Arthropods are the most successful animals! They are found in many environments. They can ADAPT to many environments.
Phylum: Arthropoda Characteristics: Arthropoda means jointed foot Appendages grow from the body The body is divided into three segments: –Head ~ 1 st part, contains the sense organs –Thorax ~ middle, joins head & abdomen walking legs are attached here - Abdomen ~3 rd part, reproductive & digestive organs are found here
All arthropods have an external skeleton called the exoskeleton. The exoskeleton has several functions: *covers *supports *protects *prevents from drying out Arthropods molt their exoskeleton.
Molting is a process of shedding the exoskeleton and replacing a new one in order to grow. What problems do you see with this process?
Types of Crustaceans Crabs Lobsters Shrimp Pill bug Barnacles Water fleas
Characteristics Cephalothorax- head & thorax fused together One or two pairs of antennae Mandibles ~ jaws used for crushing food Five pairs of legs: 1 st pair~ claws, catching food, protection Four pairs of walking Swimmerets ~ appendages on the abdomen Movement Reproduction Force water over the gills for breathing Regenerate lost appendages
CRAYFISH ~ A common crustacean Cephalothorax and abdomen Two pairs of antennae Shorter pair - Touch, taste, balance Longer pair Touch, taste, smell Compound eyes ~ located at the end of the eye stalks –Why is this an advantage?
Insects: Largest class of Arthropods Most successful animals: –reproduce in mass numbers –lives in many environments
Characteristics of Insects: 3 body parts: head, thorax, abdomen Mandible- specialized mouth part Antenna or feelers for touch or smell 1 or 2 pairs of wings Reproduction- sexual Complete metamorphosis Incomplete metamorphosis
Grasshopper Most common insect Two types of eyes- simple & compound 3 pairs of legs: –1 st two pairs- walking –3 rd pair- jumping
Grasshopper (cont.) two pairs of wings spiracles- found on the abdomen for respiration/breathing Reproduction- sexual –Incomplete metamorphosis: Egg, nymph, adult
Metamorphosis A series of distinct changes in form through which an organism passes as it develops from an egg to an adult. Complete Metamorphosis (4 stages): –egg- larva–pupa-adult Incomplete (3 stages): –egg- nymph-adult
Characteristics Two body parts: –Cephalothorax: head & thorax fused together –Abdomen no antennae four pairs of legs poison glands, stingers or fangs four pairs of simple eyes
Spider Chelicerae Fangs, Chelicerae of Zebra Jumping Spider Salticus scenicus www.microscopix.co.uk/spiders/fangs/index.htm Fangs and Chelicerae of Tarantula Spiderling Brachypelma smithi (Mexican Red-Knee Tarantula)
SPIDERS A common arachnid Eight compound eyes to sense light and darkness Cannot chew food ~ inject poison into their prey which paralyzes it and then turns the food into liquid Book lungs ~ series of flat, air filled plates used in respiration Spiracles~ openings in the abdomen that allow oxygen in and carbon dioxide out
Some arachnids are parasites! TICKS –Rocky Mountain Fever –Lyme Disease MITES –Chiggers –House dust mites –Eyelash mites
Class: Centipede 1 pair of legs per body segment usually a flat body 1 pair of antenna feed on insects and spiders move fast
Class: Millipede 2 pairs of legs per body segment rounded body 1 pair of antenna feed organic matter- leaves and wood move slow
Arthropod Review How many classes of Arthropods? 5 Name the classes Crustaceans Insects Arachnids Centipedes Millipedes