Cephalopods
From coraldigest
Cephalopods
- Class Cephalopoda [1]
Evolution
- Probably evolved from gastropods [2]
- More than 10,000 fossil species named [2]
- Belemnoids, from the Mesozoic, may be the ancestors of modern squids [2]
Life Cycle and Reproduction
- Males
- Females
- Single oviduct [2]
- Courtship rituals can include color changes and body movements [2]
- Females may mate with multiple males and have multiple paternity of offspring [1]
- Life Cycle
- Eggs are covered in a touch coating that attach to hard surfaces [1]
- No true larval stage [2]
- Large eggs hatch as paralarvae [1]
- Adult size reached in about one year [1]
- Sexual maturation occurs rapidly [1]
- Most individuals die shortly after mating once [1]
- Uniseasonal breeding [1]
- Can cause considerable seasonal fluctuations in population [1]
- These fluctuations are highly variable and inconsistently patterned
- Can cause considerable seasonal fluctuations in population [1]
Anatomy
- Buccal cavity [2]
- Radula [2]
- Ink gland [2]
- All but the family Nautilus have cells containing large amounts of pigment and contractile fibers [2]
- This is what enables the animals to change colors [2]
- Frequently occurs in response to danger or emotion
- This is what enables the animals to change colors [2]
- Can distinguish shapes with highly evolved sensory system
- Have reduced or absent calcareous shells [1]
- Squids and octopuses have lost the internal shell and its buoyancy functions [1]
- Brain
- Ganglionic masses centered around the esophagus [1]
- Well developed statocysts (gravity and movement senses) [1]
- Skin
Diet
- Carnivorous [2]
- Feed on wide range of crustacea and fish[1]
- Eat approximately 1.5 and 15% of body weight daily [1]
- Some exhibit cannibalism on smaller members of their [1]respective species [1]
- Prey are usually attacked with a forward strike and subsequently pulled toward the mouth with tentacles [1]
- Squid bite their prey with their beaks [1]
- Octopuses have a more complicated means of consuming their prey [1]
Behavior
- Rapid color change [3]
- Centralized brain with highly developed sense organs [3]
- Jet propulsion [2]
- Inking [1]
Habitat
Importance
Economic value
t of cephalopods
- As many as 3 million tonnes are consumed annually by humans [1]
- Commercial harvest has increased from about 1 million tonnes to 3 million tonnes from the 1970s-1990s
Ecological value
- Important to food chain [1]
Threats
- Human Induced Threats [4]
Species
Common Octopus [5]
- Geographic Range
- Habitat
- Physical Appearance
- Reproduction and Development
- Behavior and Diet
- Conservation Status
Caribbean Reef Squid [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 Two-Spot Octopus [8]
- Geographic Range
- Habitat
- Physical Appearance
- Reproduction and Development
- Behavior and Diet
- Conservation Status
Notes
- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 1.19 1.20 1.21 1.22 1.23 1.24 1.25 1.26 1.27 1.28 1.29 1.30 1.31 1.32 1.33 1.34 1.35 1.36 1.37 1.38 1.39 1.40 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>.
- ↑ 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 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/>.
- ↑ 3.0 3.1 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>
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 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>.