General Characteristics • Crustaceans are found in marine, freshwater, and terrestrial habitats. • Possess jaw-like appendages called mandibles and maxillae (instead of chelicerae like Subphylum Chelicerata). • Crustaceans have two pairs of antennae and two pair of maxillae. • Some appendages are biramous.
General Characteristics • Exoskeleton made of chitin without a waxy cuticle. • Respiration is through gills. • Crustaceans are the only group of arthropods that typically live in water. • Crustaceans are highly segmented. More derived forms are tagmatized and show fewer, more specialized, limbs.
Adult Female Adult Male Form I Form II Copulation Egg Immature (direct development) Crayfish Life Cycle
FemaleCrayfishes Gonopore Annulus ventralis Glair Glands
Male Crayfishes Form II Form I Male Gonopods
Crayfish Eggs Female “In berry” Eggs attached to swimmerets
Hatching and Early Development Photo by Chris Lukhaup
Other Crustaceans Water flea Robber Crab http://upload.wikimedia.org/wikipedia/en/c/c8/Cococrb2.jpg http://daphnia.cgb.indiana.edu/images/Daphnia_DGC.png
Fairy Shrimp http://news.nationalgeographic.com/news/2005/03/images/050316_fairyshrimp.jpg
Barnacles (mating) http://www.marlin.ac.uk/species/Semibalanusbalanoides.htm