As with all fish species we acknowledge there are differences between regions and breeds. The information we present is based on our observations, which are not always derived according to strict scientific protocol and may not represent the local conditions in your neck of the woods.
Additionally, there are no hard and fast rules for determining stocking density. Each situation should be evaluated based on environmental factors and goals. In cases where history or fish survey information is unavailable, stocking recommendations will be determined based on experience in similar situations. The information included in this section is to be used as a basic guideline only!
P.K. Gills provides turnkey solutions for its customers including stocking recommendations and periodic assessments measured against benchmarks. Click here to contact us or get a quote for Goldfish or Mosquito Fish.
Largemouth Bass
Name: Micropterrus salmoides
Purpose: Sport fish
Description: Calm water fish revered by anglers and largest member of the sunfish family. Light greenish to brownish sides with dark lateral line. Distinguished by an upper jaw that extends beyond the rear edge of the eye and a deep dip between the first and second dorsal fin. A predator that feeds aggressively on all other fish. Can be useful balancing lakes where species are overpopulating. Prefer some vegetative cover, muddy bottom and fertile water.
Size Range: 16-22 inches and 4-5 pounds. Females are larger and largemouth bass over 8 pounds are normally female. World record 22 lbs 4 oz.
Temperature & Water Quality: prefer 80-89F. Inactive below 50F. Non-moving, non-polluted water with adequate oxygen. A pH of 6-9.5 is best.
Spawning: 69-70F optimum and minimum of 63F. Male builds nests and guards the eggs and fry. 2-100,000 eggs are produced and males fertilize as the eggs settle into the nest. Good brood fish are over 2 years old and 10 or more inches long.
Diet: Young fish feed on zooplankton and small crustaceans. Fingerlings add insects and small fish. Adults prefer forage fish and will eat crabs, turtles, salamanders, mice, snakes, and even birds.
Stocking: Stock only where adequate forage base exists. In new lakes establish a forage base of working fish prior to bass introduction.
Bluegill
Name: Lepomis machrochirus. AKA; bream, blue bream, sun perch, blue sunfish, copperhead, copperbelly, roach
Purpose: Forage fish, sport fish, insect control
Description: In the Centrarchids family with bass, sunfish, and crappie. Small mouth and rounded body whose colour varies with age, sex, water colour and bottom type. Generally lavendar and bronze with six dark bars on their sides. Distinguished by a black spot at the rear edge of the gill cover and a black spot at the base of the posterior dorsal fin.
Reproduce well and establish a forage base for other predators like bass. Bluegills are the most notable compliment to bass in angling ponds. These fish reproduce abundantly and overpopulate or become stunted in small or weedy ponds.
Size Range: 5-7 inches and 8 ounces at maturity. Can reach 1 pound with world record at 4 lbs 12 oz. Bluegill live to 11 years old, but 7 years is average life span.
Temperature & Habitat: Up to 89F. Prefer quiet weedy water where they hide and feed. Found in lakes, ponds and slow moving rivers and streams.
Spawning: Spawn later than bass during May to October in water from approximately 68F. Spawning peaks in May and June with water at 78-80F. Bluegill males arrange a nest, which they defend against intruders. Good habitat is an important factor in achieving good spawning rates. Females lay 2,000-63,000 eggs which hatch in 30-35 hours, after which, the male protects the fry.
Diet: Carnivorous fish consuming insects, larvae, crustaceans, invertebrates, small minnows and worms.
Stocking: 2-3 pairs of brood fish per surface acre, 2 inch fingerlings at 50-100 per surface acre.
Redear Sunfish
Name: Lepomis microlophus AKA; shell cracker, bream and yellow bream
Purpose: Forage fish and a popular sport fish
Description: A centrachid and close relative of the bluegill. Redear are similar in shape to bluegill, but lacking the black spot at the posterior portion of the dorsal fin. Coloration is light olive green to gold with red to orange flecks on the breast. They all have a distinct red to orange border around the gill flap. Often stocked in lieu of, or in addition to, bluegill in bass ponds. They will not spawn as actively as the bluegill and thus will not tend to overpopulate as readily. However, will not provide bass as much forage as bluegill.
Size Range: Commonly over 1 pound and 9-10 inches. Fastest growing true sunfish and live to about 8 years old. World record size is 5 lbs 3 oz.
