Brook Trout Eggs Arrive, Brown Trout Develop into Alevins

Brown trout eggs were delivered to classrooms across the Cayuga and Seneca Lake watershed mid-October, marking the kickoff of DCL’s 2023 Trout in the Classroom Program. Throughout the school year, elementary school students will raise trout in tanks inside their classrooms, observing different phases of the trout’s life cycle through interactive experiments. By Spring, when trout develop into the Fingerling stage, students will release their trout into streams and creeks around Seneca and Cayuga Lake, where they will continue to grow and make their way into the lake where trout can live in the adult phase for 9-10 years.

Brown trout eggs were distributed to classrooms ranging from Watkins Glen to Union Springs and as far south as Newfield, NY. As the eyes were clearly visible in the trout eggs upon receiving them from the DEC Hatchery in Bath, NY, it was expected for the eggs to hatch any day. Classrooms reported within days of the eggs arrival, Alevins began appearing as trout started growing outside their yolk sack, still connected to their bellies. The Alevin stage lasts for 3-4 weeks, as trout take on more of a tadpole-like appearance with large heads connected to a tail. At this stage, they are still feeding from their yolk sack as they grow and develop their gills, fin and their digestive system. When the yolk sack is fully absorbed, trout move into the Fry stage where they start swimming to the surface to look for food. 

At the hatchery where the trout eggs were collected, the process of harvesting eggs simulates what is natural occurring outdoors. Female fish full of eggs are put under anesthesia before the eggs are stroked from their belly. Sperm is then taken from the male trout and combined with the eggs and finally water is added to activate the fertilization process. 

This mimics what is happening in nature, as male and female trout will make their way to a streams for the spawning process, where they build a nest, or a “redd” in shallow water with medium-sized rocks sufficient for moving around to protect the 500-1,000 eggs laid by the female. Males will then step in to fertilize the eggs during the process. 

Last week, DCL gathered brook trout eggs from the SUNY Morrisville Hatchery and delivered those eggs to the remainder of 25 schools hosting aquariums for the Trout in the Classroom Program. We will be working with about 1500 students and 60-plus classrooms this year. To find out more about schools involved with the program, read our latest Trout in the Classroom Blog post.

Eventually, trout will grow to the Fingerling stage, which, as you would guess, is about the size of a finger. This will be the size they reach by Spring time when its time to release the trout into streams, so they can continue to grow in the wild.

Learn more about Discover Cayuga Lake’s Educational Programs and our mission of educating kids and community members the importance of being a mindful citizen within a watershed ecosystem.