Fish Families
Members of this sunfish family—like bluegill and pumpkinseed—show off fused dorsal fins and ctenoid scales.
What is Centrarchidae?
Most modern bony fishes sport this nearly symmetrical tail type.
What is a homocercal tail?
Suspended mesh walls that catch fish by their gills or body give this classic passive gear its name.
What are gillnets?
This jawless Great Lakes invader uses a suction-cup mouth and rasping tongue to parasitize fish.
What is the sea lamprey?
These calcium carbonate “ear stones” record daily growth and help age fish.
What are otoliths?
Brook trout, lake trout, and Atlantic salmon all swim under this adipose-fin-bearing family banner.
What is Salmonidae?
Pelvic fins that sit beneath the pectorals—not behind them—are said to be in this more derived position.
What are thoracic pelvic fins?
This “three-layer sandwich” net, with a fine inner mesh and coarse outer walls, is designed to entangle—not gill—fish.
What are trammel nets?
This silvery clupeid invader—Alosa pseudoharengus—is infamous for its keeled belly of sharp scutes.
What is the alewife?
One of the oldest marking techniques removes part of a fin—simple and cheap, but often temporary.
What is fin clipping?
Carp, shiners, and dace share this family name—and none of them have true teeth in their jaws.
What is Cyprinidae?
Fish that feed at the surface often have this upward-facing mouth orientation.
What is a superior mouth?
Lights, camera, no capture! This passive, noninvasive method uses underwater video to study fish.
What is BRUV (baited remote underwater video)?
From headwaters to lowlands, stream communities change predictably in this well-known ecological framework.
What is the river continuum concept?
This tiny stainless-steel tag must be removed to read—but hatcheries rely on it for marking millions of fish.
What is a coded wire tag?
Burbot is the lone North American freshwater representative of this cod family.
What is Gadidae?
Fish biologists love counting things: these traits include dorsal spines, pectoral rays, and pores.
What are meristic traits?
In the CPUE equation, this coefficient—represented by q—describes how easily fish are caught.
What is the catchability coefficient?
Fast growth, rapid reproduction, broad tolerance, and human introduction define this ecological troublemaker.
What is an invasive species?
Representing an “ideal” population with the same genetic drift as the real one, this value helps gauge genetic health.
What is effective population size?
This tiny family includes the trout-perch, a small spotted fish with an adipose fin and sub-abdominal pelvic fins.
What is Percopsidae?
These derived scales—found on perches and sunfishes—have little comb-like teeth along their edges.
What are ctenoid scales?
Two-pass depletion studies calculate capture probability using this handy equation.
What is (C₁ − C₂) ÷ C₁?
This mussel cousin of zebra mussels has an even broader ecological niche and colonizes deeper waters.
What is the quagga mussel?
Using DNA from shed cells, gametes, and even carcasses, this technique detects species without ever seeing the fish.
What is eDNA analysis?