Arthropoda

Tavia Sin and Kelly Chen

The most successful of all animal phyla

http://www.ucmp.berkeley.edu/arthropoda/arthropoda.html

ArthropodaCheliceroforms-mostly terrestrial or marine; have chelicerae

Myriapods-terrestrial; have antennae and legs

Hexapods-mostly terrestrial; have antennae, legs (and sometimes wings), and segmented body

Crustaceans-mostly marine and freshwater; have antennae, legs, and segmented body

Kelly Chen

Sample AnimalsCheliceriforms-sea spiders, horseshoe crabs, scorpions, ticks, mites, spidersMyriapods-centipedes, millipedesHexapods-insects and their wingless, six-legged relativesCrustaceans-crabs, lobsters, shrimps, barnacles, and many others

http://kdhellner.tripod.com/id19.html Kelly Chen

Body Cavity (coelom)Coelom does exist but is not the main body cavityHemocoel-made up of the body sinuses, which are spaces surrounding the tissues and organsCoelom that forms in embryo becomes reduced

Kelly Chen

Body SymmetryBilateral symmetry

http://biology.clc.uc.edu/Courses/bio106/arthrpod.htm Kelly Chen

Nervous SystemWell-developed, mesodermal, ventral, solid nerve cordVentral-Pertaining to the front or anterior of any structure

http://bio1151b.nicerweb.net/Locked/media/ch33/ Kelly Chen

Circulatory System

Open circulatory system Fluid called hemolymph is

propelled by a heart through short arteries into sinuses

Hemolymph reenters the heart through pores equipped with valves

Kelly Chen

Digestive SystemAppendages are adapted to form mouthpartsSpiders use chelicerae to chew prey while spilling digestive juices on itMyriapods and insects use jaw-like mandibles to eat Exhibit almost every feeding mode: carnivores, herbivores, detritus feeders, filter feeders, and parasites

http://matthew.gray.org/2006_09_01_archive.html Kelly Chen

Excretory SystemGreen glands (crustaceans)- collect residue from the blood and body; connected to excretory pores under antennae.

Mapighian tubules (insects)- gather wastes from blood to release into intestine by excretory ducts.

Coxal glands (arachnids)-located in cephalothorax near limbs; participate in excretion. 

Tavia Sin

Locomotion/MusculatureInsects fly to escape predators, find food and mates, and move to new habitats.

Most have one or two pairs of wings emerging from dorsal side of thorax.

Wings are extensions of the exoskeleton so leg use is not affected.

http://biology.clc.uc.edu/Courses/bio106/arthrpod.htm Tavia Sin

Skeletal TypeExoskeleton -external skeleton constructed from layers of protein and polysaccharide chitin. Molting (Ecdysis) –an arthropod sheds its exoskeleton and produces a larger one to grow in.

http://bio1151b.nicerweb.net/Locked/media/ch32/ Tavia Sin

Sensory Structure/Features

Well-developed sensory organs, including eyes, olfactory(smell) receptors, and antennae that function in both touch and smell. Most are concentrated at the anterior end of the animal.

Cheliceriforms lack antennae 

http://photography.nationalgeographic.com/photography/enlarge/callicore-neglecta-butterfly-sartore.html

Tavia Sin

ReproductionIncomplete metamorphosis- young (nymphs) resemble adults but are smaller, have different proportions, and have no wings.

Complete metamorphosis- larval stage (eating, growing), middle stage (pupal), adult stage (dispersal, reproduction)

Reproduction is usually sexual, with separate male and female individuals.

http://teacher.scholastic.com/activities/explorations/bug/libraryarticle.asp?ItemID=126&SubjectID=145&categoryID=4

Tavia Sinhttp://www.dpughphoto.com/mason_farm.htm

Gas ExchangeGills with thin, feathery extensions- increase surface area in contact with surrounding water.

Tracheal systems- branched air ducts leading into interior from pores in exoskeleton.

Book lungs- stacked plates contained internally; increase surface area, enhance exchange of O2 and CO2. 

Tavia Sin

http://bio1151b.nicerweb.net/Locked/media/ch33/

Other Unique FeaturesLargely related to segmentation , hard exoskeleton, and jointed appendages

Arthropod means “jointed feet”

As they evolved, the segments tended to fuse and become fewer in number and the appendages became specialized for a variety of functions

http://krlphotography.typepad.com/photos/historical_artifacts/trilobite1.htmlTavia Sin

Quiz Question #1

What skeletal type do arthropods have?

        

Answer #1

Exoskeleton

Quiz Question #2

true or false: Arthropods reproduce asexually

Answer #2

False

Quiz Question #3

What sensory organ functions in both touch and smell in most arthropods?

    a) eyes  b) olfactory receptors   c) antennae   d) arms

Answer #3

C) Antennae

Quiz Question #4

The process of shedding the exoskeleton is called______

Answer #4

Molting, ecdysis