Fishes of Canada's National Capital Region
Keys
Introduction
Certain species in the NCR are very distinctive and recognisable at a glance, others are superficially similar. These keys provide a structured means to identify all the species, especially where the student of these fishes is new to the fauna. They first appeared in Coad (2001).
The first key presented here is to the families of fishes. Where there is only a single species in the family, that species will be identified here. Separate keys are given for families with more than one species.
Three species have been added to the list, that were not recorded in Coad (1986b), the most recent listing of this ichthyofauna. These are Ichthyomyzon castaneus Girard, 1858 (Chestnut Lamprey/Lamproie Brune) documented by Renaud and de Ville (2000); Carassius auratus (Linnaeus, 1758) (Goldfish/Carassin) - Goldfish have been introduced to several ponds in the NCR and seem to survive the winter but they may revert to the wild type with camouflage colouring, losing the typical "gold" colours; and Nocomis biguttatus (Kirtland, 1840) (Hornyhead Chub/Tête à taches rouges) documented by Coad and Alfonso (in prep.).
Three "species" are not included. The Oscar, a South American member of the family Cichlidae (Astronotus ocellatus (Agassiz in Spix and Agassiz, 1831)) caught in the Rideau Canal in 1999, was evidently a released aquarium specimen which became a minor media star (Anonymous, 1999b; Barker, 1999; Bonenfant A.-M., 1999; Duquette, 1999; Renaud and Phelps, 1999; Renaud and Berkowitz, 1999). A 12-14 inch fish with piranha-like teeth was found dead on the Queen Elizabeth Driveway shoreline, Dow's Lake by Hedrik Wachelka of Muskies Canada in 1994. It was observed on 23 October after the water was drained and the photograph is possibly of a pacu (Colossoma bidens (Spix and Agassiz, 1829)), another South American fish of the family Characidae, or even a piranha, and also most probably an aquarium release (Renaud and Phelps, 2001). The blind fish from groundwater at Carleton University was a hoax; the article appeared just in time for April Fool's Day (Anonymous, 1994).
Notes on the Keys
The counts and measurements given in the keys are for each species over its whole distribution: the ranges for these characters are likely to be less extensive within the restricted geographical area of the NCR.
Some characters are best examined under a microscope, require dissection and/or require some skill to observe accurately, e.g., gill raker counts, pharyngeal tooth structure. Species can often be distinguished on colour alone but colour does vary with season, by individual, by sex of the specimen, and by preservation state if live specimens are not at hand. Colour can be misleading and countable or readily observed characters are best.
A knowledge of fish anatomy and terminology of body parts is necessary to understand the keys. Some structures are briefly described where they first appear in these keys and are in bold text. The Figures also illustrate structures used in identification. Generally, closely related fish of equal size (and age) should be compared if at all possible as there are changes in characters with growth, e.g., body proportions, gill raker length. The collections of the Canadian Museum of Nature on Pink Road in Gatineau (formerly Aylmer) contain a wide variety of specimens of all National Capital Region species and these can be examined with permission of the Vertebrate Collection Manager (see www.nature.ca for contact information).
Summary and simplified distributional information is given after each species and some more recent information is included too (see Bibliography for recent works and Species Accounts for more details). "Widespread" indicates that the fish is found in several to many diverse ecological and geographical habitats and localities, usually in both Ontario and Québec, while river localities indicate the species is restricted to those rivers and/or lower reaches of tributaries. Further field work may expand the distributions given here although restricted distributions are usually indicative of narrow tolerance for environmental conditions, e.g., the Lake Sturgeon is not likely to be found outside the large Ottawa River and lower reaches of large tributaries; salmonids generally prefer cooler waters and are most common on the Québec side; the Spotfin Shiner is known only from a few localities such as Bear Creek.
gill arch with rakers to left
Key to Families
1. 7 pairs of pored gill openings; no pectoral or pelvic fins; a median
nostril; "mouth" a rounded, suctorial disc in adults, or a fleshy oral
hood in larvae (or ammocoetes) = Petromyzontidae (Lampreys/Lamproies)
1 external gill opening on each side of head; at least pectoral fins present and usually pelvic fins too; paired nostrils; mouth bounded by upper and lower jaws -->
2. Caudal fin lobes strongly asymmetrical, the upper lobe much larger than the lower and containing the vertebral column; 2 pairs of barbels in front of subterminal (under head) mouth; 5 rows of bony plates along body = Acipenseridae (Sturgeons/Esturgeons) Acipenser fulvescens (Lake Sturgeon/Esturgeon jaune) [Ottawa and Gatineau rivers]
Caudal fin lobes mostly symmetrical externally (when present), no extensive presence of vertebral column in lobes; barbels if present not anterior to mouth; body without 5 rows of plates, with regular scales, or no scales --> 3
3. Gular plate present (large bony structure on lower surface of head between jaws); anterior nostrils tubular and near snout tip = Amiidae (Bowfins/Poissons-castors) Amia calva (Bowfin/Poisson-castor) [Ottawa River]
No gular plate; anterior nostrils not as above --> 4
