Eggs to Fry
This year we are inviting you to explore the lifecycle of a salmon through our virtual Eggs to Fry program. We will be raising a batch of salmon from eggs…to fry, when they will be released as baby salmon to continue their journey. We will post weekly updates on the salmon with photos and videos so you can follow along! When the fish are ready to be released you can help! We will have the fish, directions to where they can be released, and learning tools to talk with your kids (or friends) about their journey. We hope you follow along with us!
Week One – Egg Delivery!
Our eggs have arrived! The eggs delivered are at the eyed-stage. The black dots you can see in the first image on the left are their eyes developing and pretty soon we should see the eggs start to wiggle around as the body of the fish grows inside. Our tank has about 100 eggs in it, in the wild a female can lay 2,000-5,000 eggs and only about 2% will survive to make it to the ocean. Hopefully with a little more control over the setting we will have 100 adorable fry to release this fall!
Before the eggs were delivered we made sure our tank had cool clean water for the eggs to live in. The chiller on the tank will keep the water cool while it circulates through the tank. We want it as close to the river temp as possible. The pump on the side of the tank will keep water moving through the chiller. And the filter on the back will keep the water clean. The gravel on the bottom mimics the gravel that the female salmon build her redd out of. In the river the rocks would be much larger (think golf ball to baseball sized) and the nest/redd would be bigger than the tank!
We want to give a huge thanks to the Oregon Department of Fish and Wildlife for providing our education with these salmon eggs!
Week Two - Wiggling Eggs
After being introduced to their new tank, all of our eggs survived their first week in the Middle Fork tank! They are also starting to wiggling which means tiny little fish are growing inside the eggs and we should start to see more fishy features developing. In this video you can see a few moving around. Our water has been at a cool 52 degrees. Using that to estimate our daily temperature units, they should be hatching in the next two weeks!
Week Three - Sac fry
We have been keeping our tank a cool 52 degrees, which has been perfect for our growing baby Chinook!
If you look closely at the eggs in the pictures here, you will see more developed eyes and bodies forming. If you look EXTRA close, you will see small fish mixed in with the eggs. These fish are called sac fry or alevin. At this stage, they still have very delicate bodies and are vulnerable to fast water and predators. In the wild, they would still be hiding in the rocks. The orange blob on their stomach is the nutrient-rich yolk sac that they will feed off of while they continue to grow big and strong. Over the next month they will slowly absorb the sac. We will start to see them move more, develop small fins, and look more “fishy”.
Week Four - Swimming Sac Fry
Our little fish are starting to really swim! Other than their advanced mobility, not much has changed from last week. Although, if you look closely you can start to see small fins forming! If all goes to plan these fish should be ready to be released sometime in mid December.
Week five - more development
The sac fry continue to grow! They are drawn to the recirculation flow in the tank so they are collected in a corner of the tank preparing their fins for upstream swimming! You will notice a new development to the sac fry, tiny stripes and spots are forming on their sides! These are called parr marks. A parr mark is a dark, vertical stripe on the salmon’s side that camouflage them and help them hide from predators like birds and larger fish. As the fish grow bigger, their parr marks will be more visible. Each species of salmon has different markings as fry. These markings not only help keep them safe, they also help scientists and people fishing identify what type of salmon they are! The parr marks on Chinook are oval shaped, sit evenly across the fishes’ center, and are widely spaced.