Evaluate Basic External Animal Anatomy and Morphology - AgriSETA
Evaluate Basic External Animal Anatomy and Morphology - AgriSETA
Evaluate Basic External Animal Anatomy and Morphology - AgriSETA
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<strong>Evaluate</strong> <strong>Basic</strong> <strong>External</strong> <strong>Animal</strong> <strong>Anatomy</strong> <strong>and</strong> <strong>Morphology</strong>Primary Agriculture NQF Level 1 Unit St<strong>and</strong>ard No: 11617336oEyesOn the outside of the 2 pairs of antennae is a short stalk with acompound eye at the tip. The stalks can fold into grooves in thecarapace to shield them from damage.oThe mouthpartsThe crab has biting mouthparts - one pair of hard jaws, two pairsof soft jaws <strong>and</strong> three pairs of jaw-feet (maxillipodes - footlikestructures of the upper jaw).oThe legsFive pairs of jointed legs are attached to the cephalothorax.The first pair is usually larger <strong>and</strong> stronger than the rest <strong>and</strong> endin strong pincers, which are used for holding the prey. The otherfour pairs end in strong claws <strong>and</strong> are used for movement.oBreathing gills The abdomenCrabs breathe by means of gills in a chamber on the side of thecephalothorax. In each chamber are six gills. They are structuredthat the crab can live in <strong>and</strong> outside water.In an adult crab the abdomen is permanently folded in under thecephalothorax. In the male the abdomen is roughly triangular, while in afemale it is more dome-shaped. The abdomen consists of six clearlydefined segments. If you lift it you will see the following:• Swimmerets (peapods - long, flat reproductive structurescovered with hairs)These are long, flat structures covered in hairs. Two pairs occur inmales <strong>and</strong> four pairs in females. They are used in reproduction. Theanus is on the last segment.Version: 01 Version Date: July 2006