Geographic Range
Morone chrysops
(white bass) can be seen in many parts of North America. Its range extends from
southern Canada to northeastern Mexico following a path roughly between the Mississippi
River system and the Appalachian Mountains. Notable abundance of the species is located
primarily in the Mississippi, Missouri, and Ohio River drainages. Historically, it
was found only in the Great Lakes and Mississippi River drainages, but it has been
widely introduced outside of these areas.
Habitat
White bass are principally found in large bodies of water (i.e., deep lakes and unmuddied
rivers). Reservoir systems have been shown to house higher populations compared to
natural lakes and rivers. This species prefers areas of open water with little turbidity
and where the substrate is clean and unvegetated. Lower abundances of white bass have
shown to be in direct correlation with increasing amounts of vegetation.
- Habitat Regions
- temperate
- freshwater
- Aquatic Biomes
- lakes and ponds
- rivers and streams
Physical Description
The maximum length of
Morone chrysops
is about 46 cm (18 inches) and the maximum weight reaches around 3.2 kg (7 pounds).
White bass are silvery gray fish with the belly and breast region being lighter (silver
to white) and the dorsal region silver to black in color. They exhibit numerous narrow,
uninterrupted, dark colored lines along their sides which are sometimes incomplete
below the lateral line. They have a protruding lower mandible and the mouth extends
to the middle of the eye. White bass have been recorded to be around 212 mm total
length at one year, 364 mm at two years, 401 mm at three, and 426 mm at four. Females
become larger than males on average.
Characteristics that enable more precise identification of the species include a lateral
line count of 51 to 60 scales. Dorsal fin rays number 12 to 14 anal fin rays 11 to
13. This species has 20 to 25 gill rakers and its pectoral fins have 15 to 17 fin
rays. Near the tip of the tongue, white bass have a noticeable tooth patch that lies
in one fused or two barely separate areas of the tongue.
- Other Physical Features
- ectothermic
- heterothermic
- bilateral symmetry
- Sexual Dimorphism
- female larger
Development
White bass eggs hatch about two days after fertilization. The young larvae quickly
begin to show the schooling behavior seen in adults.
Reproduction
River-dwelling white bass migrate upstream in search of tributaries to spawn, while
lake-dwelling individuals search out stream inlets and shoreline to lay their eggs.
As a female disperses her eggs, many males follow behind releasing their sperm with
the intention of fertilizing as many of the eggs as possible. No elaborate courtship
displays are practiced and no nests are built. Once spawning has taken place, breeding
individuals return to deeper water.
- Mating System
- polyandrous
Spawning of
Morone chrysops
occurs as early as mid-February in the southern United States and as late as May
in the more northern latitudes, or whenever water temperatures reach about 14-20 degrees
celsius. White bass are polyandrous, and each female can lay up to and even over half
a million eggs. Once the adhesive eggs are laid, they settle to the bottom and attach
to the substrate to await fertilization by the males. Hatching occurs about 2 days
after fertilization, with growth of the young being quite rapid. Sexual maturity
is reached around 2 years after hatching in more southerly populations, while northern
populations can take a significantly longer time to mature.
- Key Reproductive Features
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- fertilization
- broadcast (group) spawning
- oviparous
White bass do not invest parental care beyond laying the eggs. Once they migrate to
spawning grounds and the eggs are laid and fertilized, the adults abandon the eggs
and return to deeper water to leave their offspring forcing them to fend for themselves.
- Parental Investment
- no parental involvement
-
pre-fertilization
- provisioning
-
protecting
- female
Lifespan/Longevity
Morone chrysops
exhibits rapid growth in conjunction with high natural mortality, resulting in a
relatively short life. Although maturity is fairly similar in northern and southern
populations, lifespan is not. Northern fish, on average, live longer than southern
fish. Typically, southern white bass live about 4 years while northern white bass
can live 8 years. Some white bass have reached 14 years of age.
Behavior
White bass are social, they can be found traveling in dense schools in areas of open
water. Schools of white bass can be seen near the surface ravenously feeding during
certain times of the day, while at other times schools are found at depths in excess
of 30 feet. Schools are made up of individuals of about the same age, with larger
schools containing more younger fish.
- Key Behaviors
- natatorial
- motile
- nomadic
- social
Home Range
No information on home range size was found but fish have been documented traveling
large distances. A tagged fish was once recovered in Missouri that had traveled over
40 miles. White bass in Lake Erie have been documented traveling throughout the entire
lake.
Communication and Perception
White bass use their lateral line systems to detect water movement and rely on vision
and sensing chemical cues. Little is known about interspecific communication in this
species.
