Tuesday, March 25, 2014

Cephalopods

True Facts About the Cuttlefish 

True Facts About the Octopus

Habitat

Octopus-
  •          Usually live in rocks, coral, or burrows.
  •          Because they’re invertebrates, they are able to squeeze through narrow passages to find homes.
  •          Homes provide protection and they allow the females to lay their eggs.
Squid-
  •          Live in warm tropic waters while some live in colder waters.
  •          They are found near the sea floor, which is about 10,000 feet below sea level.
  •          They are generally found in four oceans.
  •          They don’t migrate for new homes.

Mollusks-
  •          Some are found on shallow coastal areas while others are In deep ocean.
  •          Usually are found where volcanic sediments come in contact with cold waters.
  •          They bury themselves in sand, silt, mud, and gravel.
  •          They are substrates to help support their heavy shells.

Cuttlefish-
  •          Usually found near the Mediterranean, Baltic, and North Sea coasts.
  •          They live in temperate waters where the cuttlefish are most comfortable.
  •          Use their camouflage to blend in with their habitat to hide from predators and hunt prey.

Feeding

Octopus:
  • Crabs
  • Whelks
  • Small fish
  • Mollusks
  • Clams
  • Lobsters
  • Sea Worms
  • Shrimp
  • Pacific Giant Octopus sometimes go after sharks
Squid:
  • Hoki (Grenadier fish)
  • Shrimp
  • Young sharks and whales (giant and colossal squid)
Cuttlefish:
  • Clown fish
  • Trigger fish
  • Gobies
  • Blennies
  • Wrasse
  • Cardinal fish
  • Seahorses
  • Damsels
  • Tangs
  • Crabs
  • Shrimp
Nautilus:
  • Small fish
  • Crabs
  • Crustaceans
  • Carrion

Types

Octopi:
  • Found in every ocean, and there are over 100 species.
  • They lack feeding tentacles; most lack fins.
  • They seize their prey, inject it with paralyzing toxins, then eat it.
  • A female octopus attaches her eggs to rocks and guards them until they hatch; then she dies.
Squid:
  • Squids have eight arms, usually two feeding tentacles (longer than arms), and a fin on each side of their mantle.
  • They are found in every ocean and are either swimming, floating, or resting on the bottom of the ocean floor.
  • Squids that live in shallow waters are active hunters.
  • They propel themselves using their siphons and swim/turn using their fins.
Nautiluses
  • The only cephalopod with an outer shell (today).
  • They are nocturnal.
  • Can live for about 20 years.
Cuttlefishes:
  • More than 100 species.
  • Eight arms and two long, lightning fast feeding tentacles.
  • Named after the chalky internal shell they possess and use for floating.

Migration

Octopus- they migrate from shallow deep waters and back again.
Squid- they migrate from the north to the south for food and climate change.
Cuttlefish- the cuttlefish migrate between May and August between False Bay and Fitzegard Bay for food.
Nautilus-Ultrasonic telemetry techniques were employed to track eleven specimens of Nautilus pompilius for variable times ranging from one to 78 days at Osprey Reef, Coral Sea, Australia.

Anatomy


Organs:
  •          High brain-to-body mass ratio; most intelligent of the invertebrates.
  •          Three hearts.
  •          Gills and Siphon for breathing and jet-propulsion respectively.
  •          Gonads typically at the top of the mantle (head).
  •          Most have ink sacs.
  •          Have bird-like beaks, and most have radulas (multiple rows of up to nine teeth).
  •          Large, highly developed eyes, yet they are colorblind. 


Appendages:
  • Most have at least eight arms and two or more tentacles
  •  Arms are lined with suction cups and tentacles usually have the suckers only at the tips
  • “Cephalopod” means “head-foot.”


Size and Color:
  •          As big as 60 feet (Giant Squid) to as little as half an inch (Pygmy Squid).
  •          Most have chromatophores which stretch and squash to change color.


Nautiluses:
  •          Still retain exterior shells.
  •          Have about 90 arms that lack suckers but are rather sticky.