Percoidei I

(Perches and darters, North American basses and sunfishes, pygmy sunfishes, and temperate basses)

Class Actinopterygii

Order Perciformes

Suborder Percoidei

Number of families 4

Evolution and systematics

The suborder Percoidei contains more than 70 families and 2,800 species. This chapter and the four Percoidei chapters that follow highlight a representative sample of Percoidei taxa. This chapter focuses on four families:

• Percidae, the perches, with 10 genera and 162 species
• Centrarchidae, the sunfishes, with eight genera and 29 species
• Elassomatidae, the pygmy sunfishes, with one genus and six species
• Moronidae, often grouped under the umbrella descriptor "temperate basses," with two genera and six species

All four families fall within the massive order Perciformes, although the placement of Elassomatidae in this order has been disputed. The current classification positions Percidae, Centrarchidae, and Moronidae within the 71-family suborder Percoidei, and the pygmy sunfishes in the single-family suborder, Elassomatoidei. Some taxonomists have suggested moving the elassomatids out of the percomorphs altogether and placing them into the atherinomorphs, a broad grouping that includes the killifishes (cyprinodonts), but at least one genetic analysis (Jones and Quattro, 1999) discounts this change. Past arrangements had placed the pygmy sunfishes together as a subfamily within Centrarchidae, but their similarities in appearance have since been attributed to evolutionary convergence.

Changes have also occurred in other families. The moronids, for example, now include species formerly within the family Percichthyidae. Some biologists consider them to be most closely related to the snooks and giant perches in the family Centropomidae, because both share two additional lateral lines on the tail, above and below the main lateral line. Little doubt exists that all four families—Percidae, Centrarchidae, Moronidae, and Elassomatidae—will undergo further taxonomic alterations in the future, as scientists learn more about the phylogenetic relationships between species, genera, and higher classifications.

Physical characteristics

The perch family is a large one, making generalizations about physical appearance rather difficult. These species do, however, have some unifying traits, such as an elongate body. All percids except the genus Zingel have either two fully separate dorsal fins or two dorsal fins that are only minimally connected. The opercle has one sharp spine. Most fishes in this family, including the North American darters, are on the small side. One exception is the walleye (Stizostedion vitreum), a popular game fish that can grow to 42 in (107 cm).

Sunfishes, many of which are described by the angler simply as "panfish," are typically broad animals with bodies one-third to one-half as tall as they are long. The single dorsal fin usually has 10–12 spines, although the range runs from 5–13. Some, like the longear (Lepomis megalotis) and pumpkinseed sunfishes (L. gibbosus), are colorful in hues of orange, green, and blue, while others are quite drab. Maximum adult sizes range from less than 4 in (10 cm) in two Enneacanthus species, to 39 in (nearly 1 m) in the largemouth bass (Micropterus salmoides).

Moronid species all have two dorsal fins, including a spiny front fin and a mostly soft-rayed hind fin. Other distinguishing

features include a two-spined opercle and a long lateral line with two additional lateral lines on the tail. Maximum adult sizes range from nearly 1.5 ft (46 cm) in the white bass (Morone chrysops), to 6.6 ft (2 m) in the striped sea bass (M. saxatilis).

Members of the pygmy sunfish family have a rounded tail fin and a three- to five-spined dorsal fin with eight to 13 soft rays. They lack a lateral line on the body. Pygmy sunfishes are less broad than the typical centrarchid and considerably smaller. Maximum adult sizes range from 1.3 in (3.3 cm) in the Carolina pygmy sunfish (Elassoma boehlkei), to 1.9 in (4.7 cm) in the banded pygmy sunfish (E. zonatum).

Distribution

Most species in this group occur in North America. Some percid species extend throughout the Northern Hemisphere, and the family Moronidae contains members that naturally occur in Europe and northern Africa. In addition to the native populations of the four families, numerous species, particularly among the centrarchids and percids, have been purposely introduced as game and/or food fishes in new geographic areas nearly around the world. As a result, various centrarchid species are now found in lakes and ponds throughout temperate Europe, Japan, and southern Africa and Australia.

Habitat

Fishes in the families Centrarchidae and Elassomatidae live in strictly freshwater habitats. Centrarchids prefer a temperate climate, and are especially common to lakes, streams, and other inland waterways in the northern United States and Canada. Many seek out weedy areas or other protective cover, such as swamps with fallen trees. Elassomatids similarly inhabit swampy areas with heavy vegetation, but favor the warmer environs of the southeastern United States.

