Position of the sun in the sky over the course of the day during the summer and winter solstice days, and both equinox days.
In the Northern Hemisphere, the Winter Solstice occurs on December 21, 2008 at 12:04 UT (Universal Time) - or 04:16 Bermuda local time.
This means that at noon on Sunday the sun will be at its lowest point relative to the southern horizon for the whole year. The angle of the sun will only be 33* South above the horizon - as opposed to June 21st, when it is almost directly overhead, at 83* South.
It will also be the shortest day of the year, with only 10 hours of daylight. The sun will rise at 7:16 am, and set at 5:18 pm - local time
The angle of the sun and the length of the day affects the amount of light available for photosynthesis by hard corals, soft corals, and macroalgae growing on reefs.
Being a coral specialist, (although learning about fish as fast as I can) I thought this butterflyfish seemed to be a hybrid between a Spotfin Butterflyfish and a Foureyed Butterflyfish, and my quick search for information did not help.
It was found by Jessie Hallett today as we were setting up an experiment out in the lagoon.
Judie Clee - a local REEF expert on fish identification, was able to correct our mistake:
Turns out the dark spot is part of the nocturnal marking of the fish - and it will get much darker at night, while the little black spot near the tail will fade. Perhaps this guy was getting ready for night at 3pm, since the days are so short right now.
You can read more about the species (Chaetodon ocellatus) on FishBase: link.