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Chlamydoselachus anguineusFrill shark(Also: Frilled shark; Greenland shark; Scaffold shark; Silk shark)

By Aubrey Lashaway

Geographic Range

Frilled sharks are wide ranging. They have been found almost worldwide, including the eastern Atlantic coast of northern Norway, the western Indian Ocean near South Africa, the western Pacific near New Zealand, and the eastern Pacific near the coast of Chile. (Compagno, 1984)

Habitat

Chlamydoselachus anguineus, is found on continental shelves and the nearshore areas of large islands, although they are occasionally reported in open waters. They are mostly benthic and occur at depths from 100 to 1,300 meters. (Tricas, et al., 2002)

  • Range depth
    100 to 1300 m
    328.08 to 4265.09 ft

Physical Description

Frilled sharks, or eel sharks (Taylor et al., 2002), have a long slender body with an elongate tail fin, giving them an eel-like appearance (Compagno, 1984). The body tends to be a chocolate brown color. They have a small dorsal fin located well towards the tail, above the large anal fin, and in front of the highly asymmetric caudal fin. The pectoral fins are short and rounded (Taylor et al., 2002). Chlamydoselachus anguineus has six gill openings (most sharks have five). The first gill is continuous across the throat, while all the gills are surrounded by frilly margins of skin-hence the name "frilled shark." The snout is short and the lower jaw is long. The teeth are alike both on the upper and lower jaws, with three elongate, sharp cusps separated by two intermediate ones (Taylor et al., 2002; Nelson, 1994). Length is usually 2 meters (Miller and Lea, 1972). (Compagno, 1984; Miller and Lea, 1972; Nelson, 1994; Tricas, et al., 2002)

  • Sexual Dimorphism
  • female larger
  • Range length
    2 (high) m
    6.56 (high) ft

Reproduction

Fertilization in all sharks is internal, taking place in the egg tubes or oviducts of the female. Male sharks must grab females, maneuver their bodies so that he can introduce his claspers to pass sperm into the vent. Males and females come together only to mate. (Parker and Parker, 1999)

Reproduction in these sharks is not well understood. Chlamydoselachus anguineus is an ovoviviparous shark that can bear anywhere from two to twelve live young (Dulvy & Reynolds, 1997). Young tend to be 40 cm long. Females apparently reproduce all year long and have a gestation period of about one to two years (Compagno, 1984). The size of an immature male is about 730 mm, whereas a mature male is about 970 mm long. Thus, the length of a mature male is anywhere from 730 mm to 970 mm (Nakaya & Bass). Female frilled shark length at maturity is about 1350 mm (Nakaya & Bass). (Compagno, 1984; Dulvy and Reynolds, 1997; Tricas, et al., 2002)

  • Breeding season
    These sharks have the ability to breed all year.
  • Range number of offspring
    2 to 12
  • Range gestation period
    12 to 24 months

There is little, if any, information on parental investment in frilled sharks. Sharks in general do not care for their young after their birth (Parker and Parker, 1999). (Parker and Parker, 1999)

  • Parental Investment
  • no parental involvement
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female

Lifespan/Longevity

Frilled sharks have never been kept in captivity. In the wild it is difficult to determine just how long these fish live. Because they are deep benthic creatures there is little information on lifespan. However, one source (Parker and Parker, 1999) estimates maximum lifespan at 25 years. (Parker and Parker, 1999)

  • Range lifespan
    Status: wild
    25 (high) years

Behavior

Chlamydoselachus anguineus is a slow-moving, deep water shark. They are among the slowest of shark species (Parker & Parker, 1999). Like most sharks, they are solitary. (Parker and Parker, 1999)

Communication and Perception

There is very little known about the communication and perception of frilled sharks because they live in deep water and are hard to observe. Based on information from other deep water sharks, they probably use their lateral line and sense of touch to navigate along the contours of the sea bed. Deep water sharks are also sensitive to sounds or long-distance vibrations, and to electrical pulses given off by animal muscles. Also, they have the ability to detect changes in water pressure to tell up from down. (Parker and Parker, 1999)

Food Habits

Because of their sharp, cuspidate teeth, it is thought that their primary foods are small deep-water fishes, and squid (Taylor et al., 2002). Because frilled sharks live on the ocean floor, they may also feed on carrion floating down from the surface (Parker & Parker, 1999). (Parker and Parker, 1999; Tricas, et al., 2002)

  • Animal Foods
  • fish
  • carrion
  • mollusks
  • aquatic crustaceans

Predation

There are few known predators of frilled sharks. Other sharks are likely predators and humans may take these sharks incidentally as fishing bycatch. Becauses they occupy the benthos, they are sometimes caught during bottom trawling or in nets when they venture near the surface. (Tricas, et al., 2002)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Frilled sharks are bottom dwellers and may contribute to removing decomposing carcasses. This carrion floats down from the open waters of the ocean above and comes to rest on the ocean floor. Frilled sharks and other benthic decomposers play an important role in recycling nutrients. (Tricas, et al., 2002)

