|
|
In
spring, when inshore waters reach about 60°F, largemouth bass swim onto spawning
grounds in shallow bays, backwaters, channels and other areas protected from prevailing
winds. Spawning grounds usually have firm bottoms of sand, gravel, mud or rock.
The sticky eggs adhere to bottom and the roots of plants. Bass seldom nest on
a thick layer of silt. Some spawning areas are in open water; others have sparse
weeds, boulders or logs.
Male bass may spend several days selecting their
nest sites. The beds are usually in 1 to 4 feet of water, but may be deeper in
clear water. Most largemouths nest in pockets in bulrushes, water lilies or other
weeds. Bass in open areas often select a site on the sunny side of a submerged
log or large rock. The males seldom nest where they can see another nesting male.
For this reason, beds are generally at least 30 feet apart, but may be closer
if weeds, boulders, sunken logs or stumps prevent the males from seeing each other.
Largemouths spawn when the water reaches 63° to 68°F and temperatures remain
within this range for several days. Cold fronts may cause water temperatures to
drop, which interrupts and delays spawning.
Preparing the nest, the male
largemouth shakes its head and tail to sweep away bottom debris. The typical nest
is a saucer-shaped depression about 2 to 3 feet in diameter, or twice the length
of the male.
Spawning occurs as the male and female move over the nest
with their vents close together. The male bumps and nips the female, stimulating
her to deposit the eggs. Then the male covers the eggs with his sperm, or milt.
A female bass lays from 2,000 to 7,000 eggs per pound of body weight. She
may deposit all of her eggs in one nest or drop them at several different sites
before leaving the spawning grounds. After spawning, the female recuperates in
deep water, where she does not eat for 2 to 3 weeks.
Alone on the nest,
the male hovers above the eggs, slowly fanning them to keep off silt and debris
and to circulate oxygen-rich water over the eggs. He does not eat while guarding
the eggs, but will attack other fish that swim near the nest. The male will not
attack slow-moving objects, such as a crayfish or even a plastic worm. Instead,
he gently picks up the object and drops it outside the nest.
Sunfish
often prey on bass eggs or newly hatched fry. In waters with large sunfish
populations, the panfish can seriously hamper bass reproduction. A school of sunfish
surrounds a nest, and while the male chases some away, others invade the nest
and devour the eggs or fry.
Bass eggs hatch in only 2 days at 72°F, but
take 5 days at 67°F. Cold weather following spawning will delay hatching. If the
shallows drop to 50°F, the fry will not emerge for 13 days. At lower temperatures,
the eggs fail to develop. A severe cold front sometimes causes males to abandon
the nest, resulting in a complete loss of eggs or fry. From 2,000 to 12,000 eggs
hatch from the typical nest. Of these, only five to ten are likely to survive
to reach 10 inches in length.
Basic Features
of Spawning Sites
|
|
|
Firm
bottoms make the best nest sites. Bass can easily sweep away light silt. The sticky
eggs adhere to bottom and the roots of plants. The male fans over the nest constantly
to circulate oxygen-rich water over the eggs.
|
|
|
Cover
such as weeds, stumps, logs and rocks provides extra protection for the eggs and
fry. Bass that build their nests next to these objects have less area to guard
against sunfish and other predators.
How Largemouth Bass
|
|
|
|
Preparing
the nest, the male largemouth shakes its head and tail to sweep away bottom debris.
The typical nest is a saucer-shaped depression about 2 to 3 feet in diamater,
or twice the length of the male.
|
Spawning
occurs as the male and female move over the nest with their vents close together.
The male bumps and nips the female, stimulating her to deposit the eggs. Then
the male covers the eggs with his sperm or milt.
|
|
|
| After
hatching, the tiny fry lie in the nest for 8 to 10 days. Once they are able to
swim, the fry remain in a compact school, hovering beneath weeds or other overhead
cover. As the fry grow larger, they spread over a wider area, but the male still
protects them. The male abandons they fry when they reach about 1 inch in length.
After that, he may eat any fry he encounters. |
|
