• Intestine － about 5 to 7 times of the fish body length
Dark peritoneum
Immune system － Spleech
• Spleech － under the swim bladder, dark red color, Flattened oval in shape.
Circulatory system － Heart
Heart － Dark red organ, located in the thoracic cavity and below the gills, which has one cardiac atrium and one cardiac ventricle.
rnal 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)
Report
Drawings of tilapia external anatomy (side view)
and labeling of anatomical structures.
Thank you !
Male tilapia
Genital papilla
Female tilapia
Anus Vas deferens and ureter
Anus Oviduct Ureter
PART 2: INTERNAL ANATOMY
Circulatory system － Heart
Reproductive system － Gonad Urinary system Digestive system Immune system Respiratory system － Kidney Liver － Gall bladder Intestine － Spleech － Gills
– 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
The coelom of tilapia is divided into 3 cavities by membranes.
INTERNAL ANATOMY
Dissecting procedure
• Lie the tilapia on right side, and cut the body wall from the front of the anus forward and to the dorsal
Urinary system － Kidney
• Kidney － The kidney is above the swim bladder and very close to the spine. Usually very dark red in color.
Digestive system
• 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
– Unpaired Fins
– Dorsal – keep fish upright – Anal – keep fish upright – Caudal – (tail) thrusts fish through the water and assists in steering
– Paired Fins
• Not all fish have gall bladders !
• Intestine － tube-shaped and connections to the anus and stomach. • Carnivores have large stomach and short intestines while herbivores have little (or no!) stomach and very long intestines.
pericardial cavity
Reproductive system － Gonad
• long cylindrical paired organs that and hang from the dorsal aspect of the peritoneal cavity. In mature fish oocytes are usually visible in the ovary. • The testes are white, and the ovaries are slightly yellow.
Tilapia External and
Internal Anatomy
March 11, 2014
OBJECTIVE:
– To become familiar with the gross anatomical
structures of tilapia.
SUPPLIES:
– Tilapia;
– Dissecting equipment (scissors, forceps, dissecting
pan, etc.);
– Ruler.
PROCEDURE:
PART 1: EXTERNAL ANATOMY
Body shape － Streamlined, or fusiform,
reducing the drag
Body regions － Head, Trunk, and Tail
Head Trunk Tail
• Then cut the body wall forward across of the pectoral fin
• Behind the operculum, cut the body wall from the ventral to the dorsal, get rid of the body wall, then the internal organs will be displayed.
– Thick cornea
– Large pupils which allow light to enter – Retinas have both rods and cones (can see in dim light and color)
The shapes of tilapia
genital papilla
• Liver － behind the heart, brown color, In tilapia one lobe of the liver extends posteriorly along the intestine almost to the anus of the fish.
• Gall bladder － Under the lobes of the liver for a small fluid-filled sack, dark green color.
Respiratory system － Gills
• Gills － Gill rakers, gill arch and gill filaments
• Swim bladder － The swim bladder is located above the peritoneum (retroperitoneal) and below the kidney. In tilapia, the swim bladder is thinwalled, transparent, and fragile.