Cephalopods

All are molluscs ^[1]
Class Cephalopoda ^[2]
- Includes octopuses, cuttlefish, squid, etc^[2]
- Present in all the world's oceans ^[2]

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]

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

- Eggs are covered in a touch coating that attach to hard surfaces ^[2]
  - Hatch directly into "paralarvae," which are essentially mini adults, but may occupy different ecological niches than adults ^[2]
  - Some octopuses stay with eggs and guard them while others spawn in open water ^[2]
No true larval stage ^[3]
Large eggs hatch as paralarvae ^[2]
Adult size reached in about one year ^[2]
- Sexual maturation occurs rapidly ^[2]
- Most individuals die shortly after mating once ^[2]
- Uniseasonal breeding ^[2]
  - Can cause considerable seasonal fluctuations in population ^[2]
    - These fluctuations are highly variable and inconsistently patterned

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
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
- Delicate epithelial tissue over layers of connective tissue ^[2]
- Chromatophores ^[2]

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]
  - Secretion of toxins/enzymes is injected into the prey ^[2]
    - Makes the flesh easier to extract from crustaceans ^[2]

Behavior

Rapid color change ^[4]
- Most frequently used for crypsis (camouflage), mating displays, and prey/predator response^[2]
  - Great evolutionary significance ^[2]
Centralized brain with highly developed sense organs ^[4]
Jet propulsion ^[3]
- Using the muscular mantle to force water through the ventral funnel ^[2]
- Coastal octopuses are more benthic in nature ^[2]
  - Use their arms to move around the ocean floor, only occasionally employing jet propulsion ^[2]
Inking ^[2]

Habitat

Importance

Economic value

Many species are eaten by humans^[3]
- This goes back as far as classical times ^[2]
- As many as 3 million tonnes are consumed annually by humans ^[2]
- Commercial harvest has increased from about 1 million tonnes to 3 million tonnes from the 1970s-1990s

Ecological value

Important to food chain ^[2]
- Eat a wide variety of fish, crustaceans, and other invertebrates ^[2]
- Preyed upon by fish, marine mammals, and oceanic birds ^[2]
  - Cephalopod remains are often found in the guts of large fish, seals, whales, and birds ^[2]
    - Sperm whales may consume up to 320 X 10^6t of cephalopods from open ocean areas ^[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 ^[6]

Geographic Range
Habitat
Physical Appearance
Reproduction and Development
Behavior and Diet
Conservation Status

Caribbean Reef Squid ^[7]

Geographic Range
Habitat
Physical Appearance
Reproduction and Development
Behavior and Diet
Conservation Status

Caribbean Reef Squid ^[8]

Geographic Range
Habitat
Physical Appearance
Reproduction and Development
Behavior and Diet
Conservation Status

Caribbean Two-Spot Octopus ^[9]

Geographic Range
Habitat
Physical Appearance
Reproduction and Development
Behavior and Diet
Conservation Status

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 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>.
↑ Case, R. 1999. "Octopus vulgaris" (On-line), Animal Diversity Web. Accessed February 25, 2014 at http://animaldiversity.ummz.umich.edu/accounts/Octopus_vulgaris/
↑ Ritter, S. 2000. "Sepioteuthis sepioidea" (On-line), Animal Diversity Web. Accessed February 25, 2014 at http://animaldiversity.ummz.umich.edu/accounts/Sepioteuthis_sepioidea/
↑ 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>.

[CBC-1] 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>.

[EOS-2] 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>.

[ADW-3] 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/>.

[UCMP-4] 4.0 ^4.1 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>

[UMD-5] 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>.

[ADW_CO-6] Case, R. 1999. "Octopus vulgaris" (On-line), Animal Diversity Web. Accessed February 25, 2014 at http://animaldiversity.ummz.umich.edu/accounts/Octopus_vulgaris/

[ADW_CRS-7] Ritter, S. 2000. "Sepioteuthis sepioidea" (On-line), Animal Diversity Web. Accessed February 25, 2014 at http://animaldiversity.ummz.umich.edu/accounts/Sepioteuthis_sepioidea/

[ADW_CRO-8] Robinson, A. 2000. "Octopus briareus" (On-line), Animal Diversity Web. Accessed February 25, 2014 at http://animaldiversity.ummz.umich.edu/accounts/Octopus_briareus/

[MSC-9] 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>.

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