Tag: Deep sea fish

Deep Sea Fish Uses Mirrors to observe

In the barely lit depths of the ocean, the four-eyed spook fish has caught scientists by surprise.

Only one other fish has been establish with such aptitude, but it uses two lenses, while the spook fish uses a lens on top and a mirror underneath.

The research side caught the four-inch fish while trawling for specimens between 2000 and 2,600 feet below the surface of the South Pacific, near the north island of New Zealand. The fish had been described as early as 1888, but none of the five researchers, with decades of deep sea diving knowledge among them, had ever seen one, and no live specimens had previously been record.

The team realizes they had amazing special when they photograph the fish from above and below and saw light reflected as of eyes in both directions. When they dissect the eye, they realized the lower part restricted a mirror, but no lens.

How is the age of a fish determined?

Mainly by two methods: Growth “rings” on scales, and/or ringlike structures found in otoliths (small bones of the inner ear), are examined and counted. The rings correspond to seasonal changes in the environment and can be compared to the annual rings of tree trunks. A series of fine rings are laid down in scales for each year of life in summer, the rings grow faster and have relatively wide separations; in winter, slower growth is indicated by narrow separations between rings. Each pair of rings indicates one year. Because scale rings are sometimes influenced by other factors, scientists often use otoliths, whose ringlike structures also indicate years of life.