In early to mid-June males of the species congregate in rocky shoreline areas of the lake , vying for clean gravel areas in which to scoop out a nest with their tails. Water temperature determines the precise time of year at which nest building and mating occurs. In Trout Lake, which has cool water at the best of time, mating usually takes place from the middle to late June. The males try and choose a nesting site in one meter of water. They normally make their nest on one side of a large object that is called an initiator. Ideally, the initiator should sit on a gravel bottom. Dirt and sediment is cleaned away by the male (with his tail). Once his nest is completed, he protects it aggressively, even if no eggs are present. He then entices a female into his nest and spawning takes place. Interestingly, the female "lies down" with her side almost touching the gravel. She goes into spasms while releasing her eggs. This induces the male to liberate his sperm. Eggs do not mature in the female all at once. Consequently she may spawn two or three times before being spent. Conversely, males may entice two or three different females into their nest before mating is completed. This maximizes the shuffling of the genes from an evolutionary perspective.

Females, heavy with eggs have a negative boyancy and swim in a "head up" position. This awkward swim we refer to as "tail walking". Once spawning is completed the male jealously guards his nest from all intruders, all the while aerating the eggs with a gentle back and forth motion of his caudal fin. The eggs hatch four to 10 days later (usually closer to 8 days in Trout Lake). At this time the larval bass are jet black, and remain on the bottom of the nest. A week to 10 days later they start rising off the nest and form black larval balls of about a meter in diameter. Few larval balls in Trout Lake number more than a thousand fry, with the average being several hundred. Predators, fungi and unviable eggs all take their toll. This small number of fry is compensated for by the male investing considerable time and energy in parental care.


At this time in their life, the larval bass are plankton eaters and are not aware of their surroundings. This makes them particularly vulnerable to predators and the male is fiercely protective of his brood during this period. About a week after that the larval bass go through metamorphosis after which their body shape changes, their colouring turns light brown to near colourless, their head enlarges and they become aware of their surroundings. Post metamorphosis larval bass are commonly called "bass fry". An incoming predator now sends them scurrying for cover among the rubble or dense weed cover.
As the fry mature, they wander further and further from the nest and the "ball" of fry that the male is trying to protect becomes less well defined and harder to protect. The male now makes larger and larger circles trying to protect his brood. Not having eaten now for some time, the male will actively feed on bottom invertebrates while circling his fry. Eventually the job of protecting the fry becomes impossible as they wander further and further from the nest, and the male returns to deeper water for summer feeding.

Males reach sexual maturity around age 4-5 while females mature around age 5-7. Lifespan, for smallmouth bass, is around 15 years. A number of factors make smallmouth bass particularly vulnerable to over-harvesting. They mature late, and produce few fry (compared to many other species of fish). Because they produce few fry, they invest parental care to protect the small brood. Illegal angling, even catch-and-release angling during the spawning season causes serious harm as predators raid the nest while the male is angled off the nest. In Trout Lake, bass research has shown that smallmouth bass may be being overharvested and the nesting densities may be crashing. Each year we find evidence of illegal angling, even in the fish sanctuaries (like the jig shown in the picture). We encourage you to give the fish a chance to mate and produce their young. We also encourage you to practice Catch-and-Release bass angling and in so doing, help ensure that a quality bass fishery will continue to exist in Trout Lake. If you own shoreline property, you may also want to consider providing suitable habitat for smallmouth bass to, on their own, construct a nest along your shoreline.




Largemouth Bass ( Micropterus salmoides )
This species of bass prefers warmer water than smallmouth bass, usually has faster growth rates and attains a larger size than smallmouth bass. However in Trout Lake, habitat restrcitions usually make the average smallmouth bass somewhat larger, and more plentiful than its largemouth cousin. Largemouth bass are often found in shallow weedy bays, basking under lilypads and the like, while smallmouth prefer open water areas, especially underwater cliffs and ridges.

Spawning begins in the month and June and goes on, sometimes, into August. Peak spawning usually occurs in mid-June. Males build the nest when water temperatures hit 15.5 C (60 F) and spawning usually begins when temperatures reach 16.7 to 18.3 C (62-65 F). In Trout Lake, largemouth bass spawn a little earlier than smallmouth since the shallow bays that they select for spawning purposes usually warm up a little quicker than the rocky shoals used by smallmouth.

Males choose either a sandy/gravel bottom or a sandy/muddy bottom to make their nests, usually in proximity to weedy areas, which will serve as rearing habitat for the fry. Largemouth like shallow areas (about 1 meter or less) in which to make their nests. Contrary to smallmouths, nests are usually separated by at least 10 meters. It is not uncommon to find smallmouth bass nests 3 meters apart. Spawning behaviour in largemouth bass is not unlike that of the smallmouth, with the female laying her eggs in two or three different spawning bursts, usually on different nests. The male jealously guards his clutch of eggs, aerating the eggs with his tail until they hatch four or five days later. The eggs are quite susceptible to attack by fungi (see photo), which often result in substantial egg mortality.Larval largemouth bass are pale to semi-clear in colour whereas the smallmouth larvae are black. About a week later, the larval bass have absorbed their yolk sack and start swimming up off the bottom. At this time they form a larval school. Their coloration slowly darkens to a pale green. Usually due to a lack of hiding spaces, survival is poorer than for their smallmouth counterparts. Avering nesting hatch is around 5000, but fewer than 10 survive to a length of 25 cm.

Males reach sexual maturity at age 3-4, whereas females mature at an age of 4-5. Largemouth bass are rarely angled at depths greater than 6 meters, preferring warm weedy bays. In a lake like Trout Lake, where there are few warm weedy bays, largemouth bass are susceptible to being overharvested. This species is almost alwasys associated with muddy, weedy bottoms, lush with emergent and submergent vegetation, particulary water lilies. Smallmouth and largemouth bass are thought not to compete very much for available food because of their habitat preferences, even if both are found in the same lake. In the winter, largemouth head for deeper water, and remain more active than their smallmouth couterparts, sometimes being caught by winter anglers. One interesting note. Largmouth bass tend to canabilize young of its own species. Stomach analyses sometimes show that up to 10% of contents are comprised of young of the year of their own species.This behaviour, coupled with poor reproductive success and limited habitat in Trout Lake, make largemouth bass vulnerable to overhavest. Lifespan is approximately 15 years. Please practice catch-and-release fishing when angling for bass.

[ Back ]





--------------------------------------------------------------------------------