Life History of a Fish: Largemouth Bass

by Scotty Kyle

Americans probably know more about me than any other fish, freshwater or marine. I am a prime “sport” angling species with perhaps more fanatical followers than any other American fish. There is a very large “industry” built around my species and a lot of money is being spent annually on trying to outwit my kind. There are TV series, massive prize tournaments, extremely specialised boats and motors, every kind of lure and bait you can imagine, plus some others beyond imagination, all aimed at helping humans to outwit me. Yet, despite all this effort and expense, I remain abundant and continue to spread through all the continents, except Antarctica, where it is far too cold for us. I am the largemouth bass.

Some people write songs and poems about us, others curse the day my species was brought to their shores. Most North American anglers were raised, or introduced to, fishing for largemouth bass, and, because it is such fun and yet very complex, they remain “hooked” on angling. I have heard it said that more people go bass fishing than to football or baseball. I, however, also stand accused of “causing declines, displacement or extinction” of indigenous species of fish, amphibians, invertebrates and even a species of South American birds, the Lake Atitlan grebe. My presence has substantial impacts on local environments, economies and biodiversity, so no wonder people pay attention to my species wherever I am found. 

Like me or hate me, I am an amazing species. I evolved in the lakes and rivers of the middle and eastern states of the USA with outlying populations in southeastern Canada and northern Mexico.  I evolved to be among the fish species most tolerant of poorer water quality (poorer than trout can tolerate) and can even live in estuaries with up to about 13 parts/thousand of salt. I can thrive in warm waters and, as long as at some time of the year temperatures rise to allow my species to spawn, I can also tolerate cooler areas. In many waters I am the “apex” predator and, in many others although some species may predate on me, I breed so well and feed so voraciously that I dominate the underwater community.

A largemouth bass about to strike a soft lure
A largemouth bass about to strike a soft lure

Who are you, largemouth bass?

I am not the biggest freshwater fish around and can only attain about 11.4 kg. (29 lbs) mass and a length of 75 cm. (29.5 in.), but I have my secret weapons. Unlike many fish, we can adapt to local circumstances, either environmental or biological. We can avoid cold water by going deeper in winter and we can change to new food sources dependent on what is locally abundant.  I can live from about 10 to 16 years and can spawn multiple times within my first year. My colours, mostly greenish, greyish, or yellow on the upper body with a ragged blotched black line down my flanks and a pale belly, allow me to blend into weedy and rocky backgrounds and be an efficient and deadly ambush predator. 

I can feed on almost anything that moves – plus some things that don’t. As juveniles we feed on the abundant invertebrates such as daphnia, copepods, crunchy scuds and gooey worms plus tiny fish. As we grow, we expand our diet to include things like crawfish and crabs, frogs and salamanders, many kinds of fish plus the occasional mice, snakes or anything that looks potentially edible or interesting and, in fact, almost anything that we think can fit into our mouths. 

It is this adaptability that causes us to be such a “difficult” and impactful species as we can often avoid, or circumvent, potentially challenging temperatures/conditions and find and exploit new foods. Not only can we survive and breed in a diverse range of wetland conditions but, once we have established ourselves, it is very difficult to remove all of us should negative impacts on the environment or local species become evident. We are very good at spreading ourselves upstream and downstream from new introductions plus, during extreme flooding events, we can often go and establish wherever the floodwaters take us. As well as this ability to spread “naturally”, there are many instances all over the world where a few or even one bass enthusiast has taken a “bucket” of small bass to a waterbody and begun a new population. 

A male largemouth bass near its nest
Male largemouth bass build nests for the female to lay eggs in, and defend them from predators.

Why are largemouth bass so successful in reproduction? 

Our breeding behaviour is quite involved and very successful, involving mostly the male fish. In early spring, in the warmer areas and later spring in the cooler areas, males begin to create “nests” in the substrate using mostly their tail fins. The nest is roughly circular and about twice the fish’s length in diameter and usually made in sand or soft substrate, but weedy areas also work for us. Males will then swim up to females cruising the area and, using mechanisms best known to themselves, entice the female to the nest. Both will then circle the nest with their lower abdomens tilted towards the nest and, as the female extrudes eggs the male will squirt out milt or sperm to fertilise them. The female’s part is now complete and she will move off and may spawn again with one or possibly two other males. 

The male will then “guard” the eggs until they hatch, which may take as little as two days or quite a bit longer in cold conditions. Once the eggs hatch, the male will “hover” around the nest protecting the young and attacking any apparent predator. Inconsiderate humans know of this and will search out our nests and cast dangerous looking baits towards them. Fortunately, if the fish is caught and released, he will often go back to continue protecting his offspring. 

A largemouth bass released
Practicing catch-and-release is especially important for such a long-living fish as largemouth bass.

Do largemouth bass fisheries require management?

