Crustaceans are arthropods in the subphylum Crustacea and include crabs, shrimp, lobsters, barnacles, copepods, krill, isopods, and amphipods. They have a jointed exoskeleton and specialized appendages for locomotion, feeding, breathing through gills, and sensing the environment. Crustaceans can be predators, scavengers, or filter feeders. They have separate sexes and males release sperm packets for females to store until fertilizing their eggs, which hatch externally.

1. Subphylum Crustacea
Phylum Arthropoda
Kingdom Animalia

2. Background
• Crabs,
• Shrimp,
• Lobster,
• barnacles,
• Copepods (70% of all crustaceans are copepods),
• Krill (largest biomass of any species on earth),
• Isopods,
• Amphipods

3. Anatomy
Jointed appendages with
specialized jobs:
Locomotion:
-Pereopods – walking legs
-Pleopods – swimming legs
Feeding:
-Maxillipeds
-Mandibles
-Chela – pincers (claws)

4. Anatomy contintued
Breathing – gills (usually under)
Sensory – antennae
Tail – telson and uropods
Body segments:
-cephalothorax (head & body cavity AKA the carapace)
and
-abdomen (muscular dorsal part of body)

5. Anatomy continued

7. Feeding
• Most predators or
scavengers
• Some filter feeders
(barnacles)
• Some parasites on fish
or whales (ex.
isopods)

8. Reproduction
• Separate sexes
• Males release sperm packet using
modified appendages
• Females mate during molting, hold
sperm packet till fertilization
• Females carry fertilized eggs under
body till hatching; fan them for oxygen

9. Life Cycle of the Crustacean

10. Statistics
• Largest crab - Japanese Spider Crab (13 feet)
• Heaviest crab - Alaskan King Crab (up to 24 pounds)
• Heaviest Crustacean – American Lobster (up to 48 pounds)