Insects of Texas: A Practical Guide

Crustaceans

40 crustacea Crustaceans Class: Crustacea (kruh-STay-shuh) crusta, crust, shell Characteristics: Size: variable Shape: Variable Antennae: Two pairs Mouthparts: Chewing Eyes: Usually present Wings: absent Legs: Five or more pairs; first pair sometimes with large claw Miscellaneous: abdomen segmented Habitat: Mostly marine; some fresh water; a few terrestrial Food: variable Crustacea is a large group of about thirty thousand to fifty thousand species worldwide that live primarily in marine environments. However, several species live in fresh water, and a few are terrestrial . Crustaceans are quite variable in shape and appearance but typically possess two body regions: cephalothorax and abdomen. all crustaceans, however, have two pairs of antennae, although one pair is often smaller. The order Decapoda includes the familiar lobsters, crayfish, crabs, and shrimp. This group is characterized by having five pairs of legs on the cephalothorax with the first pair modified as large claws. Most members of this group are scavengers. The order isopoda is the only terrestrial group of crustaceans and includes the very common sowbugs and pillbugs. isopods have seven pairs of legs on the cephalothorax. The abdominal region is very short and does not possess legs. Sowbugs have tail-like projections and cannot roll into a ball, whereas the pillbugs (also known as “roly-polies”) do not have these projections and roll up when disturbed. Most isopods are scavengers but occasionally feed on plants and sometimes cause damage. Crayfish Sowbugs Pillbugs ...