Vampyroteuthis infernalis

Geographic Range

The vampire squid occupies meso- to bathypelagic depths throughout the world's tropical and temperate oceans where little to no light penetrates. The vampire squid is vertically distributed between depths of 300-3000m with a majority of vampire squids occupying depths of 1,500-2,500m. Studies conducted at the Monterey Bay Aquarium Research Institute in California revealed that the Vampyroteuthis infernalis is confined to the oxygen minimum layer in this bay at an average depth of 690m and oxygen levels of 0.22 ml/l. The vampire squid's north-south distribution is localized between the fortieth degree north and south latitudes where the water is 2-6 degrees Celsius.

(Grzimek 1972)

(Wood and Ellis 1999)

Habitat

The vampire squid lives in the tropical and subtropical oceans of the world at depths ranging from 300-3000m with a majority of squids living between the ranges of 1,500-2,500m. Vampire squids live in the oxygen minimum layer of the ocean where virtually no light penetrates. The vampire squid prefers a temperature between 2 and 6 degrees Celsius.

(Grzimek 1972)

Physical Description

Vampyroteuthis infernalis has eight long arms and two retractile filaments that can extend well past the total length of the animal and can be retracted into pockets within the web. These filaments function as sensors because of the cirri that cover the entire length of the arm with suckers only on the distal half. There are also two fins on the dorsal surface of the mantle. The vampire squid is so named because of its jet-black skin, webbing between the arms, and red eyes - supposedly characteristics of a vampire. The squid is considered small - reaching a maximum length of 28 cm with the approximate size of a football. There is sexual dimorphism in size: females are larger than males.

The vampire squid has the consistency of a jellyfish, but its most intriguing physical characteristic is that it has proportionally the largest eyes of any animal in the world. A squid six inches long will have eyes that are an in inch across which are comparable to the eye size of a full grown dog.

The vampire squid has black chromatophores with reddish-brown ones interspersed. In contrast to other cephalopods, these chromatophores are non-functional because they have lost the muscles that enable rapid color change. The vampire shares most other features with other octopods and decapods, but it has several adaptations that allow it to live in a deep-sea environment. The loss of most of the active chromatophores and the ink sac are just two examples. The vampire squid also has photophores which are large circular organs which are located posterior to each adult fin and are also distributed over the surface of the mantle, funnel, head, and aboral surface. These photoreceptors produce luminescent clouds of glowing particles that allow the vampire squid to glow.

(Grzimek 1972, Wood and Ellis 1999, Wood 1999)

Reproduction

Because small vampire squids occupy deeper water than larger squids, spawning probably occurs in very deep water. It is most likely that males transfer spermatophores to the female from their funnel. The female vampire squid is larger than the male and discharges the fertilized eggs directly into the water. Mature eggs are fairly large at 3-4mm in diameter and are found free-floating in small masses in deep water.

(Grzimek 1972, Young 1999)

Behavior

The vampire squid was always thought to be a slow swimmer because of its weak-muscled gelatinous body, but it can swim surprisingly fast by using its fins to fly through the water. Their highly developed statocyst, the organ responsible for balance, also contributes to their agility. Through video analysis, the squid has been estimated to reach speeds around two body lengths/sec and to accelerate to these speeds in five seconds. Vampyroteuthis infernalis can move rapidly over short distances, but it is not capable of long migrations or extended fight and flight responses. When threatened, the vampire squid makes an erratic escape by quickly moving the fins toward the funnel followed by a jet from the mantle as it zig-zags through the water. The squid's defensive posture occurs when the arms and web are spread over the head and mantle in a position known as the "pineapple posture". This position of the arms and web makes the squid more difficult to injure because of the protection provided to the head and mantle and also because this position exposes the heavy black pigmented regions on the animal which make it difficult to identify in the dark depths of the ocean.

The vampire squid can luminesce for longer than two minutes as a result of the photophores which either glow simultaneously, flash one to three times per second, or pulsate. The arm tip organs can also luminesce by glowing or flashing which is usually followed by an escape response. The third and final form of luminescence are luminescent clouds which appear as a mucous matrix with glowing particles in it. The particles are thought to be released by the arm tip organs or an undiscovered visceral organ and can glow for up to 9.5 minutes.

The vampire squid's principal escape response involves the glowing of the light organs on the tip of the arms and at the base of the fins. This glowing is followed by a flailing of the arms which makes it very difficult to determine exactly where the squid is in the water. The squid then ejects the luminescent mucous cloud. When the light show has ended, it is practically impossible to tell whether the squid has glided away or has blended into the abyssal waters.

