Odd Foxface Behaviour (not a problem)

[Mark Goode]

I aquired a young Black spot Foxface on Saturday, 1½" - 2" long. He (or she) had been in the shop for a couple of weeks, and though I didn't see him feeding, he looked well fed and active.

After spending a couple of hours in the drip bucket (LFS salinity was low), I put him in the DT (don't ask about QT ) where he donned cammo and hid.

Yesterday morning he was out and about, swimming with a couple of Spotted Cardinals - but after a while he disappeared, and I found him in a far corner of the tank, almost motionless, about a quarter inch above the sand. I became more and more concerned as the day progressed, but I could see no fast breathing, no spots, marks or lesions on his skin, and his colour was good. He just stayed motionless in the same place.

Then I twigged. That side of the tank is the only part that faces a dark wall, and he was simply staring at his reflection. Not fighting it or trying to mate with it, just watching it. Constantly. So I taped a piece of white paper against the side of the tank, and he then rejoined to the two Cardinals.

What a strange creature.

 

[Timfish]

Actually fish don't see any reflections from inside a tank. The reflections we see is an optical illusion caused by light going through air/water surface and is only seen from the outside. It's been my experience it's fairly common to see new fish hang out in a corner for a bit while acclimating to a new tank.

 

[Mark Goode]

Actually fish don't see any reflections from inside a tank. The reflections we see is an optical illusion caused by light going through air/water surface and is only seen from the outside. It's been my experience it's fairly common to see new fish hang out in a corner for a bit while acclimating to a new tank.

Really? Why could I see reflections in the glass when looking through the water from the opposite side of the tank? Sorry, I'm not convinced.

 

[Reefer Matt Verified Media Partner]

The foxface is acting normal. They are more skittish than other fish, and will take time to adjust.

 

[TastesLikeChicken]

This wouldn’t have happened if you had quarantined

 

[Timfish]

Really? Why could I see reflections in the glass when looking through the water from the opposite side of the tank? Sorry, I'm not convinced.

You're still not looking at it from the fish's perspective. I have, but if you don't believe me spend some time looking up the science.

 

[Mark Goode]

5

You're still not looking at it from the fish's perspective. I have, but if you don't believe me spend some time looking up the science.

Two minutes with Google:

"One thing to note though is that if the tank contains a bright light and the room it is in is relatively dark, then even though only a small proportion of light from inside the tank is reflected from the glass walls, that small fraction may dominate over any exterior light passing through the glass from the outside - thus giving it the appearance of being mirror-like. This is the principle behind one way mirrors."

This is precisely the situation before I covered the dark background with white paper.

Happy to help.

 

[Timfish]

As they are talking about observing a tank from the outside they are correct about the reflection (my guess this is a hobbyest website and not one looking at the science as I suggested). But when the observer is on the inside they can see out just fine, they won't see their reflection. Excellent example of conformational bias by the way.

 

[Mark Goode]

Yeah, yeah. Whatever.

 

[Waters]

I am not sure either way to be honest, but I can say that when I have used a mirror outside of the tank to keep an aggressor busy, the fish definitely acts differently when looking through the glass at the mirror.

 

[Murica]

It’s so funny what people argue about online

 

[jetskiwilly]

Stick your head in the tank and tell me if you see a reflection.