phylum mollusca, class cephalopods cephalopods (class cepahlopoda) are a group of molluscs that...
Post on 23-Jan-2016
218 views
TRANSCRIPT
![Page 1: Phylum Mollusca, Class Cephalopods Cephalopods (Class Cepahlopoda) are a group of molluscs that include squid, nautilus, cuttlefish and octopus They are](https://reader035.vdocuments.us/reader035/viewer/2022062500/56649d495503460f94a24c74/html5/thumbnails/1.jpg)
Phylum Mollusca, Class Cephalopods
• Cephalopods (Class Cepahlopoda) are a group of molluscs that include squid, nautilus, cuttlefish and octopus
• They are the most highly evolved of all molluscs; nearly all are agile swimmers with a complex nervous system
• Cephalopods have a reduction in or loss altogether of the shell
![Page 2: Phylum Mollusca, Class Cephalopods Cephalopods (Class Cepahlopoda) are a group of molluscs that include squid, nautilus, cuttlefish and octopus They are](https://reader035.vdocuments.us/reader035/viewer/2022062500/56649d495503460f94a24c74/html5/thumbnails/2.jpg)
Phylum Mollusca, Class Cephalopods
• Cephalopods (which means “head-footed”) have heads surrounded by a foot modified into arms and tentacles, usually equipped with suckers that are used to capture prey
![Page 3: Phylum Mollusca, Class Cephalopods Cephalopods (Class Cepahlopoda) are a group of molluscs that include squid, nautilus, cuttlefish and octopus They are](https://reader035.vdocuments.us/reader035/viewer/2022062500/56649d495503460f94a24c74/html5/thumbnails/3.jpg)
Phylum Mollusca, Class Cephalopoda
• Largest of all Molluscs• All have a radula, beak-like structure• Cephalopods have large eyes, with acute
vision, extremely sensitive to slight details and impressions
![Page 4: Phylum Mollusca, Class Cephalopods Cephalopods (Class Cepahlopoda) are a group of molluscs that include squid, nautilus, cuttlefish and octopus They are](https://reader035.vdocuments.us/reader035/viewer/2022062500/56649d495503460f94a24c74/html5/thumbnails/4.jpg)
Phylum Mollusca, Class Cephalopods
• Cephalopods pump water through the siphon, or funnel into their mantle cavity
• By forcing water out of the mantle cavity through the siphon, cephalopods swim by means of “jet propulsion”
• By changing the direction of the siphon, cephalopods can move backward or forward, or can remain motionless in one place
![Page 5: Phylum Mollusca, Class Cephalopods Cephalopods (Class Cepahlopoda) are a group of molluscs that include squid, nautilus, cuttlefish and octopus They are](https://reader035.vdocuments.us/reader035/viewer/2022062500/56649d495503460f94a24c74/html5/thumbnails/5.jpg)
Jet Propulsion
Water enters mantle cavity
Water exits from funnel or siphon
Direction of water out of siphon
Direction of cephalopod motion
![Page 6: Phylum Mollusca, Class Cephalopods Cephalopods (Class Cepahlopoda) are a group of molluscs that include squid, nautilus, cuttlefish and octopus They are](https://reader035.vdocuments.us/reader035/viewer/2022062500/56649d495503460f94a24c74/html5/thumbnails/6.jpg)
Octopus: Order Octopoda
• One of the most iconic cephalopods is the octopus
• Octopuses have 8 long arms (“octo” means 8) and no shell
• Common bottom dwellers, they are efficient hunters– Bite their prey (mostly shellfish)
with a pair of beak-like jaws– Ink sac emits a dark cloud of fluid
to deter predators
![Page 7: Phylum Mollusca, Class Cephalopods Cephalopods (Class Cepahlopoda) are a group of molluscs that include squid, nautilus, cuttlefish and octopus They are](https://reader035.vdocuments.us/reader035/viewer/2022062500/56649d495503460f94a24c74/html5/thumbnails/7.jpg)
Squids: Order Teuthoidea
• Squids are better adapted for swimming than octopuses