Food Habits
Larval white bass feed mostly on zooplankton, especially
Daphnia
species. As development proceeds, juveniles begin feeding on macro-invertebrates,
such as chironomid larvae (
Chironomidae
), mayfly larvae (
Ephemeroptera
), dragonfly larvae (
Odonata
), damselfly larvae (
Zygoptera
), bugs (
Hemiptera
), amphipods (
Amphipoda
), and crayfish (
Cambaridae
). Adults, or fish over 350 mm, become highly piscivorous and begin feeding upon
fish. Common prey includes, fathead minnows (
Pimephales promelas
), johnny darters (
Etheostoma nigrum
), gizzard shad (
Dorosoma cepedianum
), threadfin shad (
Dorosoma petenense
), young sunfish (
Centrarchidae
), yellow perch (
Perca flavescens
), saugers (
Stizostedion canadense
), freshwater drum (
Aplodinotus grunniens
), carp (
Cyprinus carpio
), bullhead species (
Ameiurus
), and others. When feeding, schools of white bass prey upon schools of feeder fish
(various shad and minnow), causing the small, feeder fish to splash wildly at the
surface as they try to escape. Anglers calle this the "jumps." Up to 4 peaks in daily
feeding activity can occur, but this varies seasonally.
- Animal Foods
- fish
- insects
- aquatic crustaceans
- zooplankton
Predation
White bass are easily preyed upon by many carnivorous fish species, including other
white bass.
Ecosystem Roles
White bass are important as intermediate predators in the ecosystems in which they live, they are food for larger fish and other predators.
Economic Importance for Humans: Positive
There is renewed angling interest in white bass. Their vigor when hooked has led to
increasing popularity. They are also a popular food for consumption.
- Positive Impacts
- food
Economic Importance for Humans: Negative
There are no known adverse effects of Morone chrysops on humans.
Conservation Status
Not listed on any conservation lists, white bass are abundant where they occur. Unlike
other species that may have minimum size limits and creel limits, many states do not
impose size or creel limits for white bass caught inside their waterways. Of the states
that do impose creel limits, they are typically very liberal. One potential problem
with white bass populations is high variation of recruitment from year to year. The
problem seems to revolve around the amount of precipitation for that year, but this
has not been confirmed.
Additional Links
Contributors
Tanya Dewey (editor), Animal Diversity Web, Mary Hejna (editor), University of Michigan-Ann Arbor.
Tyler Morgan (author), Eastern Kentucky University, Sherry Harrel (editor, instructor), Eastern Kentucky University.
- Nearctic
-
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- temperate
-
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
- freshwater
-
mainly lives in water that is not salty.
- ectothermic
-
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
- heterothermic
-
having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- polyandrous
-
Referring to a mating system in which a female mates with several males during one breeding season (compare polygynous).
- seasonal breeding
-
breeding is confined to a particular season
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- fertilization
-
union of egg and spermatozoan
- external fertilization
-
fertilization takes place outside the female's body
- oviparous
-
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
- natatorial
-
specialized for swimming
- motile
-
having the capacity to move from one place to another.
- nomadic
-
generally wanders from place to place, usually within a well-defined range.
- social
-
associates with others of its species; forms social groups.
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- chemical
-
uses smells or other chemicals to communicate
- zooplankton
-
animal constituent of plankton; mainly small crustaceans and fish larvae. (Compare to phytoplankton.)
- food
-
A substance that provides both nutrients and energy to a living thing.
- carnivore
-
an animal that mainly eats meat
- piscivore
-
an animal that mainly eats fish
References
Etnier, D., W. Starnes. 2001. The Fishes of Tennessee . Knoxville: The University of Tennessee Press.
Gilbert, C., J. Williams. 2002. National Audubon Society Field Guide to Fishesl . New York, United States: Alfred A. Knopf, Inc..
Guy, C., R. Schultz, M. Colvin. 2002. Ecology and Management of White Bass. North American Journal of Fisheries Management , Volume 22 Issue 2: 606-608.
Hartman, K. 1998. Diets of White Bass in the Ohio Waters of Lake Erie during June–October 1988. American Fisheries Society , Volume 127: 323-328. Accessed November 24, 2005 at http://afs.allenpress.com/perlserv/?request=get-document&issn=1548-8659&volume=127&issue=2&page=323 .
Quist, M., C. Guy, R. Bernot, J. Stephen. 2002. Ecology of larval White Bass in a large Kansas Reservoir. North American Journal of Fisheries Management , Volume 22 Issue 2: 637-642.
Schultz, K. 2004. Field Guide to Freshwater Fish . Hoboken, New Jersey: John Wiley & Sons, Inc..
Walden, H. 1964. Familiar Freshwater Fishes of America . New York, NY: Harper & Row, Publishers, Inc..
Willis, D., C. Paukert, B. Blackwell. 2002. Biology of White Bass in Eastern South Dakota Glacial Lakes. North American Journal of Fisheries Management , Volume 22 Issue 2: 627-636.
2005. "Aquatic Habitat Assessment" (On-line). American Fisheries Society. Accessed October 16, 2005 at http://www.fisheries.org/html/publications/bookpdf/aquaticmethods.pdf .