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In Search of Giant Squid



The giant squid lives in most


of the world's oceans and is among

the biggest animals in the sea . . .

BUT

. . . it is rarely seen.

It hunts smaller sea creatures . . .

BUT

. . . larger animals feed on it.

It has inspired fantastic tales . . .

BUT

. . . the facts are even more fascinating
than the fiction.






From Myth to Reality



For over 2,000 years the giant squid has inspired fear, fascination, and fantastic stories. Why?


Encounters with this huge invertebrate have always been rare--and distant. And only recently has there been scientific evidence to dispute the legends.









Ocean Planet Exhibition Floorplan



Smithsonian Natural History Web Home Page

gene carl feldman / gene@seawifs.gsfc.nasa.gov

Myths Arise . . .



Centuries ago, people invented explanations for what their astonished eyes saw - - or thought they saw.

Mermen?

1500s: When several large, unfamiliar sea creatures were stranded in Norway, people decided they were mermen.


1854: Professor Japetus Steenstrup of Denmark, the leading cephalopod specialist of his time, concluded that the mythical mermen were very large squid.


Monsters?

1861: An alleged encounter between a giant squid and French naval ship fueled the imagination of author Jules Verne, who used it as the basis for Captain Nemo's encounter with a "squid of colossal dimensions" in Twenty Thousand Leagues Under the Sea.


1900s: Hollywood embellished the monster myth in its film version of Verne's novel.



Curiosity Kills the Myth

1874:

Rev. Moses Harvey of Newfoundland bought a dead giant squid caught by fishermen and displayed it as a local curiosity. The first whole specimen available for study, it was an important turning point.


Photo of first whole squid specimen in Harvey's bathtub

1880: Using Rev. Harvey's specimen, Professor A.E. Verrill of Yale University carried out the first scientific study and description of the giant squid.



Slowly, the Facts Emerge . . .

Additional specimens and bits of knowledge accumulated over the past century have enabled scientists to replace the myths with a more accurate picture.

Food for Whales

Beaks and other pieces of giant squid are frequently found in sperm whale stomachs.


Imagine what ferocious battles must take place when these huge ocean predators lock in combat!
Battle Scars

Photo of whale skin with many sucker marks

Can you find the giant squid sucker marks in this photograph of real whale skin?
Click on the photograph above for a closer look.






The Giant Squid is Not Alone . . .



At least 10 species of large squid-- 2 m (7 ft) or longer-- patrol the world's oceans. As far as is known, none comes close to the giant squid in size.




Moroteuthis robusta

Found off the coast of California in the 1960s, with naturalist S. Stillman Berry.
Maximum length: 2 m (7 ft).

From the S.S. Berry Collection


The Search Goes On . . .



"If we went out to capture a giant squid today, we still wouldn't know exactly where to look."

Clyde F.E. Roper
Resident Teuthologist
National Museum of Natural History

How long do giant squid live?

What exactly do they eat?

How deep do they live?

How quickly do they grow?

How big do they really get?

How fast do they swim?

Do they live in schools or alone?

How do their eggs get fertilized?

What happens to the eggs after they're laid?

How many species of large squid are there?

Why are they so seldom seen in the wild?

Why do they get stranded in certain areas?

Why are they so rarely captured?

Why can whales catch them, but scientists and fishermen can't?

Compare Two Large Squid



The Giant Squid vs. Taningia

These rare, preserved specimens may seem a sad sight compared to the living animals. But they provide virtually all the information available about the two species.


The World's Largest Invertebrate
Architeuthis dux



The World's Biggest Flasher
Taningia danae


The World's Largest Invertebrate

Architeuthis dux



This is the species commonly known as the giant squid. Because scientists do not know exactly where in the sea it lives, they have not been able to study it alive.

How big does it get?

        1. Up to 18 m (59 ft)

        2. Up to 900 kg (1,980 lb, nearly 1 ton)




Look at the diver above and compare with the illustration of Architeuthis to see how enormous that is. And scientists probably haven't found the largest specimen!

Where does it live?

Dots on the map indicate where specimens have been caught or found stranded. Scientists suspect giant squid live mostly at depths of 200-700 m (660-2,300 ft).




Where did this specimen come from?

Washed ashore on Plum Island, Massachusetts, in 1980, it is only the third giant squid found stranded on U.S. shores.


Total length of specimen: 2.7 m (9 ft)
Weight: 200 kg (440 lb)
Sex: female
Missing parts: long feeding tentacles and maroon-colored skin. They were lost when the squid washed ashore.
Estimated length with feeding tentacles: 9 m (30 ft)


What does it eat?

Mainly fishes and other squids, based on scientific analysis of the stomach contents of two giant squid specimens.

