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.
A male veiltail can breed with a female comet, a male lionhead gpldfish can breed with a female black moor goldfish, and so on. This is because all goldfish are really the same species: Carassius auratus auratus. The different types or varieties are physically different, but genetically compatible.