Species Accounts
Percidae - Perches - Perches et Dards
Perches, darters, pike-perches and their relatives are found in freshwaters across the northern hemisphere. There are about 162 species total with 148 in North America. The Canadian members number 16, including 1 exotic species from Europe. There are 9 species in the NCR.
Perches have 2 dorsal fins, the first spiny (6-9 spines) and the second soft rayed, which are usually separate or only slightly joined. The anal fin has only 1-2 spines (rather than 3 as in related families). The pelvic fins are under the pectorals (thoracic) and have 1 spine and 5 soft rays. There are 5-8 branchiostegal rays and the branchiostegal membrane is not attached to the isthmus. Scales are ctenoid. Teeth may be long and sharp or small and in bands. The operculum has a sharp spine. There are 2 kinds of perches - large species with compressed bodies and a swimbladder, and derived from them small species with depressed bodies and reduced or absent swimbladders. This condition is believed to have arisen twice within the family. In North America the larger species include the Yellow Perch, Sauger and Walleye and the smaller species are the darters. In darters the mouth is small, not extending back past the anterior eye margin, and the lower edges of the preopercle bone on the side of the head are smooth.
Perches are found in warm southern waters to subarctic ones, in both flowing and still water. Some larger species are commercially important in Canada while smaller species make attractive aquarium fishes. The small darters rival coral reef fishes for colour when in breeding condition.
Darters are sensitive to environmental change and are useful indicators of the health of aquatic ecosystems. The Sauger, Walleye and Yellow Perch are very important species in sport fisheries in Canada. Walleye and Sauger are the first two sport fishes in order of priority for anglers in the Ottawa River below Ottawa (Hopkins, 2000).
Perches have a variety of reproductive strategies which include broadcasting, stranding, burying, attaching, clumping and clustering. During the breeding season tubercles develop, particularly on the male. These may be on the body, fins or head and are used to maintain contact and enhance grip between males and females during the spawning act. Darters in the genus Percina have enlarged and strongly toothed scales between the pelvic fin bases and along the belly mid-line in males. The male probably uses these scales during spawning to stimulate the female. Female darters often have enlarged genital papillae and in those species which lay eggs in gravel or plants the papilla is an elongate tube. Some darter males have egg-shaped knobs on the dorsal or paired fins and these are used to attract females to a nest site. Females are thought to be more likely to spawn with successful males, which already have eggs or convincing mimics of eggs, in their nests.
Certain darters, such as the Iowa and Johnny Darters, have large secretory cells in their skin. These release a chemical alarm substance into the water when damaged in a predator's attack. The chemical signals other darters to "freeze", hopefully avoiding detection by the predator. Studies in southern Ontario indicate that darters are not often food for other fishes, despite their small size, but they are an important food for common mergansers during the spring migration of this bird.
Iowa Darter / Dard à ventre jaune
Etheostoma exile (Girard, 1859)
Taxonomy
Other common names include Yellowbelly, Red-sided Darter, Weed Darter and Dard d'herbe.
Key Characters
This species is distinguished from other darters by having the anal fin smaller than the soft dorsal fin, the snout and upper lip joined (i.e. premaxillaries not protractile), belly scaled, cheeks and opercles scaled (may be obscured by skin), dorsal fin spines longer than eye diameter, 7-12 (usually 8-9), soft rays 9-13 (usually 10-11), and lateral scales 45-69 (usually 48-60) with 18-35 pored.
Description
Anal fin with 1-2 spines and 6-9 soft rays. Pectoral rays 12-14. Gill rakers short, numbering 8-10. The opercles are scaled. Males have larger first dorsal and anal fins than females.
Colour
Overall colour is olive-brown to dark brown fading to cream or yellowish on the belly. There are bars radiating from the eye. The back has 7-12 vague saddles and the mid-flank 9-14 short bars or squarish blotches. The caudal fin is barred and there is a basal spot, flanked by a spot above and sometimes one below. Breeding males have a first dorsal fin with a blue basal band or a series of blue spots each surrounded by a clear halo, a transparent band, an orange-red band and a deep blue or blue-green marginal band. The bars on the flank are dark blue or blue-green and the spaces between them yellow, orange or brick red. The belly is yellow, orange or red. The pectoral and anal fins are orange-yellow or yellow-red. Simon and Faber (1987) give a description of pigmentation of larvae from Lake Heney, north of the NCR.
Size
Reaches 7.5 cm.
Distribution
Found from eastern and southern Québec westward through the Great Lakes basin and tributaries of Hudson Bay to Alberta and across the northern U.S.A. paralleling this distribution. Also reported from northern Alberta.
Origin
This species entered the NCR from a Mississippian refugium or possibly a Missourian refugium (Mandrak and Crossman, 1992).
Habitat
The habitat of this darter is weedy areas of lakes, ponds, marshes, bogs, streams and rivers with clear water. Water current is slow to still and there is usually vegetation. At night it hides in crevices, holes and under logs and branches. Iowa Darters have an alarm substance in their skin. Damage to the skin as in a predator's attack releases the alarm substance which other darters can detect, initiating predator avoidance behaviour. The preferred temperature range is 12-25°C.
Age and Growth
Iowa darters may live 4 years and females are larger than males. Maturity is attained at 1 year.
Food
Food is aquatic insects and crustaceans, snails and fish eggs. Midwater food items are taken, unusual in darter.
Reproduction
Spawning occurs in May-June in Canada preferentially on roots, usually those under banks, or on sand or pebbles in shallow wate. Males have territories and females spawn with several males. The male lies alongside or over the female with his tail depressed and paralleling hers and his pelvic fins over her dorsal fin. In a stream tributary to Lac LaPêche, a male and a female or two males and a female, vibrated simultaneously and eggs fell on leaves, twigs or algae-covered logs or in crannies or gravel in clear water 6-8 inches (15-20 cm) deep with moderate current. This occurred at the end of May and the beginning of June at 9°C (McAllister, 1971). Eggs are laid in groups of 3-7 and are up to 1.3 mm in diameter. Eggs attach to roots and weeds. The male continues to guard his territory but does not care for the eggs directly. Large females may lay up to 2048 eggs. Eggs hatch in 9-10 days at 13-16°C. Larvae are 3.0-4.0 mm long at hatching.
Importance
None although it is common in eastern Canada and is probably food for other fish species.
Fantail Darter / Dard barré
Etheostoma flabellare Rafinesque, 1819
Taxonomy
Other common names include Striped Fantail Darter and Barred Fantail Darter.
Key Characters
This species is distinguished from other darters in Canada by having the anal fin smaller than the soft dorsal fin, the snout and upper lip joined (i.e. premaxillaries not protractile), belly is scaled, dorsal fin spines short, about eye diameter or less, 5-10, usually 7-8, soft rays 10-15, lateral scales 38-60 with 11-59 pored.
Description
Anal fin with 2 spines and 6-10 soft rays. Pectoral rays 10-14. Gill rakers short, numbering 10-12. The nape, cheek, opercle and breast lack scales.
