As for the visual documentation of a living or dead specimen, digital photography has largely replaced traditional illustrations of the living specimen as the standard method of recording the colour and anatomy of the specimen in the field today. Earlier traditional illustration (coloured and black and white) are still considered scientifically important because they can stress fine anatomical features that are often obscured by liquid. Even today, these earlier traditional illustrations are referred in research and, in fact, are sometimes the only physical records of what a now-extinct (or near-extinct) fish look like in life. New technologies can only add to information we know about previously described species. Different kinds of animals have different body coverings. Marine vertebrates include 5 major groups based on observable features including body covering, among other characteristics: * Fish have skin covered with wet scales
* Amphibians have bare skin that is usually moist or wet
* Reptiles have skin covered with dry scales
* Birds have skin covered with feathers
* Mammals have skin covered with hair (fur)
1. Learn to use digital photography for visual documentation of specimen. 2. Locate and discuss the external and internal anatomy of the cartilaginous fish. 3. Draw and identify the external and internal features.
4. Describe the function for each feature.
1. The briefing on the experiment is given by the demonstrator. 2. The full images of the specimens and other important features are taken for identification purposes by using white slate board as the background. 3. Ruler is used as a scale.
4. A shark is dissected by the demonstrator. The external and internal features are identified. A summary on the digestive and the reproductive system of a shark is written. 5. The steps how to observe the internal anatomy of a stingray is told briefly by the demonstrator. 6. The steps that have been told are followed when observing the internal organ of the stingray. 7. The organs are observed and identified, and their physiological roles are discussed. 8. All the dissection materials are washed, the dissection pan is cleaned and dried and the lab is cleared from any fluid once complete. 9. The students’ hands are washed thoroughly.
10. A report which using only the materials from the practical is written.
Posterior dorsal fin
Anterior dorsal fin
External naris/ nostril
External gill slits
Dissection of Bamboo shark
Placoid scale of a shark
Mouth| The mouth used to take food and teeth in the mouth are used to hold and tear food rather than to chew it.| Gills| The place where the gas exchange occurs which are the oxygenated water must always be flowing over the gill filaments for respiration to occur.| Nostril| Allow sharks to smell and detect chemical in water.| Eyes| To see the presence of preys.|
Scales| Used for protection against predators and aid in swimming which have a hydrodynamic function.| Fins| The cartilaginous fins are used for the stabilization.| Snouts| Function as electro receptive organ, sensitive to electric charges of prey buried in the ground.|
Liver| Act as the energy storage and to help keep the shark buoyant.| Oesophagus| Connects the mouth to the stomach.|
Stomach| Food goes here after being consumed. Digestion takes place here.| Heart| To pump blood throughout the shark’s body.|
Pancreas| Secrete the digestive enzyme. |