Christian Vinciquerra, UR, Breaking Bones

Last week in lab we had another guest from NOAA, Ms. Dennis. She is an expert on fish otolith and how to extract them. So a fish otolith is a calcium carbonate structure located behind the fishes brain. They are commonly called "earstones" and are part of the fishes inner ear. Otoliths grow with the same structure as a tree trunk; as it gets older it forms a ring.

Class extracting Otoliths

Scientists can use the otoliths to find migration patterns of the fish by locating chemicals and tracing back to a site that matches the water chemical levels. After we watched her presentation, she showed us extremely quick on how to extract one and the process of doing so. Then we dove in. To start we have to measure our fish from nose to fork in the trial. Then we begin by lifting the gill plate and scraping away the the gills and tissue on the bone. Looking for a discoloration in the bone and start to chisel away the 'clearer' part. Use tweezers to remove the bone and then start gently feeling around for the otolith which should be just inside. This took everyone a few minutes to do and understand the process and what to look for. After you find the otolith move to the next fish. We extracted three otoliths each and massed each otolith. After, we logged our data into excel. 

Fish Otolith Graph

So my graph here shows the relationship between the otoliths weight and the fishes length. As you can see there in not a good relationship between these two due to the extremely low R squared value.