Googly-Eyed Glass Squid
Encyclopedia
The googly-eyed glass squid (Teuthowenia pellucida) is a rare deep-sea glass squid
whose habitat ranges throughout the oceans of the southern hemisphere
. Specimens have been discovered as early as 1910; however, little was known of the species until 2007, when it was mentioned in Clair Nouvian's The Deep.
s. Mantle
thickness is only a few millimeters. Females are slightly larger than males. The squid has eight short tentacle
s and a slightly longer pair at the end of its rather swollen body. The only visible internal organ is the digestive gland, similar to the liver
of a chordate
. As a defense, the squid is able to engorge itself with surrounding water to dramatically increase in size, appearing more intimidating. The squid is also able to escape predators using jet propulsion
.
s. Immature googly-eyed glass squid are usually found at depths of around 900 m (2,953 ft). Mature squid exist at depths of between 1,600 and 2,400 m (5,249-7,874 ft).
s are laid in clusters attached to rocks and plants on the ocean floor. Newly hatched squid develop rapidly into paralarvae. Female squid mature between 150 and 190 mm; males mature at 140 mm. Pregnant females carry between 6,000 and 8,000 eggs with diameters of 2.2 mm. These eggs are often visible through the squid's thin mantle.
s of a googly-eyed glass squid's eyes and tentacles form small, bioluminescent organs called photophores. These organs release light
, making the organism
distinguishable among the darkness of the bathyal zone
. The use of bioluminescence requires energy
in the form of adenosine triphosphate
(ATP).
Glass squid
The family Cranchiidae comprises the approximately 60 species of glass squid, also known as cranchiid or cranch squid. Cranchiid squid occur in surface and midwater depths of open oceans around the world. They range in mantle length from to over , in the case of the Colossal Squid. The common...
whose habitat ranges throughout the oceans of the southern hemisphere
Southern Hemisphere
The Southern Hemisphere is the part of Earth that lies south of the equator. The word hemisphere literally means 'half ball' or "half sphere"...
. Specimens have been discovered as early as 1910; however, little was known of the species until 2007, when it was mentioned in Clair Nouvian's The Deep.
Characteristics
The googly-eyed glass squid is a blue, transparent organism with a body size of approximately 200 mm (7.9 in.) and notably large eyeCephalopod eye
Cephalopods, as active marine predators, possess sensory organs specialized for use in aquatic conditions. They have a camera-type eye, which consists of a lens projecting an image onto a retina. Unlike the vertebrate camera eye, the cephalopods' form as invaginations of the body surface , and...
s. Mantle
Mantle (mollusc)
The mantle is a significant part of the anatomy of molluscs: it is the dorsal body wall which covers the visceral mass and usually protrudes in the form of flaps well beyond the visceral mass itself.In many, but by no means all, species of molluscs, the epidermis of the mantle secretes...
thickness is only a few millimeters. Females are slightly larger than males. The squid has eight short tentacle
Tentacle
A tentacle or bothrium is one of usually two or more elongated flexible organs present in animals, especially invertebrates. The term may also refer to the hairs of the leaves of some insectivorous plants. Usually, tentacles are used for feeding, feeling and grasping. Anatomically, they work like...
s and a slightly longer pair at the end of its rather swollen body. The only visible internal organ is the digestive gland, similar to the liver
Liver
The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...
of a chordate
Chordate
Chordates are animals which are either vertebrates or one of several closely related invertebrates. They are united by having, for at least some period of their life cycle, a notochord, a hollow dorsal nerve cord, pharyngeal slits, an endostyle, and a post-anal tail...
. As a defense, the squid is able to engorge itself with surrounding water to dramatically increase in size, appearing more intimidating. The squid is also able to escape predators using jet propulsion
Jet propulsion
Jet propulsion is motion produced by passing a jet of fluid in the opposite direction to the direction of motion. By conservation of momentum, the moving body is propelled in the opposite direction to the jet....
.
Habitat
Googly-eyed glass squid live consistently along the circumglobal 40° southern parallel, in the Pacific, Atlantic, and Indian OceanIndian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
s. Immature googly-eyed glass squid are usually found at depths of around 900 m (2,953 ft). Mature squid exist at depths of between 1,600 and 2,400 m (5,249-7,874 ft).
Growth and development
EggEgg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
s are laid in clusters attached to rocks and plants on the ocean floor. Newly hatched squid develop rapidly into paralarvae. Female squid mature between 150 and 190 mm; males mature at 140 mm. Pregnant females carry between 6,000 and 8,000 eggs with diameters of 2.2 mm. These eggs are often visible through the squid's thin mantle.
Bioluminescence
The cellCell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
s of a googly-eyed glass squid's eyes and tentacles form small, bioluminescent organs called photophores. These organs release light
Light
Light or visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light has wavelength in a range from about 380 nanometres to about 740 nm, with a frequency range of about 405 THz to 790 THz...
, making the organism
Organism
In biology, an organism is any contiguous living system . In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of homoeostasis as a stable whole.An organism may either be unicellular or, as in the case of humans, comprise...
distinguishable among the darkness of the bathyal zone
Bathyal zone
The bathyal zone or bathypelagic – from Greek βαθύς , deep – is that part of the pelagic zone that extends from a depth of 1000 to 4000 metres below the ocean surface. It lies between the mesopelagic above, and the abyssopelagic below. The average temperature hovers at about 39°F...
. The use of bioluminescence requires energy
Energy
In physics, energy is an indirectly observed quantity. It is often understood as the ability a physical system has to do work on other physical systems...
in the form of adenosine triphosphate
Adenosine triphosphate
Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...
(ATP).