Colour
Overall colour is olive-brown with 5-15 dark flank bars or sometimes thin stripes, or both on a yellow-brown background. There are about 8-10 dark brown to black saddles. Belly cream, yellowish, yellow-orange or dusky. The second dorsal fin has 6 narrow stripes and the caudal fin has 4-7 wavy, dark bars. Bars are present before and behind the eye but the one below the eye is weak to absent. Spawning males develop white to yellow-orange, fleshy knobs at the tips of the dorsal fin spines. The base of the fin becomes thickened, perhaps to produce an anti-bacterial and anti-fungal mucus. Cheeks are olive-green and the rest of the head black or dusky. The breast is dusky. The spiny dorsal fin develops basal and marginal orange stripes and the flanks are yellowish.
Size
Attains 8.6 cm.
Distribution
Found from southern Québec and eastern New York across the southern Great Lakes to Iowa and Kansas and south to Louisiana and Mississippi. In Canada it is recorded from the upper St. Lawrence River drainage in southernmost Québec, along the lower Ottawa River and tributaries of Lakes Ontario, Erie and southern Lake Huron.
Origin
This species entered the NCR from a Mississippian refugium.
Habitat
The preferred habitat is streams with slow to moderate or even fast current. Riffles and raceways are used by this species. Deep areas are used for a winter retreat and gravel and boulder bottoms for spawning. Also found less frequently in lakes. The preferred temperature is 22.4°C.
Age and Growth
Males live longer than females and are larger. Males usually reach 4 years and females 3 years of age, but these fish are mature at 1-2 years of age. Maximum age is 5 years.
Food
Food is aquatic insects, such as net-spinning caddisflies, blackflies and stoneflies, and crustaceans taken from between and under rocks in the morning and evening. Some molluscs are taken occasionally. The fantail spends most of its time on the bottom in crevices waiting for prey. Food items can be almost as long as the fish.
Reproduction
Males set up a territory in spring (April to June) under a rock, cleaning the rock surface with the fleshy knobs of the dorsal fin spines. The male becomes very dark when chasing away intruders. Males threatened by other fishes "freeze" for 2-3 minutes and then resume normal activity. Females enter male territories, poking their heads under rocks and darting from rock to rock. Courtship involves leading a female to the rock cavity with circling, figure-of-eight swimming, nudging and prodding, and entry and exit from the cavity until the female turns upside down. The swimming patterns are repeated with the male right side up and head to tail with the female. The female eventually quivers and lays 1-3 eggs which stick to the rock, the male flips over to quiver and fertilise the eggs and then flips back again. Up to 45 eggs are laid and fertilised in this manner with the female inverted for up to 2 hours. The cavity under the rock is narrow enough so that the female's dorsal fin contacts the bottom and offers some support. The male may mate with several females and the female with up to 5 males in each spawning season. He guards the eggs and brushes them with his dorsal fin knobs. It is probable that the male is smearing mucus on the eggs to prevent bacterial and fungal attack. The number of eggs in a nest can vary from 8 to 562. The eggs are up to 2.7 mm in diameter. In the NCR a ripe female had eggs 1.6 mm in diameter on 20 May.
Importance
This darter makes an excellent aquarium fish.
Johnny Darter / Raseux-de-terre noir
Etheostoma nigrum Rafinesque, 1820
Taxonomy
Another common names is Central Johnny Darter. Hybrids with the Tessellated Darter are reported in the NCR (McAllister et al., 1972).
Key Characters
This darter is recognised by the small mouth not extending beyond the anterior eye margin, a smooth edge to the preopercle bone on the side of the head, an anal fin smaller than the soft dorsal fin, belly scales present or absent but no enlarged scales in mid-line, premaxillaries protractile, i.e. a deep groove separates the upper lip from the snout, 1 thin anal spine, 1-11, usually 9 or less, pores in the preoperculomandibular canal (the head sensory canal running from the lower jaw onto the preopercle bone), and 9-15, usually 12 or less, dorsal fin soft rays.
Description
Dorsal fin spines 6-10, anal soft rays 6-10. Pectoral fin rays 10-14. Lateral line scales 35-59. There are 8-11 short gill rakers. The breast, cheek and nape are usually scaleless.
Colour
Overall colour is pale brown or sandy with yellowish or greenish tints depending on habitat. The back has about 4-7 dark brown saddles. The flanks have 7-12 distinctive X-shaped pigment marks which may also resemble M- or W-shapes. The caudal fin usually has 2-4 (up to 6) complete bars. Breeding males are black and flank markings are not always visible or appear as bars. The dorsal, anal and pelvic fin spine tips may be swollen white knobs.
Size
Reaches 7.7 cm.
Distribution
Found in southern Québec, Ontario, Manitoba and eastern Saskatchewan. Occurs southward to Mississippi and Alabama.
Origin
This species entered the NCR in a northward dispersal from a Mississippi refugium via the Great Lakes and Ohio River drainages, 12,000 years B.P. (Chapleau and Cooper, 1992).
Habitat
The Johnny Darter occurs in lakes, large rivers and streams although preferring the latter. It is found in relatively fast water or in still water and is most frequent over sand, gravel or boulder bottoms. In competition with other darters, it dominates weed beds. It may also be found in lakes down to 64 m. Its preferred temperature is 22.8°C. It is less sensitive to pollution compared to other darters in the NCR.
Age and Growth
Females live about a year longer than males, to age 4, but males are larger. They can mature at 1 year.
Food
Food is various aquatic insects and crustaceans taken from the bottom. This common darter is eaten by many other fishes.
Reproduction
Spawning occurs from April to June in Canada, the peak depending on environmental conditions (temperature range 10-25°). Males clean the undersurface of rocks with their fins and maintain a territory, defending it against other males by a display with erect fins. Male fights involve head butting and fin nipping. Males also defend the nest site against crayfish which favour territories under rocks and eat fish eggs. Crayfish with a carapace length up to 3.2 cm were chased away by Johnny Darter nips to the abdomen. Females are courted by the male's invitation under the rock and his movements there upside down. The pair move over the rock surface together inverted and an adhesive egg is deposited and fertilised every few seconds. Should the female turn upright, the male prods her into inverting and continuing the egg laying. The female may deposit 30-200 eggs at each site and visit 5-6 sites. A single site may have up to 1150 eggs, collected from a series of females. Males guard the eggs and fan them with their pectoral fins to keep them clean and aerated. The eggs are also rubbed with the swollen dorsal fin spines. Eggs which develop a fungal infection are eaten. Eggs are up to 1.5 mm in diameter.
Importance
This species is an excellent aquarium denizen and has been used in behavioural studies.
Tessellated Darter / Raseux-de-terre gris
Etheostoma olmstedi Storer, 1842
Taxonomy
Also known as dard tesselé. This species was long confused with the Johnny Darter and so comparatively little is known of its biology in Canada. It hybridises with the Johnny Darter in the NCR (McAllister et al., 1972). Some authors consider it to be a subspecies of Etheostoma nigrum (Goodchild, 1994a).