The large family Percidae is primarily a freshwater group, with species in just about every type of waters, from lakes and swamps to both fast- and slow-moving streams and other bodies of water. Some live in the brackish waters of estuaries and in salt lakes. Moronids are the most versatile of the four families in regard to habitat, with members existing in fresh, brackish, and marine waters along coasts.

Various species within these families may coexist in a single body of water. For example, a typical inland lake in the Great Lakes region may be home to numerous species, including largemouth bass, bluegill (Lepomis macrochirus), and

others in the family Centrarchidae, as well as the yellow perch (Perca flavescens), walleye, and others in the Percidae.

Behavior

Because of the breadth of this four-family group, behavior varies widely. Some species school; some exist alone. Some are broadcast spawners; others build nests and mate one-on-one. Numerous species provide no parental care; others build nests and guard eggs and/or young.

The centrarchids are particularly known for their nest-building and parental care. Nest-building typically involves the male setting up a small territory, fanning its tail to create a depression in the substrate, then enticing a receptive female to his nest to lay her eggs, which he fertilizes. In many centrarchids, as well as darter perches, more than one female may be attracted to a male's territory. This often results in the male mating with different females in a single breeding season. Male centrarchids defend the nest at least until the eggs hatch, and the males of a few species continue to watch over the young for several weeks.

One unusual behavior has gained some attention. Largemouth bass in the family Centrarchidae will frequently eat whirligig beetles (Dineutes hornii), which are flat, round insects that move along calm water surfaces in looping, swirling patterns. These beetles secrete a noxious slime that repels most predators. The bass, however, have developed a way to get around the goo. According to researchers, they rinse off the beetle by repeatedly taking the insect into the mouth, gargling it, and spitting it out until the unpleasant taste is gone, or until the bass gives up. If the bass is persistent enough to rinse off the slime (which can take more than a minute) it eats the beetle. If not, the beetle escapes.

The darters comprise a huge group within the perch family, and the 146 species live in waters of North America. Members are characterized by their wary nature: Whenever the slightest threat arises, they quickly "dart" for cover. They also exhibit other interesting behaviors. The johnny darter (Etheostoma nigrum), for instance, has atypical spawning habits. The male prepares a spot under some cover, perhaps a rock overhang. When a mate arrives, the male and female both swim to the site and turn upside down to spawn. The female's eggs stick to the overhead cover. The male's job is to tend and guard the eggs for the next several weeks until they hatch. Other fishes in the Percidae may mate in pairs like the johnny darter, spawn in small assemblages of one female and several males, or engage in mass spawning.

The breeding season for moronids begins with male courtship displays, usually involving one female and several males. The routine typically includes the males closely following a female and nudging her vent area, and in some species, stereotypically swimming in circles. When appropriately stimulated, the female rises to the surface with the males in tow, and spawning occurs. Occasionally, some Morone species will hybridize with each other.

Perhaps the most interesting behavior among the elassomatids occurs during territorial and courtship displays. The territorial display takes place when a male approaches another's territory. The territorial male displays toward the intruder by expanding and/or rapidly flitting his fins, turning sideways as to present his largest view, bending his head and tail toward the intruder, and as a last resort, striking with his head. During courtship, a male elassomatid displays toward a female by bobbing up and down and waving his fins, while swimming toward the spawning site. When a female approaches, the male develops a bright spawning coloration and begins to tremble, while bumping and nipping at the female. Courtship continues for several minutes before the release of eggs and milt.

Feeding ecology and diet

Many centrarchids and percids are near or at the top of the food chain in their habitats. Largemouth bass and wall-eye, for example, are typically top predators, feeding on herbivorous as well as smaller carnivorous fishes. Even the much smaller yellow perch and bluegill are primarily carnivorous and will take invertebrates and minnows. Centrarchids also include a number of specialized mollusk-feeding forms, such as the longear and the red-ear (Lepomis microlophus) sunfishes. Many centrarchids and percid species are known as crepuscular feeders, but anglers often take considerable numbers of

these species at midday (although fishing does peak around dawn and dusk).

Some centrarchids are also known to alter their feeding ecology depending on the species composition of their neighbors. Bluegills living in waters with predatory largemouth basses, for instance, are more likely to forage in weeds rather than in open water. This action may protect them from the jaws of a bass, but it also limits their ability to find food. Additional studies of bluegill and pumpkinseed sunfishes report that they will shift their diet to zooplankton or bottom-dwelling prey in deference to the apparently dominant green sunfish (L. cyanellus) when all three occur together. Elassomatids and moronids are also carnivorous. Both eat invertebrates, especially crustaceans, and adult moronids are also piscivorous.

