Embryology

flat =Viewing Zebrafish= 1. Using a medicine dropper, place the egg in the depression on your slide with several drops of liquid. Rotate the egg gently with the tip of the dropper to view different areas of the egg. 2. Examine your egg under low magnification with a compound microscope. Label any identifiable structures including the **chorionic filaments**, **egg** **membrane**, and **oil droplets**. 3. Take a picture with the Motic cam. 4. Remove the egg from the depression slide and place it back in the container. 5. You will also need to change your water daily. You will do this by using a dropper to remove a little over half the water and then replacing it with new spring water.

http://www.exploratorium.edu/imaging-station/students/zebrafish.html =Pictures and information to collect:= 1. Take a picture and label any visible structures of your egg. Eventually, you should be able to see **__a streak or embryonic shield__** lying on the surface of the yolk. This is the beginning of the body of your embryonic fish. . Ectodermal cells from this area will form the nervous system of your embryo (brain, spinal cord). **__Optic buds__** may also be visible projecting from the primitive brain. These form an **optic cup** from which the parts of the eye develop. As development progresses during the second day, the embryo lies over the surface of and curves around the yolk. Various numbers of **__somites__** may also be visible in the tail or caudal region of your embryo. Somites form blocks of muscle tissue and bone tissue. A **primitive heart** may be visible below the head region by the end of the second day of development. By the end of the second day of development the three main regions of the brain should be visible.

2. On each subsequent day, carefully observe, take pictures, label, and identify observable structures. Rotate and examine your egg at different angles and from different views to try and observe all structures. A possible sequence of events follows although the times at which structures appear vary with a number of environmental conditions.

3. When the **heart** is clearly visible and beating, count and record the number of heartbeats during each day that you observe your embryo. As more **somites** are formed, count and record their number. Blood vessels should be visible over the yolk sack. Make sure you include these on your drawings. Carefully observe the eyes. Take pictures of new structures that you can observe as they form such as the **lens** or **cornea**. **Pigmentation** of the eye will also increase. The embryo is actively growing. The gut or digestive tube should be visible below the somites. Otoliths forming internal ear structures are present behind the area of the brain. **Fins** will begin to appear at the end of this period.

4. Keep careful records of the heart rate and numbers of somites and any other information that you can record. Major stages of development (heart beat, seeing pink blood, twitching...) are all notable and determine the stages of the embryo.

=Your Zebrafish story Infographic= You can tell about the development from the fish's point of view, create an anticipation for the great day of hatching, use some interesting narration to create interest, development of Zebrafish and other chordates, or other creative ideas. In your story, you must:
 * show pictures of the various stages (enough pictures to show all parts that were required).
 * discuss structures and the functions throughout (a good idea would be to include a did you know about structures that are similar with other vertebrates - other fish or animals - like us!)
 * discuss developmental stages you saw (first heartbeat, etc.)
 * basics of what Zebrafish require to survive to hatching **and** beyond hatching
 * be creative in your presentation. some examples: "how not to kill a fish", "what my fish must be thinking", "As new parents, we can't wait!", "The life and times of _", "What to expect when you are waiting for your fish to hatch," and more....
 * You will create an Infographic. Use any multimedia tool that can embed in the wiki. Some great applications you can use: comic life, cartoon online apps like pixton, powerpoint/keynote, word, pages...
 * Include "did you know" information such as how long it takes a fish to hatch, comparison of different kinds of fish, other organisms that have the same kind of structures when they develop, etc.

=Required Labels=
 * oil droplets
 * heart
 * fin(pectoral, caudal, or dorsal)
 * optic cup/eye
 * brain
 * Yolk sac
 * somites

=Grading= One page Infographic, All required labels found on your pictures, Title and text to create an interesting/informative story about your fish, Discussion of various events in the development of the fish, Discussion of zebrafish and how eggs develop, Organized and shows a plan (not pictures just inserted randomly)

=Examples of Infographics:=

=Study Guide=