Key Characters
This darter is recognised by the small mouth not extending beyond the anterior eye margin, a smooth edge to the preopercle bone on the side of the head, an anal fin smaller than the soft dorsal fin, belly scaled or naked but no enlarged scales in mid-line, premaxillaries protractile, i.e. a deep groove separates the upper lip from the snout, 1 thin anal spine, 9-13, usually 11, pores in the preoperculomandibular canal (the head sensory canal running from the lower jaw onto the preopercle bone), and 10-17, usually 13 or more, dorsal fin soft rays. Usually confused with the Johnny Darter but has continuous infraorbital (under the eye) and supratemporal (over back of head) canals.
Description
Dorsal fin spines 5-11 (usually 8-10), anal fin usually with 1 spine in Canada and 5-11 (usually 7-9) soft rays, and pectoral fin rays 11-14. Lateral line scales 34-64. There are 7-10 short gill rakers. Scales on the nape, breast, belly and cheek vary from absent to fully scaled but are more scaly than the Johnny Darter.
Colour
The back is yellowish to light green and has 6 dark brown saddles. The flank has 7-12, usually 8-11, brown w-, x-, or v-shaped marks. The belly is white. There is a bar below the eye and in front of the eye. The caudal fin has 4-11, usually 5-8, complete bars and the dorsal and pectoral fins are also barred. There is a faint spot at the caudal fin base. Breeding males develop 12-13 bars along the flank and lose the w-, x-, and v-shaped markings. Fin membranes become dark and the unpigmented rays stand out in contrast, the reverse of the non-breeding appearance. Breeding males have a blotch between the first 2 spines of the dorsal fin. Pelvic spine and ray tips form white knobs. The second dorsal fin is large and often reaches back to the caudal fin.
Size
Reaches 8.8 cm standard length.
Distribution
Found in Atlantic drainages from southeastern Ontario and southwestern Québec south to Georgia and Florida but not in maritime Canada.
Origin
This species entered the NCR from an Atlantic coastal refugium.
Habitat
This darter prefers larger rivers, but may also occur in streams and lakes, and is generally found over sand, mud or rock bottoms in slow to still water. It is replaced in some streams by the Johnny Darter. It is tolerant of polluted water. The preferred temperature is 22.8°C. They are often buried in the sandy substrate with only the eyes and caudal fin tip showing.
Age and Growth
Maximum age is between 3 and 4 years. All are mature at 2 years, and some at 1 year of age.
Food
Food is crustaceans, insects, snails and algae taken mostly during the day.
Reproduction
Eggs are laid in clusters up to 7.5 cm wide on the underside of rocks in spring (April-June), when both sexes are upside down. Temperatures range from 12.5-18.5°C and spawning usually occurs during the day, although it may occur at night too. Current is moderate and water depth is a few centimetres to over 2 m. The eggs are guarded and cleaned by the male. Up to 1435 eggs are laid with a diameter up to 1.6 mm. They hatch in 97 hours at 25-26°C. Eggs are laid in clutches of 19-324. This darter is unique among fishes in that males clean and defend eggs which they did not fertilise. A nest may contain over 2000 eggs. Large males are dominant over smaller males and defend the few rocks in a stream which can be used for spawning. However the dominant male will move from his original rock to others because they have more uncovered spawning area and attract females. Subordinate males take over the abandoned rock, clean the surface not yet used and also clean the dominant male's eggs. In effect the dominant male is exploiting the subordinate male's lack of access to spawning sites. The dominant male can spawn repeatedly at different sites but is assured of care of "his" eggs by the subordinate male.
Importance
The Committee on the Status of Endangered Wildlife in Canada placed this species in the "Not at Risk" category in 1993.
Yellow Perch / Perchaude
Perca flavescens (Mitchill, 1814)
Taxonomy
Other common names include Common Perch, Lake Perch, American Perch, Raccoon Perch, Coontail, Ring Perch, Striped Perch, Redfin Perch, Convict, Yellow Ned and Jack Perch.
Key Characters
The most distinctive feature of the perch is the 5-10 wide black bands on the flank although these may be faint in some populations. In addition the mouth is large with the upper jaw extending back to the middle of the eye or further, the preopercle bone on the side of the head is serrated at its angle, and there are only 6-9, usually 7-8, soft rays in the anal fin.
Description
Lower jaw teeth are small and none are canines. First dorsal fin spines 11-15, second dorsal fin with 1-2 spines and 12-16 soft rays. There are 2 anal fin spines. Pectoral rays 13-15. There are 19-22 moderately slender gill rakers. The space between the pelvic fin bases is less than 1 base width. Ctenoid scales number 50-70 in the lateral line. Cheeks are scaled. There are 3 short, thick, pyloric caeca.
Colour
The back and sides are green, olive or yellow-brown fading ventrally to grey or white. The flanks may be a rich golden yellow. The eye is yellow or green. The spiny dorsal fin is yellowish to green with a black margin and often with black on the membranes anteriorly and posteriorly. Other fins are usually yellowish but the pectoral and pelvic fins may be more orange. The pelvic fins may be silvery. Fin membranes may be clear to cloudy and usually not coloured. Breeding males have orange to bright red lower fins and colours generally are more intense. Faber (1985a) illustrates a larva.
Size
Reaches 53.3 cm. The world, all-tackle angling record from Bordentown, New Jersey in 1865 weighed 1.914 kg. The Ontario record as of the year 2000 weighed 1.0 kg.
Distribution
Found from Nova Scotia except Cape Breton Island, through New Brunswick, southwest Quebec, Ontario and Manitoba including the Hudson Bay lowlands, Saskatchewan, Alberta and north to Great Slave Lake. Present in southern Columbia River drainages of British Columbia from the spread of specimens introduced to Washington. In the U.S.A. south to Missouri and to South Carolina east of the Appalachians. Widely introduced outside this natural range.
Origin
This species entered the NCR from a Mississippian or an Atlantic coastal refugium and possibly a Missourian refugium (Mandrak and Crossman, 1992). The presence of this species in Gatineau Park may be from introductions (Rubec, 1975a).
Habitat
Perch are commonly found in lakes, ponds and rivers where there is some vegetation, clear open water, slow to no current and low turbidity. They are often found associated with structures in the water, whether natural or man-made like breakwaters and boat docks. Preferred temperatures are in the 20-24°C range (21.4°C) and they are limited by the 31°C summer isotherm in the south. pH as low as 4.4 is tolerated. Depth range is down to 46 m but they are mostly found in water shallower than about 9 m. They travel in schools of up to 200 fish, daily and seasonally for spawning and feeding and in response to temperatures. Schools of young perch may be mixed in with schools of Spottail Shiners swimming near the surface. Predators such as the larger Yellow Perch, Northern Pike and Walleye swim below the mixed school and are 10 times more likely to take a shiner than a perch. They rest at night on the lake or river bottom and, unlike Walleyes and Saugers, are most active during the day. Schooling by adult, predatory perch reduces the chances of a prey fish to escape - it may encounter another school member. Yellow Perch are active under winter ice.