Predation on the species within these four families is primarily by larger piscivorous fishes. For example, northern pike (Esox lucius) will eat even quite large yellow perch, which will, in turn, feed on smaller fishes. Other predators of shallow water fishes include piscivorous birds, such as herons and ospreys.

Reproductive biology

Percid reproduction varies. Some scatter their eggs and milt into the water or over vegetation, while others spawn over gravel nests. Some species deposit individual eggs; others, such as the yellow perch and the European perch (Perca fluviatilis), lay their eggs in masses. Some species, such as the yellow perch and sauger (Stizostedion canadense), leave the area almost immediately after spawning; others, such as the johnny darter and tessellated darter (Etheostoma olmstedi), remain with their eggs until hatching. Among centrarchids, the bluegill and longear sunfishes prefer to spawn in still waters, others, including many darters, opt for the running water of a stream.

During mating season, males generally develop brighter coloration, which apparently assists in attracting females and announcing their territories to other males. Sunfishes spawn in one of three ways. A male may make a nest and attract females for mating there. Females may spawn with smaller males known as satellite and sneaker males. During breeding season, satellite males take on coloration of a female and trick the nesting male into allowing them to approach, giving them access to females coming to the nest. Sneaker males hide among vegetation near a nesting male's site, watch the females arrive, then dash through the nest site ejecting milt as they reach the females. Non-nesting males mature earlier than nesting males, commonly going through the sneaker stage when they reach the age of two years, then becoming satellite males in later years. Nesting males are usually older individuals that top the seven-year mark. Some controversy exists over whether elassomatids are nest builders. Scientists have reported spawning with and without nests in some species, leading to the hypothesis that substrate conditions determine whether nesting occurs.

Of the moronids, perhaps most is known about the behavior of the striped sea bass, probably because of its popularity as a sport fish. These fishes inhabit coastal waters along both the Atlantic (its native distribution) and Pacific coasts. The Pacific introduction can be traced to 1879 and 1882, when the fishes were translocated to the San Francisco shore. Striped sea basses are migratory, moving to cooler northern waters in summer and warmer southern waters in the fall. As breeding season approaches, they return to their home stream to spawn, apparently via olfactory cues. Feeding ceases prior to the annual breeding season, during which the fishes engage in broadcast spawning. One study of the European sea bass (Dicentrarchus labrax) indicated that its gender can be influenced by temperature. Experiments showed that temperature differences during the development of eggs could affect the ultimate sex ratio.

Conservation status

Careful monitoring of species fished for sport maintains these populations in adequate numbers. Nongame species, and those with very small distributions, fare less well. For example, numerous darter species, which are neither sport fishes nor broadly distributed, are listed as threatened or endangered. Some species in these families have been widely introduced outside of their geographic ranges. The successful naturalization of percids and centrarchids in areas well outside of their aboriginal ranges has often had deleterious effects upon faunas of indigenous fishes.

The IUCN Red List categorizes 1 species from this group as Extinct; 2 species as Critically Endangered; 4 species as Endangered; 30 species as Vulnerable; 12 species as Lower Risk/Near Threatened; and 7 as Data Deficient.

Significance to humans

A great number of species within these four families are prized sport fishes. Examples are walleye and perch in the family Percidae, as well as both large- and smallmouth bass in the family Centrarchidae. A few, such as the banded pygmy sunfish (Elassoma zonatum) are considered indicator species, and provide scientists with information about the environmental health of a particular waterway. Several members of these families, particularly the yellow perch and walleye (in the family Percidae), are commercial food fishes.

Species accounts

List of Species

Rock bass

Ambloplites rupestris

family

Centrarchidae

taxonomy

Ambloplites rupestris Rafinesque, 1817, Lakes of New York, Vermont, United States. No subspecies are recognized.

other common names

English: Goggle eye, northern rock bass, redeye; French: Crapet de roche; German: Gemeiner felsenbarsch, gemeiner sonnenbarsch.

physical characteristics

Maximum total length 17 in (43.2 cm), typically little more than one-half that. Large-mouthed, red-eyed fish with rows of small, chocolate-colored squares along the sides of its greenish to brownish body.

distribution

North America from the Mississippi Valley almost to the Atlantic coast, and Lake Winnipeg to Missouri and the northern boundaries of Georgia and Alabama. Also widely introduced worldwide.

habitat

Heavily vegetated areas of freshwater lakes and ponds, as well as clear, rocky streams.

behavior

Schools in winter, becomes solitary when breeding season commences in the spring.

feeding ecology and diet

Feeds on aquatic plants, invertebrates, and fishes, occasionally conspecifics.

reproductive biology

Spawns in late spring and early summer over male-constructed and guarded nests. The demersal, adhesive eggs hatch in three to four days. The male continues to protect the young as long as they remain in the nest area. Once they scatter, usually within a few days, protection ceases. They reach sexual maturity at three to five years.

conservation status

Not threatened.

significance to humans

Minor sport and commercial fishes.

