Cephalopods
From coraldigest
Cephalopods
Evolution
- Probably evolved from gastropods [3]
- More than 10,000 fossil species named [3]
- Belemnoids, from the Mesozoic, may be the ancestors of modern squids [3]
- 800 extant species [4]
Life Cycle and Reproduction
Males
- Specialized arm or tentacle that transfers spermatophores to the female's genital pore [3]
- This specialized appendage is sometimes left behind in the female's mantle cavity (known as a hetocotylus arm) [3]
Females
- Single oviduct [3]
- Courtship rituals can include color changes and body movements [3]
- Females may mate with multiple males and have multiple paternity of offspring [2]
Life Cycle
- No true larval stage [3]
- Large eggs hatch as paralarvae [2]
- Adult size reached in about one year [2]
Anatomy
- Buccal cavity [3]
- Radula [3]
- Coarse, rasping tongue [1]
- Ink gland [3]
- All but the family Nautilus have cells containing large amounts of pigment and contractile fibers [3]
- This is what enables the animals to change colors [3]
- Frequently occurs in response to danger or emotion
- This is what enables the animals to change colors [3]
- Can distinguish shapes with highly evolved sensory system
- Have reduced or absent calcareous shells [2]
- Squids and octopuses have lost the internal shell and its buoyancy functions [2]
- Brain
- Ganglionic masses centered around the esophagus [2]
- Well developed statocysts (gravity and movement senses) [2]
- Skin
Diet
- Carnivorous [3]
- Feed on wide range of crustacea and fish[2]
- Eat approximately 1.5 and 15% of body weight daily [2]
- Some exhibit cannibalism on smaller members of their [2]respective species [2]
- Prey are usually attacked with a forward strike and subsequently pulled toward the mouth with tentacles [2]
- Squid bite their prey with their beaks [2]
- Octopuses have a more complicated means of consuming their prey [2]
Behavior
- Rapid color change [4]
- Centralized brain with highly developed sense organs [4]
- Jet propulsion [3]
- Inking [2]
Habitat
Importance
Economic value
- Many species are eaten by humans[3]
Ecological value
- Important to food chain [2]
Threats
Human Induced Threats [5]
- Bioaccumulation of toxins [5]
- Noise pollution [5]
- Altered seasonal migration patterns related to ocean warming [5]
- Possible decrease in availability of calcium carbonate, related to declining pH [5]
- Overfishing [5]
Species
Common Octopus Octopus vulgaris
Lifespan of 12-24 months [6]
- Geographic Range
- Found all over the world, including the Eastern Atlantic Ocean [6]
- Habitat
- Physical Appearance
- Reproduction and Development
- Eggs laid in shallow water [6]
- Females brood in isolation
- Behavior and Diet
- Conservation Status
- Potential for overfishing [6]
Caribbean Reef Octopus [7]
- Geographic Range
- Habitat
- Physical Appearance
- Reproduction and Development
- Behavior and Diet
- Conservation Status
Caribbean Two-Spot Octopus [8]
- Geographic Range
- Habitat
- Physical Appearance
- Reproduction and Development
- Behavior and Diet
- Conservation Status
Caribbean Reef Squid Sepioteuthis sepioidea [9] Important as a food source for humans
- Geographic Range
- Found all throughout the Caribbean [9]
- Habitat
- Newly hatched organisms live very close to shore [9]
- Found anywhere between .2-10m deep and frequently near vegetation [9]
- Older specimens are denizens of turtle grass in the shallows near shore [9]
- Non-breeding adults prefer open water, enjoying ample space in depths of up to 100m at night [9]
- Breeding adults spend their time in coral reefs, reaching depths of no greater than 8m [9]
- Newly hatched organisms live very close to shore [9]
- Physical Appearance
- Reproduction and Development
- Behavior and Diet
- Highly social [9]
- Complex signal communication [9]
- Can change the color of their brow ridges and central arms to express alarm [9]
- Can eject ink in open water as a means of evading predation [9]
- At rest, individuals may adopt a red or brown color [9]
- Younger squid often display bars that make them more closely resemble vegetation, presumably a defense mechanism [9]
- Primarily consume sardines and other fish [9]
- Sometimes shrimp [9]
- Hunting is dependent on vision[9]
- Highly social [9]
- Conservation Status
- No special status [9]
Notes
- ↑ 1.0 1.1 Judkins, Heather L. "Cephalopods of the Broad Caribbean: Distrution, Abundance, and Ecological Importance." Diss. University of South Florida, 2009. Scholar Commons. Graduate School at Scholar Commons. Web. 21 Feb. 2014. <http://scholarcommons.usf.edu/cgi/viewcontent.cgi?article=3033&context=etd&sei-redir=1&referer=http%3A%2F%2Fwww.google.com%2Furl%3Fq%3Dhttp%253A%252F%252Fscholarcommons.usf.edu%252Fcgi%252Fviewcontent.cgi%253Farticle%253D3033%2526context%253Detd%26sa%3DD%26sntz%3D1%26usg%3DAFQjCNF6Q0NU3If5jMRKW7UQ1KtCo117qQ#search=%22http%3A%2F%2Fscholarcommons.usf.edu%2Fcgi%2Fviewcontent.cgi%3Farticle%3D3033%26context%3Detd%22>.