A study on perch in the Ottawa River (Stobo, 1971) showed 65-100% mortality below effluents for caged fish and mortalities of 10-20% up to a mile below, partly due to less food and less variable food supplies than in natural areas. Tag recoveries at 56.5% indicated a restricted home range and populations in the river are possibly distinct.
A fish kill along extensive stretches of the Rideau River and Canal was reported in spring 1956 (newspaper reports). The raising of water levels in the Rideau River and Canal system starting in late April 1996 was detrimental to perch populations. The lowering of the sluice gates at Hog's Back, to fill canal sections to the south, cut off water flow to the north. Submerged aquatic vegetation near Carleton University was exposed stranding both eggs and adult fish (RMOC, 1996a).
Age and Growth
Young-of-the-year perch in the Ottawa River show linear growth from 73 to 114 mm fork length from 3 June to 26 September. Growth of these fish over winter was negligible as fish caught the following May were of similar size to those caught in late September (Rodgers, 1976). Females grow faster than males and reach a larger final size. Males are usually mature at 2-3 years at females at 2-4 years but this varies with latitude as does growth. Some one-year-old males are mature in Lake Erie. In Québec it takes 4-5 years minimum to produce fish of a harvestable size (18-20 cm). Maximum age may be about 21 years although 13 years is a more usual figure in the literature. In the Ottawa River at Ottawa 5 age groups are reported (Qadri and Rubec, 1974) while Pluritec Ltée (1982) record a 11+ fish from Lac Philippe, Gatineau Park. In the Plantagenet Reach of the South Nation River an age range of 2-6 years was recorded (Lauzon, 2003) and fish up to 11 years are reported from the Rideau River (Setterington, 2004). Stobo (1971) showed that fish from polluted areas in the Ottawa River had decreased growth compared to more pristine areas in the NCR. Maximum age was 7 years for both sexes.
Perch in rivers of James Bay have a slower growth rate and shorter maximum length but longer life span than perch from southern Québec. Some populations of perch comprise stunted fish because of their strong appetite, high rate of reproduction, competition for food and such factors as predators and available space. Stunting is often a feature of small lakes while the best growth occurs in large water systems. A stunted population has been known from Lac Hertel, Québec for over 20 years yet when young perch were grown under optimal conditions in the laboratory, their growth was comparable to normal populations. Lac du Printemps in Gatineau Park contains only perch and this population has been stunted for at least a decade (Ridgway and Chapleau, 1994). Females grew faster than males and reached greater lengths and ages (24.1 cm and 10 years compared to 17.2 cm and 7 years). Growth rate was well below the average for other Québec populations of perch, age-classes converged towards a similar size at earlier ages and males and females reached maturity at earlier ages (0+ and 1+ respectively), all features consistent with stunting. The average gonadosomatic index of 0+ males was 9.3%, one of the highest ever reported for perch. Perch biomass in small lakes and ponds without other species can reach 215 kg/ha but in lakes with other species it is usually under 65 kg/ha.
Food
Food changes with age but is principally insects and other invertebrates, and fishes including all life stages. Young-of-the-year perch feed diurnally and have a diet dominated by benthic invertebrates (amphipods, chironomids, ephemeropterans, trichopterans and plecopterans) through the summer in the Ottawa River with zooplankton (cladocerans, copepods) important in June and fish (Hybognathus regius) in August and September. These changes reflect the availability of prey (Rodgers, 1976; Rodgers and Qadri, 1982). Peak feeding occurs at sunrise and sunset. Perch may hunt in packs which improves the chance of capturing active prey. Large perch eat young perch. Older perch in Lac du Printemps, Gatineau Park did not eat young-of-the-year in October because of their large size and this may contribute to stunting. Perch are food for many other fishes and birds but also compete with such sport fishes as trout and bass. Perch are a major food of Walleye and are eaten by Northern Pike and Smallmouth Bass in Lac LaPêche, Gatineau Park and by Smallmouth Bass in Lac Meach (Pluritec Ltée, 1982).
Reproduction
Spawning occurs usually from mid-April to May but may be as late as July. Egg masses have been seen attached to bottom debris in the Rideau Canal in downtown Ottawa (Wachelka et al., 2000). A spawning run of perch occurs in the Rideau River near Carleton University below the train bridge in early May (Hopkins, 2000). There is a spawning migration upriver or onto lake shallows and spawning occurs at temperatures of 5.6-19.0°C. Fish return to the same spawning ground in subsequent years. Males arrive earlier and stay longer than females on the spawning grounds. Spawning takes place during the night and early morning hours over vegetation, roots or fallen trees or over sand and gravel. Each female is attended by a double line of males, numbering up to 25! The first 2 males keep their noses pushing the female's belly and the remaining males follow as the female pursues a curved course. The female lays up to 210,000 eggs of 3.5 mm diameter in a twisted, gelatinous, transparent string up to 2.1 m long and 10.2 cm wide, weighing as much as 2 kg. The string has a central tube and holes to afford oxygen circulation and is folded in convolutions like an accordion. The egg mass adheres to vegetation and is often twisted around it during a spiral clockwise movement by the female.
Importance
Yellow Perch are important commercially, as sport fish and are used in schools and universities to typify a fish for anatomy classes. In the Ottawa River it has been used to develop a pollutant accumulation model which predicts uptake of PCBs and methylmercury in fish tissues (Norstrom et al., 1976). Anglers take this species in both summer and winter and enjoy its white, flaky flesh. Bait is usually minnows, worms or cut fish and perch can be caught on plugs, spoons and even flies. The Ontario Ministry of Natural Resources publishes a print and on-line "Guide to Eating Ontario Sport Fish" (www.mnr.gov.on.ca/MNR/) and has advisory limits for eating this species in the Mississippi Lake and River, Rideau River, South Nation River and Ottawa River. Environnement Québec also has recommended limits, in meals per month (1 to 8) for size of fish (small, medium or large), for such areas as Lac Deschênes at Aylmer and Quyon, Deschênes Rapids, the Ottawa River below Gatineau, above Hull, and at Masson, the Lièvre River above and below Buckingham and the Gatineau River at Chelsea, among others (www.menv.gouv.qc.ca, downloaded 13 October 2004). As these limits are apt to change, anglers consuming this fish should consult the most recent version.
Commercial fisheries centre on the Great Lakes where pollution and overfishing have taken their toll. A catch of 32.7 million kg was made in the Great Lakes in 1934 but catches have been as low as 4% of this figure. The total Canadian catch in 1988 was 6400 tonnes. Dymond (1939) records catches from 1896 onward in the general vicinity of the NCR but trends cannot be determined as fisheries data is recorded from different areas at different dates. For example, in 1898 the catch was 42,000 lbs (19,068 kg) in the Ottawa River from Carillon to Pontiac (Québec), the highest recorded. On the Ontario side the catch was highest in 1896 at 9400 lbs (4268 kg) from Prescott and Carleton counties. Commercial fisheries for perch above and below Hull from the Québec side of the Ottawa River is documented by Pluritec (1982b) for the period before 1964 and for the Ontario side of the Ottawa River from Carillon to Ottawa-Hull (Ontario Ministry of Natural Resources (OMNR) and Gouvernement du Québec Faune et Parcs,1999). Unbreaded perch fillets sold for as much at $17.50/kg in the mid-1980's and demand exceeded supply. In August 2005 in St. Jacobs, southern Ontario, perch sold for $12.99 a pound (lb).
