Symmetry Radial symmetry
Movement
Water vascular system that using water pressured for suction in the tube feet.
Support
Small hard plates beneath the epidermis.
Body Covering
Epidermis
Nutrition/ Digestion
Nutrition: Clams and oysters
Digestion: The stomach secretes enzymes to liqife the food so it can be absorded and transported to the digestive glands.
Respiration
Gases exchange through the gills on the coelom.
Circulation (open/closed)
Open.
Excretion
Excretion occurs the same way Respiration does, through the gills on the coelom.
Response/
Nervous System
A nerve cirlce around the mouth and ties to the radial nerves that go to each ray.
Reproduction
Reproduction is sexual. They send sperm and eggs into the water and they unite.
Classes (list examples) Asteroidea: Starfish
Echinoderoida: Sea urchin
Holpthuroidea: Sea cucumbers
Ophuroidea: Brittle stars and basket stars
Crinoidea: Sea lillies and feather stars
Phylum Arthropoda
Subphylum Crustacea Arthropoda
Subphylum Chelicerata
Symmetry Bilateral symmetry Bilateral symmetry
Movement
Legs Legs
Support
Exoskeleton Exoskeleton
Body Covering
Tough exoskeleton made of chitin Exoskeleton
Nutrition/ Digestion
Nutrition: Anything edible.
Digestion: Fine particles are sent to the digestive glands while course particles and indigestable material pass through the anus and are excreted. Nutrition: Insects.
Digestion: Food is transported to the digestive gland, where it is stored for furture use.
Respiration
Blood travels through the thin gills and realeases carbon dioxide while absorbing oxygen. Book lungs. Oxygen and carbon dioxide are exchanged through the page-like folds in the spider abdomen. Also, some spiders have tracheaes that take oxygen straight to tissues.
Circulation (open/closed)
Open.
Excretion
Crayfish excrete waste through the anus.
Response/
Nervous System
Eyes, antennae and antennules. At the bottom of the antennule is a statocyst which it uses for balance. Pedipalps
Reproduction
Crayfish reproduce sexually. The female stores the sperm until the spring. Spiders reproduce sexually. The male places a tiny sperm filled web sac in his pedipalps. The male then