Blue-spotted sunfish

Enneacanthus gloriosus

family

Centrarchidae

taxonomy

Enneacanthus gloriosus Holbrook, 1855, South Carolina, Georgia, and Cooper Rivers, South Carolina, United States. No subspecies are recognized.

other common names

German: Kiemenfleck-diamantbarsch.

physical characteristics

Maximum total length 3.7 in (9.5 cm). Similar in general appearance to a bluegill, but with proportionally longer fins; dark "teardrop" band beneath eye; vertical, dark banding on body; and numerous metallic blue spots in the head, body, and vertical fins.

distribution

Eastern United States, from southern New York to western Florida.

habitat

Prefers vegetated freshwater lakes, ponds, pools, and stream backwaters.

behavior

Solitary; seldom strays far from cover. Easily dominated by other centrarchids; typically found in substantial numbers only in habitats Lepomis species do not find congenial, such as the highly acidic black waters of the New Jersey pine barrens.

feeding ecology and diet

Normally feeds on snails and other invertebrates near cover of vegetation.

reproductive biology

Males build nests 4–12 in (10.2–30.5 cm) in diameter in algae or soft substrate. Spawning occurs in spring, perhaps extending from late winter to early summer. Little is known of its reproductive biology in the wild.

conservation status

Not listed by the IUCN.

significance to humans

Sometimes kept as an aquarium fish.

Bluegill

Lepomis macrochirus

family

Centrarchidae

taxonomy

Lepomis macrochirus Rafinesque, 1819, Ohio River, United States. Two or three subspecies are recognized.

other common names

English: Bluegill sunfish, sunfish; German: Blauer Sonnenbarsch; Spanish: Pez sol.

physical characteristics

Maximum total length 16 in (41 cm). Broad, rather flat fish with a small mouth. Distinguished from its relatives by an all-black opercular flap, general gray-blue coloration, a dark spot at the rear edge of the soft dorsal fin, and dark banding on the sides of the body.

distribution

Common in North America from southern Canada to northern Mexico; widely introduced throughout the world.

habitat

Freshwater, inland waters from large lakes to small ponds, also slow-moving streams. Prefers some type of cover, such as rocky or vegetated areas.

behavior

Schooling fishes. Schools of several dozen smaller fishes ranging up to 4 in (10.2 cm) long are commonly seen along lake shores in 1–2 ft (0.3–0.6 m) of water, darting from beneath docks and boats. Larger fishes generally remain further from shore in deeper water. Cleaning behavior has been recorded for Florida populations.

feeding ecology and diet

Mainly diurnal feeders. Diet comprises invertebrates and small fishes.

reproductive biology

Breeds in the late spring and early summer, when groups of males enter shallow water to begin building nests, which are depressions in the substrate. The male guards its nest. Females may also spawn with smaller males known as satellite and sneaker males, which take on the female coloration and fool nesting males into allowing them to approach and mate with females coming to the nest. Sneaker males may also lie in ambush in vegetation near a nesting male's site, wait for females to arrive, then quickly swim through the nest site, ejecting milt. The spherical, demersal eggs, which are laid singly or in small clusters, typically hatch in two to three days. Bluegills in the field typically attain sexual maturity at two to three years and about 4–5 in (10.2–12.7 cm) in length. Bluegills hybridize with pumpkinseeds and many other sunfish species.

conservation status

Not threatened.

significance to humans

Sport and minor commercial food and aquarium fishes.