Logperch / Fouille-roche zébré
Percina caprodes (Rafinesque, 1818)
Taxonomy
Other common names include Zebra Fish, Jackfish, Manitou Darter, Rockfish, Hogmolly, Hogfish, Fouille-roche zébré and Dard-perche. Percina caprodes semifasciata (DeKay, 1842), the Northern Logperch, is the subspecies in the NCR.
Key Characters
This darter is separated from its relatives by having an obviously protruding snout, a large anal fin at least as large as the soft dorsal fin, belly mid-line either naked (females) or with 20-37 enlarged scales (males), 2 anal fin spines, no groove between the snout and lip (premaxillaries not protractile), 67-103 lateral line scales and, most distinctively, by 14-25 flank bars.
Description
First dorsal fin spines 12-17, usually 14-16, second dorsal rays 13-18, usually 15-16, soft anal fin rays 8-13, usually 10-11. Pectoral fin rays 12-16, usually 14-15. Short gill rakers number 14-20. The cheeks and opercles are scaled and the breast is naked. This darter is very variable in characters over its wide range.
Colour
Overall colour is yellow-green to grey-green. The back has 8-10 saddles. The flank bars may terminate in a ventral tear-drop. Alternate bars reach to, and pass below, the lateral line. The dorsal fins are striped orange and black and the caudal fin has 3-4 bars. The caudal fin has a large black basal spot. The pectoral and pelvic fins are mostly clear but may have yellow tinges. The ventral scales develop tubercles in spawning males, which are darker than females but have no bright colours except sometimes for orange around the caudal spot.
Size
Reaches 17.8 cm, perhaps 20.0 cm.
Distribution
Found from east-central Alberta, central Saskatchewan, Manitoba, Ontario and southeastern Québec south to the Gulf of Mexico. Also reported from the north shore of the Gulf of St. Lawrence opposite Anticosti Island as an isolated population.
Origin
This species entered the NCR from a Mississippian refugium.
Habitat
This species has the widest distribution of any darter and is found in streams, rivers and lakes over a variety of bottoms and in varying currents. It may even be found buried in sand with only the eyes showing. It tends to prefer rocky substrates with little vegetation. Reported down to 40 m in Lake Erie but can be commonly found in shallows. Spawning takes place at temperatures over 16°C in Manitoba.
Age and Growth
Maximum age is about 4 years with maturity at 2 years.
Food
Food includes aquatic insects and crustaceans and some molluscs revealed when stones and debris are overturned by the snout. Logperch also eat fish eggs and non-spawning males are fond of eggs of their more successful siblings.
Reproduction
Spawning occurs from early May to early August when males move into sandy shallows of lakes in schools of up to several hundred fish or into streams with shallow rapids. Females swim through this school, and if one stops on the sand, a male will settle on her back, clasping with his pelvic fins and depressing his caudal fin alongside hers. Both fish quiver and eggs are fertilised in a cloud of sand which coats the eggs. The eggs are not guarded and males do not defend a territory. In streams males have a moving territory around a female as she swims onto the spawning bed. Both lake and stream spawning behaviours of Logperch are very primitive among darters. About 10-20 colourless eggs are released each time and the female may spawn with several males. Eggs are 1.3 mm in diameter and number up to 3085 in large females. Young Logperch are poorly developed in contrast to other darters and must drift from flowing to still waters where suitable small plankton is available as prey. Other darters can start feeding immediately on small insects.
Importance
Logperch thrive in an aquarium and are used as bait fish for Smallmouth Bass among others in Canada.
Channel Darter / Fouille-roche gris
Percina copelandi (Jordan, 1877)
Taxonomy
Other common names are Copeland's Darter or Dard gris. It hybridises with the Logperch.
Key Characters
A small member of the family, this darter species is recognised by the small mouth not extending beyond the anterior eye margin, a smooth edge to the preopercle bone on the side of the head, a large anal fin at least as large as the soft dorsal fin, belly midline either naked or with enlarged scales, 2 anal fin spines and a deep groove between the snout and lip (premaxillaries protractile).
Description
Dorsal fin spines 9-13 (usually 10-11), dorsal soft rays 10-14 (usually 11-12), anal fin rays 7-10 (usually 8-9). Lateral scale rows 43-61. Males have 6-11 enlarged, modified, star-shaped scales in a row on the belly where females are unscaled or scaled only posteriorly. Tubercles are present. Females have an elongate tubular papilla in the genital area.
Colour
Overall colour is brown to olive, semi-translucent, with about 5-9 faint saddles. The flank has 8-18 brown to black oblong and partly confluent blotches linked by a faint, thin brown to black stripe. A dusky bar or spot may extend from beneath the eye to the snout. Fins are mostly clear. There is usually a spot at the caudal fin base and 2 bars radiating down and forward from the eye. Breeding males have black basal and marginal bands with white at the tip on the spiny dorsal fin, a black head, throat and pelvic fins, a greenish cast to the upper flank and a bluish one to the lower flank. The basal part of the anal fin is blackish.
Size
Reaches 6.1 cm standard length or 7.3 cm total length.
Distribution
Found in the upper St. Lawrence River basin east and west of Montréal and at Ottawa, and along the shores of lakes Erie and Huron. It is only found west of the Appalachians in the U.S.A., south to the Gulf of Mexico.
Origin
This species entered the NCR from a Mississippian refugium.
Habitat
An uncommon darter found over sand, gravel and rock mixes in larger rivers, stream pools and on lake shores where current is slow and depths are shallow. It may move into very shallow waters at night. It is intolerant of pollution. Competition with other darters, such as Etheostoma nigrum and Percina caprodes, for spawning territory may limit this species.
Age and Growth
Males grow larger than females. Maximum age is 5 years with maturity at 1-2 years.
Food
Insects and crustaceans are the major foods, and large amounts of algae and detritus are also swallowed.
Reproduction
Spawning occurs in relatively shallow running water in June in Canada at 14.5-25.0°C, July in the northern U.S.A. at temperatures over 20°C, perhaps earlier (May-June) in other localities. A short migration is made to appropriate spawning sites. Males have a territory based on a central rock. Females join the male over gravel or small rocks behind the central rock. The female partly buries herself in the gravel, the male presses down on her from above with his pelvic fins on each side and his tail area paralleling hers, and adhesive eggs are released and fertilised into the gravel. Several females may spawn with 1 male, depositing 4-10 eggs. Each female may have over 720 eggs up to 1.4 mm in diameter. The eggs are not guarded by the parents. The Farmers rapids on the Gatineau River are a spawning site (www.fapaq.gouv.qc.ca, downloaded 7 October 2002).
Importance
This darter was given the status "threatened" in 2002 by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC, 2002).
