Fish
Longnose Sucker
Catostomus catostomus · also called longnose suckers
Beneath a thick sheet of ice covering a subarctic lake, a longnose sucker continues foraging slowly along the bottom, one of the most cold-tolerant freshwater fish in North America, still active through a winter that would leave most other fish species dormant or gone entirely.
Overview
The longnose sucker, Catostomus catostomus, is a cold-tolerant bottom-feeding fish native to lakes and rivers across a very broad range of northern North America, extending from Alaska and Canada south into parts of the northern United States. Its extreme cold tolerance, elongated snout, and ability to remain active beneath ice through long winters make it one of the most geographically widespread and physiologically hardy freshwater fish on the continent.
A fish that never really stops for winter
While many freshwater fish become largely dormant in the coldest northern waters, the longnose sucker keeps foraging beneath the ice through months of frozen conditions, a resilience that has let it colonise lakes and rivers few other sucker species can tolerate.
Status
Least Concern — widespread and abundant across suitable lake and river habitat throughout its very broad northern North American range.
Longnose Sucker: common questions
How far north does the longnose sucker live?
This species tolerates colder water than almost any other North American sucker species, found in lakes and rivers well into the Arctic and subarctic regions, giving it one of the broadest natural ranges of any freshwater fish on the continent, extending from the Arctic Circle south into the northern United States.
How does the longnose sucker survive under ice all winter?
This species remains active beneath ice cover during long northern winters, continuing to feed at a reduced pace on bottom-dwelling invertebrates and organic material even when surface water is frozen solid for months at a time, an adaptation that allows it to persist in lakes and rivers many other fish species could not tolerate year-round.
Why is it called the longnose sucker?
This species has a notably long, elongated snout relative to its body compared with several other sucker species, a distinguishing feature reflected directly in its common name and useful for separating it from more short-snouted relatives sharing similar habitat.
What does the longnose sucker eat?
This species feeds on small aquatic invertebrates, algae, and organic debris, using its distinctly downward-facing, sucker-shaped mouth to vacuum food items directly from the bottom of the lakes and rivers it inhabits.