Evaluate Basic External Animal Anatomy and Morphology - AgriSETA

Evaluate Basic External Animal Anatomy and MorphologyPrimary Agriculture NQF Level 1 Unit Standard No: 11617312- The pelvic finThey are found towards the lowersurface of the trunk. Their positionvaries in different species but isusually situated below the pectoral fins. The function ofthe paired fins is to balance the fish. They also allow thefish to steer slowly through the water- The dorsal finThere is also an unpaired fin foundon the trunk of the fish namely thedorsal fin. This prominent fin is found on the uppersurface of the trunk.- The anal finThe other unpaired fin is called theanal fin and occurs below the lateralline on the lower surface of the trunk.Both the dorsal and anal fins help tokeep the body of the fish upright when it changescourse in the water.• The tailThe trunk narrows gradually and then widens out again into anunpaired fin that forms the tail. This enlarged tail with a bigsurface plays an important part in the forward and othermovements of the fish.oRespirationFish breathe by means of their gills. The gills are situated on eachside of the head. Four vascular (rich in blood vessels where theblood exchanges oxygen and carbon-dioxide) gills are found ineach gill chamber on each side of the head.Water passes through the open mouth to the gill chambers andsurrounds the gills. Gas (oxygen and carbon dioxide) exchangesbetween the water and the blood-filled capillaries (small bloodvessels) within the gills. The water leaves the gill chambersthrough the gill slits covered by the gill covers on each side of thehead.Version: 01 Version Date: July 2006