Sauger / Doré noir
Sander canadensis (Griffith and Smith, 1834)
Taxonomy
Other common names include Sand, Blue, or Grey Pickerel, Pike or Pike-perch, River Pike, Spotfin Pike, Pickering, Jack Salmon, Horsefish, Spotted Trout and Rattlesnake Pike. Saugeyes are hybrids between Sauger and Walleye, characterised by partially scaled cheeks, a yellower colour than either parental species but with rows of spots like the Sauger, and more than 3 pyloric caeca (as in Sauger) but these are as long as the stomach (as in Walleye).
Key Characters
This species has a large mouth with the upper jaw extending back to the rear edge of the pupil, the preopercle bone on the side of the head is serrated at its outer angle, there are 10-14 soft rays in the anal fin after 2 spines, 2 canine teeth are present at the lower jaw tip, the spiny dorsal fin is clear with small spots and there are 3-4 brown saddles on the back.
Description
The Sauger is more slender than the Walleye and has a pointed snout. First dorsal fin spines 10-15, second dorsal fin with 1-2 spines and 16-22 soft rays. Pectoral fin rays 12-14. There are 3-9, usually 5, pyloric caeca attached to, but shorter than, the stomach. Gill rakers 6-8 on the lower limb and 3-5 on the upper limb, moderately long and denticulate. Scales number 78-100 in the lateral line.
Colour
Overall colour yellowish-brown, golden olive, or even grey, saddles are a darker brown. Flanks may have several large, dark brown spots. Generally this species is darker than the Walleye taken from the same waters. Belly a milky-white. The first dorsal fin has a dark margin and the membranes are spotted black in 2-3 rows, each spot being a half-moon shape. The second dorsal fin has 2 rows of spots forming narrow bands. The caudal fin is also barred and its lower margin may be white. The anal and pelvic fins are clearer but have dark specks. The pectoral fin has a black, basal spot.
Size
Reaches 76.2 cm. The world, all-tackle angling record weighed 3.96 kg and was caught in 1971 in Lake Sakakawea, North Dakota. A 3.52 kg Sauger from the Saskatchewan River, Saskatchewan is the Canadian record. The largest Sauger may be Saugeyes, hybrids with Walleye.
Distribution
Found from southern Canada southward west of the Appalachians to Arkansas and Tennessee but introduced into some eastern and southern areas. In Canada from the North Saskatchewan River in Alberta and east to James Bay drainages, essentially in the southern half of Alberta, Saskatchewan and Manitoba, to southwestern Quebec and waters southward.
Origin
This species entered the NCR from a Mississippian refugium.
Habitat
Saugers prefer more turbid water than Walleyes whether in large, shallow lakes or large rivers with slow current. They are widely distributed in the Ottawa River in the NCR but absent from most local lakes. Sauger are abundant in new reservoirs which tend to be turbid but their numbers decrease as the reservoir stabilises. Turbid conditions may protect young fish from predators by reducing visibility, prevent eggs from sticking together and being deprived of adequate oxygen supplies and may concentrate plankton to lighted surface waters where the young sauger can feed easily. Sauger are usually found in the upper part of the water column but may descend to 20 m. The tapetum lucidum, a layer in the eye which causes a silvery eyeshine, serves to stimulate the visual cells by reflection. In low light conditions of turbid waters, vision is enhanced and since the Sauger's tapetum is better developed than that of a Walleye's, it is at an advantage in turbid water. Sauger are more active in shallow water when it is windy, and presumably waves are increasing turbidity. Its preferred temperature is 19.2°C. In the Ottawa River, eutrophication from impoundments and other human activities mean that this species and it's relative, the Walleye, compete for the same prey in the littoral zone. Prey species are excluded from the sublittoral zone because of warmer temperatures and siltation. As a result, Osterberg (1978) predicted that Sauger will disappear from the Ottawa River. Two-thirds of Sauger moved into feeding areas in Governor's Bay in the Ottawa River between sunset and midnight, most of the rest before 3 a.m. They leave the bay in daylight hours to be in 5-13 m depths around rocks and debris (Osterberg, 1978).
Age and Growth
Growth varies with the habitat, richer waters showing more rapid growth than poor waters such as those on the Precambrian Shield. Old, slow-growing populations in the north reach 18 years while young, fast-growing populations in the south are up to 6 years old. Sauger in rivers draining to James Bay have a slower growth rate, shorter maximum length but a longer life span than Sauger in southern Québec. Males are mature at 2 years and females at 3-4 years of age. Sauger in the Ottawa River reach 9 years (McAllister and Coad, 1975). Osterberg (1978) showed that growth in the Ottawa River was the lowest recorded for this latitude, the mean total length at 6 years being 29.4 cm while in the Great Lakes it was 41 cm. Growth is less rapid than in the related Walleye. At age 5 the average Walleye in the Ottawa River was 37 cm long and weighed 481 g and life span was 8 years in Osterberg's study. Growth was faster below Ottawa than above, 50% of 3-year-old males were mature and 50% of 4-year-old females.
Food
Food of small Sauger is plankton, fish fry and insect larvae, with larger Sauger taking crayfish, insects and a variety of other fishes. Sauger are known to favour demersal fish prey throughout the day in some habitats and can be cannibals when other prey is less abundant. In Governor's Bay on the Ottawa River, the Emerald Shiner Notropis atherinoides, is the main food item at more than 75%, taken in nocturnal feeding movements into the bay, with Yellow Perch being an important secondary food when shiners were at a low density (Osterberg, 1978; Qadri and Rubec, 1974). Osterberg (1978) found that feeding peaked in August and food passed through the gut in 48 hours. Yellow Perch are predators of Sauger in the Ottawa River (Osterberg, 1978).
Reproduction
Spawning occurs at the end of May and beginning of June on gravel shoals down to 6.1 m of rivers or lakes at about 4-11°C. Males arrive first on the spawning ground while females are the first to leave. Spawning takes place at night with each female accompanied by one to several males. The eggs are shed, fertilised and fall into interstices of the gravel. A large female may produce up to about 210,000, non-adhesive eggs of 1.5 mm diameter.
Importance
Sauger are important commercially. They are caught with gill nets, pound nets and trap nets and in Manitoba as much as 2.5 million kg may be caught annually. The catch in Lake Erie has declined from 2.7 million kg to almost nothing. Anglers may catch Sauger on minnow or frog baited hooks, trolled or drifted, or with various artificial lures and it is a strong fighter although not as popular a sport fish as Walleye. Sauger are good eating with a firm white flesh sold usually as fillets. Few anglers pursue this species in the NCR, preferring Walleye. The Ontario Ministry of Natural Resources publishes a print and on-line "Guide to Eating Ontario Sport Fish" (www.mnr.gov.on.ca/MNR/) and has advisory limits for eating this species in the South Nation River and Ottawa River. Environnement Québec also has recommended limits, in meals per month (1 to 8) for size of fish (small, medium or large), for such areas as Lac Deschênes at Aylmer and Quyon, Deschênes Rapids, the Ottawa River below Gatineau, above Hull, and at Masson, the Lièvre River above and below Buckingham and the Gatineau River at Chelsea, among others (www.menv.gouv.qc.ca, downloaded 13 October 2004). As these limits are apt to change, anglers consuming this fish should consult the most recent version.
