Animals – Invertebrates Part 2
Ø Echinoderms (phylum Echinodermata) are à
1) All echinoderms have à
§ Ossicles are à
§ Catch connective tissue allows echinoderms to change their à
§ The combination of a firm skeleton and a surface covered with spiny projections helps à
2) Echinoderms have a à
§ A water vascular system is à
§ Canals store à
§ Changes in à
· Tube feet are à
· Tube feet are used à
3) Echinoderms have a à
§ Made up of a à
§ They feed on à
§ To get the clam out of its shell they à
§ Food is digested and absorbed and stomach is retracted
§ Wastes pass through anus located on dorsal side
4) Echinoderms can à
5) Most echinoderms can à
Ø There are five classes of echinoderms:
1) Class Crinoidea à
§ Feather stars can move their arms but à
§ Sea lilies are à
§ Both are à
2) Class Asteriodea à
§ Some are à
§ Others are à
§ Others are à
3) Class Ophiurodea à
§ Some are à
§ Others are à
4) Class Echinoidea à
§ Sea bisuits & sand dollars are covered with tiny projections for à
§ Sea urchins have à
5) Class Holothuroidea à
§ Instead of arms sea cucumbers have à
§ Have a à
§ Only echinoderms that à
§ Use tentacles to à
Ø Arthropods features are highly adapted
o Arthropods share several features:
§ Exoskeleton à
· Made of à
· Chitin protects the animal from à
· In order to grow, they must à
o This is called à
§ Jointed appendages à
· Used for à
§ Segmented body parts à
Ø Arthropods are classified into 5 groups:
1) Trilobites à
2) Crustaceans à
§ Diverse group that includes à
§ Evolved as à
§ Share common features:
· Two distinct body sections à
· Two pair of à
· Exoskeleton
· Carapace à
§ Crustacean appendages are used for a variety of à
· Collecting & manipulating à
· Attracting à
· Protection
§ Appendages include à
§ There are many different types of crustaceans
· Crustaceans vary in both à
o Decapods (lobsters & crabs) have à
o Barnacles are à
o Isopods (pill bugs) have à
o Tongue worms are parasites found in à
3) Chelicerates à
§ There are 3 major groups of chelicerates:
· Horseshoe crabs
· Sea spiders
· Arachnids
§ Chelicerates share several features:
· No à
· 4 pairs of à
· One pair each of à
· Chelicerae à
· Pedipalps à
· Two body sections à
§ Arachnids are the largest group of chelicerates & they live on à
· Eight legs
· Fanglike pincers that à
· Silk glands
§ Arachnids have four different adaptations that à
· Waterproof à
· Book lungs à
· Malpighian tubules à
· Spiracles à
§ Arachnids have evolved into a diverse group
· Spiders make up à
· Arachnids also include à
4) Insects à
§ They are in nearly à
§ Insects have a body with 3 parts:
· Head
o One pair of à
o One pair of à
o Many have mandibles for à
o Others have modified mouth parts for à
· Thorax
o 3 pairs of à
o In adults they have à
o Only four groups of animals have evolved true flight à
· Abdomen
§ Some insects live independently, others live in à
§ Insects undergo à
· In incomplete metamorphosis à
o There are three life stages of incomplete metamorphosis:
1. Larva
2. Nymph à
Ø Six legs
Ø Head, thorax & abdomen
Ø No wings
Ø No sex organs
Ø Get larger with each molt but à
3. Adult
· In complete metamorphosis à
o There are four stages of complete metamorphasis:
1. Egg
2. Larva
3. Pupa
4. Adult
5) Myriapods have à
§ 1st pair of legs bear à
§ Include à