Nervous System

Not much is known about the basking shark's nervous system, but scientists think that the nervous system makes the shark makes it virtually free of feeling pain.

Skeletal and Muscular System

The skeleton of the basking shark is partially calcified.  The red muscle of the basking shark is aerobic and needs oxygen to function.  The white muscle of the shark is anaerobic and does not need oxygen to function, the white muscle is used for the sudden bursts of speed.

Respiratory System

Water enters the gill chambers through the mouth.  The mouth opens and closes to pump water over the gills to respirate.  The blood in the gills absourb oxygen.  The gill rakers protect the fragile gill filament from harmful substances in the water.  The spiracles in the body deliver the oxygenated blood to the eye and brain through a seperate blood vessel.

Circulatory System

The heart is a two chambered, s-shaped tube.  The blood flows from the heart to the gills and then to the body tissues.  The basking shark has low blood pressure.  The walls of the sacs that enclose the heart are rigid.  This then creates suction to maintain the flow of blood.  To maintain the flow of blood the basking shark must be constantly be swimming.

Digestive System

http://www.youtube.com/watch?v=PhWaCYWqO9g

The esophagus is short and wide, which leads to the stomach.  The stomach leads to a spiral valve which is twisted and coil to increase surface area to increase nutrient absourbtion.  After the spiral valve is the rectum which is used to excrete waste from the sharks body.

Integumentary System

The basking shark has a cartilagenous skeleton and a streamlined body.  They have a covering of dermal denticles that protect it from parasites and damage.  The dermal denticles also help the shark to swim faster, although the basking shark only goes about four miles an hour.

Diet

Basking sharks are planktonic feeders.  They swim with their mouths wide open and sift the water and plankton through their gill rakers.  The excess water exits the body through gill slits.  The gill rakers are shed in the winter, which is why the sharks lose weight during the winter months, and then are replaced in spring.

Internal and External

Reproduction

A female basking shark is reaches maturity at about eight months and the males reach maturity at about five months.  There has only ever been one sighting of a pregnant female carrying six pups which leads scientists to believe they give birth at areas with litle or no fishing pressure.  The fertilized eggs develop within the womb until the entire egg yolk is absourbed and it is fully developed.  Basking sharks do what is known as oophagy.  This is when the pups feed on the unfertilized eggs that the mother sends into the uterus.  The gestation period for basking sharks is about 14 months.

Distribution and Habitat

     In the winter the basking sharks are rarely seen by humans because they swim at depths of about 900 meters.  During the sping and summer the sharks are seen basking in the sun.  These sharks live in arctic waters to warm temperate waters, depending on where they were born. 

Size

     Basking sharks are most easily distinguished by their massive size.  The male basking shark reaches about nine meters, while the female can reach up to about ten meters in length.  The baby basking sharks are about one and a half to two meters in length.  The adult sharks weigh about four and a half tons.  One fourth of that weight is carried by the liver which is very big in these sharks.

Classification

Kingdom: Animalia

     Phylum: Chordata

          Class: Chondrichthyes

               Order: Elasmobranchii

                    Family: Lamniformes

                         Genus: Cetorhinidae

                              Species: Maximus