Walleye / Doré jaune
Sander vitreus (Mitchill, 1818)
Taxonomy
Other common names include various combinations of Yellow, Walleye, Pickerel and Pike; Pike-perch, Dory, Gray Pike, Green Pike, Jack Salmon, Glass Eye, Marble Eye, Doré, Doré blanc and Doré bleu. Anglers often call the Walleye "pickerel" but the words pickerel and pike should be confined to members of the unrelated Pike Family. Hybrids with Sauger are known (see above).
Key Characters
The Walleye has a large mouth with the upper jaw extending back to the rear edge of the eye, the preopercle bone on the side of the head is serrated at its outer angle, there are 10-14 soft rays in the anal fin after 2-3 spines, 2 canine teeth are present at the lower jaw tip, in particular there is a large, black blotch at the rear base of the spiny dorsal fin, and 5-8 saddles on the back.
Description
First dorsal fin spines 11-16, second dorsal fin with 1-2 spines and 17-22 soft rays, and pectoral rays 13-16. Lateral line scales 77-108. Gill rakers 11-17. There are 3 pyloric caeca attached to, and as long as, the stomach.
Colour
Overall colour has brassy tones and is dark green, olive-brown or yellow with gold flecks on the sides. The belly is white to yellowish. The lower lobe tip in the caudal fin and the anal fin tip are white. Males have a more pronounced white lower lobe to the caudal fin. The spiny dorsal fin membranes are not spotted but dusky. The second dorsal and caudal fins are speckled in rows. Pelvic fins are yellowish to orangish. Pectoral fins have a dark, basal blotch. The peritoneum is white. The eyes are silvery from reflections of the tapetum lucidum and the cornea is milky (hence "walleye"). Young fish often have 4-14 bars on the flank, particularly in clear water. Faber (1985a) illustrates a larva.
Size
Reaches 1.04 m. The world, all-tackle angling record weighed 11.34 kg and was caught in 1960 in Old Hickory Lake, Tennessee. The Ontario record as of the year 2000 weighed 10.1 kg. Fish up to 8.6 kg are known from the Lièvre River (Campeau, 2002), and a 10 lbs 2 oz fish from the Lièvre was only 28 inches long but 18 inches in girth (http://iquebec.ifrance.com/maclaren/johnsim1.htm). Fish in the 7-9 lb range are caught at Petrie Island in the Ottawa River (Ottawa Sun, 10 June 2004), a 28 inch fish was caught there in mid-May 1996 (www.fish-hawk.net/gallery/walleye/Walleye-jun01.htm), another on New Year's day was more than 12 pounds (Hopkins, 1995), and one from there, caught through an 8-inch hole in the ice by Bob Presland on 12 January 2004, was 15 lbs 4 oz and 32 inches long (newspaper reports). A 10 lb 5 oz fish was taken near the Connaught Ranges (newspaper report); a 9 lb fish was taken at the Champlain Bridge on the Ottawa River (Anonymous, 1962b); a 27 inches and 7 lbs fish from the Mississippi River on 17 July 1999 (www.fish-hawk.net/gallery/walleye/Walleye-jun01.htm); a 9 lbs fish from the Gatineau River on 15 September 1999 (www.fish-hawk.net/gallery/walleye/Walleye-jun01.htm); a 9 lbs and 28.5 inch fish was taken on the Rideau River on 4 January 2003 (www.fishontario,com, downloaded 20 May 2003) and also a 14.5 lbs fish from the Rideau River (www.rideaufriends.com/fishing.html, downloaded 20 June 2003); 8lbs 4 oz in Dow's Lake on 24 December 1984 (www.ottawafishing.com, downloaded 20 May 2003); a nearly 10 lbs fish at Wendover on the Ottawa River (www.fish-hawk.net, downloaded 20 May 2003); a 10 lbs 9.6 oz and 28 inch long fish from Fitzroy Harbour on 17 January 2004 (www.fishontario.com/photo_gallery/page2/page2.html, downloaded 23 June 2004).
Distribution
Found from western Quebec, throughout Ontario, Manitoba, Saskatchewan and Alberta and north to the mouth of the Mackenzie River including Great Bear and Great Slave lakes and extreme northeastern British Columbia, and southward to the Gulf of Mexico in Alabama. Also introduced outside native range. This species has been stocked in Mississippi Lake in 1908 (Brown, 1984), in the South Nation River system, 5.5 million fry being released prior to 1950 (Anonymous, 1950). Lac LaPêche was stocked with about 4.5 million fry in 1968 but this may have failed due to predatory Yellow Perch while 200 adults stocked in the same lake appear not to have reproduced (Rubec, 1972). The Ottawa and Rideau rivers were heavily stocked in the 1940s and early 1950s and again in the 1980s. One million eggs were planted between Kars and Beckett's Landing in 1942 and 200,000 eggs were planted near Kars in 1947 (Bebee, 2004). The 1980s stocking improved fishing between Burritts Rapids and Kars for a short period (Hopkins, 2000). The Ottawa River stocking in 1947 comprised 200,000 eyed eggs released at Woodruffe below the Britannia Rapids, 200,000 at Galetta, 200,000 in the Madawaska and Ottawa rivers near Arnprior and 100,000 at Rockland (newspaper reports). Other reports form this period list releases of a million eggs in both the Rideau and Ottawa rivers.
Origin
This species entered the NCR from a Mississippian or Atlantic coastal refugium and possibly from a Beringian or Missourian refugium (Mandrak and Crossman, 1992). The presence of this species in Lac Philippe, Gatineau Park is an unauthorised introductions (Chapleau et al., 1997).
Habitat
Walleye favour both turbid and clear lakes but the very sensitive eyes limits their activity in clear water. They rest on the bottom during the day in clear waters. They prefer less turbid conditions and shallower water with slower current than Sauger. Large streams and rivers which are turbid or have deep, sheltered pools, weed beds or fallen trees, also harbour Walleye. A temperature range of 0-30°C is tolerated although 20-23°C is preferred. A fish kill along extensive stretches of the Rideau River and Canal was reported in spring 1956 (newspaper reports). They are active in winter and swim in schools often associated with other sport fish such as Northern Pike, Yellow Perch, Muskellunge and Smallmouth Bass. Water depth preferred is moderate, down to about 21 m, usually shallower. There are morning and evening migrations into shallow or surface waters to feed. Some fish have been recorded as moving 160 km, but this movement is unusual apart from regular spawning migrations. Walleye have been tagged with radio transmitters in the Jock River of the NCR to monitor their movement as they are an indicator species for good habitats (Spears, 1999a). Tagged Walleye moved 15 km downriver from Governor's Bay in the Ottawa River (Osterberg, 1978). Two-thirds of Walleye moved into feeding areas in Governor's Bay in the Ottawa River between sunset and midnight, most of the rest before 3 a.m. They leave the bay in daylight hours to be in 5-13 m depths around rocks and debris (Osterberg, 1978).
