Wednesday, January 05, 2011

Giant Pacific Octopus (Enteroctopus dofleini)

Chameleon-like, giant Pacific octopuses can change their appearance to mimic rocks and highly patterned coral.
Photograph by Bob Cranston—Animals Animals - Earth Scenes

The giant Pacific octopus grows bigger and lives longer than any other octopus species. The size record is held by a specimen that was 30 feet (9.1 meters) across and weighed more than 600 pounds (272 kilograms). Averages are more like 16 feet (5 meters) and 110 lbs (50 kilograms).

They live to be about four years old, with both males and females dying soon after breeding. Females live long enough to tend fastidiously to their eggs, but they do not eat during this months-long brooding period, and usually die soon afterwards.

Giant Pacific octopuses have huge, bulbous heads and are generally reddish-brown in color. Like the other members of the octopus family, though, they use special pigment cells in their skin to change colors and textures, and can blend in with even the most intricately patterned corals, plants, and rocks.

They hunt at night, surviving primarily on shrimp, clams, lobsters, and fish, but have been known to attack and eat sharks as well as birds, using their sharp, beaklike mouths to puncture and tear flesh. They range throughout the temperate waters of the Pacific, from southern California to Alaska, west to the Aleutian Islands and Japan.

Highly intelligent creatures, giant Pacific octopuses have learned to open jars, mimic other octopuses, and solve mazes in lab tests. Their population numbers are unknown, and they do not currently appear on any lists of endangered or vulnerable animals. However, they are sensitive to environmental conditions and may be suffering from high pollution levels in their range.

Facts

Type:Invertebrate
Diet:Carnivore
Average life span in the wild:3 to 5 years
Size:9.75 to 16 ft (3 to 5 m)
Weight:22 to 110 lbs (10 to 50 kg)
Did you know? The appendages of octopuses are called arms, not tentacles.
Size relative to a 6-ft (2-m) man:


nationalgeographic.com


Halo (Optical Phenomenon)


Sun Halo Phenomenon in Yogyakarta January 4th 2010

A halo (ἅλως; also known as a nimbus, icebow or Gloriole) is an optical phenomenon produced by ice crystals creating colored or white arcs and spots in the sky. Many are near the sun or moon but others are elsewhere and even in the opposite part of the sky. They can also form around artificial lights in very cold weather when ice crystals called diamond dust are floating in the nearby air.

There are many types of ice halos. They are produced by the ice crystals in cirrus clouds high (5–10 km, or 3–6 miles) in the upper troposphere. The particular shape and orientation of the crystals is responsible for the type of halo observed. Light is reflected and refracted by the ice crystals and may split up into colors because of dispersion. The crystals behave like prisms and mirrors, refracting and reflecting sunlight between their faces, sending shafts of light in particular directions.

Atmospheric phenomena such as halos were used as part of weather lore as an empirical means of weather forecasting before meteorology was developed.

Other common optical phenomena involving water droplets rather than ice crystals include the glory and the rainbow.


photo from 2.bp.blogspot.com
wikipedia.com