Largemouth Bass, Bluegill and Other Sunfishes

0

Notes from Fundamentals of Aquaculture, James W. Avault, Jr., Ph.D., pgs. 84-85

Carnivorous largemouth bass is farmed commercially in Taiwan on a limited scale, this species is mainly sought for sport in areas it occurs naturally, or has been introduced. Largemouth bass has wide distribution range, from Southern Canada, the Great Lakes, south into Mexico, and on the Atlantic Coast from Virginia to Florida. The Florida strain is sought after because it grows faster and reaches a large size, making it a trophy fish. Because of its popularity, State and national hatcheries have propagated the largemouth bass for decades. Fingerlings have been stocked into public waters and distributed to citizens for private ponds.

The bluegill (Lepomis macrochirus) has been produced in state and national hatcheries in combination with largemouth bass. In new sportfishing ponds that are fertilized, bluegill fingerlings are stocked in the fall at 3707/hectare (1500/acre). The following spring, largemouth bass are stocked at rate of 247 fingerlings per hectare (100 acres).

With most species, when a culture species is grown for food it is not desirable to reproduce in grow-out ponds. But in largemouth bass-bluegill ponds, the pond may never be drained as long as the fishing remains productive. The pond owner would naturally want both species to spawn naturally. Bluegill are prolific and usually spawn the first summer after stocking, and may spawn up to three or four times, depending on water temperature (above 27 degreesºC (80ºF).

Bass spawn once annually, in the spring when water temperature reaches 21ºC or 70ºF. The largemouth bass depend on the bluegill for a source of food, to realize maximum growth potential. Thinned down, bluegill have ample food supply and also reach a desirable size for sportfishing. Both species expand, filling the pond to its maximum carrying capacity and fish population ultimately reaches a "balance".

This balance is determined by three causes
1. Both species must reproduce each year.
2. Good fishing must exist. Though it may vary, generally the pond should allow harvesting up to 56 kg/ha (50 lb/ac) of largemouth bass and 225 kg/ha (200 lb/ac) of bluegill.
3. The population of forage (F) species (bluegill) must be in a proper ratio by weight in contrast with the carnivore (C) (largemouth bass), determining that a pond ratio F/C ratio may range from 1.4 to 10.

A number of other sunfishes are popular for sportfishing. The red-ear (Lepomis microlophus) has been stocked into largemouth bass ponds, to add variety to fishing. It grows slightly larger than bluegills, but is not prolific enough to be stocked alone with largemouth bass. Both white crappie and black crappie (Pomoxis annularis and P. nigromaculatus) are both sport-fish that grow well in large reservoirs, more than 20 ha (50 acres), with largemouth bass, bluegill and red-ear. Crappie compete with these species for food and space, and all species may become stunted in smaller farm ponds.

Entrepreneurs who are considering propagating largemouth bass and sunfish for commercial purposes must take into account the existing competition with state and national hatcheries. Some states prohibit farming of sportfish for commercial food purposes. However, there are limited possibilities for private investors, probably the best being operations of fee-fishing managed lakes, which appeal to urban citizens. Fishing rights can be leased by the day or annually, or charging by weight of fish which are caught.

Read More »

Largemouth Bass Culture

0

Largemouth Bass, Micropterus salmoides

Largemouth bass are freshwater bass which belong to the family Centrarchidae.

Two subspecies:
1. Northern strain
2. Florida strain (Rook.org)

Scientists and anglers had already recognized by 1932 that largemouth bass in peninsular Florida grew to a larger size and had different coloration than their northern counterparts. These differences, as well as other physical characteristics, were used to classify Florida largemouth bass as a distinct subspecies in 1949. Although each is recognized as a unique biological unit, the two subspecies (Florida bass [Micropterus salmoides floridanus] and northern bass [Micropterus salmoides salmoides]) freely interbreed. Florida bass have been widely introduced throughout the nation because of their potential for producing trophy-size fish. However, native populations of this subspecies are unique only to the central and southern portions of the Florida peninsula. As a result, they represent a natural resource that is both biologically unique and economically valuable.(Black Bass Genetics in Florida)

Closely related species that are cultured:
1. Smallmouth bass (M. dolomieui)

2. Spotted bass (M. punctulatus)
(Texas State)

Largemouth bass live in warm, slow moving waters around rich vegetative soft bottoms. Smallmouth bass are a related game species found in faster, cooler water that may require less vegetative cover. Largemouth bass, Smallmouth bass and Spotted bass are known collectively as the Black bass.

