By: Katrina Anderson and Megan MuthPeriod 3

Requirements for a Medaka Egg to Survive Until Hatching

To be sure that your Medaka egg does not die you must fill its container that it is staying in with freshspring water once everyday. Make sure to not change the type of water that you are placing the egg in!

Keep eachMedaka egg in a petri dish or some type of dish so that it is safe until it has hatched.

The water in your dish should be no more than 5 mm deep at all times.

The temperature should be between 15-25 °C at all times.

Day 1April 16th, 2009

Hello my name is Arnold. I am about 23 hours old. I am going to tell you the story of my life. Today after a little car ride from Clarion University I finally arrived at Punxsutawney Area High School. I met the people that would be taking care of me until I’m born or hatched. There is a picture of me to the right showing stage 17 of my birth. As you can see, I am not that developed yet but pretty soon I will be hatched and swimming around happily.

Day 2April 17th, 2009

Today is the second day at Punxsutawney Area High School. I am really enjoying it here because my babysitters are taking care of me real well. The container that I am staying in is really comforting because my babysitters fill it up with fresh spring water everyday. They also examine me under their microscope everyday to make sure that I am alright. My babysitters take a picture of me everyday I feel like I’m famous! Today was a very important day because I finally got a heartbeat for the first time! Therefore, I am on stage 23 of my developing process. My heartbeat rate is 90 beats per minute today.

Day 5April 20th, 2009

After a very long weekend at Mrs. Wolfgang’s house I arrived back at Punxsutawney Area High School again for the whole week. Today is the fifth day of being at Punxsutawney. I’m on stage 26 today in my life therefore I am about 56 hours old. My heartbeat today was about 102 beats per minute! My heartbeat rate increases everyday meaning that I’m healthy. Today was another important day because my blood circulation began to flow through the egg! As you can see in the picture on the right I have developed a lot since before the weekend.

The Heartbeat Videos of MeDay 2 Heartbeat (90 beats per minute)

Day 5 Heartbeat (102 beats per minute)

Day 6April 21st, 2009Today is the sixth day at Punxsutawney Area High School. My optic cups/eyes were finally visible today. If you look in the picture on the right my eyes are the two big black dots that are to the left of the oil globule. As you can see in the picture I am developing rather quickly. I am already on stage 28 of my process and have a heartbeat of 104 beats per minute! At this point in my life I have a lot of cytoplasm as you can see in the picture which is a very good sign. So far I don’t have any developing problems which is also a good thing! I can’t wait until I’m finally hatched and can swim around everywhere!

Day 7April 22nd, 2009Today is the seventh day at Punxsutawney Area High School. As you can see from the picture on the right, my eyes are very visible today! Today I am on stage 29 of my developing process therefore I am 84 hours old already! You can also see from the box on the lower left hand corner of the picture that I am increasing in size everyday. Today my blood was still circulating throughout my body however there was more blood today which is good. I think my other structures will start developing very soon! I am having a great time at this school!

Day 8April 23rd, 2009Today is the eighth day at Punxsutawney Area High School. I am on stage 30 of my developing process therefore I am about 102 hours old. As you can see from the picture of me on the right, I am developing very fast! Towards the bottom of the picture you can see my tail beginning to form. In the picture you can also see that my body is beginning to develop more and more everyday. The cytoplasm in my egg is beginning to disappear. This is a sign that I will be hatching any day now!

Day 9April 24th, 2009

Today is the ninth day at Punxsutawney Area High School. As you can see from the box in the upper right hand corner of the picture I have increased in size a lot since yesterday. Today was a very important day in my developing process because my fins began to move today. This means that I should be hatching very soon! Unfortunately today is Friday therefore I will probably hatch over the weekend while I’m at Mrs. Wolfgang’s house.

Day 12April 27th, 2009Today is the twelfth day at Punxsutawney Area High School. After another long weekend at Mrs. Wolfgang’s house I was very excited to come back to the school so that my babysitters could see me. As you can see in the picture I did hatch over the weekend! It has been great to swim around my container all day long! Now that I have finally hatched you can really see a lot of my structures such as my spleen which is the red dot beside the oil globule. My babysitters had a choice of taking me home with them or putting me in the community bowl with all the other fish. My one babysitter, Megan, decided to take me home and take care of me. Therefore, I have to take another small trip with Megan on the bus to her house.

Day 13April 28th, 2009

I am having a wonderful time at Megan’s house she takes such great care of me! My home is now in a fish bowl in Megan’s kitchen. She takes care of me by changing my water to fresh spring water everyday. Megan also feeds me fish food twice a day! I am growing bigger and bigger each day. In conclusion, it took 13 days for me to be born and I’m very happy that I have finally hatched! I’m a very healthy baby boy!

Requirements for a Medaka Egg to Survive After HatchingThe water temperature should be between16-28°C

after hatching. Remember that you should stay with the same water you first entered the egg into. It is important to not take the egg from spring water and put the hatched fish into tap water. Keep using the same type of water!

For the first seven to fourteen days after hatching you should feed it protozoa and newly hatched brine shrimp. After three weeks, you can feed it finely chopped white worms and tropical fish food sparingly.

The most important thing to remember is to NOT overfeed the newly hatched fish.

After four to six weeks, they are considered adults. They have a life span of about four or more years!

Day 1 Labeled StructuresVitelline Membrane: This is the delicate cytoplasmic membrane surrounding the ovum also known as the yolk membrane. The function of this is to protect the ovum.

Filament: These are the hair-like structures coming out of the Medaka. The function of these is to protect the Medaka.

Cytoplasm: This is enclosed within the plasma membrane. The cytoplasm contains many cell parts and is the location where many cell processes occur.

Day 2 Labeled StructuresOil Globule: This is one or several small spherical shapes of oil within the yolk-sac.

Chorion: This is a membrane that is found between the mother and a fetus. It is formed by layers and surrounds or protects the embryo.

Yolk Sac: This is a membrane sac attached to the embryo.

Day 6 Labeled Structures

Heart: The heart is a muscular organ responsible for pumping blood through the blood vessels which then transports the blood to the rest of the body.

Day 12 Labeled StructuresOptic Eyes/Cups: These are the eyes that are found on the Medaka egg. The eyes allow the Medaka to see its surroundings.

Spleen: This functions as a reservoir of blood.

Pectoral Fins: These are paired fins located on each side of the fish. The fins act as the forelimbs of the fish.

Somites: These are distributed along the sides of the neural tube that will eventually become dermis, muscles, and vertebrae.

Day 12 Labeled Structures Continued…Brain: The brain is the center of the nervous center. In vertebrates, it is located in the head, close to the sensory apparatus like vision, hearing, taste, etc.

Mouth/Jaws: The jaws form the opening of the mouth. The mouth is the natural opening in which food passes enters into the body. It encloses the pharynx, the tongue, gums, and teeth.

Resources http://en.wikipedia.org/wiki/Somite http://en.wikipedia.org/wiki/Fish_anatomy http://en.wikipedia.org/wiki/Spleen http://en.wikipedia.org/wiki/Heart http://sealifebase.org/glossary/Glossary.php?q=oil%20globule http://en.wikipedia.org/wiki/Chorion http://en.wikipedia.org/wiki/Yolk_sac http://en.wikipedia.org/wiki/Vitelline_membrane http://en.wikipedia.org/wiki/Cytoplasm http://www.merriam-webster.com/dictionary/mouth http://www.merriam-webster.com/dictionary/jaws http://www.embl-heidelberg.de/mepd/medakaStages/MedakaDevStages.html http://biog-101-104.bio.cornell.edu/BioG101_104/tutorials/Medaka_stills.html