Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.
-
Upload
keeley-panter -
Category
Documents
-
view
241 -
download
3
Transcript of Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.
![Page 1: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/1.jpg)
Class Chondrichthyes 1
Sharks, Skates, Rays and Chimeras
![Page 2: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/2.jpg)
Class Chondrichthyes 2
Class Chondrichthyes
Subclass Elasmobranchii• Sharks• Skates and Rays
Subclass Holocephali• Chimaeras (Ratfish)
Traits
Habitats
![Page 3: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/3.jpg)
Class Chondrichthyes 3
Adaptations
Buoyancy Respiration External covering Feeding Movement Sensory systems
![Page 4: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/4.jpg)
Class Chondrichthyes 4
Buoyancy Huge oil-filled liver
• A shark that has an air weight of 1,000 kg. weighs only 3.3kg in water
Lift created by a heterocercal tail
![Page 5: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/5.jpg)
Class Chondrichthyes 5
Caudal Fin Types
Homocercal Heterocercal
![Page 6: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/6.jpg)
Class Chondrichthyes 6
Respiration
Chondrichthyes employ 3 different methods of respiration• “Two pump” method
Ram ventilation• Spiracles
![Page 7: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/7.jpg)
Class Chondrichthyes 7
![Page 8: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/8.jpg)
Class Chondrichthyes 8
External Covering
All Chondrichthyes have placoid scales in one form or another
Placoid scale modifications • Spine of stingray,
dorsal spine of dogfish, defensive spines in the skate, and teeth
![Page 9: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/9.jpg)
Class Chondrichthyes 9
Scale Types
Placoid:Sharks, Skates and Rays
Cycloid: Tarpon and Ladyfish
Ganoid: Sturgeon & Paddlefish
Ctenoid
![Page 10: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/10.jpg)
![Page 11: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/11.jpg)
Class Chondrichthyes 12
Feeding
Digestion• Spiral valve
![Page 12: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/12.jpg)
Class Chondrichthyes 13
Movement
Pelagic sharks have
rete mirabile
![Page 13: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/13.jpg)
Class Chondrichthyes 14
Sensory Systems
Elasmobranchs a have well-developed sensory system which acts in concert to locate prey and find their way around the environment• Some species can detect a drop of
blood as dilute as 1 part per billion• Also, very good at following an odor trail
![Page 14: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/14.jpg)
Class Chondrichthyes 15
Sensory Systems
Hearing Olfaction Lateral line
![Page 15: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/15.jpg)
Class Chondrichthyes 16
Sensory Systems
Visual systems are well developed for use during night and day• Tapetum lucidum =
increased vision at night
Nictitating membrane
![Page 16: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/16.jpg)
Class Chondrichthyes 17
Sensory Systems
Ampullae of Lorenzini
![Page 17: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/17.jpg)
![Page 18: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/18.jpg)
Class Chondrichthyes 19
Chondrichthyes Reproduction
Most species have extended gestation periods in egg cases or in the body cavities of females• Young traits
•Internal fertilization, through the use of claspers on the male
![Page 19: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/19.jpg)
Class Chondrichthyes 20
Chondrichthyes Reproduction
Oviparity Viviparity
• Yolk-sac Viviparity• Uterine Viviparity• Cannibal Viviparity• Placental Viviparity
![Page 20: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/20.jpg)
Class Chondrichthyes 21
Oviparity - Egg Laying
Oviparity
![Page 21: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/21.jpg)
Class Chondrichthyes 22
Viviparity
Yolk-sac Viviparity (Ovoviviparity)• Eggs are produced and retained inside the
mother• Shell disappears and young are retained until
fully developed
Uterine Viviparity• Mother secretes nutrient rich fluid which is
taken up through the skin of the embryo
![Page 22: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/22.jpg)
Class Chondrichthyes 23
Cannibal Viviparity
Young in each oviduct consume unfertilized eggs or other siblings
![Page 23: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/23.jpg)
Class Chondrichthyes 24
Placental Viviparity
Nutrients are supplied to the embryo directly from the mother via a umbilical cord
![Page 24: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/24.jpg)
![Page 25: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/25.jpg)
Class Chondrichthyes 26
Chondrichthyes Life History
Strategy of Elasmobranchs • Produce precocial young with high
survival rates• Slow growing, long lived, and reach
sexual maturity at a late age• This reproductive strategy is why
elasmobranchs can not sustain an intensive fishery
![Page 26: Class Chondrichthyes 1 Sharks, Skates, Rays and Chimeras.](https://reader036.fdocuments.net/reader036/viewer/2022062304/56649c865503460f9493c87f/html5/thumbnails/26.jpg)
Class Chondrichthyes 27
Class Chondrichthyes
Subclass Holocephali• Possess cartilaginous
skeleton, intromittent organs, spiral valve intestine, and oil filled liver
• As a group found mostly between 80-2,600 meters, feeding on hard shelled invertebrates