What is a Scud?

Long Story Short

While scuds aren’t “bugs” per se, they fall into the same Arthropoda phylum as insects, crayfish, sowbugs, etc. Not surprising, considering Arthropods account for over 75% of all animal species.

According to the University of Wisconsin-Milwaukee, there are approximately 150 species of freshwater scuds in North America. Scuds stay near the bottom of cool, well-oxygenated bodies of water. Some research even suggests scud size is related to the availability of oxygen. Meaning the more oxygenated a fishery is, the bigger the resident scuds can grow.

Scuds are know to be good swimmers and will move about frequently. They love to inhabit thick underwater vegetation or decaying leaves lying on the bottoms of rivers or lakes. Some scuds can grow to over an inch long, but are usually much shorter than half an inch.

Why Scuds Matter for Anglers

These freshwater shrimp are a major food source for trout in tailwaters and stillwater.

According to UWM, in the Western lakes where scuds were introduced, they account for almost 50% of a trout’s diet! Understandable, considering a female scud has the potential to produce over 24,000 offspring in a single year.

Scuds are a soft-shelled, protein-packed delicacy for trout. These freshwater shrimp are key to fish packing on major size, especially in smaller lakes where baitfish populations can be lacking. Due to the sheer abundance of scuds in North American fisheries (especially out West), you'd be crazy not to add a few to your boxes. It might just be the slumpbuster you’ve been looking for!

Scud Colors 101

In a entomology article from Blue Quill Angler, we learn that scuds are found in a wide variety of colors. The palette includes black, tan, brown, green, cream and white, out of which the tan and green are most common.

In our experience, the most effective colors for scud patterns have been orange, pink, or green.

The green, because it is the most frequently found color of live scud. South Platte authority Pat Dorsey says 99% of the scuds he finds in seine samples are gray-olive. Turn over any given rock (especially in vegetation-dense areas) in places like Waterton Canyon or Deckers of the South Platte River and you’ll likely find a dull green scud wriggling around. Or hit the upper Colorado river during high water; you’ll find olive scuds up to 3/4”!

The pink, because it has been the most productive for our team. The color seems to work best in alpine lakes, creeks, and freestone rivers. Not totally sure why, considering we’ve never actually seen a pink scud.

And the orange, because of advice from guys who have fished the South Platte for years and years, like Dakota Wentworth and Ben Baxter. Based on their knowledge, the incorporation of orange scuds into our arsenal has been a game changer on Colorado tailwaters like the South Platte, the Blue, and the Arkansas below Pueblo.

If you needed more than our anecdotal evidence on the efficacy of orange scuds, read the following excerpt from an article penned by the South Platte wizard Pat Dorsey:

“Orange scuds are important too. Tailwaters with substantial flow variations due to hydroelectric power generation leave scuds stranded along the streambed when the river drops. The scuds turn orange quickly after they die, and then get knocked loose when the flow rises again, creating a feeding frenzy. This occurs on most tailwaters where flow fluctuations occur.”
— Pat Dorsey, Crustaceans and Their Limitations

Match the Hatch

While scuds aren’t a traditional “hatch” like mayflies or caddis, being able to imitate the resident population (both living and dead) is still just as crucial for putting fish in the net.

Here’s a list of the scud patterns and colors we try to keep on hand at all time.

  • Bighorn Shrimp (#12-#14, Orange OR Pink)

  • Dorsey’s UV Scud (#14-#16, Olive OR Orange)

  • Softex Scud (#14-#18, Gray, Pink, OR Orange)

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