Overview
The Quillback (Carpiodes cyprinus), often called the Quillback Carpsucker, is a widespread North American freshwater fish in the sucker family Catostomidae. Easily recognized by the dramatic, elongated anterior ray of its dorsal fin that projects high above its back like a quill pen, this gleaming silver fish is an industrious benthic feeder of slow-moving river pools and large lakes.
Biology and Physical Characteristics
The Quillback is a deep-bodied, laterally compressed fish with a high, arched back and shimmering silvery-bronze to olive-gold scales. Its most diagnostic characteristic is the first several rays of its dorsal fin, particularly the first branched ray, which is greatly elongated into a slender quill that often extends halfway or more down the length of the fin base. Its mouth is small, ventral, and toothless, with thin, smooth lips specialized for delicate bottom feeding.
Behavior and Ecology
Quillbacks congregate in moderate schools over sandy, silty, or organic river bottoms, swimming with their heads tilted downward to sift through the top layer of substrate. They filter out bloodworms (chironomids), fingernail clams, copepods, and detritus while expelling non-nutritive sediment through their gill slits. Spawning occurs in late spring when schools move into shallow sandbars and tributary gravel shallows to deposit adhesive eggs.
Conservation and Human Impact
The Quillback is categorized as Least Concern by the IUCN, boasting extensive distribution and abundant numbers across the eastern and central United States and Canada. Siltation from agricultural runoff and pollution occasionally impact delicate benthic insect communities, but the species shows high general resilience.
Interesting Factoid
The long, feather-like fin spine that gives the Quillback its name can grow so tall that when the fish feeds in shallow river shallows, the quill cuts the water surface like a miniature sail.