(Portner, et al 1994, Seibel, et al 1997, Young 1999, Wood 1999)

Food Habits

Carnivorous. The vampire squid has the lowest mass-specific metabolic rate of any cephalopod because of its decreased reliance on locomotion for escaping predators and capturing prey in the light-limited deep sea. The vampire squid uses its sensory filaments to find food in the deep sea and also has a highly developed statocyst indicating that it descends slowly and balances in the water almost effortlessly. Despite its name and reputation, Vampyroteuthis infernalis is not an agressive predator. While drifting, the squid deploys one filament at a time until one of them contacts an animal of prey. The squid then swims around in a circle hoping to catch the prey.

(Seibel, et al 1998, Wood and Ellis 1999, Wood 1999)

Economic Importance for Humans: Positive

The vampire squid has no positive economic benefit to humans.

Economic Importance for Humans: Negative

The vampire squid also does not have a negative economic benefit to humans.

Conservation Status

The vampire squid and its habitat are not threatened.

Other Comments

An interesting phenomenon in relation to the growth of the vampire squid occurs in the metamorphosis of the size, shape, and position of the squid's fins. When the squid's mantle is 15-25mm in length, the squid begins to grow a second pair of fins more anteriorly than the first pair. When the new pair of fins reach maturity, the original pair is reabsorbed. The development of the new pair of fins changes the vampire squid's swimming style from jet propulsion to using the fins for propulsion. Another interesting development in the vampire squid has to do with the sensory filament which were first thought to be modified arms. Scientists now know that the composition and structure of the filaments is completely different from the arms. As a result, the sensory filaments are believed to be a "uniquely derived" trait.

(Portner, et al 1994, Wood 1999)

Contributors

Brad Johnson (author), Southwestern University, Stephanie Fabritius (editor), Southwestern University.

Glossary

Atlantic Ocean

the body of water between Africa, Europe, the southern ocean (above 60 degrees south latitude), and the western hemisphere. It is the second largest ocean in the world after the Pacific Ocean.

World Map

Pacific Ocean

body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.

benthic

Referring to an animal that lives on or near the bottom of a body of water. Also an aquatic biome consisting of the ocean bottom below the pelagic and coastal zones. Bottom habitats in the very deepest oceans (below 9000 m) are sometimes referred to as the abyssal zone. see also oceanic vent.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

coastal

the nearshore aquatic habitats near a coast, or shoreline.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

native range

the area in which the animal is naturally found, the region in which it is endemic.

oceanic vent

Areas of the deep sea floor where continental plates are being pushed apart. Oceanic vents are places where hot sulfur-rich water is released from the ocean floor. An aquatic biome.

References

Grzimek, D. 1972. Grzimek's Animal Life Encyclopedia. New York: Van Nostrand Reinhold Company.

Portner, H., R. O'Dor, D. Macmillan. 1994. Physiology of Cephalopod Molluscs: Lifestyle and Performance Adaptations. Switzerland: Gordon and Breach Publishers.

Seibel, B., E. Thuesen, J. Childress. 1997. Decline in pelagic cephalopod metabolism with habitat depth reflects differences in locomotory efficiency. The Biological Bulletin, 192: 262-278.

Seibel, B., E. Thuesen, J. Childress. 1998. Flight of the Vampire: ontogenetic gait-transition in Vampyroteuthis infernalis (Cephalopoda: Vampyromorpha). The Journal of Experimental Biology, 201 (16): 2314-2324.

Wood, J. February 12, 2000. "The Cephalopod Page; Octopuses, Squid, Cuttlefish, and Nautilus" (On-line). Accessed February 14, 2000 at http://is.dal.ca/~ceph/TCP/index.html.

Wood, J. April 22, 1999. "Vampyroteuthis" (On-line). Accessed February 14, 2000 at http://is.dal.ca/~ceph/TCP/vampy.html.

Wood, J., R. Ellis. April 19, 1999. "Vampyroteuthis" (On-line). Accessed February 14, 2000 at http://is.dal.ca/~ceph/TCP/vsfh.html.

Young, R. August 6, 1999. "Vampyromorpha Vampyroteuthidae: Vampyroteuthis Infernalis" (On-line). Accessed February 14, 2000 at http://www.soest.hawaii.edu/tree/cephalopoda/coleoidea/octopodiformes/vampyromorpha/vampyromorpha.html.