Longear sunfish

Lepomis megalotis

family

Centrarchidae

taxonomy

Lepomis megalotis Rafinesque, 1820, Licking and Sandy Rivers, Kentucky, United States. Five or six subspecies are recognized.

other common names

English: Creek perch, Great Lakes longear, northern longear.

physical characteristics

Maximum total length 9.5 in (24 cm). Similar in body shape to bluegill, but with a notably larger opercular flap, especially in the adult male. Young olive with yellow specks; adults red above and orange below, and decorated on the body with small, blue spots and on the opercle with blue, curving lines.

distribution

Northeast North America, from northeastern Mexico and north to the Great Lakes.

habitat

Prefers shallow, weedy waters of lakes and ponds; also found in quiet streams.

behavior

During the spring-to-summer breeding season, males prepare nests in shallow waters along the shoreline. More than one females may approach one male's nest. Spawning occurs over the nests, and the male offers parental care to the young. In addition, some males engage in the sneaker-spawning behavior typical of many centrarchids.

feeding ecology and diet

Feeds in shallow waters on small mollusks, insects, and small fishes. Predators include other piscivorous fishes.

reproductive biology

Females lay demersal, adhesive eggs, which hatch in three to seven days. Sexual maturity occurs at about two to three years.

conservation status

American and Canadian populations are not considered to be at risk. Mexican populations are threatened by degradation of their habitat due to poor water-management practices.

significance to humans

The basis for a recreational fishery; sometimes kept as an aquarium fish.

Largemouth bass

Micropterus salmoides

family

Centrarchidae

taxonomy

Micropterus salmoides Lacepède, 1802, Carolinas, United States. Two subspecies are recognized.

other common names

English: Green bass, largemouth black bass, northern largemouth bass; French: Achiganà grande bouche; German: Forellenbarsch; Spanish: Huro, lobina negra.

physical characteristics

Maximum total length 38 in (97 cm). About one-third as wide as long, distinguished in part by a deeply cut dorsal fin. Differs from its relative the smallmouth bass (M. dolomieui) by its lack of horizontal striping on the head, the presence of a dark horizontal stripe on each side of the body instead of vertical banding, and a maxillary that reaches just past the eye.

distribution

North America from the Great Lakes east to the Atlantic coast, and from Lake Winnipeg south to northern Mexico. Also widely introduced throughout the United States and around the world, including Europe, South America, and Africa.

habitat

Freshwater fish, prefers lakes, ponds, swamps, and river/stream backwaters with considerable hiding places, including thick vegetation or rocky structures.

behavior

Juveniles school, but adults are solitary animals that remain near cover, such as logs or heavy vegetation and seldom venture into waters deeper than 20 ft (6 m).

feeding ecology and diet

Diurnal feeder on crustaceans and other invertebrates, also fishes.

reproductive biology

Spawns in the late spring and early summer. The male becomes territorial and makes depressions in the substrate of weedy areas to serve as nests. A single female may lay eggs over several nests. Both males and females provide parental care, and have been known to guard the eggs and young for up to a month after hatching. Parental care continues as long as the young fishes remain schooled.

conservation status

Not threatened.

significance to humans

Part of a large, popular fishing industry in the United States and Canada.

Black crappie

Pomoxis nigromaculatus

family

Centrarchidae

taxonomy

Pomoxis nigromaculatus Lesueur, 1829, Wabash River, Indiana, United States. No subspecies are recognized.

other common names

English: Calico bass, grass bass, moonfish, oswego bass, speckled bass, strawberry bass; French: Marigane noire.

physical characteristics

Maximum total length 19.3 in (49 cm). Rather flat, broad, silvery fishes with sloping foreheads and a black, mottled pattern on the sides. Fins are also noticeably mottled. The similar white crappie (P. annularis) is less mottled and has vertical banding on its sides.

distribution

Central and eastern North America, south to Florida and Texas, United States, and north to Quebec and Manitoba, Canada. Widely introduced throughout the United States and other countries.

habitat

Freshwater species. Prefers clear, weedy lakes, ponds, and slow-stream backwaters.

behavior

Schools during the day in deep water around structures. Crepuscular feeder; moves to shallower water to feed. Exciting sport fish that puts up a good fight when hooked by anglers.

feeding ecology and diet

Feeds both amidst vegetation and in open waters on small fishes and invertebrates. Primarily feeds at dawn and dusk.

reproductive biology

Spawning occurs in late spring and early summer. Males make nests, sometimes near other males, in the substrate of weedy or rocky areas. Females may mate with several males. Females lay spherical, demersal, adhesive eggs singly or perhaps in small clumps. Males guard the eggs and young, which hatch in two to three days. Reach sexual maturity by two to four years old.

conservation status

Not threatened.

significance to humans

Fished for sport in the United States and Canada.