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 2.15 2.16 2.17 2.18 2.19 2.20 2.21 2.22 2.23 2.24 2.25 2.26 2.27 2.28 2.29 2.30 2.31 2.32 2.33 2.34 2.35 2.36 2.37 2.38 2.39 2.40 Boyle, P. "Cephalopods." Encyclopedia of Ocean Sciences 1 (2001): 436-42. Science Direct. Elsevier B.V., 11 Apr. 2013. Web. 22 Feb. 2014. <http://ac.els-cdn.com/B9780123744739001958/3-s2.0-B9780123744739001958-main.pdf?_tid=4e6f9af6-9e64-11e3-bd04-00000aacb360&acdnat=1393364120_b8c509396a239367521c18e75d90ee5a>.
- ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 3.13 3.14 3.15 Wheeler, Kristen, and Daphne G. Fautin. "ADW: Cephalopoda: INFORMATION." Animal Diversity Web. Regenst of the University of Michigan, 2001. Web. 22 Feb. 2014. <http://animaldiversity.ummz.umich.edu/accounts/Cephalopoda/>.
- ↑ 4.0 4.1 4.2 Jann, Vendetti. "The Cephalopoda." University of California Museum of Paleontology. UC Berkeley, n.d. Web. 24 Feb. 2014. <http://www.ucmp.berkeley.edu/taxa/inverts/mollusca/cephalopoda.php>
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 LaRosa, Ginni A.. "Learning from the Soft Intelligence: Cephalopods as Indicators of Ocean Changes." UMD Library. University of Maryland, 01 Dec 2011. Web. 25 Feb 2014. <http://drum.lib.umd.edu/bitstream/1903/12427/11/LaRosa_ResearchPaper.pdf>.
- ↑ 6.00 6.01 6.02 6.03 6.04 6.05 6.06 6.07 6.08 6.09 6.10 6.11 6.12 6.13 6.14 Case, R. 1999. "Octopus vulgaris" (On-line), Animal Diversity Web. Accessed February 25, 2014 at http://animaldiversity.ummz.umich.edu/accounts/Octopus_vulgaris/
- ↑ Robinson, A. 2000. "Octopus briareus" (On-line), Animal Diversity Web. Accessed February 25, 2014 at http://animaldiversity.ummz.umich.edu/accounts/Octopus_briareus/
- ↑ Tokarz, Jessica. " Caribbean Two-Spot Octopus." Field guide to marine inhabitants - Invertebrates. Marine Science Center of Florida. Web. 25 Feb 2014. <http://www.marinesciencecenter.com/Octopodidae.htm>.
- ↑ 9.00 9.01 9.02 9.03 9.04 9.05 9.06 9.07 9.08 9.09 9.10 9.11 9.12 9.13 9.14 9.15 9.16 9.17 9.18 9.19 9.20 9.21 9.22 9.23 9.24 9.25 9.26 9.27 9.28 9.29 Ritter, S. 2000. "Sepioteuthis sepioidea" (On-line), Animal Diversity Web. Accessed February 25, 2014 at http://animaldiversity.ummz.umich.edu/accounts/Sepioteuthis_sepioidea/