Nan Schmidt's Homepage
Pima Community College


Current Classes & Activities
  Bio 105 Environmental Bio
  Bio 182 Bio for Majors II
  GLG 140 Intro to Ocean.
  Bio 183 Marine Biology

Fieldtrips and Fieldtrip Classes

Contact Information
Interesting Links
Marine Life Photo Gallery

Phylum Arthropoda

The Arthropod phylum is the largest on Earth, and marine arthropods encompass a huge variety of familar organisms, including barnacles, shrimps, lobsters, and crabs. The arthropod body plan is bilaterally symmetrical and segmented, with jointed appendages that are moved by muscles. Another characteristic of arthropods is a chitinous external skeleton, or exoskeleton. All arthropods grow by molting; they shed their exoskeletons, expand their bodies by absorping water, and then secrete a new, larger exoskeleton into which they grow. Jointed appendages and an exoskeleton provide protection, support, flexibility, and increased surface area for muscle attachment.

Subphylum Crustacea
Almost all marine arthropods belong to the Subphylum Crustacea. Crustaceans possess gills to obtain oxygen from sea water, have appendages specialized for the marine environment, and calcium carbonate in their chitinous exoskeletons to strengthen them.

Click on the links below to learn more about different types of Arthropods that are found in the intertidal of the Gulf of California. To go back to the Gallery of Marine Life, click here.

To take a practice quiz on the Phylum Arthropoda, click here.


page last updated on 7/15/03

All contents copyrighted © 2003-2012. All rights reserved.