Paired fins: pelvic fins, pectoral fins help the fish turn Caudal fin: (tail fin) propels fish forward Lateral line: found running along the side of the body from head to just before the tail

Internal anatomy: the digestive system Most fish are carnivorous Food moves through the mouth to the pharynx then the esophagus into the stomach In the stomach, acid & other digestive juices break down the food The food then moves into the intestines

Fish have many accessory organs like humans to help digest the food. Liver: lies next to the stomach & secretes bile to help break down fats Gallbladder: stores extra bile & releases it into the intestines when needed

Pancreas: also lies near the stomach & releases additional digestive juices into the intestine to finish digestion of food After all possible nutrients are removed from the food, the remains are pushed out of the body through the anus

Circulatory system The circulatory system of the fish delivers oxygen & nutrients to all the cells of the body It also picks up waste products from the cells & delivers it to the gills for removal The circulatory system consists of a heart, blood vessels & blood

The heart has two chambers Deoxygenated blood comes from the body & fills the atrium chamber The atrium contracts & the blood is pushed into the larger more powerful ventricle chamber The ventricle contracts sending the blood to the gills to pick up oxygen This oxygenated blood is then pumped to the rest of the body

Respiratory system The large surface area of the gills allows for rapid gas exchange The gills are supported by four sets of curved bones on each side of the head Water is taken into the mouth & then pumped over the gills Oxygen is removed from the water as it passes over the gills & then is released through the operculum

Excretory system (urine production) The kidney’s filter the blood & removes waste products The resulting solution is called urine Urine is carried from the kidneys to the bladder where it is later expelled from the body

The nervous system The nervous system includes the brain, spinal cord, nerves and various sensory organs The forebrain processes smell The cerebrum coordinates messages coming from the rest of the body

The midbrain processes sight, sound & lateral line information The cerebellum coordinates muscles & balance The medulla oblongata controls the circulatory, respiratory & digestive systems

The End