Economic Importance for Humans: Positive

When frilled sharks are caught as bycatch during net or long line fishing, they may be ground up for fishmeal and fish food. Frilled sharks are unique and fascinating members of oceanic ecosystems. (Compagno, 1984)

  • Positive Impacts
  • food
  • body parts are source of valuable material

Economic Importance for Humans: Negative

These are not dangerous sharks, but their teeth have lacerated the hands of the unwary scientist and or fisherman examining or holding them. (Compagno, 1984)

  • Negative Impacts
  • injures humans
    • bites or stings

Conservation Status

Frilled shark are classified as a near threatened species on the IUCN Red List. There are no current conservation plans for this species (Fowler & Paul). (Fowler and Paul, 2004)

Other Comments

Today, frilled sharks are the only living species in the family Chlamydoselachidae (Sheikh-Miller, 2001). Scientists also believe that, although frilled sharks rarely come to the surface, they could be the cause for sightings of "sea serpents" because of their unusual, snakelike shape (Twist, 2002). (Sheikh-Miller, 2001; Twist, 2002)

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Aubrey Lashaway (author), University of Michigan-Ann Arbor, Kevin Wehrly (editor, instructor), University of Michigan-Ann Arbor.

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.

World Map

acoustic

uses sound to communicate

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.

biodegradation

helps break down and decompose dead plants and/or animals

carnivore

an animal that mainly eats meat

carrion

flesh of dead animals.

chemical

uses smells or other chemicals to communicate

coastal

the nearshore aquatic habitats near a coast, or shoreline.

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

detritivore

an animal that mainly eats decomposed plants and/or animals

ectothermic

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

electric

uses electric signals to communicate

fertilization

union of egg and spermatozoan

food

A substance that provides both nutrients and energy to a living thing.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

internal fertilization

fertilization takes place within the female's body

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

molluscivore

eats mollusks, members of Phylum Mollusca

motile

having the capacity to move from one place to another.

natatorial

specialized for swimming

native range

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

nocturnal

active during the night

ovoviviparous

reproduction in which eggs develop within the maternal body without additional nourishment from the parent and hatch within the parent or immediately after laying.

piscivore

an animal that mainly eats fish

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

saltwater or marine

mainly lives in oceans, seas, or other bodies of salt water.

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

vibrations

movements of a hard surface that are produced by animals as signals to others

year-round breeding

breeding takes place throughout the year

References

Bass, d'Aubrey, & Kistnasamy, , Cadenat & Blache, Compagno, Gudger, Gudger & Smith. 2005. "Figis and FAO" (On-line). Species Fact Sheet: Chlamydoselachus anguineus. Accessed September 24, 2005 at http://www.fao.org/figis/servlet/FiRefServlet?ds=species&fid=11367.

Compagno, L. 1984. Sharks of the World. FAO Species Catalogue, 4 (1): 14-15.

Dulvy, N., J. Reynolds. 1997.

Evolutionary transitions among egg-laying, live-bearing and maternal inputs in sharks and rays.
. Proc. R. Soc. Lond. B, 264: 1309-1315.. Accessed September 24, 2005 at http://www.fishbase.org/Summary/SpeciesSummary.php?id=635.

Fowler, S., L. Paul. 2004. "Chlamydoselachus anguineus; IUCN Red List of Threatened Species" (On-line). Accessed October 13, 2005 at http://www.redlist.org/search/details.php?species=41794.

Merriam-Webster, Incorporated, 2005. Merriam-Webster Online Dictionary. Accessed October 19, 2005 at http://www.m-w.com/cgi-bin/dictionary?book=Dictionary&va=ovoviviparous.

Miller, D., R. Lea. 1972. Guide to the Coastal Marine Fishes of California.

Nakaya, K., A. Bass. 1978. The frill shark Chlamydoselachus anguineus in New Zealand seas. N.Z. Journal of Marine and Freshwater Research, 12 (4): 397-8.

Nelson, J. 1994. Fishes of the World; 3rd Edition. New York, Chichester, Brisbane, Toronto, & Singapore: John Wiley &Sons, Inc.

Parker, J., S. Parker. 1999. The Encyclopedia of Sharks. Canada & United States: Firefly Books Ltd..

Sheikh-Miller, J. 2001. Sharks. 555 Broadway, New York, NY 10012: Scholastic Inc..

Tricas, T., K. Deacon, P. Last, J. McCosker, T. Walker, L. Taylor. 2002. The Nature Companions Sharks and Whales. 814 Montgomery Street, San Francisco CA, 94133 USA: Fog City Press.

Twist, C. 2002. Shark and other sea creatures Dictionary. 557 Broadway, New York, NY 10012: Scholastic and Tangerine Press Inc..

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