark so the newcomer feels safer & your other fish are more likely to be concerned with finding a sleep spot than to chase that new guy in the tank.

    Introduce the "nervous nellies" to your tank first.  This way they can get settled in & make/find their own "safe place" without the hassle of the more aggressive or avid swimmers.

    Do not keep animals known for being bullies/territorial like Damsels, Coral Banded Shrimp etc.

    Inspect ALL rock before placing it in your tank.  See my Self Help article: Killer Hitchhikers - Crabs

There will be times when we won't ever identify the cause of the kamikaze behavior but you CAN investigate & intervene when cause is found.  If you follow the above steps you can be confident your fish will stay happily in your tank.