Egg Sizes Versus Fish Species

The smallest egg sizes we find in most any river or lake are usually in the 1 to 2 mm size for the many sucker species, whitefish, crayfish, and frog egg sizes. Yes, brown trout, steelhead trout, rainbow trout, brook trout, and cutthroat trout will eat eggs of all these mentioned! When I mention to fishermen crayfish, suckers, whitefish and frog eggs they look at me in dismay, but after considering the thought for a moment, they understand the many other sources of eggs than just trout and salmon eggs! We have introduced our small 2 x 2 mm "Soft Sucker Spawn"© OS-3 pattern eggs to exactly mimic these small eggs mentioned. Also, many of these small types of eggs have a tendency to stick and adhere together after they are expelled by the female; hence, you can find small "clusters" or" batches" of eggs in a small mass. This is especially true for the many species in the sucker families. Using our small 2 x 2 mm "Soft Sucker Spawn"© eggs lets you amass these tiny eggs in a group or "batch" to exactly mimic the real thing! I typically tie up 10 and 12 of these small eggs to form a globule of eggs.

Most trout eggs range in the 3.5 mm to 4.5 mm diameters, with the larger diameters on larger trout. For example, a foot long trout and up to at least 20 inches will usually have an egg size of approximately 3.5 up to 4 mm in diameter. Then larger trout will go up to the 4.5 mm size. For those size ranges, we offer the 4 mm egg size which fits all these fish size ranges for the trout species.

Moving up in size of trout, say from the mid 20 to mid 30 inch size range, you will find the actual egg sizes of approximately 6 mm to fit the diameter of these large rainbow trout, brown trout, cutthroat trout, and in this same size range you will also find the Steelhead ( Lake or Ocean run rainbow trout). Salmon species in this range include Sockeye salmon, Pink salmon, Dolly Varden, and Arctic Char. Most all these large fish will have an egg size in the 6 mm diameter range; hence we produce the 6 mm Otter's "Soft Milking Egg"© in that size egg. I have caught many steelhead hens up to 19 pounds whose eggs are still in this 6 mm size.

As you move further up in size of fish, from the very large steelhead up into the larger salmon, such as the King Salmon, you will find their eggs to be in the 8 mm size range. Remember, these large steelhead range up to 35# and the King salmon get into the 30 to 60 # class quite frequently, so these eggs are very large compared to smaller trout. The smaller salmon species, such as the Coho salmon, Sockeye salmon, Pink salmon, Arctic Char, Grayling, Dolly Varden, smaller Lake Trout and Chum salmon will have egg sizes that are best matched by our large trout/steelhead egg in the 6 mm size.

Although these sizes mentioned above are the normal ranges for those species and sizes of fish, remember that even small trout will aggressively eat and devour all sizes of eggs; from small sucker spawn eggs up to large 8 mm salmon sized eggs, and even our 10 mm size egg. I have caught many small trout, in the 6 to 10 inch range, on our larger 3 x 6 mm three egg clusters, and on 8 and 10 mm single egg size patterns! Size really matters!

Fish biologists have observed that fish actively prey and devour all sizes of eggs and according to them, eggs have the highest amount of protein, by volume, compared to any other stream/lake food. For that reason, you should consider fish eggs one of the most primary and sought after foods that are available in the water to all trout and salmon species. Fish love them, see them all the time, and will actively take them all year long.

Using this data to produce a fish size versus actual egg size chart, you would have the following:

Actual Egg Size, mm: 2 x 2mm Soft Sucker Spawn 3 mm 4 mm 6 mm 3 x 6 mm Cluster 8 mm 10 mm
Suckers, Whitefish, Crayfish, Frogs X X          
Small trout   X X        
Medium trout     X        
Large trout & Steelhead       X X    
Medium Salmon       X X    
Large Salmon           X X

Introduction to Basic Data on Fish Eggs | Timing to Use Our Egg Patterns | Color Ranges of Eggs | Structure of Fish Eggs | Our New "Dead Egg White" Color | Recommendations on Hook Styles and Manufacturers | Why Otter's "Soft Milking Egg"© patterns Work So Well

For more information, contact:
Blue River Designs, LLC
6977 S. Madison Way
Centennial, CO 80122

All "Soft Milking Egg"® patterns are registered trademarks of Blue River Designs, LLC.
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