Banded pygmy sunfish

Elassoma zonatum

family

Elassomatidae

taxonomy

Elassoma zonatum Jordan, 1877, Little Red River, Arkansas; R. Brazos, Texas; United States. No subspecies are recognized.

other common names

German: Gebänderter Zwergbarsch.

physical characteristics

Maximum total length 1.9 in (4.8 cm). White and grayish black, speckled fish with two stripes on the anterior sides of the body. One stripe extends from the mouth through the eye, and the other begins above and behind the eye. Tail and fins are also speckled.

distribution

South-central United States south of a line from southern Illinois to North Carolina.

habitat

Muddy-bottomed freshwaters, including swamps and other weedy aquatic areas.

behavior

Normally solitary; males in limited space will defend their territories against encroachment by other males. Territorial displays include a more intense body coloration, a rapid beating of the tail and pectoral fins, and if necessary, a quick strike at the intruder.

feeding ecology and diet

Carnivore; feeds on crustaceans, worms, and other invertebrates.

reproductive biology

During breeding season, the male takes on brighter coloration and begins enticing a female to his spawning site by wiggling all his fins in a distinctive pattern. Once a female appears receptive, the male trembles and "points" to the site with his snout, and then gently prods the female. Nest building may or may not occur, perhaps depending on the suitability of the substrate. Relatively little is known of its reproductive biology in the wild.

conservation status

Not listed by the IUCN.

significance to humans

Of minor importance to the pet trade, also important as indicator species of environmental quality.

Striped sea bass

Morone saxatilis

family

Moronidae

taxonomy

Morone saxatilis Walbaum, 1792, New York, United States. No subspecies are recognized.

other common names

English: Linesider, roccus, rock, rockfish, striped bass, striper bass; French: Bar d'Amérique, bar rayé; Spanish: Lubina estriada.

physical characteristics

Maximum total length 6.6 ft (2 m). Body silver, with more or less interrupted, black, parallel stripes along the sides of the body.

distribution

Tributaries along the U.S. Atlantic coast, also Gulf of Mexico west to Louisiana; widely introduced throughout the United States and other countries.

habitat

Fresh and brackish bays and tributaries, also inland coastal waterways. Found in rivers during spawning.

behavior

Social; typically lives in large size-graded schools. When handled or threatened, responds with grunts and clicks as it attempts an escape.

feeding ecology and diet

Carnivores; larvae feed on zooplankton, juveniles eat various invertebrates, and adults take invertebrates and fishes.

reproductive biology

Broadcast spawners, produce fairly buoyant eggs during an annual reproductive season. Eggs are laid in moving water, which keeps the eggs afloat until they hatch in two to seven days. No parental care for eggs or young. Males reach maturity at about two to three years and 12–15 in (30.5–38 cm); females at about three to four years and 20–24 in (51–61 cm) long.

conservation status

Not threatened.

significance to humans

Important sport and minor commercial food fishes.

Rainbow darter

Etheostoma caeruleum

family

Percidae

taxonomy

Etheostoma caeruleum Storer, 1845, Fox River, Illinois, United States. No subspecies are recognized.

other common names

German: Regenbogen-Springbarsch.

physical characteristics

Maximum total length 3 in (7.7 cm). Brownish orange fish with about a dozen vertical, green bands on the sides of its body and green markings on its face. It has two dorsal fins.

distribution

Eastern North America from southern Ontario, Canada to Mississippi and Louisiana, and from Minnesota to West Virginia in the United States.

habitat

Bottom-dwelling, freshwater fishes that inhabit the swift currents of creeks, as well as average-to-small rivers.

behavior

Solitary, stations in the lee of rocks as it moves over the bottom in search of food. Individuals are very wary and seek shelter among rocks at the slightest disturbance.

feeding ecology and diet

Feeds primarily on crustaceans and invertebrates, but also eats fish eggs and larvae. Feeding can involve suction, in which they draw water and prey into their mouths, or diving head-first toward sandy and gravely substrate after prey.

reproductive biology

Males become more brightly colored during breeding season, which occurs in the spring. Females wait in slower waters of a stream, half-buried in the substrate, while males enter stream riffles. As a female approaches the spawning site, a male swims up, following her closely and defending her from any other interested males. He continues to maintain this "moving territory" until mating occurs. During mating, males align themselves next to the female and spawn while both vibrate. Females typically lay three to seven eggs at a time, but spawn multiple times, sometimes laying up to 1,000 eggs per season. Females typically bury their eggs, which hatch in 10–12 days. They reach sexual maturity at one year.

conservation status

Not listed by the IUCN.

significance to humans

None known.

