January 11, 2011. 1  According to Education Next, teachers retire, on average, at around the age of 58. AARP reports that 33 percent of all beginning teachers leave the teaching profession within three years of beginning their careers, but the majority of teachers continue teaching and can reap retirement benefits later in life.
Deep-sea anglerfish, hatchetfish, and lantern fish are among the best-known luminescent fishes. In most such fishes, luminescence is produced intracellularly; the light is emitted by special cells called photocytes. The anatomical structure of the luminous organs of many fishes is similar to that of squids.
Guanine is also found in the outer layers of the skin. Metallic-scale goldfish can be orange/red, white, yellow, black, metallic blue, brown, bronze or a variegated combination. Solid colored metallic-scale goldfish are often called self colored. There can also be a variegated pattern with two or more of these colors.