Age and Growth
Growth varies with latitude and northern populations may be only half the length of southern ones at the end of their first growing season. Northern populations may live 26 years and southern ones up to 12 years. Age groups up to 12 years are recorded for the Ottawa River at Ottawa (Qadri and Rubec, 1974), 17 years for the Mississippi Lake and Mississippi River at Carleton Place (Kerr, 1999c), and 21 years for the Madawaska River at Arnprior based on a von Bertalanffy growth curve (Haxton, 2000). The Madawaska population had an exploitation rate in 1997 of 2% and an annual mortality of 80.6% based on tagged fish recaptures and an annual mortality based on age-frequency distributions of18.4-43.8% for 1997-1999 (within the common mortality range of 40-55% for Walleye generally). Males are usually mature at 2-4 years and about 28 cm while females are usually mature at 3-6 years and about 36 cm or more. However maturity of females is governed by temperature - in the southern U.S.A. it is attained at 2 years but only at 10 years in the N.W.T. Females grow more rapidly than males. Osterberg (1978) showed that growth in the Ottawa River was the lowest recorded for this latitude, the mean total length at 6 years being 40.2 cm while in the Great Lakes it was 49 cm. At age 5 the average Sauger in the Ottawa River was 29 cm long and weighed 186 g and life span was 8 years in Osterberg's study. Growth was faster below Ottawa than above, 50% of 3-year-old males were mature and 50% of 4-year-old females.
Food
Food when adult is a wide variety of available fishes but young and adults can be cannibals if other food is not available. Frogs, mudpuppies and small mammals may also be taken. In the Ottawa River food is mainly Yellow Perch and Emerald Shiners (McAllister and Coad, 1975). In Governor's Bay on the Ottawa River, the Emerald Shiner Notropis atherinoides, is the main food item at more than 75%, taken in nocturnal feeding movements into the bay, with Yellow Perch being an important secondary food when shiners were at a low density (Osterberg, 1978; Qadri and Rubec, 1974). Osterberg (1978) found that feeding peaked in late July and food passed through the gut in 48 hours. Young Walleye are of the same size in a school and attempts at cannibalism may have peculiar results. A chain of up to 4 Walleye may happen when successive fish try to ingest the tail of the one ahead. The end of the chain will eventually digest the tail in its mouth and reject the rest. Young feed on invertebrates and even adults will take mostly mayflies and chironomids when these are emerging. Northern Pike are generally the most important Walleye predator but Yellow Perch are important predators of Walleye in the Ottawa River (Osterberg, 1978).
Reproduction
Spawning occurs in early April in southern Ontario to June or later in the north usually after ice break up at 2.2-15.6°C, usually 5-10°C. Some populations spawn under the ice in lakes. Males arrive on the rocky or gravel spawning ground first. Spawning takes place at night in groups of up to 2 females and 6 males. There is some spawning behaviour with chases, pushing and fin erection before the group swims rapidly into shallow water where the females roll on their sides and release their eggs at the surface. Eggs number up to 615,000, are up to 2.1 mm in diameter and fall into crevices between rocks. Eggs hatch after 12-18 days. Larvae hatch at 7.0-8.0 mm and live in open waters of lakes and rivers. Just south of the NCR there is a "pickerel" run at Innisville on the Mississippi River that is regularly reported in local newspapers. It takes place in the last half of April and early May, lasting up to 3 weeks (Anonymous, 1965; 1966; 1967; Fisher, 1987). The peak of the run in 1965 was 29 April for example. The run is said to have started in 1910 when two game wardens first placed 38 adult pickerel in the rapids (Ottawa Citizen, 29 April 1965). Spawning below the weir at Arnprior in the Madawaska River was completed by 13 May in 1997 and some females were ripe on 27 April in 1999 (Haxton, 2000). There are also runs at Burritts Rapids, Black Rapids and Kilmarnock on the Rideau River (Sarsfield, 1967; Hopkins, 2000), Walleye spawn in the Ottawa River at the base of Rideau Falls in April (Hopkins, 2000), and at the base of Chaudière Falls from mid-April to early May beginning at sunset in water temperatures of 4-8ºC with about 200 fish in 5ºC water at the peak in the last week of April (Osterberg, 1978), among many other sites in the NCR. The Kemptville Creek estuary wetland is a regionally significant spawning site (Schueler et al., 1996). There is an annual contest between poachers and conservation officers at these runs (Fisher, 1987).
Importance
The Walleye is the most economically important fish in Canadian freshwaters. It is both a commercial and sport fish with firm white or pinkish flesh. The Ontario Ministry of Natural Resources publishes a print and on-line "Guide to Eating Ontario Sport Fish" (www.mnr.gov.on.ca/MNR/) and has advisory limits for eating this species in the Mississippi Lake and River, Rideau River, South Nation River and Ottawa River. Environnement Québec also has recommended limits, in meals per month (1 to 8) for size of fish (small, medium or large), for such areas as Lac Deschênes at Aylmer and Quyon, Deschênes Rapids, the Ottawa River below Gatineau, above Hull, and at Masson, the Lièvre River above and below Buckingham and the Gatineau River at Chelsea, among others (www.menv.gouv.qc.ca, downloaded 13 October 2004). As these limits are apt to change, anglers consuming this fish should consult the most recent version.
In 1999 it was the second most frequent species at 16.0% (after "basses" at 37.4% of events) sought at competitive fishing events in Ontario, although the proportion of events targeting Walleye had declined substantially from the previous year (Kerr, 1999d). Anglers catch it in both summer and winter using live minnows or artificial lures and drifting and trolling techniques. The best fishing is at dusk or dawn, during the night or on cloudy days. Ontario competitive fishing events in 1999 for Walleye featured minimum size limits (e.g. 12") for tournament entry, functioning live wells were mandatory, "let it live" awards were offered and there were penalties for sick or dead fish (Kerr, 1999d). The peak commercial catch in 1956 weighed 9.5 million kg and was worth $3.1 million. Pollution and overfishing, particularly in Lake Erie, has greatly reduced this resource. Mercury contamination of Walleyes in Lake Erie was discovered in 1970 and led to closure of commercial fisheries. The stock has recovered dramatically indicating overfishing was the main cause of stock decline. The total Canadian catch was an estimated 8153 tonnes in 1988 and was worth $28 million. Dymond (1939) records catches from 1881 onward in the general vicinity of the NCR but trends cannot be determined as fisheries data is recorded from different areas at different dates. For example, in 1898 the catch was 54,750 lbs (24,857 kg) in the Ottawa River from Carillon to Pontiac (Québec), the highest recorded. On the Ontario side the highest catch was in 1896 at 7700 lbs (3496 kg) from Prescott and Carleton counties. Walleye are a favourite of local anglers in the NCR but most are 2-3 lbs (0.9-1.4 kg) (McAllister and Coad, 1975).
© Brian W. Coad (www.briancoad.com)