• Squids have two triangular fins modified for swimming
• Elongated body• Squids have eight arms &
2 tentacles, all with suckers which circle the mouth
http://cas.bellarmine.edu/tietjen/images/Image32.gif
Long & retractable
![Page 8: Phylum Mollusca, Class Cephalopods Cephalopods (Class Cepahlopoda) are a group of molluscs that include squid, nautilus, cuttlefish and octopus They are](https://reader035.vdocuments.us/reader035/viewer/2022062500/56649d495503460f94a24c74/html5/thumbnails/8.jpg)
Squids: Order Teuthoidea
• Suckers only at broadened tips on tenacle• The shell is reduced to a stiff pen embedded in the upper surface of the mantle
![Page 9: Phylum Mollusca, Class Cephalopods Cephalopods (Class Cepahlopoda) are a group of molluscs that include squid, nautilus, cuttlefish and octopus They are](https://reader035.vdocuments.us/reader035/viewer/2022062500/56649d495503460f94a24c74/html5/thumbnails/9.jpg)
Cuttlefish: Order Sepiida
• Cuttlefish are among the most intelligent invertebrates
• Cuttlefish have a calcified internal shell called a cuttlebone, which aids in buoyancy– Chambered, gas-filled
• Called “chameleons of the sea” for their astonishing ability to change skin color at will
![Page 10: Phylum Mollusca, Class Cephalopods Cephalopods (Class Cepahlopoda) are a group of molluscs that include squid, nautilus, cuttlefish and octopus They are](https://reader035.vdocuments.us/reader035/viewer/2022062500/56649d495503460f94a24c74/html5/thumbnails/10.jpg)
Chromatophores
• Cephalopods control their skin pattern and color by way of chromatophores
• Chromatophores are pigment-containing and light-reflective cells used for camouflage
• Inside the chromatophore, pigment granules are enclosed in an elastic sac– To change color, the sac is distorted by way of
muscular contraction
![Page 11: Phylum Mollusca, Class Cephalopods Cephalopods (Class Cepahlopoda) are a group of molluscs that include squid, nautilus, cuttlefish and octopus They are](https://reader035.vdocuments.us/reader035/viewer/2022062500/56649d495503460f94a24c74/html5/thumbnails/11.jpg)
Nautilus: Order Nautilida
• Nautilus are called “living fossils”; only 6 species remain of an extinct superfamily• Survived relatively unchanged for millions of years• Gas-filled chambers aid in buoyancy
• Paper nautiluses are actually pelagic octopus; named for the paper-thin eggcase in females
![Page 12: Phylum Mollusca, Class Cephalopods Cephalopods (Class Cepahlopoda) are a group of molluscs that include squid, nautilus, cuttlefish and octopus They are](https://reader035.vdocuments.us/reader035/viewer/2022062500/56649d495503460f94a24c74/html5/thumbnails/12.jpg)
You will never be as cool as a cephalopod
• Mimic octopus http://www.youtube.com/watch?v=H8oQBYw6xxchttp://www.youtube.com/watch?v=ygh1-ul6E94
• Vampire squid from hellhttp://www.youtube.com/watch?v=S3CJIKKSUpg
www.islandream.com/sangalakigallery7.htm http://www.itsnature.org/sea/other/colossal-squid/ www.flickr.com/photos/maxcdc/3615629745/
![Page 13: Phylum Mollusca, Class Cephalopods Cephalopods (Class Cepahlopoda) are a group of molluscs that include squid, nautilus, cuttlefish and octopus They are](https://reader035.vdocuments.us/reader035/viewer/2022062500/56649d495503460f94a24c74/html5/thumbnails/13.jpg)
…or as smart???
• Octopuses and cuttlefishes have a remarkable capacity for learning
• Giant nerve fibers rapidly conduct impulses allowing cephalopods to capture prey or escape at amazing speeds
• Most cephalopods display color changes correlated with particular behaviors and moods
• Octopus are known to use tools, and predict World Cup champions!