Can you find these parts on the specimen in the tank?




Head: houses a complex brain.
Eyes: largest in the animal kingdom. They can grow to 25 cm (10 in.) in diameter--about the size of a volleyball.
Fins: relatively small in this species. They help balance and maneuver the huge animal as it swims.
Mantle: the main body. This muscular sac contains most of the organ systems.
Arms (8): studded with two rows of suckers.
Feeding tentacles (2): missing in this specimen.
Funnel: a multipurpose tube used in breathing, jetting, squirting ink, laying eggs, and expelling waste.

How is a Squid like a Snail?



They're both molluscs, one of the major groups of invertebrates
(animals without backbones)

Molluscs (about 200,000 species) have:

Cephalopods (about 1,000 species) have:

        1. well developed brains

        2. a circulatory system with three hearts, veins, and arteries

        3. ink sacs—usually

        4. no external shell-in most cases

They:

        1. live only in the sea

        2. use jet propulsion

        3. can rapidly change skin color and texture--in most cases

Squids (about 500 species) have:

*long, cylindrical bodies

*8 arms and 2 tentacles--usually

*an internal, blade-shaped gladius

*fins



Can you find the cephalopod? There's an octopus in this photo. It has changed its skin color to blend with its surroundings.


Octopus, squid, and other cephalopods have developed hiding to a fine art. They can change color in a split second using pigment cells called chromatophores. Their survival depends on it!

Photo: Clyde F.E. Roper/National Museum of Natural History


Squid: The Inside Story



On the outside a squid looks relatively simple. But not on the inside! A set of complex systems enables squid to meet the same basic needs you have for survival.



Learn more about:








How does a squid move?



Click on the image above to see an mpeg video (128 Kbytes) which shows a squid jet propelling itself by forcing water through its body. Squid also swim by flapping their fins.
Video credits

A series of split-second reactions make jet propulsion possible.

1- Suck in water - Mantle opening
2- Shut mantle - Locking mechanism
3- Tell mantle muscles: Contract! (uses the Brain and Giant axon)
4- Jet out water - Funnel

What supports a squid's body?




As an invertebrate, a squid has no bones. A feather-shaped blade, or gladius, helps support the body and serves as a site for muscle attachment. It is made of chitin, like your fingernails. Cartilage (tough, gristle-like tissue) surrounds a squid's brain.

Photo label: Gladius from the giant squid, Architeuthis dux

Photo Credit: Frederick Aldrich/Memorial Univeristy of Newfoundland



What do these three things have in common?

Squid tentacle
Elephant trunk
Human tongue


None have bones.

The muscles attach to and pull against each other. Move your tongue to feel how.

How does a squid reproduce?



It takes two

Females release thousands of transparent eggs in jelly-like strands into the water.


Take a close look at a developing squid, or paralarva. It looks like a miniature adult.

Males produce long tubes, or spermataphores, filled with millions of sperm. Most species have a modified arm for depositing these in or on the female. This spermataphore cluster is implanted on the head of a female (Abraliopsis sp.). No wonder scientists are puzzled as to how squid eggs get fertilized!

A female squid lays eggs through a series of steps involving a number of different body parts:


Eggs produced...

Eggs released...

Eggs packaged...

Eggs laid

Ovary

Oviduct

Nidamental gland

Funnel


How does a squid defend itself?



The ink congeals into a squid-like shape that holds the enemy's attention while the squid turns pale and jets away. Click on the image above to see this happen (128 Kbytes mpeg).

Video credits

It ejects a blob of dark ink from the Ink Sac through the Funnel



Variations on a Theme




Scientists estimate there are about 500 species of squids, ranging in length from about 2.5 cm (1 in.) to 18 m (60 ft). Despite differences in size and shape, all work basically the same way inside.








Idiosepius pygmaeus
mantle length
to 2 cm (0.8 in.)
Promachoteuthis megaptera
mantle length
to 5 cm (2 in.)
Watasenia scintillans
mantle length
to 7 cm (2.8 in.)






Leachia atlantica
mantle length
to 11 cm (4.3 in.)
Ctenopteryx sicula
mantle length
to 15 cm (5.9 in.)
Lycoteuthis diadema
mantle length
to 15 cm (5.9 in.)






Chiroteuthis calyx
mantle length
to 20 cm (7.9 in.)
Cranchia scabra
mantle length
to 20 cm (7.9 in.)
Batoteuthis scolops
mantle length
to 20 cm (7.9 in.)






Histioteuthis bonnellii
mantle length
to 33 cm (13 in.)
Loligo pealeii
mantle length
to 50 cm (19.7 in.)
Taonius pavo
mantle length
to 54 cm (21.3 in.)


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