Habitat: Found in most freshwater systems in the eastern USA. Like sandy or shell-covered areas of ponds and lakes and often locate near grasses. Prefer quiet water and congregate near stumps, roots and logs. Redear can tolerate brackish water and can be abundant in tidal areas near river mouths. Like to spend time in deep open water especially in winter.
Spawning: Mainly spawn in May to July at water temps of 70F. Males make nesting sites near aquatic vegetation in 3-4 feet of water. Females lay 15-30,000 eggs and males guard the young.
Diet: Aquatic insects, clams and snails (hence the nickname “shellcracker”). Opportunistic bottom feeders that also eat larval insects, fish eggs, small fish and crustaceans.
Green Sunfish
Name: Lepomis cyanellus
Comment: Do not recommend stocking as they quickly overpopulate and compete with bass for available food.
Crappie (white or black)
Name: Promoxis annularis, Promoxis nigro maculatus AKA; speckled perch, specks, calico bass, white perch
Purpose: Sport fish
Description: Excellent tasting sport fish inhabiting larger lakes and reservoirs. Silvery-green to yellowish with large dorsal and anal fins almost identical in size and shape. Sides are marked with black blotches, as are the dorsal, anal and caudal fins. Difficult to manage in small lakes as they tend to overpopulate and compete with other species like bass. A schooling fish that prefers large deep lakes with good submerged structure and clear water.
Size Range: World record 4 lbs 8 oz.
Temperature: Prefer 70-75F and tolerate 80F.
Spawning: February to April in 62-65 degree water. Normally spawn in colonies. The males fan circular nests in shallow water. Female produces 11-188,000 eggs, which the males guard.
Diet: Crustaceans, insects and small fish. Adults mainly eat small forage fish like threadfin shad.
Catfish (Channel)
Name: Ictalurus punctatus AKA; spotted cat, blue channel cat, river catfish
Purpose: Detritus consumption, Sport fish and Food fish.
Description: A hearty fish that scavenges along the bottom. Popular for catch and release fishing programs. Deeply forked tail and rounded anal fin with 24-29 rays. Look for black spots along their back and sides (larger catfish will lose the spots). Small narrow head and body is blue-gray to silvery-gray with white belly.
Size Range: Average 2-4 pounds with some reaching 45 pounds. World record is 58 pounds. Live to a max of 14 years.
Habitat: More common in big rivers and streams. Like some current but adapt well to still water lakes.
Spawning: Spawn in temps of 75-80F. Deposit eggs in nests secluded under logs, riverbank or over open bottom. Males select the nesting site often a natural cavern or hole. Females lay 2-21,000 eggs that hatch in 6-10 days. Males protect the fry until they leave the nest in about a week.
Diet: Effective at consuming the bodies of dead and dying fish. Often stocked to lower the impact of winter tilapia die off. Channel cats feed mostly at night using sensory organs in the barbels to locate prey. Primarily bottom feeders however, will feed throughout the water column. Consume insects, crustaceans, fishes, molluscs and invertebrates.
Fathead Minnows
Name: Pimephales promelas
Purpose: Forage fish
Description: A suitable forage fish for all species of game fish like catfish and bass. A cyprinidae like carp, goldfish, or shiners that likes slow moving streams and ponds with abundant vegetation.
Size Range: Up to 3.5 inches
Temperature: 45-85F
Spawning: Spawn several times a year in water above 55F. Good habitat is required to increase spawning rates. Long season with up to 12 spawns per season. Numerous eggs per spawn in the range of 12,000.
Diet: Dead animal and plant materials including larvae on the bottom. Eats selected small insects that land on the water.
Stocking: 1-2,000 per surface acre. Varies widely depending on the number of predator fish in the system.
Goldfish
Name: Goldfish (Carassius auratus)
Purpose: Insect control
Description: Peaceful schooling fish that resembles carp. A cyprinid family member generally used as an ornamental or feeder fish in aquariums and small ponds. There are numerous ornamental forms with exotic features developed through deliberate breeding. As a feeder fish, goldfish are usually consumed rapidly because they stand out in a crowd. This may also make them susceptible to bird predation. Goldfish consume insect larvae that live in the bottom sediments. Midge fly and mosquitoes both have larvae stages that exist in the lake bottom. Goldfish are inexpensive and good at consuming red worm (midge fly larvae).
Size Range: Average 1-6 inches up to 18 inches.
