Suckers Don’t Suck-Suckers are a variety of benthic, or bottom-dwelling fish in the family Catostomidae. They are called suckers because their mouths are on the bottom of their faces, and they have big, fleshy lips to help them suck up food from stream beds. Suckers are a true North American native—all but two species of Catostomids are found exclusively in North America. Some examples of common suckers are White Suckers, Longnose Suckers, Silver Redhorses, and Quillbacks.
These fish are often referred to colloquially as bush fish, or garbage fish, as they are thought to be undesirable and harmful—but that could not be farther from the truth. All fish have their purpose in an ecosystem, and suckers are no different. They are the janitors of the river, keeping the system clean by eating decomposing organic matter—like dead fish and plants—that would otherwise foul up the water. Additionally, their abundance makes them a key food source for sportfish like trout and pike, especially as medium and large forage fish, as suckers can get quite large themselves; the bigger species can grow over 1 meter long!
Suckers are also a common food source for terrestrial animals. They are migratory spawners, just like trout and other Salmonids, and make their spawning runs up rivers in late spring. These runs are especially important for lake sucker species; since they spend all their time at the bottom of the lakes, they are generally inaccessible to terrestrial animals, but when they run up rivers and streams to spawn, they become an abundant resource for the terrestrial world. These big spawning fish are a nutritious meal for bears, who are fresh out of hibernation and hungry for meat, as well as other piscivores, like osprey, fishers, and otters. Their eggs are also a rich meal for other fish, from minnows to trout to sturgeon.
Suckers also offer many recreational activities for humans. They can be fun angling, as the bigger Catostomids especially can put up quite a fight on the line. They are good eating, with big, fat fillets that supposedly taste a little sweet. During dawn and dusk, you can often find young suckers foraging in river pools, swimming deliberately along the river bed, their pale bellies flashing in the sunlight when they twist and flick their bodies under rocks to dislodge their invertebrate prey. When they make their spawning runs, some suckers will get a bright red or orange stripe across their body, and they will run upstream by the hundreds. As suckers are extremely tolerant of human activity and pollution, some of these runs even occur in urban waterways, like the Longnose Sucker run in Whitemud Creek, Edmonton, AB. Watching these spawning runs can be a fun activity for the whole family; if you’re lucky, you may even be able to see ospreys and eagles fishing for suckers during the run!
Generally, suckers are a hardy, adaptable group of fish. However, some Catostomid species are in decline. The Bigmouth Buffalo (Ictiobus cyprinellus) is the largest and longest-lived North American sucker—the biggest fish caught was 126 cm long and 76 pounds, and they can live to be over 110 years old, making them the oldest freshwater teleost (a group of fish with over 12,000 species). These suckers can also take over 10 years to reach maturity, and they do not always spawn every year, sometimes waiting up to a decade between spawning events. Unfortunately, these combined life history traits make them extremely sensitive to any rapid changes. As a result, their population has been declining throughout Canada, and they are officially recognized as a species of special concern. The biggest threats that the Bigmouth Buffalo face are reduced access to spawning habitat, competition with the invasive common carp, and a general lack of knowledge and awareness about their existence. So few people know about the Bigmouth Buffalo that anglers often confuse them with invasive carp, and mistakenly kill them.
Another sucker at risk is the Plains Sucker (Pantosteus jordani). In contrast to the Bigmouth Buffalo, these little fish are the smallest North American sucker, averaging around 16 cm in length, and only living to 7-9 years old. Despite their short lifespan, some individuals may take up to 5 years to mature. There are only a few populations of Plains suckers in Canada, and they are all restricted to cool, clear streams in the Great Plains—a habitat that has become increasingly fragmented and disturbed by human activities. Due to their small area of occurrence, fragmented habitat, and habitat degradation caused by flow augmentation, the Missouri Drainage populations of Plains Sucker in Alberta and Saskatchewan were assigned a designation of Threatened by COSEWIC in 2010. Flow augmentation is utilized widely in southern Alberta and Saskatchewan, where there is a lot of agriculture. Water is held back in reservoirs throughout the year, then released into the river during the growing season to bolster water availability for crop irrigation. However, this massive influx of water drastically increases the flow and temperature of the river and drags a lot of sediment from eroding banks into the water column. This is the exact opposite of the cool, clear streams that the Plains Suckers need, and as such, they have been in decline.
So next time you see a sucker, or catch one, or even think about one, remember: suckers don’t suck! They are cool little (or big!) fish in their own right, and they face their own unique challenges. Our aquatic ecosystems simply would not be the same without them.