Giant squid

   

Giant squid
<tr><th bgcolor=pink>Scientific classification <tr><td>
<tr><td>Kingdom:<td>Animalia <tr><td>Phylum:<td>Mollusca <tr><td>Class:<td>Cephalopoda <tr><td>Subclass:<td>Coleoidea <tr><td>Order:<td>Teuthida <tr><td>Suborder:<td>Oegopsina <tr><td>Family:<td>Architeuthidae <tr><td>Genus:<td>Architeuthis </table> <tr><th bgcolor=pink>Species <tr><td> Architeuthis dux
Architeuthis hartingii
Architeuthis japonica
Architeuthis kirkii
Architeuthis martensi
Architeuthis physeteris
Architeuthis sanctipauli
Architeuthis stockii </table> Giant squid are marine mollusks of the class Cephalopoda, represented by the eight species of the genus Architeuthis. They are deep-ocean dwellers that can grow to tremendous size: recent estimates put the maximum size at 10m (30 feet) for females and 13m (37 feet) for males from caudal fin to the tip of the two long tentacles. The mantle length, though, is only about 2m in length (more for males, less for females), and the length of the squid excluding its tentacles is about 5m. However, there are reported claims of specimens of up to 20m (60 feet), but none have been scientificly documented. Despite their great length, giant squid are not particularly heavy in weight when compared to their chief predator, the sperm whale, because the majority of their length is taken up by their eight arms and two tentacles. The weights of recovered specimens have been measured in hundreds, rather than thousands, of pounds. Though an adult has never been seen alive, post-larval juveniles have been discovered in surface waters off New Zealand, and there are plans to capture more such juveniles and maintain them in an aquarium in an attempt to learn more about the creature's biology and habits. The reproductive cycle of the giant squid is still a great mystery, but what has been learned so far is both bizarre and fascinating; male giant squid are equipped with a prehensile spermataphore-depositing tube of over three feet in length, which extends from inside the animal's mantle and apparently is used to inject sperm-containing packets into the female squid's arms – how exactly the sperm then is transferred to the egg mass is a matter of much debate, but the recent recovery in Tasmania of a female specimen having a small subsidiary tendril attached to the base of each of its eight arms could be a vital clue in the solution of this enigma. Giant squid possess the largest eyes of any living creature, over one foot (30cm) in diameter, and their arms are equipped with hundreds of suction cups in total; each is mounted on an individual "stalk" and equipped around its circumference with a ring of sharp teeth to aid the creature in capturing its prey by firmly attaching itself to it both by suction and perforation. The size of these suction cups can vary from one to two inches in diameter (2-4cm), and it is not uncommon to find their circular scars on the head area of sperm whales that have fed – or attempted to feed – upon giant squid. The only other known predator of the giant squid is the sleeper shark, found off Antarctica. One of the more unusual aspects of giant squid (as well as some other species of large squid) is their reliance upon the light weight of ammonia in relation to seawater to maintain neutral buoyancy in their natural environment, as they lack the gas-filled swim bladder that fish use for this function; instead, they use vast numbers of tiny "statocysts" (ammonia-filled cellular structures) throughout their bodies. This makes the giant squid unfit for human consumption, although sperm whales seem to be attracted by its taste. Tales of giant squid have been common among mariners since ancient times, and may have led to the Norwegian legend of the kraken, a tentacled sea monster as large as an island capable of engulfing and sinking any ship. However, it is thought to be impossible for any known giant squid to lift its tentacles from the water. Recently, a possibly even more massive squid, the little known Colossal Squid Mesonychoteuthis hamiltoni, has been described in more detail due to a new specimen being found. It is an inhabitant of Antarctic waters, and unlike the giant squid, relies upon both claw-like hooks and suction cups on its arms and tentacles to capture prey. Although its body may be of greater size than the giant squid, its tentacles appear to be considerably shorter in length; it is also believed to be responsible for scars on the backs of sperm whales, through the use of hooks on its tentacles.

Species

  • Atlantic Giant Squid, Architeuthis dux
  • Architeuthis hartingii
  • Architeuthis japonica
  • Architeuthis kirkii
  • Architeuthis martensi
  • Architeuthis physeteris
  • Southern Giant Squid, Architeuthis sanctipauli
  • Architeuthis stockii

External links


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