Intensive Largemouth Bass Culture Commercial Production
North Carolina is one of the few states which permit commercial culture of bass. It is the only state on the East Coast that specifically permits licensed fish farmers to culture food-size Largemouth bass.

The Largemouth bass market is small. Currently live sales go to Asian-Americans in the northeastern US. Live haulers pick up live largemouth bass at the farm, and may pay up to $6 per lb, in cash. These fish must be at least 1.5 lbs, excellent physical condition and disease-free to bring this price. High price and ready market has resulted in recent interest in intensive commercial production of largemouth bass.

Dr. James Tidwell and others at Kentucky State University conducted research which demonstrate largemouth bass can be stocked at high rates, up to 5,000 per acre. Fed a high-protein pelleted feed, and grown to market size in a reasonable period of time (from 6” fingerlings to 1.5 lb fish in 12-18 months).
(Kentucky State University)

Problems with intensive production of Largemouth bass:
1. Cannibalism (well graded fish at stocking, additional grading may be required before fish are finished out).
2. Bird predation Compared with other species, birds are one of the greatest predators.
3. Unknown nutritional requirements.
4. No approved disease treatments.
5. Other problems yet to be determined (Very little intensive culture experience to go on at this point). (Purdue.edu)

Bass-Bream Culture in Farm Ponds
Farm ponds are most often hill ponds (also known as watershed ponds [Watershed or embankment ponds, are formed by constructing a dam to collect stream or surface runoff] NC State Fisheries). Excavated ponds are also sometimes constructed in low areas in the coastal plain for the same purpose.

Most farm ponds are located in the upper coastal plain and the piedmont in NC. They are used for many and varied purposes on farms throughout the U.S.A., including:
1. Irrigation
2. Livestock watering
3. Flood control
4. Erosion control

For reasons #3 and #4 above, many of these ponds have been constructed with large (up to 75% of cost) subsidies from the Soil Conservation Service since the 1930’s. More than 100,000 have been constructed in NC alone (NC has 60,000 farms, and most have at least 1 farm pond on the property).

Farm ponds once served another important function on farms in the Southeastern US: Production of fish as food for the farm family.

Homer Swingle (Auburn University, Alabama) conducted extensive research on the use of farm ponds as a source of high-quality fish protein for farmers in the South, beginning in the 1930’s. Swingle’s work laid the foundation for further research on farm-pond fish culture that continues to the present day.

Many states provide largemouth bass and bream fingerlings free of charge to farmers for farm-pond stocking. Many states, including North Carolina have discontinued this practice.

Largemouth bass and bream of various species are produced by private hatcheries for sale to individuals for private lake or ponds. It is a lucrative business, and there are several suppliers of Largemouth bass, bluegill, red-ear, hybrid bluegill, etc. in NC, including graduates of the BCC aquaculture program. (Southeast Pond Stocking of Pender County, specializes in largemouth bass, bluegill, shellcracker, channel catfish, grass carp, hybrid striped bass, koi, fathead minnows, hybrid bluegill, tilapia, black crappie, F1 hybrid largemouth bass) (NC State Agriculture) Currently only 3-4 active gamefish hatcheries exist in North Carolina and Southeast Pond Stocking, is run by BCC graduates Kevin Patterson and Rick Stuckman.

Most suppliers purchase fingerlings from private hatcheries and provide stocking services for private pond and lake owners. (A list of services, seponds.com)

Largemouth bass become carnivorous when they become adults, and having a preference for smaller fish, so ponds and lakes must be stocked with a suitable forage species to support Largemouth bass populations.

Debate continues over
1. Largemouth bass stocking rate.
2. Forage species stocking rate.
3. The best forage species to use.


Commercially, the most common forage species for Largemouth bass is the Bluegill (Lepomis macrochirus).
Bluegill image based on Michigan Science Art

Recommended stocking in North Carolina:

Unfertilized ponds:
a. 350/acre 1-2” bluegill stocked in Oct-Nov
b. 150/acre 1-2” red-ear sunfish stocked in Oct-Nov
c. (optional) 50/acre 2-4” channel catfish stocked in Oct-Nov
d. 50/acre 2-4” LMB stocked the following June

Fertilized (or fed) ponds:
a. 700/acre 1-2” bluegill stocked in Oct-Nov
b. 300/acre 1-2” red-ear sunfish stocked in Oct-Nov
c. (optional) 50/acre 2-4” channel catfish stocked in Oct-Nov
d. 100/acre 2-4” LMB stocked the following June

Many people avoid stocking catfish because catfish may upset the bass-bream “balance”. Some scientific evidence exists for this.

