Watasenia scintillans

Luminous squid ( Watasenia scintillans )

The luminous squid ( Watasenia scintillans ) is a squid ( Coleoidea ) and belongs to the class of cephalopods ( Cephalopoda ).

Description

The luminous squid is a small squid, which is only about 7.5 to 8 cm in size. It has as usual for octopus ten arms, two of which are elongated and serve as tentacles. Eight arms are covered with stalked suckers. The tentacles are free of suckers and have 2 to 3 hooks in a row. At the rear end, two lateral fins are used for rapid locomotion. The animals are distributed over the body called chromatophores ( pigment-containing cells) and photophores ( light emitting cells), (but not on the dorsal photophores ) can produce the light. The species can differ with their highly developed lens eye colors.

Nutrition

The luminous squid lures with the photophores on small fish, which he then begins with the poor.

Dissemination

The species is found only on the shelf and the shallower waters around Japan and the China Sea to the north to the Sea of ​​Okhotsk. The animals usually live at depths of 200 to 400 m, but come to mate and to lay eggs in shallower waters and in the Toyama Bay also relatively close to the coasts.

Development

The eggs are deposited mainly in the months of February to July in the upper 80 m in the open water. In some areas the oviposition occurs almost throughout the entire year. A female can lay up to 20,000 eggs in strands up to 1 m in length. The single egg measures about 1.5 x 1 mm. The young hatch, depending on the water temperature after 6 to 14 days out of the egg ( the warmer the water, the faster the young hatch ). The hatchling measures about 1.2 to 1.4 mm. The average life expectancy of the animals is only about 1 year.

Enemies

Luminescent squid are hunted by large demersal and relatives of salmon.

Implications for fisheries

The luminous squid is fished commercially in waters around Japan. Between 1990 and 1999, each year were caught about 5000-7000 tons. The animals are fished from March to June.

Taxonomy

The species is the only species of the genus Watasenia ( Ishikawa, 1914).