BIO 2135 Study Guide - Final Guide: Suboesophageal Ganglion, Ventral Nerve Cord, Malpighian Tubule System
Document Summary
Suphylum chelicerata: spiders, scorpions, mites, ticks, and horseshoe crabs, presence of chelicera on the first body segment; its how they got their formal name of chelicerata--animals with chelicera. If eyes are present, they are simple eyes. No antennae: predatory animals and consume their food in liquid form, and extracorporeal (where digestive enzymes are regurgitated into the food. Development of the fertilized egg is usually direct in terrestrial species and indirect in marine chelicerates. Subphylum crustacea: lobster, crab, shrimp, or crayfish which are carnivores or omnivores, ancestrally: Five-segmented head and a multisegmented trunk, he head included compound eyes and two preoral appendages, antennules and antennae. Behind the mouth were paired mandibles and two pairs of maxilla. Each leg was involved in locomotion, feeding, and respiration. Presently: legs found on the trunk now assisting the maxillae in processing food and became maxillipeds. The head and the trunk segments, with the maxillipeds, became the cephalothorax.
