Fish
Bass
Micropterus, Morone, and others · also called black bass, sea bass
“Bass” is one of the least precise names in the fish world. It has been attached, over centuries, to dozens of unrelated spiny-finned predators on several continents, from the largemouth bass in a farm pond to the striped bass running up a tidal river to the “Chilean sea bass” on a restaurant menu, which is really a Southern Ocean toothfish. What the fish share is a shape and a way of life, not an ancestor.
Overview
Bass is a common name, not a scientific group. The main fish it refers to are the black basses (largemouth, smallmouth, and spotted bass), which are actually large members of the sunfish family; the temperate basses such as the striped bass and European sea bass; and the true sea basses and groupers. All are carnivores that take prey with a fast lunge and a large sucking mouth.
The largemouth’s outsized role
The largemouth bass is the most sought-after freshwater sport fish in North America, at the centre of a recreational fishery worth many billions a year and a professional tournament circuit, and it has been stocked into warm waters worldwide. Heavily fished bass learn to avoid lures, a wariness that fishing pressure appears to select for.
Breeding and migration
In the black basses the male builds and guards a nest, fanning the eggs and fry for weeks. The striped bass is anadromous, living in coastal seas and running into fresh water to spawn, its drifting eggs needing a long river to stay suspended.
A bass that emptied a lake
The Nile perch, sold as bass, was introduced to Lake Victoria and, as it boomed in the 1980s, was a major factor in the loss of several hundred endemic cichlid species — while building a large export fishery.
Status
Bass as a whole is Not Evaluated because it is not one group. The largemouth is abundant; striped bass recovered from a 1980s collapse and now fluctuates; several grouper and sea bass stocks are overfished; the giant sea bass is Critically Endangered but slowly recovering.
Bass: common questions
Are all fish called bass related?
No, and this is the key thing to understand about the name. Bass is an old English word, originally the same as barse, applied over centuries to any number of medium-sized, spiny-finned, predatory food fish with no regard for their actual relationships. The largemouth and smallmouth bass of North America are really large members of the sunfish family. The striped bass and European sea bass belong to the temperate bass family. The many groupers and sea basses are yet another family. The Chilean sea bass is a Southern Ocean toothfish that was renamed for marketing. So the fish share a body type and a lifestyle, not a common ancestor.
What is the difference between largemouth and smallmouth bass?
They are close relatives, both North American black basses in the genus Micropterus, but they differ in look and habitat. In the largemouth, the corner of the mouth extends back past the eye, and the fish has a broad dark horizontal stripe along the side; it prefers warm, weedy, still or slow water such as ponds, lake margins, and backwaters. In the smallmouth, the mouth ends under the eye, the body is browner or bronze with vertical bars, and it favours cooler, clearer, rockier water with current, such as stony lakes and rivers. Smallmouth are generally considered the harder fighters for their size.
Why is the largemouth bass such a popular sport fish?
Several things line up. It is widespread and adaptable, thriving in farm ponds, reservoirs, and natural lakes across a huge climate range, so it is available to tens of millions of anglers close to home. It grows to a satisfying size, one to five kilograms commonly and up to about ten, and it strikes lures aggressively and fights hard near the surface with jumps and runs. It can be caught on a great variety of methods and lures, which supports a large tackle industry, and it is the focus of a professional tournament circuit. A strong catch-and-release ethic means the same fish supports many anglers over its life.
How did the Nile perch damage Lake Victoria?
The Nile perch, a large predatory fish often sold as bass or perch, was deliberately introduced to Lake Victoria in East Africa in the 1950s and 1960s to create a commercial fishery. It remained scarce for years, then its population exploded in the 1980s. As a voracious predator reaching well over a metre, it preyed heavily on the lake's extraordinary flock of endemic cichlid fishes, several hundred species found nowhere else, and combined with pollution, nutrient enrichment, and overfishing it contributed to the disappearance or severe decline of a large fraction of them, one of the most dramatic vertebrate extinction events of modern times. The perch did build a major export industry, with mixed social and economic effects.