With regard to humans fishing for us, there have been some improvements recently but there’s lots of potential to get a lot better. Not too long ago almost all bass caught were killed without thought for the fish or future fishing. With a potential lifespan of 16 years there’s an excellent chance for a 5 year old fish, caught and released, to be caught again, possibly repeatedly and for it to spawn and live a long life. Many waters are now “catch and release” and, with a little care, there’s an excellent chance of a carefully and rapidly handled and released fish to survive. 

While there are still many areas where “wild, natural” bass may be caught, most are now caught in places with some degree of fisheries management or control. However, unlike many trout species, which have to be bred and reared in “hatcheries” and carefully introduced in thoroughly calculated numbers and sizes, we largemouth bass are mostly capable of looking after ourselves. Some manipulations, for example introduction of “bait fish”, such as bluegill, or bait organisms, such as various invertebrates, to try and improve the bass fishing may be made. However, we are usually so prolific and can eat such a variety of foods that any manipulation is either unnecessary or ineffective.

Often, the purpose of such manipulations s to try and reduce numbers of small fish, in order to increase the numbers of large specimens.  Many bass fisheries are traditionally unstable in that, after a period, we either increase markedly in abundance with our average size decreasing, or our numbers decline, but the mean size increases. People try and interfere with this, but this kind of cycle is natural. In new dams or places where we are introduced our numbers and sizes can vary markedly for some years, but then may settle down into some kind of pattern and become fairly stable. Some areas will consistently produce “trophy” bass, while others almost never do this and people can spend a lot of time, energy and money trying to “improve” bass waters.

Spinning is perhaps the most efficient technique to catch a largemouth bass

How to catch a largemouth bass?

In terms of angling, people use almost any method, depending on their preferences and resources to catch us. We are routinely caught, with light to medium spinning gear, on a stunning variety of artificial lures plus live or dead bait of many different types. Some use small lures while others go overboard with huge monster baits. Some are soft, flaccid jellies while others are hard, shiny metal lures that spin, and wobble. Some recently developed lures clunk, rattle or emit any number of weird and wonderful sounds. 

Fly fishing has gained popularity  in recent years, also using an incredible diversity of “flies” from the conservative traditional patterns to the weird and wonderful and these can also, amazingly, be successful. The reality is that we have enormous appetites when conditions are right and we use all our senses, such as sight, smell, hearing and sensing vibrations, to find prey. We also eat things speculatively, just to see if they are indeed edible. 

As a species we are caught by anything from the youngest, beginner angler, right up to the highly paid professional bass angler. The first fish that many anglers caught is probably a bass and it is well known that, more than most species, the most untrained, uninformed, ill-equipped, but “lucky” angler can catch a very large bass. 

A hooked largemouth bass tries to go away
Largemouth bass can get rid of the lure in a number of ways, including delving into structures and jumping out of water.

When is the best time for largemouth bass fishing?

The best times to catch bass vary with location, altitude, water conditions, presence of structure and other parameters unknown to mortals. Even in ideal-looking conditions we can suddenly stop feeding or almost go into a feeding frenzy. Generally, with our large eyes, we feed mostly during the day and we are regarded as a “warm water” species. Where we are found in temperate to cool areas, the period of the year in which we can be routinely caught is fairly small and may also be limited to the warmer times within a day. Overall, summer is the most consistent time for bass fishing, but in warmer areas, we can be caught all year round. In really warm conditions mornings and evenings are usually best for catching my species. 

During winter we are usually fairly quiet but, as temperatures warm, this is the time of year many bass anglers relish most. We move a lot and are very active in looking for food. We usually spawn in fall and this opens up opportunities for bass fishers. When males defend their nests, often located in the shallows, they are easy to notice. At the same time both sexes have to eat fairly voraciously to build up resources to produce sperm or eggs, build nests, and seek mates . Once we have spawned, we again need to feed to rebuild condition and then again, towards winter, we need to prepare for lower food availability.

A trophy 12-pound largemouth bass

Why are anglers so excited about largemouth bass?

Some recreational anglers do not like us due to our impacts on other species, such as by predating on young trout, walleye or even pike, but many more simply love bass fishing. We have a well-earned reputation for being good and exciting fighters when hooked. We really do not want to be landed and do everything within our power to prevent or avoid this. We can leap high out of the water and also poke our heads out of the water and shake vigorously to try and dislodge hooks. We are very often found near structures like trees, rocks or weeds and, after taking a bait, we often head straight for them and entangle people’s lines.  

In conclusion, we the largemouth bass are a wonderful asset, in terms of fishing, generally need little management and can be caught with the simplest, or most carefully designed, equipment and occasionally by the least experienced angler. We are widespread in our distribution, often abundant, fairly fast growing and can eat an amazing variety of foods. All in all, the fishing world would be much poorer without us and, as an angling species, we deserve and often get, a lot of respect. The fondest memories of many anglers, particularly in the USA, are of the capture, or loss, of a particularly big largemouth bass. 

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