Temperature & Water Quality: Like warm water and develop well in temperatures exceeding 72F. pH and hardness are not a big factor as these fish are tolerant.
Spawning: Prolific spawner that lays its eggs on plants
Diet: Omnivorous, consumes animal and vegetable material, live and dried food.
Koi
Name: Nishikigoi (Cyprinus carpio)
Description: Striking patterns and delicate coloration typify this carp whose popularity is increasing with spectators and enthusiasts. Koi are characterised by the presence of two barbels. Although often associated with Japan, koi originated in eastern Asia and China some 2500 years ago. It was not until the 20th century that koi keeping flourished as a hobby. Koi have been bread to produce over 100 varieties of colour pattern and lustre or scalation. Dedicated enthusiasts prefer to choose each fish for its specific qualities.
Size Range: Commonly 6-14 inches. Koi show classifications reach 32 inches and fish exceeding 100 pounds have been recorded.
Temperature & Water Quality: A hardy fish comfortable in a wide range of temperatures 36-85F. Prefer pH in the range of 7-8 with oxygen levels of at least 6ppm. Maintaining minimum ammonia and nitrite levels are also important to healthy koi.
Spawning: In the late spring and early summer koi of 15 inches may spawn. Spawning is frantic and usually occurs on warm days when cool nights are present. Koi will eat their own eggs so all spawning ropes should be removed when spawning is complete.
Diet: Varied diet including redworms, snails, lettuce, cockles, prawns, tadpoles, frogs, and fish feeds containing 35% protein, carbohydrates, vitamins and minerals. Quality koi food should also contain minimum fat and stabilized vitamin C. Metabolism changes seasonally making feeding rates during winter much lower.
Stocking: Rates are a function of pond size and biofiltration capacity. Stocking is assessed for each pond and generally too expensive as a biological control agent.
Mosquito Fish
Name: Gambusia affinis AKA potbellies
Purpose: Insect control. Mosquito and midge fly.
Description: A small silver-colored, sometimes quarrelsome schooling fish. Anal fin on the smaller male terminates in a sharp point while the female have a more rounded anal fin. Stocked to control insects and mosquitoes and they have a voracious appetite. A natural weapon against disease transported by mosquitoes such as west nile virus or malaria. By feeding on all life stages of the mosquito, Gambusia assisted in making the Panama Canal habitable. Gambusia can serve as a forage fish for small bass and are normally found in shallows among vegetation.
Size Range: 1-3 inches. Males are smaller.
Temperature & Water Quality: 37-100F. Can live in brackish water. These fish are sensitive to oxygen levels and can be difficult to transport for that reason.
Spawning: Bear their young alive and have become a popular aquarium fish for this reason. Prefer 75F to spawn. Prolific spawners and will eat their young.
Diet: Primarily insect larvae at the surface. Consume the equivalent of their body weight every day.
Stocking: 1-3,000 per surface acre depending on the severity of the insect problem.
Israeli Carp
Name: Cyprinus carpio nudus AKA; Carp, German Carp. Mirror Carp, Leather Carp
Purpose: Insect control, weed control, algae control, sport fish
Description: A relative of the common carp. Scale patterns among carp vary from scaleless leather carp to fully scaled common carp. Israeli Carp are partially scaled including both large and small scale patterns. The colors range from golden to olive brown. The carp is debated as a species both beloved and despised. Individuals are either pro or con with regards to carp’s sporting value, flavour and ability to maintain ecological balance.
Size Range: Carp are reported to live 50 years with most reaching the age of 12. In the first year they often reach 9 inches and can reach 80 pounds although that is the exception. Growth rates vary widely based on the usual factors of geography, biological activity, and the environment.
Temperature and Water Quality: Carp are very adaptable and hardy. They can survive in water temps up to 96 degrees F for short periods and handle low oxygen environments.
Spawning: Males mature in year 2 while females reproduce in year 3. Several males accompany a solo female to shallow vegetated areas where eggs are released and fertilized. Females release 100,000 eggs per pound of body weight. The eggs are left unattended for 3-10 days until fry hatch. Fry adhere to vegetation at birth and absorb a yolk sac before graduating to algae or weed consumption.
Tilapia (African Cichlids)
Name: Tilapia is the genus of large cichlids with more than 100 species. The most common in N. America include Nilotica, Blue Aureus, Zilli, and Mozambique. Mixed gene pools are also common.
