4th Grade Science Project

This year Joshua had the opportunity to learn about the thyroid gland.  He hatched 29 Axolotyls (known as the Mexican salamander or Mexican walking fish) eggs and conducted an experiment where he kept some axolotyls as controls and to others he gave different doses of thyroxine (thyroid hormone).

Axolotyls are native to lakes in Mexico where there is no iodine in the water.  They are unusual because they reach adulthood without undergoing changing from water animals to land animals.  Instead of developing lungs and taking to land, the adults remain in the water and use their gills to breath.  If however thyroid hormone is introduced into their water they will loose their gills, the lungs will develop and they will become land animals and air breathing.

He attempted to start giving newly hatched axolotyls thyroid hormone and see if they would metamorphosis sooner than what has been done before with them as adults.  Needless to say - experiments do not always work but he learned a lot about having a hypothesis, setting up control subjects and a medicated subjects.  He had to develop a brine shrimp hatchery to feed them every three days for months and change their water often.  

He also learned about thyroid function in humans and was able to explain all of this to each person who stopped by to see his project.  He did a fantastic job.  Wonder what he will choose to do next year?

Also had to throw this one in here…this was his grade on his final book report of the year!