"Rhino" wrote in message
...
I have a 20watt 12v underwater spotlight that shines up toward the
waterfall
from the opposite side of the pond. The beam of light shines upward at
about a
20deg angle. I have noticed at night that when the goldfish swim
perpendicular
to the beam they "tilt" and orient themselves 100% broadside to the light
no
matter which direction the are swimming to. This makes them appear to be
leaning sideways as they glide through the water. When I first saw this
last
season at first I thought they were sick but now it is normal. Any
comments?

The has been discussed in rec.aquaria.freshwater.misc a few times.
Apparently fish orient themselves to the sun, or surface of the water. If
you place a light from a different angle, they will orient to it as if it is
the sun. The thread in r.a.f.m that I remember had to do with someone
wanting to put lights in the bottom of their aquarium.

BV.