DEFINITIONS AND KEY POINTS FOR OBJECTIVES OF THE FISHES
| TERMS | |
| DEFINITIONS | |
| Ostracoderms | bony armor fishes called ostracoderms |
| Agna bans | Thejawless fishes are called agnathans |
| Aestivation | Aestivation is a dormant state that helps an animal withstands hot. dry periods. |
| Homoccereal tail | In this case, the tail fin has equal upper and lower lobes. |
| Caviar | The eggs of sturgeons are caviar. |
| Ram ventilation | Some fishes keep their mouths open during swimming. It maintains Water flow in the pharynx. This method is called ram ventilation. |
| Gill arches | Gill arches support gills. |
| Gill filament | Gill filaments extend from each gill arch. Gill filament is composed pharyngeal lamellae |
| Counter current mechanism | ‘The opposite flow, of blood and gases is called countercurrent mechanism. |
| Rete mirabile | Rete mirabile is a vascular network |
| Electroreception | Electroreceptionis the detection of electrical fields that the
fish or another organism generates in the environment. |
| Osmoregulation | ‘The maintenance of water and salt balance in the body is called osmoregulation. |
| Excretion | The removal of nitrogenous wastes from the body is called excretion. |
| Diadromous | Diadromous fishes migrate between freshwater and marine environments. |
| Claspers | Male elasmobranchs have modified pelvic fins called claspers. |