the crustaceans -- marine arthropods & their relatives

The Crustaceans --The Crustaceans --Marine Arthropods & their RelativesMarine Arthropods & their Relatives

March 7, 2012March 7, 2012

ALL ARTHROPODS …ALL ARTHROPODS …

are covered with an exoskeletonare covered with an exoskeleton

are bilaterally symmetricalare bilaterally symmetrical

have a segmented bodyhave a segmented body

have jointed appendageshave jointed appendages

moltmolt

The The overwhelming overwhelming majority of majority of marine marine arthropods are arthropods are CRUSTACEACRUSTACEANS.NS.

What is the difference between an What is the difference between an exoskeletonexoskeleton and an endoskeleton? and an endoskeleton?

Made of chitin

What does it mean when a What does it mean when a crustacean crustacean moltsmolts??

Video of blue crab molting

Because they Because they must carry it must carry it around, the around, the heavy, rigid heavy, rigid exoskeleton of exoskeleton of crustaceans limits crustaceans limits their growth. their growth. Most are small.Most are small.

Barnacles vs. CopepodsBarnacles vs. CopepodsPlanktonic larvae; sessile adultsFilter feeders

PlanktonicSome filterers; some parasitic

How can you tell the difference How can you tell the difference between an between an amphipodamphipod and an and an isopodisopod??Amphipods –Amphipods –Laterally compressedLaterally compressed

Isopods –Isopods –Dorsoventrally flattenedDorsoventrally flattened

Giant Isopods- Yikes!Giant Isopods- Yikes!

What is the significance of krill to the food chains in polar waters?

Antarctic Krill Provide Carbon Sink In Southern OceanScienceDaily (Feb. 6, 2006) — New research on Antarctic krill (Euphausia superba), a shrimp-like animal at the heart of the Southern Ocean food chain, reveals behaviour that shows that they absorb and transfer more carbon from the Earth's surface than was previously understood.

DecapodsDecapods

• The word The word decapoddecapod means “ten legs.” means “ten legs.”• This group includes:This group includes:

1.1. Lobsters & crayfishLobsters & crayfish2.2. ShrimpsShrimps3.3. Hermit crabsHermit crabs4.4. True crabsTrue crabs

The Decapod Body PlanThe Decapod Body Plan

cephalothorax

abdomen

How can you tell the difference How can you tell the difference between a male and female true crab?between a male and female true crab?

Blue Crab Abdomens

As you can see highlighted in red, the aprons allow you to quickly determine the gender and maturity of the blue crab.

Male - “Jimmy”

Immature Female – “Sally”

Mature Female – “Sook”

Blue Crab Mating

http://www.serc.si.edu/education/resources/bluecrab/migration.aspx

What is the difference between a What is the difference between a maxilliped and a pereopod?maxilliped and a pereopod?

Specialized for bringing food to the Specialized for bringing food to the mouth, ripping, tearing, and eating.mouth, ripping, tearing, and eating.3 pairs3 pairs

Specialized for walkingSpecialized for walking5 pairs, first modified into claws called 5 pairs, first modified into claws called

chelipedschelipeds

Max

illip

eds

Pereopods

Swimming CrabsSwimming Crabs

Clockwise from top left: Clockwise from top left: common swimming crab, common swimming crab, ocellated swimming crab, ocellated swimming crab, chocolate brown swimming chocolate brown swimming crabcrab

Circulation and RespirationCirculation and Respiration

• Crustaceans have a(n) ____________ circulatory system and rely on _____________ to exchange gases with their surroundings.

openopengillsgills

Nervous SystemNervous System

Most have compound eyes – bundles of light sensing units

Antenna hold chemoreceptors for smell; sensitive to chemicals in water

BehaviorBehavior• Use body postures and movements to

communicate with each other

Male fiddler crabs wave large claws to attract females

Reproduction Reproduction

• Males use specialized appendages to transfer sperm directly to females

• In decapods, mating takes place after the females terminal molt while the exoskeleton is still soft– Females can hold sperm for long periods of time

• Most crustaceans have planktonic larvae that look nothing like the adulet

Horseshoe CrabsHorseshoe Crabs

• Only surviving member of Class Merostomata• Considered to be “living fossils”• An extract of the horseshoe crab's blood is used by

the pharmaceutical and medical device industries to ensure that their products, e.g., intravenous drugs, vaccines, and medical devices, are free of bacterial contamination. No other test works as easily or reliably for this purpose.

http://horseshoecrab.org/med/med.html

Work CitedWork CitedAnderson, Genny. Buckshot barnacle. Marine Science: The Splash Zone. 26 June 2003. 9 Feb. 2009 <http://www.marinebio.net/marinescience/03ecology/flimg/02804buk5466.jpg>. "Antarctic Krill Provide Carbon Sink In Southern Ocean." Science Daily: News & Articles in Science, Health, Environment & Technology. 6 Feb. 2006. British Antarctic Survey. 09 Feb. 2009

