Arthropods

BIOL 1407

Phylum Arthropoda

• Cheliceriformes– Horseshoe Crabs– Arachnids: spiders, scorpions, ticks, mites

• Myriapoda: millipedes and centipedes

• Hexapoda: insects and springtails

• Crustacea: crabs, lobsters, barnacles, etc.

Cheliceriformes: Horseshoe Crabs

Cheliceriformes: Arachnids

Cheliceriformes: Arachnids

Video: Click on “Trapdoor Spider” and “An Amazing Web”http://www.bbc.co.uk/sn/tvradio/programmes/lifeintheundergrowth/video.shtml

Myriapods

Millipede Centipede

Hexapods: Insects

Photo Credit for Caterpillar: UNK Student, Vieques 2008

Videos: Click on “Titan Beetle”, “Moth and Lantern Bug”, “Feather-Legged Bug”, “Bot Flies”, “Giant Asiatic Honeybees”, and “Mangrove Ants”.

http://www.bbc.co.uk/sn/tvradio/programmes/lifeintheundergrowth/video.shtml

Hexapods: Springtails

Video: Click on “Dancing Springtails”http://www.bbc.co.uk/sn/tvradio/programmes/lifeintheundergrowth/video.shtml

Photo Credit: Sarefo, 2005 Wikimedia Commons

Crustaceans

Photo Credit for Spiny Lobster: UNK Student, 2008, Vieques

Crustaceans

Photo Credit for Artermia: Betsy Maxim, 2008

Characteristics of Arthropods

• Bilateral symmetry• Triploblastic• Coelomate• Photo Credit: Alvesgaspar, 2008,

Wikimedia Commons

Characteristics of Arthropods

• Segmentation• Chitinous

Exoskeleton• Photo Credit for Striped Love Beetle: Adrian

Pingstone, 2005, Wikimedia Commons

Characteristics of Arthropods

• Jointed Appendages

• Photo Credit for Praying Mantis in Defense Posture: Tibor Duliskovich, 2007, Wikimedia Commons

Characteristics of Arthropods

• Ecdysis• Video of Cicada

Nymph Molting: http://

www.youtube.com/watch?v=go4MqVq9HVM

• Photo Credit: Macau500, 2004, Wikimedia Commons

Characteristics of Arthropods

• Complete Digestive System

• Open Circulatory System

• Gills or book lungs or tracheal tubes

• Centralized nervous system

Metamorphosis

• Developmental stage in insects

• Young feeding form adult reproductive form

Incomplete Metamorphosis

• Young resemble adults

• Smaller with different proportions

• Photo Credit for Eurydema oleraceum nymph: James K. Lindsey, 2007, Wikimedia Commons

• Photo Credit for Eurydema oleraceum adult: Guido Gerding, 2006, Wikimedia Commons

Complete Metamorphosis

• Larval stages do not resemble adults

• Pupa stage transformation

• Video: http://www.youtube.com/watch?v=GTUgUEpqBrA&feature=related

• Photo Credit for Monarch Butterfly Pictures: Derek Ramsey, 2006 (adult), 2007 (caterpillar), Wikimedia Commons

Wings

Photo Credit: André Karwath, 2005, Wikimedia Commons

Complete Digestive System

Transport

• Open Circulatory System

• Heart = Pump

• Vessels• Hemolymph

= Fluid

Gas Exchange

• Gills• Book Lungs• Tracheal Tubes• Respiratory Pigments

– Hemocyanin (crustaceans and horseshoe crabs)

– Photo Credit for Terebellid Polychaete: Matthias Buschmann, 2007, Wikimedia Commons

Cellular Respiration• Food is needed to

provide fuel for cellular respiration

• Cellular respiration:– ATP

– Use O2

– Release CO2

CO2

O2

Surface-Area-to-Volume

• As body size ↑, Surface Area increases more slowly than Volume increases

• Large bodies have smaller surface-area-to-volume ratio than small bodies

Surface-Area-to-Volume

• Exchange occurs across surfaces• Dependent upon surface area• Folding ↑ Surface Area

Surface-Area-to-Volume

• Volume determines demand for:– Materials– Energy– Oxygen

• Volume generates:– Metabolic Wastes– Carbon Dioxide

Advantage of Folding

• Folding of internal structures increases surface area

• Exchange rate can meet demands of organism

Arthropod Excretory Systems: Antennal Glands and Malpighian Tubules

Centralized Nervous System

The End

Unless otherwise specified, all images in this presentation came from:

Campbell, et al. 2008. Biology, 8th ed. Pearson Benjamin Cummings.