The preferred stocking strategy for ponds and small lakes (described above) in NC is because,

1. Bluegill and red-ear have traditionally shown to be an excellent forage species for bass.

2. Bluegill itself is an excellent foodfish for people. Some people prefer bluegill over bass.

3. Largemouth bass do a good job of keeping sunfish populations in check, preventing overpopulation and stunting.

The greatest problem in Largemouth bass/sunfish ponds is overfishing of bass, and/or underfishing sunfish, resulting in overpopulating the pond with sunfish. The sunfish then may become stunted, too small to be eaten by people, while bass population is reduced in number and larger, which are seldom caught by anglers.

To maintain the pond's “balance” a farm pond should be harvested on a regular schedule by angling :

Depending on productivity:

1. 10-40 lbs/acre of bass should be harvested each year.
2. 40-160 lbs/acre of sunfish should be harvested each year.

Use the lowest figures for unfertilized ponds constructed in soils of low fertility. Use the highest figures only for well-managed fertilized ponds built on highly productive agricultural land, or fed ponds. If a pond owner can’t eat 160 lbs of bream from his pond each year, give them away or bury them!

Stocking alternative forage species:

1. Red-ear sunfish (Lepomis microlophus) – has a lower reproductive rate than bluegill, so may be less likely to overpopulate or become “stunted”.


Red-ear sunfish (Lepomis microlophus), an alternative forage species for Largemouth bass.
Red-ear sunfish image based on Texas Parks and Wildlife
2. A 70:30 mix of bluegill and red-ear (as recommended by NC Cooperative Extension).

3. Hybrid bluegill – usually a cross between male bluegill and female green sunfish. Very popular with pond and lake owners, but not recommended, because:

a. Hybrids are 90% male, have a very low reproductive rate, and may not provide adequate forage for the bass.

b. The hybrids back-cross and revert back to a fish that most resembles green sunfish after 1-2 generations. Green sunfish rapidly overpopulate the pond and become stunted, useless as a foodfish for people.

Many other stocking and management strategies in other states and other regions of the US, depending on:

1. Climate
2. Soil fertility
3. Watershed chartacteristics
4. Other environmental factors.

Each state has developed its own recreational fishing pond management strategies and recommendations. Consult your local Cooperative Extension office for recommendations in your area.

References: Largemouth Bass, Texas State Parks and Wildlife

Notes from BCC with modifications and additions, January 28, 2006

Read More »

Largemouth Bass, Micropterus salmoides

0

Largemouth Bass, Micropterus salmoides



Image based on (Texas State Wildlife)

Physical Description and Taxonomy
Micropterus, from the Greek, "small fin" salmoides, from the Latin, salmo, "trout"; hence "trout-like" Common name from large mouth, the line of which extends back past the eye. Other common names include: Bigmouth Bass, Bigmouth Trout, Black Bass, Bucketmouth Bass, Green Bass, Green Trout, Hawg, Hog, Lineside, Lake Bass, Openmouth Bass, Oswego Bass, Slough Bass, Welshman

Taxonomy:
Kingdom Animalia
Phylum Chordata, animals with a spinal chord
Subphylum Vertebrata, animals with a backbone
Superclass Osteichthyes, bony fishes
Class Actinopterygii, ray-finned and spiny rayed fishes
Subclass Neopterygii
Infraclass Teleostei
Superorder Acanthopterygii,
Order Perciformes, perch-like fishes
Suborder Percoidei
Family Centrarchidae, sunfish
Genus Micropterus, black bass, largemouth bass (Rook.org)