Ruffe

Gymnocephalus cernuus

family

Percidae

taxonomy

Gymnocephalus cernuus Linnaeus, 1758, European lakes. No subspecies are recognized.

other common names

English: Pope; French: Frash, grémille; German: Kaulbarsch, Pfaffenlaus; Spanish: Acerina.

physical characteristics

Maximum total length 9.8 in (25 cm). Small, dark-spotted, brownish fish with 15 to 19 long dorsal spines. Dorsal fins are fused.

distribution

France to eastern Siberia. Accidentally introduced to Lakes Superior and Michigan in the United States.

habitat

Prefers deep waters of lakes and ponds, but also found in streams.

behavior

Releases alarm pheromones that alert conspecifics to danger. Adults have particularly well-developed neuromasts, sensory organs that can detect even slight vibrations in the water and thus allow the fishes to hunt for food in the cover of darkness.

feeding ecology and diet

Nocturnal feeders of shallow-water zooplankton.

reproductive biology

Spawns in shallow water, where strands of sticky, whitish yellow, demersal eggs adhere to weeds and/or rocks along the bottom. No parental care for eggs or young, which hatch in 5–12 days. They attain sexual maturity in two to three years at 4.3–4.7 in (11–12 cm) in length. In warmer areas, sometimes become sexually mature in just one year.

conservation status

Not threatened.

significance to humans

Sport and minor food fishes. Considered an undesirable, invasive species in the Great Lakes, where it likely arrived via ballast water from Eurasian ships.

Yellow perch

Perca flavescens

family

Percidae

taxonomy

Perca flavescens Mitchill, 1814, New York, United States. No subspecies are recognized.

other common names

English: American perch, lake perch, perch; French: Perchaude, perche canadienne, perche jaune; German: Amerikanischer Flußbarsch.

physical characteristics

Maximum total length 19.7 in (50 cm), but anglers rarely see one longer than 12 in (30.5 cm). Greenish yellow, full-bodied, fusiform fishes with six to nine vertical dark bars along the sides.

distribution

North America from northwestern Canada to the far northwestern United States, through central and southern Canada, the north-central United States, and the Great Lakes region, and into the southeastern Canadian provinces, as well as the eastern United States south to South Carolina. Also introduced to various locations around the world. In North America, for instance, it has been introduced to the western and southern United States and has spread into British Columbia in western Canada.

habitat

Freshwater streams, rivers, ponds, and lakes. Prefers sites with submerged vegetation, also inhabits brackish water and salt lakes.

behavior

Shoals of young fishes are commonly seen in very shallow waters near shore, often darting between docks in water less than 3 ft (0.9 m) deep. Shoals of larger fishes prefer somewhat deeper waters.

feeding ecology and diet

Feeds on small to large insects and other invertebrates, fish eggs, and fishes, sometimes taking bait almost as large as themselves. Predators include larger fishes, walleye, small-mouth bass, northern pike (Esox lucius), and numerous salmon species.

reproductive biology

Spawns from late winter to midsummer. They frequently lay their long, spiral egg masses in vegetation. There is no parental care.

conservation status

Not threatened, although stocks in many areas have been severely overexploited, and these fisheries are increasingly regulated by fishery managers.

significance to humans

Commercial food and sport fishes.

Logperch

Percina caprodes

family

Percidae

taxonomy

Percina caprodes Rafinesque, 1818, Ohio River, United States. Three subspecies are recognized.

other common names

English: Manitou darter, zebrafish; French: Dard-perche, fouille-roche.

physical characteristics

Maximum total length 7 in (18 cm). Long, fusiform fishes with conical nose and banding on the sides of the body that becomes more irregular posteriorly. Body color is greenish brown.

distribution

North America from Hudson Bay east to the Atlantic coast, west to Saskatchewan, and south through the Great Lakes region to the Gulf of Mexico.

habitat

Spread through many habitats, but primarily gravel- or sandy-bottomed, medium-sized rivers. Also bottom dweller in weedy lakes, usually some distance from the shoreline.

behavior

Perhaps their most notable behavior occurs during feeding, when they frequently use their noses to root prey out of the substrate and from beneath stones.

feeding ecology and diet

Feeds on zooplankton, particularly copepods.

reproductive biology

Moves into shallow waters or rivers to spawn in the spring. The male becomes more vividly colored and develops tubercles on its ventral side. A gravid female approaches a school of males, which follows her to the substrate. Following the release of eggs and milt, the female and often the males engage in rapid wriggling, which serves to churn up the bottom and bury the eggs. No parental care for eggs or young.

conservation status

Not listed by the IUCN.

significance to humans

None known.

