Shark Reproduction

note presence of claspers

"Great White Shark." Wikipedia, The Free Encyclopedia. 5 April 2008, at 23:51 UTC. Wikimedia Foundation, Inc. 22 April 2008. http://en.wikipedia.org/wiki/Great_white_shark

Sharks are sexually dimorphic, meaning, there are visual differences between males and females.

MALES

Claspers- rolls of cartilage that become stiffened with calcium in the adult males. Males also have paired testes.

The testes are internal and are located in the anterior end of the body cavity. The urinary and reproductive tracts join together to form the urogenital sinus.  From there the sperm is eventually released into the groove of the claspers and is then delivered to the female during copulation.

FEMALES

Females do not have claspers.  Instead they have a cloacal opening between the anal fins.  The internal ovaries are found anteriorly in the body cavity and are paired.

Cloacal Opening:

www.sciencebugz.com

INTERCOURSE

Many species of sharks have to travel long distaces to mate because they live in different parts of the ocean. The male chases and bites the female to initiate mating.

* Fertilization is occurs inside the females body after the male inserts his claspers (unless they are bony fish.)
* Sharks produce only a few large eggs. Most of them are ovoviviparous. The baby sharks grow in eggs inside the mother's body and also hatch inside. They then grow more and are "born again" as live pups.
* Young look just like parents, only smaller.
* Gestation period is long, up to two years in some species, such as the spiny dogfish.
* Sharks can store sperm.
* Although many give birth to fully formed live young, some sharks are oviparous, meaning, their young hatch from an egg case laid outside the mother. The cases are attached to structures such as algae and coral and once secure, the mother leaves and does not return---- 30% of sharks hatch from fertilized egg cases.

Internal Organs : 3 is Graafian follicle

www.sciencebugz.com

sources:

http://www.marinebiodiversity.ca/shark/english/reproduction.htm- GOOD PICTURES

http://elasmophiles.tripod.com/id18.html

Eye witness (sharks)

Created By,

Livia Erwin