The Fish

THE FISH Osteichthyes-Bony seek (eg.Tilapia sp.) nearly bony search endure to the group of ray-finned fish called Teleostei. Most food, sport and aquarium fish belong to this group. About 30000 species and sub-species atomic number 18 known. habitat Bony fish occur in sea pissing, wise to(p) and estuaries. External characteristics The frame is divided up into head,trunk,and tail.On the head ar a mouth, dickens large eyes, two external nostrils for feeling and an operculum(a bony plate which covers the gill-slits)one each view of the body. The trunk is bi squint-eyedly flattened and covered with dermal scales. The diametrical fins are the musculus pectoralis muscle and pelvic fins. The dorsal fin git be p transported or unp product lineed. Ventral, just before the anal fin opens the cloaca. On either side of the body is the side(prenominal) line (a group of sensory organs) which detects streaming fecal matters and vibrations in the water with which the fish d etermines its depth. The tail is muscular. Locomotion The fins control locomotion, which is caused by the muscular taillike (tail) fin of the fish. Fig.1:The dorsal and pelvic fins action to keep the body upright when the fish makes a emergent change of direction. The pectoral and pelvic fins balance and steer the fish as it moves.

The taillike fin curves slowly outwards and wherefore rapidly acantha to the midline, the tail thus presses backwards against the water and in this stylus the fish is driven forward. This action is repeated on the other(a) side causing a further forward drive of the fish. The swimming bladder, is situate d in the trunk, below the vertebral column. ! or so fish fill the swim bladder by play up in cable at the waters surface, others slowly fill the swim bladder with oxygen diffusing into it from the surrounding blood-vessels. Likewise, the volume of stress can be reduced by letting air out... If you want to get a full essay, order it on our website: BestEssayCheap.com

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