Live in Idaho Waters (Part 2): Everybody Loves a Sucker

In our first installment of “Live in Idaho Waters” we talked about the diminutive and camouflaged sculpin. The next group of Idaho native non-game fish get bigger and are easier to observe—the suckers. 

These native species are often misunderstood and sometimes disliked; but their appreciation is increasing amongst anglers and the public. We have six native species in Idaho: the bridgelip, largescale, mountain, longnose, green, and Utah suckers. 

Native suckers are found in all of our major watersheds. If you’re fishing a decent size stream or river (and many lakes), there’s a pretty good chance you’re fishing sucker water. But, different species are found in different parts of the state. For instance, sucker species are different above and below Shoshone Falls on the Snake River.

Basic Life History

Like quite a few of our native species, suckers are springtime spawners. Some species make spawning runs similar to our native trout and move impressive distances from larger mainstem rivers into spawning tributaries in the spring and early summer as water warms. We also have some species which spawn in shallow waters in lakes. Female suckers can deposit a lot of eggs when they spawn, often in the tens of thousands. In a number of instances male suckers get bright red or orange coloration during spawning and are really quite pretty!

Juvenile and adult suckers often feed on algae or something called detritus (i.e. other stuff on the bottom) of the waters they live in. They are setup to do this given that their mouth faces the stream bottom instead of straight ahead like a trout. But, that’s not the only thing they eat. Most sucker species also eat aquatic bugs like mayflies and caddis flies, small aquatic organisms called zooplankton, and terrestrial bugs like beetles and ants. A few species have had fish eggs found in their stomachs, but it doesn’t appear to be a main food item.

Depending on the species, suckers can get old and large compared to other native non-game species. Most Idaho sucker species can reach ages of 9-12, but occurrences of older individuals have been reported for some species, even over 20 years. 

As for size, here again there is a fair amount of variation by species, but some can get pretty dang large. The current angling certified-weight record for largescale sucker in Idaho comes in at an impressive 9.04 pounds and 27 inches!

Why We Care

Similar to other native non-game species in Idaho, suckers serve an important role in our aquatic ecosystems. They are a valuable food source for larger predatory fish, birds, and mammals, and all those eggs they produce when they spawn are another potential food source for other parts of the ecosystem. 

Once suckers are hatched and swimming around, they serve a unique role by ‘converting’ plants and algae over to protein that can be used by other parts of the food web. Not many other native fish species serve in this role. Because of this and the similarity of mouth shape, native suckers can sometimes be grouped in with non-native species like common carp that have a similar diet and feed near the bottom. 

This is an unfair comparison, since even though native suckers have a similar diet and some can live in harsh water conditions, none of them prefer it, and they don’t actively churn up stream and lake sediments like some non-natives. 

In reality, a healthy sucker population is more an indication of a healthy stream or lake, not the opposite. There is no doubt that sometimes suckers can become so numerous they cause aquatic environments (most often lakes) to become out of balance. In those instances, Fish and Game will try management techniques to reduce their abundance and improve conditions for species more highly valued by anglers. But overwhelmingly, suckers are good to have around, and improve the function of our aquatic communities providing various benefits to our game fish species.

Given their diet, suckers are not encountered by anglers on a regular basis unless you’re really trying to catch one. That being said, you will absolutely catch them in some places and using certain techniques. A nightcrawler fished along the stream or lake bottom can get you a sucker, but they can also be caught on lures and flies, especially species with more diverse diets like the largescale sucker. 

If you do happen upon one next time you’re out, know that you’re handling an Idaho native species since all our suckers are native, and please don’t throw it up on the bank. Instead, consider keeping one and giving it a try (while they are bony, they are a food fish in parts of the country, and you can find recipes for cooking, smoking, and canning online) or enjoy a unique catch and release it to keep serving its’ role in the ecosystem.