Are you Shark Smart? Shark Anatomy

Made of calcified cartilage Shark Skeleton Made of calcified cartilage Spinal Nerve Cord- carries nerve impulses Vertebrae- form the shark’s backbone of cartilage

External Features of the Shark The backbone side of the shark is known as the Dorsal Side. The belly side of the shark is known as the Ventral Side. Anterior means towards the head and Posterior means towards the tail.

Male or Female?? The male shark has claspers, the female shark does not.

What do the various fins do? Dorsal fins: Help the shark maintain stability (unpaired) 2nd Dorsal fin: Stabilizes the shark’s forward swimming motion (unpaired) Pectoral fin: helps the shark move up or down or left or right (paired) Pelvic fin: Helps the shark change course (paired) Anal fin: Offers stability and an extra bit of turbulent push (unpaired) Caudal Fin: Helps with movement

Shark Sensors Ampullae's of Lorenzini: Lateral Line: Pores which help locate prey Lateral Line: sharks sense of distant touch

Shark Senses Eyes –similar to the eyes of man Nictitating Membrane- protective membrane that covers the eye Nostrils –help the shark detect blood and injured flesh at great distances

How does the shark breathe? Gill Slits: Water taken into the mouth passes over the gill slits so oxygen can be removed Spiracle: Help bring water into the mouth for breathing when the shark’s mouth is closed

Shark Teeth – On the skin and in their mouth! Denticles:Tooth-like projections on the skin. They help with protection and movement Shark Teeth: Several rows size and shape varies with the type of shark

Shark Internal Anatomy Upon incision of the belly from the pelvic fins to the pectoral fins the first organ encountered is the liver.  The liver of sharks occupies most of the body cavity.  This large, soft and oily organ can comprise up to 25% of the total body weight.  It serves two functions within the shark.  The first is as an energy store since all fatty reserves are stored here.  The second function of the liver is to serve as a hydrostatic organ.  Oils that are lighter than water are stored in the liver.  This decreases the density of the body providing buoyancy to counteract the sinking tendency of sharks.

Digestive System Esophagus- Tube leading to the stomach Stomach- “J” shaped organ –from here food passes into the intestine Intestine –This is found posterior to the stomach. Part of the intestine is marked by rings. The intestine has a spiral valve. Waste material leaves the body through the cloaca. Kidney- excretes liquid waste Anus- where waste leaves the body

Internal Organs Spleen- dark, triangular structure found near the posterior end of the stomach. It helps to filter the blood of dead blood cells. Pancreas- Whitish organ found on the ventral side of the stomach. Further breaks down food. Gall Bladder- Small organ near the stomach which stores bile.

Cardiopulmonary System Heart- two chambered heart blood enters one chamber at a time Gills- Oxygen –rich water comes in through the mouth- gills filter out the oxygen and release the water and waste gases.

Reproductive System Ovary- 2 round female organs which produce eggs The ova (eggs) form in the ovaries of the female shark and move down the oviducts to the uterus.

The Brain A partial list of functions: the cerebellum is in charge of body movement; the hindbrain processes most sensory information and moves the head; the tectum integrates sensory information; the olfactory lobes are for the sense of smell; the diencephalon regulates hormones and some behaviors; the forebrain coordinates sensory information.

Are you ready for dissection?