Chondirchthyes

Chondrichthyes- Kaitlin Delaney

https://docs.google.com/presentation/d/1bjRoebrE3811s-J8aKDnps5_0tIhgX4v8fMs-XtK284/edit
 * PowerPoint: **


 * Kingdom: ** Animalia


 * Phylum: ** Chordata


 * Class: ** Chondrichthyes


 * Body Plan: ** Chondrichthyes have bodies made of cartilage instead of bone. There is a notochord present in the young, and is eventually replaced by cartilage. They also lack ribs. This allows for extreme flexibility. Their bodies are covered in a thick skin. This skin is covered dermal teeth, often called denticles, making it feel like sand paper.


 * Germ Layers: ** Chondrichthyes have Endoderm, Mesoderm, and Ectoderm germ layers and a notochord is formed during development as well.


 * Symmetry: ** Chondrichthyes have bilateral symmetry.


 * Coelomate: ** Chondrichthyes have a coelomate.


 * Habitat: ** Chondrichthyes live in aquatic environment, more times than not in salt water.


 * Movement: ** Chondrichthyes have paired fins and flexible bodies making movement in water very feasible.


 * Skeletal System: ** Chondrichthyes have a body made of cartilage instead of bone and they do not have ribs or bone marrow.


 * Evolutionary Advancements: ** Chondrichthyes have denticles on their skin for protection from potential predators. Additionally, they have large jaws and many sets of sharp, protruding teeth. These evolutionary adaptations make Chondrichthyes fierce predators and able to fight off almost any source of danger.


 * Special Adaptations: ** Because Chondrichthyes do not have bones or bone marrow, their red blood cells are made in the Leydig's organ, an organ which is only found in cartilaginous fish, but not all cartilaginous fish have it.


 * Feeding Patterns: ** Chondrichthyes are carnivores and they use their sharp, jagged teeth and extensive jaws to devour other vertebrate animals as large as dolphins.


 * <span style="font-family: 'Lucida Sans Unicode','Lucida Grande',sans-serif; font-size: 110%;">Respiration: ** Chondrichthyes breathe through 5-7 gills and often times have to be swimming to keep oxygenated water streaming through their gills. They also have a spiracle, a small hole behind the eye, that opens to the Chondrichthyes' mouth.


 * <span style="font-family: 'Lucida Sans Unicode','Lucida Grande',sans-serif; font-size: 110%;">Circulation: ** Chondrichthyes have a closed circulatory system with a two-chambered heart.


 * <span style="font-family: 'Lucida Sans Unicode','Lucida Grande',sans-serif; font-size: 110%;">Excretory: ** Generally, Chondrichthyes have a digestive system that consists of a stomach, intestines, and an anus. This anus is called a cloaca. This cloaca is an opening shared by the genital organs and connects to the urinary and intestinal tracts.


 * <span style="font-family: 'Lucida Sans Unicode','Lucida Grande',sans-serif; font-size: 110%;">Nervous: ** The nervous system of Chondrichthyes consists of a relatively small brain, a spinal column, and a network of nerves. Additionally, most Chondrichthyes, especially sharks, have very keen senses and some particularly sensitive areas. Sharks are very sensitive around their noses.


 * <span style="font-family: 'Lucida Sans Unicode','Lucida Grande',sans-serif; font-size: 110%;">Reproduction: ** Fertilization in Chondrichthyes is internal. Often times, offspring are born live. However, in some cases, offspring develop from eggs. Additionally, there is no parental care after birth.



**Information URLs:** > > >
 * http://www.ucmp.berkeley.edu/vertebrates/basalfish/chondrintro.html
 * http://www.cyhaus.com/marine/sharks.htm
 * http://www.woodbridge.tased.edu.au/mdc/Species%20Register/class_chondrichthyes.htm
 * http://www.biodiversityexplorer.org/chondrichthyes
 * <span style="font-family: 'Lucida Sans Unicode','Lucida Grande',sans-serif; font-size: 110%;">Picture URLs: **
 * http://www.cyhaus.com/marine/sharks/hammer1.jpg
 * http://www.enchantedlearning.com/sgifs/Sharkdigestion.GIF
 * http://images.nationalgeographic.com/wpf/media-live/photos/000/178/cache/rays01-spotted-eagle-ray_17857_600x450.jpg