Largemouth bass grow 4 to 6 inches (10 to 15 cm) during their first year, 8 to 12 inches (20 to 30 cm) in two years, 16 inches (40 cm) in three years. They are usually green with dark blotches that form a horizontal stripe along the middle of the fish on either side. The underside ranges in color from light green to almost white. They have a nearly divided dorsal fin with the anterior portion containing nine spines and the posterior portion containing 12 to 13 soft rays. Their upper jaw reaches far beyond the rear margin of the eye. (Texas State Parks and Wildlife)
Micropterus salmoides has a large mouth, a notch between the two dorsal fins, and a dark stripe along the side of the body (Bailey et al., 2004). This black band is seemingly made up of small oval shapes to a closer eye. Coloration is variable, but is usually a darkish green on the back and sides, fading to an off-white on the belly. The anterior dorsal fin has nine to eleven spines while the posterior dorsal fin has twelve to fourteen rays (Boschung et al., 2004). The average weight of M. salmoides is one kilogram; however, certain individuals have reached weights of over ten kilograms. Males usually do not surpass 40 cm, while females can reach up to 56 cm in length. (Bailey, Latta, and Smith, 2004; Boschung, Mayden, and Tomelleri, 2004) (University of Michigan)

Range/Habitat
Largemouth bass were originally distributed throughout most of what is now the United States east of the Rockies, including many rivers and lakes in Texas, with limited populations in southeastern Canada and northeastern Mexico. Because of its importance as a game fish, the species has been introduced into many other areas worldwide, including nearly all of Mexico and south into Central and South America. Largemouth bass seek protective cover such as logs, rock ledges, vegetation, and man-made structures. They prefer clear quiet water, but will survive quite well in a variety of habitats. (Texas State Parks and Wildlife)
Micropterus salmoides is native to eastern North America and historically ranged from southern Canada to northern Mexico, and from the Atlantic coast to the central region of the United States. Since the beginning of the twentieth century largemouth bass have been introduced successfully all over the world. (Carlander, 1977; Hubbs, 1964; Page and Burr, 1991) Largemouth bass prefer quiet, clear waters with abundant vegetation (Iguchi and Matsuura, 2004). More specifically, they prefer shallow water that is usually no deeper than 2.5 meters, but they sometimes occupy deeper regions. Abundant vegetation is important because it allows bass to hide from their prey and provides protection against predators.
Several countries report adverse ecological impact after introduction.(University of Michigan and fishbase.org)

Temperature Requirements
Growing: 55-80 F / 10 – 32°C; 47°N - 26°N (fishbase.org)
Spawning: 60-65 F (Purdue.edu

Feed/Diet
Fry feed primarily on zooplankton, aquatic insects and insect larvae. At about two inches in length they become active predators. Adults feed almost exclusively on other fish and large invertebrates such as crayfish and frogs. Larger fish prey upon smaller bass. Sunfish are the food of choice for most adult largemouth bass. Sometimes cannibalistic. (Olsen and Young, 2003, Texas State Parks and Wildlife, University of Michigan, fishbase.org)

Commercial Production
The production, rearing and stocking of largemouth bass (Micropterus salmoides) represents a large economic asset in the aquaculture industry of the midwestern U.S., requiring extensive information on the biology of this species.
(Calstate.edu Comparison of Experimental Growth Rates of Pond-Raised Largemouth Bass, Micropterus salmoides, Fed Natural and Artificial Foods)
Size: 1.0 - 2.5 lbs for food and 4-8 inches for fingerlings
Feed requirements: Protein: 40% diets are normally fed from fingerlings to adults after fingerlings have been trained to accept commercial diets.
Fat: 8-10%. Ponds for spawning and grow-out to food fish size. Small fingerlings are normally removed from ponds and trained to accept commercial diets using flow through systems. (Purdue.edu)

Spawning Requirements
In Texas spawning begins in the spring when water temperatures reach about 60°F. This could occur as early as February or as late as May, depending one where one is in the state. Males build the nests in two to eight feet of water. Largemouth bass prefer to nest in quieter, more vegetated water than other black bass, but will use any substrate besides soft mud, including submerged logs. As in Guadalupe bass, once the female has laid eggs in the nest (2,000 to 43,000) she is chased away by the male who then guards the precious eggs. The young, called fry, hatch in five to ten days. Fry remain in a group or "school" near the nest and under the male's watch for several days after hatching. Their lifespan is on average 16 years. (Texas State Parks and Wildlife)

Natural Enemies
Larval and juvenile largemouth bass are prey species of yellow perch, walleye, northern pike, and muskellunge. As adults, largemouth bass can usually escape most predators. The primary predators on adult largemouth bass are humans. (Paulson and Hatch, 2002) Preyed upon by herons, bitterns, and kingfishers (Ref. 1998). Excellent food fish (Ref. 1998). (University of Michigan and fishbase.org)

References: Largemouth Bass

Read More »