Walleye

Stizostedion vitreum

family

Percidae

taxonomy

Stizostedion vitreum Mitchill, 1818, Cayuga Lake, Ithaca, New York, United States. Two subspecies are recognized.

other common names

English: Walleyed pike, blue pike, gray pike, green pike, yellow pike, pickerel, dory, glass eye, marble eye, pikeperch; French: Doré doré jaune; German: Amerikanischer Zander.

physical characteristics

Maximum total length 42 in (107 cm), but fishes below (often well below) 24 in (61 cm) are the norm. Long, fusiform body with large, translucent eyes. Body is typically brownish.

distribution

Most of the United States and Canada, except for far northern and eastern Canada, and far southern and western United States.

habitat

Freshwater (rarely brackish); inhabits lakes, ponds, and larger rivers, prefers sites with shallow, somewhat murky waters.

behavior

Beginning in late winter, small groups of up to a half-dozen males will begin chasing one or two gravid females. The females are noticeably larger than the pursuing males. Eventually, the females will lead the groups to very shallow water, sometimes only a few inches below the surface, for a single night of spawning.

feeding ecology and diet

Feeding sessions begin at sunset and carry on into the night. An opportunistic predator, the diet comprises fishes, especially yellow perch and invertebrates, but it is also known to take frogs and mudpuppies.

reproductive biology

A broadcast spawner, reproduces over a variety of substrates, including sandy, gravelly, or rocky lake and river bottoms, as well as stream vegetation, usually in an area where the water is moving either via a slow current or shoreline waves. The female scatters her eggs. Breeding occurs in spring to early summer, sometimes even in late winter. Egg production in the females begins much earlier, and anglers find females well laden with eggs in early winter. Eggs hatch in one to two weeks. No parental care of eggs or young.

conservation status

Not threatened.

significance to humans

Major sport fishes and minor commercial food fishes.

Resources

Books

Helfman, Gene S., Bruce B. Collette, and Douglas E. Facey. The Diversity of Fishes. Malden, MA: Blackwell Science, 1997.

Johnson, G. D., and A. C. Gill. "Perches and Their Allies." In Encyclopedia of Fishes, edited by John R. Paxton and WilliamN. Eschmeyer. 2nd edition. San Diego: Academic Press, 1998.

Nelson, Joseph S. Fishes of the World. New York: John Wiley & Sons, Inc., 1994.

Periodicals

Jones, W. J., and J. M. Quattro. "Phylogenetic Affinities of Pygmy Sunfishes (Elassoma) Inferred from Mitochondrial DNA Sequences." Copeia 199, no. 2 (1999): 470–474.

Koumoundouros, G., M. Pavlidis, L. Anezaki, C. Kokkari, A. Sterioti, P. Divanach, and M. Kentouri. "Temperature Sex Determination in the European Sea Bass, Dicentrarchus labrax (L., 1758) (Teleostei, Perciformes, Moronidae): Critical Sensitive Ontogenetic Phase." Journal of Experimental Zoology 292, no. 6 (2002): 573–579.

Maniak, P. J., R. D. Lossing, and P. W. Sorensen. "Injured Eurasian Ruffe, Gymnocephalus cernuus, Release an Alarm Pheromone that Could Be Used to Control Their Dispersal." Journal of Great Lakes Research 26, no. 2 (2000): 183–195.

Organizations

American Fisheries Society. 5410 Grosvenor Lane, Suite 110, Bethesda, MD 20814-2199 USA. Phone: (301) 897-8616. Fax: (301) 897-8096. E-mail: [email protected] Web site: <http://www.fisheries.org/>

North American Native Fishes Association. 1107 Argonne Dr., Baltimore, MD 21218 USA. Phone: (410) 243-9050. E-mail: [email protected] Web site: <http://www.nanfa.org>

Other

"Animal Diversity Web." University of Michigan Museum of Zoology [cited January 20, 2003]. <http://animaldiversity.ummz.umich.edu>

Finley, L. "An Introduction to Enneacanthus obesus (Girard), the Banded Sunfish (with Special Reference to Rhode Island Distribution)." The North American Native Fishes Association [cited January 20, 2003]. <http://www.nanfa.org/articles/acobesus.htm>

"TNHC: The North America Freshwater Fishes Index" [cited January 20, 2003]. <http://www.tmm.utexas.edu/tnhc/fish/na/naindex.html>

Leslie Ann Mertz, PhD