Purpose: Food fish, control filamentous and lyngbya algae.
Description: Tilapia is a robust tropical fish originally imported from East Africa and the Middle East thus cold intolerant. Some species tend to be aggressive. They do best in warm water and have minimal respiratory demands making them easy to transport. Tilapia reproduce rapidly and will tend to overpopulate. They are a favoured product for consumers and food fish farmers becoming better known at grocery stores worldwide. Tilapia is a good forage fish for bass and catfish due to their rapid reproduction rates. Tilapia is an excellent tool for controlling filamentous and lyngbya algae. Do no tolerate winter temperatures in most regions of the US although work continues to breed a more cold tolerant Tilapia. Being a warmer water species they die off in winter making cleanup and restocking a necessity.
Size Range: 3-8 inches up to 3 lbs average with blue aureus reaching 10 pounds.
Temperature: Lowest 54-56F, Optimum 70F, upper range 86-100F
Spawning: Tilapia reaches adulthood in the second six months of life and will spawn after they reach about 6 inches. They require water temperatures of 68-70F to spawn, which they will do repeatedly at 4-5 week intervals.
The male constructs a nest in shallow water by digging a hole in the lake bottom. The size of the nest is determined by the size of the fish and should be considered if the lake is constructed with a liner. Nesting holes several feet deep have been noted. Eggs are laid and fertilized in the nest, then watched or held in the female’s mouth to protect and aerate them until hatched. Hence some species of Tilapia are called mouth-brooders. Hatches of several hundred to several thousand offspring hatch in about six days.
Diet: Omnivorous with each species having a distinctive food preference. Some prefer microorganisms, while others add plant materials to their diet. Breeds from mixed gene pools have a voracious appetite and will control chemically resistant blue green algae like lyngbya. Smaller fish 3 inches and under will consume more algae than larger fish. Most Tilapia will eat insect larvae, crustaceans and decaying organic matter.
White Amur
Name: Grass Carp (Ctenopharyngodon idella)
Purpose: Aquatic weed control, minor algae control
Description: These fish were originally imported for the Amur and other great rivers of China. They have a long silvery to gray body, large scales and short powerful fins. Grass carp have been known to churn up the bottom and compete for food and space with more desirable game fish. As such, this is a highly regulated species and normally allowed only as sterile hybrids. Triploid grass carp have 3 sets of chromosomes instead of the normal two making them sterile.
Triploids are produced artificially using hormones by stripping the eggs and mixing them with milt then subjecting the fertilized eggs to hydrostatic pressure and finally suspending them in a well aerated container until they hatch.
Size Range: At maturity can exceed 110 lbs and 5 feet in length under ideal conditions. Can live over 20 years. However, for weed control purposes they are generally harvested every few years.
Temperature & Water Quality: Optimum temperature is 77F. Prefer large rivers or canals with strong currents. Growth rate is closely related to water temperature. Can tolerate water from freezing to 100F and high salinity (brackish water). They will stand oxygen levels down to 0.5ppm but obviously prefer more.
Spawning: Reach sexual maturity between 4-9 years and spawn when temperature exceeds 77F. Grass Carp lay pelagic eggs fertilized by the male, which float in the water during incubation.
Diet: A herbivorous fish with voracious appetite that feeds on grass, rooted aquatic weeds and some filamentous algae. Larger fish consume less aquatic vegetation and it is necessary to introduce various age classes when weed control is the objective.
Stocking: Check your state for local regulations. Generally, triploid fish are allowed in lakes and canals after site inspection and stocking permits are issued. As triploids are sterile, maintenance stocking is required every few years to maintain adequate density for weed consumption.
Trout (Rainbow)
Name: Salmo gairneri
Description: Numerous types of salmo gairneri due to extensive cross breeding. Two more common types are steelhead, a breed that migrates to the sea, and rainbow which does not migrate. Best-suited, easiest and most attractive fish for production of table trout.
Size Range: To 17 inches in 3 years and in excess of 1 pound
Temperature & Water Quality: Maximum 68-75F. Not suitable for warm water lakes. A cold-water fish requiring high levels of dissolved oxygen.
Spawning: January to May
Diet: Generally carnivorous although respond to artificial feed well. Feed on the bottom taking worms and molluscs.
Stocking: Dependent on environment.