Complex Invertebrates
Arthropods and Echinoderms
15-3 Arthropods
Arthropods More than a million
have been identified
Main competition for food
Insects, Crustaceans, spiders, and scorpions
15-3 Arthropods
3 Main Characteristics Exoskeleton
Rigid covering Does not grow
Must be shed (molting)
15-3 Arthropods
3 Main Characteristics Segmented body Jointed appendages
15-3 Arthropods
Open Circulatory system Blood is not
contained in tubes From heart through
open spaces in body
Blood carried food but not oxygen
Reproduce sexually Stay males and
females
15-3 Arthropods
Crustaceans Crabs Lobsters Barnacles Shrimp
15-3 Arthropods
Crustaceans Body divided into
segments A pair of
appendages is attached to each segment
Claws, legs, or antennae
Can regenerate certain body parts
15-3 Arthropods
Crustaceans Most live in watery environments Breath through gills
15-3 Arthropods
Centipedes Have one pair of
legs in each segment of their body
Have claws that inject venom
Carnivores Live in moist
environments
15-3 Arthropods
Millipedes Have 2 pairs of
legs for each segment of their body
Herbivores Roll up in ball when
in danger Live under logs and
rocks
15-3 Arthropods
Arachnids Body divided into 2
parts Head and
abdomen 4 pairs of legs
Are attached to their head
15-3 Arthropods
Spiders Feed on insects or
small vertebrates Webs
Made of silk Secreted by
structures in abdomen
Most are remade every day
15-3 Arthropods
Funnel Web
15-3 Arthropods
Trapdoor Web
15-3 Arthropods
Spiders Injects venom in
prey through fangs Either kills or
paralyzes prey Preserves living
creatures
15-3 Arthropods
Spiders Have book lungs
Has several sheets of tissue
As oxygen passes over sheets it is removed
15-3 Arthropods
Scorpions Have large stingers Hold prey with
claws Live under rocks
and logs Nocturnal
15-3 Arthropods
Ticks and Mites Live on other
organisms Live off body fluids
Juices of plants Blood of animals
15-3 Arthropods
Insect Structure 3 Parts
Head Chest (Thorax) Abdomen
Has 3 pairs of legs attached to the chest
15-3 Arthropods
Insect Structure Many eyes
Compound eyes Contain many
lenses Detect
movement Simple eyes
Detect light and dark
15-3 Arthropods
Insect Structure Most have wings
Can have many pairs
Has series of tubes for carrying oxygen
Reproduce sexually
15-3 Arthropods
Growth and Development Grow rapidly
Must shed exoskeleton
Metamorphosis When an insect
changes their appearance during development
15-3 Arthropods
Metamorphosis Complete
4 stage process Egg Larva
Spends most of the time eating
Pupa Usually
covered in cocoon or chrysalis
Adult
15-3 Arthropods
Metamorphosis Incomplete
Egg Young
Nymphs Looks like adult
but doesn’t have all characteristics
Adult
15-3 Arthropods
Insect Behavior Most live solitary
lives Do not directly
compete for available food
Males must attract females
Buzzing Colors/lights Pheromones
Chemicals that attract opposite sex
5-3 Arthropods
Insect Behavior Social insects
Can not survive on their own
Form colonies or hives
Individuals perform specific jobs
15-3 Arthropods
Defense Mechanisms Mimics
Look like surroundings
Look like a predator
Weapons Stingers Bite Venom
15-3 Arthropods
Syrphid Fly
15-3 Arthropods
Walking Stick
15-3 Arthropods
Viceroy Butterfly
15-3 Arthropods
Owl Butterfly
11-3 Echinoderms: The “Spiny-Skinned” Animals
Echinoderms Spiny skin Internal skeleton
Bone like plates Made of calcium
5 part body
11-3 Echinoderms: The “Spiny-Skinned” Animals
Echinoderms Water vascular
system Fluid-filled
internal tubes that…
carry food and oxygen
Remove waste Help with
movement
11-3 Echinoderms: The “Spiny-Skinned” Animals
Echinoderms Tube feet
Suction-cuplike Use to walk Use to open
shells and catch food
11-3 Echinoderms: The “Spiny-Skinned” Animals
Starfish Have 5 or more
arms extending from a central body
Have hundreds of tube feet
Used to open clams
Regenerate
11-3 Echinoderms: The “Spiny-Skinned” Animals
Sea Lilies
11-3 Echinoderms: The “Spiny-Skinned” Animals
Feather Star
11-3 Echinoderms: The “Spiny-Skinned” Animals
Sea Cucumber
11-3 Echinoderms: The “Spiny-Skinned” Animals
Sea Urchins
11-3 Echinoderms: The “Spiny-Skinned” Animals
Sand Dollar
11-3 Echinoderms: The “Spiny-Skinned” Animals