Hatchetfish And Lights?

[Electric Warrior]

Hi, I have a group of silver hatchetfish in my tank, and the surface is about 60% covered by floating plants. Oddly enough, they really only seem to hang out at the top in the open water, directly under the lights. But, as soon as the lights go out, they go BONKERS! They start flying around the tank everywhere like they are caught in a tornado, smashing into the glass, throwing themselves in between the heater and the glass, etc. Is this a common thing with them? I am wondering if I should try and find some sort of dimmer to dim the lights out, rather than them just going off when the times shuts them off? I have started making sure that all of the room lights are on when the lights go out, which doesn't seem to make them freak out as bad, but they still do it.

 

[Chad]

I have no idea the answer to your questions but I really want to know the answer so I'm going to follow along until someone gives a good answer. Clearly there's some issue with the lights but I was always under the impression that hatchet fish liked shade but you are saying they like the lighted areas more...

 

[Electric Warrior]

Yeah, that is what i always thought, but they do seem to really like riding the current in front of the spray bar, and obviously, the floating plants get blown away by the current... I guess when they have decide between shade and current, they choose the current, lol! But yeah, they go completely nuts, it's crazy. The lights are out now, and they usually calm down after about 10 minutes, but they are all still in front of the spray bar.

 

[Chad]

So odd. Maybe it's as simple as that though...the current attracts them.

 

[Electric Warrior]

Yes, but it still doesn't explain why they loose the plot when the lights go off?

 

[fluttermoth]

Mine do it too. They live in my bedroom and I can hear them hitting the condensation tray when I put the lights out! I've never had one hurt itself though.

I don't really want to run more electrics over there, so I've been thinking about sticking some glow in the dark stars on the inside of the lid! Adding a little blue LED light might also solve the problem, if you'd rather.

 

[Chad]

Yes, but it still doesn't explain why they loose the plot when the lights go off?

That I get. My marine fish do it as well and my lights go off slowly over a half hour period and the lights at night mirror the phase of the moon in my time zone yet they still get freaked at night. I have always thought it was a fear response since that is a time where they are vulnerable. They can't see above them and they haven't found a cave for the night yet.