Tyler Peace and Maddison Kernich's Madaka Egg Project

Keiko the fish

Day 1


Day 2


Day 3


Keiko's First Heart Beats

Day 4



Day 8


Day 9


Day 10



Day 11


Medaka Egg:

Japanese madaka are a freshwater fish and are found in indigenous areas of Japan, Taiwan, and southeastern Asia. These fish are very common in rice paddies. The type of madaka we are raising is the golden strain. They are a very peaceful community fish.

Day 1:

The egg is 2653.30189 um. It has some weird kind of nucleus thing in the center and little hairs on the outside. The nucleus has a dark ring around the center and a light spot in the middle.

Day 2:

The egg pretty much looks the same as day 1, with a dark ring around the center and in the center is a little lighter.

Day 3:

The egg has a heart beat. The stage that it is on is stage 21. The egg should hatch in approximately 9.5 days. Keiko has about 82 heartbeats per minute at this point. Every few minutes the dense material that surrounds the center of the cell moves in closer to the center.

Day 4:
The egg now has formed two optic cups and the heartbeat has become increasingly visible. Our egg is now on stage 25 and it will be about 8.5-9 days. Keiko's heart rate should be between 100-120 beats per minute at this stage and he is at roughly 95 beats per minute.

Day 8:
The egg now has pectoral fin movement, twitches occur, the eyes have developed and became larger, and the retinal pigment has become very dense. Our egg is now on stage 33 and it will be about 5 days before Keiko will hatch. Keiko's heart rate is at about 140 beats per minute.

Day 9:
Keiko is now on stage 34. He should have a heartrate of about 170 beats per minute at this point but he is only at 155 bpm. The ventral fin has become larger and the pectoral fin is still twitching and flutters occasionally. He has jaw movement and yellow coloration. The jaw twitches once in awhile and the eyes have slight movement.

Day 10:
Keiko is now on stage 35 and his spleen and mouth have developed. The jaw has become more visible. Golden spots are visible over the dorsal surface. There is much fin movement. His heartrate is at about 165 beats per minute.

Day 11:
Today Keiko has hatched after about 264 hours. He is now on stage 36, which is hatching. He has very coordinated swimming and you can see his breathing movements. He is swimming around and is very active. A heartrate was not able to have been taken. The fins, eyes, heart, and spleen are clearly visible.