1. Phylum Arthropoda animals with jointed appendages includes insects, crustaceans, centipedes, millipedes, and arachnids exoskeleton made of chitin must shed shell to grow

2. Chelicerates Includes spiders, ticks, scorpions, horseshoe crabs, and sea spiders –Six pairs of appendages –One pair of chelicerae (for feeding)

3. Horseshoe crabs

4. Sea spiders

5. Mandibulates Crustaceans –Decapods Crabs, lobsters, shrimp

8. Durban Dancing Schrimp

9. Crustaceans The crustaceans are a large group of arthopods –Lobsters –Crabs –Shrimp –Crawfish –Barnacles –copepods –The majority are aquatic, living in either freshwater or marine environments, –Some are terrestrial

10. Crustaceans Continued The majority move about independently a few are parasitic and live attached to their hosts –Sea lice, fish lice, whale lice (crustacean lice) adult barnacles live a sessile life — they are attached head-first to the substrate and cannot move independently.

16. Sea lice are parasitic

17. Structure of crustaceans Crustaceans have three distinct body parts: –head, thorax and abdomen the head and thorax may fuse to form a cephalothorax

18. Structure continued The head has two pairs of antennae, one pair of compound eyes and mouthparts –Mandibles –maxillae Each body part usually has a pair of appendages –chelipeds –Walking legs –swimmerets

19. Molting Like other arthropods, crustaceans have a stiff exoskeleton which must be shed to allow the animal to grow or molt.

20. Reproduction crustaceans all have a larval form known as the nauplius most crustaceans have separate sexes, in many decapods, the eggs are retained by the females until they hatch into free- swimming larvae.

23. Crustaceans of the Gulf of Mexico Decapods – Shrimp –Crabs –Lobsters and Lobsterettes –Hermit crabs –Squat crabs and Porcelain crabs

24. Common Name of some species American Spider Crab Sentinel Crab Pebble Crab