Why do salmon eggs come in different colors?
Salmon eggs (roe) range in color from pale yellowish-orange to dark reddish-orange. The color varies both by species and within species and is determined by water temperature, sediment composition, age, and other factors. The eggs vary in size from the tiny sockeye roe (average ¼ inch or 5.6 mm) to the large chum roe (average almost ½ inch or 8.3 mm). Also, if a salmon egg does not get fertilized, it can lose its bright hue and turn a milky shade with patches of color.
The red color of eggs comes from carotenoids (antioxidant pigments) that the salmon get from their diet. Salmon deposit carotenoids in both their skin and eggs in preparation for spawning. It protects tissue from oxidative damage and helps regulate immune response. In a spawning adult, the red color is a signal of fitness and status, and is used to attract mates.
Learn more: Questions and Answers about Salmon
Related Content
How do salmon know where their home is when they return from the ocean?
How far do salmon travel?
Why do salmon change color and die after they spawn?
How long do salmon usually live?
When can salmon be seen migrating to their spawning area?
Why are there so few salmon left?
How many species of salmon are there and how large can they get?
Where are salmon most endangered?
Are salmon endangered worldwide?
Community flood protection may also help endangered salmon to thrive
Building a river setback levee to reduce the risk of flood for a community may also help endangered fish species to thrive, according to the results of a novel computer model reported by the U.S. Geological Survey.
Endangered Salmon Population Monitored with eDNA for First Time
CORVALLIS, Ore. — Scientists from the U.S. Geological Survey and Washington State University have discovered that endangered Chinook salmon can be detected accurately from DNA they release into the environment. The results are part of a special issue of the journal Biological Conservation on use of environmental DNA to inform conservation and management of aquatic species.
New Method Monitors Riverbed and Flows to Protect Spawning Salmon
USGS scientists took high-tech sensors typically found in devices such as smart phones and embedded them into a new method to monitor riverbed movements that can help protect spawning habitat for endangered salmon. Developed in cooperation with Seattle Public Utilities for the Cedar River, the new method is published in the Journal of Hydrology.
Removal of Obsolete Forest Roads Can Reduce Erosion and Sediment That Impair Salmon-bearing Streams
Removing abandoned forest roads and restoring the natural characteristics of slopes and stream channels in the Redwood National and State Parks in northern California have substantially reduced the delivery of sediment to salmon-bearing streams, according to a research geologist with the U.S. Geological Survey.
Chinook Salmon
Chinook Salmon. Photograph courtesy of Michael Humling, U.S. Fish and Wildlife Service
An Alaskan Sockeye Salmon. USGS photo gallery. BLM photo.
Pacific Herring Eggs on Macrophytes
Naturally-deposited herring eggs attached to submerged macrophytes. Coiled embryos are evident inside the eggs.
Coho salmon
Coho salmon spawning on the Salmon River in northwestern Oregon. This photo was taken during a coho spawning survey conducted by the Bureau of Land Management in November 2014.
Female Pallid Sturgeon
CSRP Biologist Sabrina Davenport holding reproductive feamle pallid sturgeon, PLS11-020.
Fish Eggs in Organic Debris
Ten minutes of larval sampling in the Missouri River on May 24, 2011, resulted in this mass of organic debris and fish eggs.
A Time to Spawn
Salmon and steelhead migrating through Bonnerville Dam.