<http://www.sciencedaily.com/releases/2006/02/060206230630.htm>. Brooks, Cassandra. "Zooplankton Soup | Ice Stories: Dispatches From Polar Scientists." Exploratorium. 15 Mar. 2008. 09 Feb. 2009 <http://icestories.exploratorium.edu/dispatches/zooplankton-

soup/>. Copepod shortly before oviposition. Research Activities in the Haus des Meeres. Haus de Meeres - Aqua Terra Zoo. 9 Feb. 2009 <http://www.haus-des-meeres.at/forschung/7_copepod.jpg>. Dr. Eckart Pott/Bruce Coleman Ltd. Common swimming crab (Portunus holsatus), showing its paddle-shaped feet. Encyclopedia Britannica. 10 Feb. 2009

<http://www.britannica.com/EBchecked/topic-art/577077/9685/Common-swimming-crab-showing-its-paddle-shaped-feet>. Human_endoskeleton. Hermit crab housing: Part 1: how and why, physical. 9 July 2008. Affordable Housing Institute: U.S. 9 Feb. 2009 <http://affordablehousinginstitute.org/blogs/us/wp-

content/uploads/imageshuman-endoskeleton->. Ironman. Power Suits and Bionic Bones. 2009. How stuff works express. 9 Feb. 2009 <http://express.howstuffworks.com/gif/express-exoskeleton-ironman.jpg>. "Krill Discovered Living In The Antarctic Abyss." Science Daily: News & Articles in Science, Health, Environment & Technology. 26 Feb. 2008. British Antarctic Survey. 09 Feb. 2009

<http://www.sciencedaily.com/releases/2008/02/080225122334.htm>. Lobster. How stuff works express. 2009. 9 Feb. 2009 <http://express.howstuffworks.com/gif/express-exoskeleton-lobster.jpg>. "Lysianassid Amphipod &mdash; ::Centre for Marine Biodiversity::." ::Centre for Marine Biodiversity:: &mdash; ::Centre for Marine Biodiversity::. 09 Feb. 2009

<http://www.marinebiodiversity.ca/cmb/Photo%20galleries/atlantic-benthic-invertebrates/picture10.jpg/view>. MacDiarmid, Alison. Crayfish moulting. Crabs, crayfish, and other crustaceans. 21 Sept. 2007. Te-Ara The Encyclopedia of New Zealand. 9 Feb. 2009

<http://www.teara.govt.nz/EarthSeaAndSky/SeaLife/CrabsCrayfishAndOtherCrustaceans/1/ENZ-Resources/Standard/2/en>. Matuta / Ashtoret (always confusing these two), Madagascar. Flickr.com. 24 July 2008. Lunar crab's friendly face. 10 Feb. 2009 <http://flickr.com/photos/80125969@N00/2699936081/>. "Nauplius Larva of a Barnacle, Light micrograph of Nauplius larva of a barnacle at a magnification of x100., &Acirc;&copy; Visuals Unlimited/Corbis, RM, Animals, Barnacle, Biology, Color effect,

Crustacean, False color, Invertebrate, Larva, Life science, Microbiology, Micrography, Natural science, Natural sciences, Nobody, One animal, Plankton, Science, Sciences, Zoology, Zooplankton." Stock photography, footage, rights: Corbis. 09 Feb. 2009 <http://pro.corbis.com/search/Enlargement.aspx?CID=isg&mediauid=%7B0D5B64B4-F4F1-4B15-A2AD-989C3C0AB8F7%7D>.

Orstan, Aydin. "An isopod from Canada: Procellio spinicornis." Weblog post. Snail's Tails. 22 Oct. 2007. 9 Feb. 2009 <http://snailstales.blogspot.com/2007/10/isopod-from-canada-porcellio.html>. Palaemon pacificus. Key to Aquatic Arthropods. 2008. AECOS, Inc. 10 Feb. 2009 <http://www.aecos.com/CPIE/Palaemon_pacificus.jpg>. SPLASH Protecting Water and Habitat Through Education. 09 Feb. 2009 <http://www.sacsplash.org/cimages/copepod2.jpg>. Swimming crab (Thalamita sp.). Flickr.com. 10 Feb. 2009 <http://flickr.com/photos/wildsingapore/427830551/>. T-800 Endoskeleton Cinemaquette. RTM News. 2009. Raving Toy Maniac. 9 Feb. 2009 <http://www.toymania.com/news/images/1205_t800.jpg>. Two-eyed or ocellate swimming crab (Portunus sebae), Caribbean coast of Panama. Flickr.com. 10 Feb. 2009 <Two-eyed or ocellate swimming crab (Portunus sebae), Caribbean coast of Panama>. Underside of giant isopod. Ocean Explorer. 11 July 2005. National Oceanic and Atmospheric Association: United States Department of Commerce. 9 Feb. 2009

<http://oceanexplorer.noaa.gov/explorations/02mexico/logs/oct13/media/isopod.html>. Zinski, Steven C. "BLUECRAB.INFO - Blue Crab Identification." BLUECRAB.INFO - The Blue Crab Archives. 2006. 09 Feb. 2009 <http://www.bluecrab.info/identification.html>.