文档介绍：Tilapia External and Internal Anatomy
March 11, 2014
OBJECTIVE:
Tilapia;
Dissecting equipment (scissors, forceps, dissecting pan, etc.);
Ruler.
To e familiar with the gross anatomical structures of tilapia.
SUPPLIES:
Head Trunk Tail
PROCEDURE:
 
PART 1: EXTERNAL ANATOMY
Body shape - Streamlined, or fusiform, reducing the drag
Body regions - Head, Trunk, and Tail
External Anatomy
Scales – cycloid scales
Thin
Oval
Overlapping
Used for speed
Reduce friction
Contain growth rings (circuli)
Fins –
Used to maintain position, move, steer, and stop.
Composed of fin rays (provide support)
Unpaired Fins
Dorsal – keep fish upright
Anal – keep fish upright
Caudal –(tail) thrusts fish through the water and assists in steering
Paired Fins
Pectoral – behind the gills (act as brakes; side to side motion)
Pelvic - below and behind the pectoral fins (up and down motion)
Gills –
Take in oxygen and give off carbon dioxide
Opercula – hard plate that covers the gills
Gill arches – 4 arches in tilapia
Gill rakers – strain unwanted particles from the water
Gill filaments - where gas exchange takes place
Lateral Line –
allows fish to sense change in water pressure
Allows fish to sense movement in water
Avoid objects in their path
Sense chemicals in the water (attracting a mate)
Lateral Line
Mouth
Used in place of hands to feel objects
Nares
Nasal openings in the snout
Contain smell receptors
Sense of smell
Eyes
Eyes are on the sides of their heads
No eyelids
Thick cornea
Large pupils which allow light to enter
Retinas have both rods and cones (can see in dim light and color)