Phylum Arthropoda:

Subphylum Mandibulata:

Class Crustacea


Class Crustacea

"Crusted Forms" - hard flexible crust

Over 38,000 species

Nearly all are aquatic - "Insects of the Sea"

Microscopic to Largest Living Arthropods


Characteristics of Crustacea

1. External

a. Appendages

b. Tagmata

c. Exoskeleton

2. Feeding and Digestion

a. Nearly all are suspension filter-feeders

b. Larger species predator/scavengers

c. Appendages specialized for cutting, tearing, collecting

d. Foregut enlarged into cardiac and pyloric stomach

e. Midgut bears two digestive glands (hepatopancreas)

3. Gas Exchange, Circulation, and Excretion

a. Respiration

b. Circulatory System

c. Excretion

4. Nervous and Sensory Structures

a. CNS is typical for arthropods:

b. Eyes of two types

c. Prioprioceptors and statocysts

d. Sensory hairs for mechano- and chemoreception


Class Crustacea


Subclass Malacostraca


Subclass Malacostraca: Order Decapoda ("Ten Legs")


Subclass Malacostraca: Order Amphipoda ("Double Legs")


Subclass Malacostraca: Order Isopoda ("Same Legs")


Subclass Branchiopoda


Subclass Ostracoda


Subclass Copepoda


Subclass Cirripedia