4. No pelvic fins; body extremely elongate; dorsal, caudal and anal fins continuous; scales so small as not to be readily visible = Anguillidae (Freshwater Eels/Anguilles d'eau douce) Anguilla rostrata (American Eel/Anguille d'Amérique) [Ottawa, Gatineau and Mississippi rivers]
Pelvic fins present; body not extremely elongate; dorsal, caudal and anal fins separate; scales absent, or present and obvious --> 5
5. Scales like armour, exceptionally thick, close fitting, non-overlapping and diamond-shaped; jaws very elongate and narrow, longer than rest of head, armed with teeth = Lepisosteidae (Gars/Lépisostés) Lepisosteus osseus (Longnose Gar/Lépisosté osseux) [Ottawa River]
Scales thin and overlapping, or absent; jaws not as above --> 6
6. Second spine of anal fin massive; lateral line runs to end of caudal fin; head canals greatly enlarged = Sciaenidae (Drums and Croakers/Tambours) Aplodinotus grunniens (Freshwater Drum/Malachigan) [Ottawa, Gatineau and Rideau rivers]
Anal fin without spine, or spine not massive; lateral line when present not extending to end of caudal fin; head canals not greatly enlarged --> 7
7. Soft dorsal fin preceded by 2-12 isolated spines, not joined by a membrane = Gasterosteidae (Sticklebacks/Épinoches)
Dorsal fin without spines or, if spines present, not isolated but joined by a membrane --> 8
8. Single barbel on chin tip; pelvic fins clearly inserted anterior to pectoral fin origin = Gadidae (Cods/Morues) Lota lota (Burbot/Lotte) [Ottawa, Gatineau and Mississippi rivers]
No chin barbel (other barbels may be present on the jaws); pelvic fins under or behind pectoral fin origin --> 9
9. Adipose fin present --> 10
Adipose fin absent --> 13
10. Scales absent; 4 pairs of long barbels present; very strong spine-like rays in the dorsal and pectoral fins = Ictaluridae (North American Catfishes/Barbottes et Barbues)
Scales present; no barbels, or barbels not in 4 pairs; no very strong fin spines --> 11
11. Pelvic fin anterior, overlapped by pectoral fin; mouth under head; scales weakly ctenoid (minute spines at posterior margin); teeth very fine, difficult to see = Percopsidae (Trout-perches/Omiscos) Percopsis omiscomaycus (Trout-perch/Omisco) [widespread]
Pelvic fin more posterior on abdomen, not overlapped by pectoral fin; mouth at tip of head; scales cycloid (no minute spines); teeth small to large but easy to see --> 12
12. Pelvic axillary process (flap at fin base) absent; pelvic fin origin below or in front of dorsal fin origin = Osmeridae (Smelts/Éperlans)
Pelvic axillary process present; pelvic fin origin behind dorsal fin origin = Salmonidae (Trouts and Salmons/Truites et Saumons)
13. Pelvic fins abdominal (about mid-body, behind the pectoral fin tip); one dorsal fin; no true fin spines (Cyprinus carpio and Carassius auratus have a single anterior spine-like ray in the dorsal and anal fins) --> 14
Pelvic fins thoracic (anterior, under pectoral fin); two dorsal fins or, if one fin, then several spines anteriorly --> 21
14. Gill openings narrow (gill membranes joined to isthmus, the area between the gill openings on the lower head surface - right below) --> 15
Gill openings wide (gill membranes not joined to isthmus - left below) --> 16
15. Lips thick and fleshy; mouth under head; pharyngeal teeth (throat teeth, lying behind the gill arches and accessible via the gill opening by dissection) in a single row, numerous, more than 15; anal fin posterior, the distance between the posterior opercle edge to the anal fin origin clearly greater than the distance from anal fin origin to the caudal fin base = Catostomidae (Suckers/Catostomes)
Lips thin; mouth usually at tip of head (under head in Rhinichthys cataractae but this species has 2 rows of pharyngeal teeth, 1-4 in each row); pharyngeal teeth in 0-3 rows but never more than 5 in a row; anal fin more anterior, the distance between the posterior opercle edge to the anal fin origin marginally greater than the distance from anal fin origin to the caudal fin base = Cyprinidae (Carps and Minnows/Carpes et Ménés)
16. Scales on top of head --> 17
Top of head scaleless --> 20
17. Groove between upper lip and snout (premaxillaries protractile - anteriormost bones of upper jaw can extend) = 18
No groove (premaxillaries not protractile) --> 19
18. One dorsal fin; anal fin with 9-13 rays, no spine = Fundulidae (Topminnows/Fondules) Fundulus diaphanus (Banded Killifish/Fondule barré) [widespread]
Two dorsal fins (the first small and easily missed) over the anal fin; anal fin with 20-27 rays after a spine = Atherinopsidae (New World Silversides/Poissons d'Argent) Labidesthes sicculus (Brook Silverside/Crayon d'argent) [Ottawa and Rideau rivers]
19. Snout a duck-bill shape; caudal fin forked; strong teeth; lateral line scales 105-176 = Esocidae (Pikes/Brochets)
Snout normal-shaped; caudal fin rounded; teeth minute; lateral line scales 30-37 = Umbridae (Mudminnows/Umbres) Umbra limi (Central Mudminnow/Umbre de vase) [widespread]
20. Dorsal fin over pelvic fins; no obvious teeth on tongue; lateral line absent; belly with scutes (sharp scales); gill rakers (bony projections on the inner side of the gill arch) numerous and elongate; anal fin rays 15-21; nostrils near eye = Clupeidae (Herrings/Harengs) Alosa pseudoharengus (Alewife/Gaspareau) [Rideau River]
Dorsal fin over anal fin; strong teeth present on tongue; lateral line present; no belly scutes; gill rakers few and knob-like; anal fin rays 26-31; nostrils near snout tip = Hiodontidae (Mooneyes/Laquaiches) Hiodon tergisus (Mooneye/Laquaiche argentée) [Ottawa, Gatineau and Mississippi rivers]
21. Body mostly naked (some minute prickles), no scales; pectoral fin large and fan-shaped; head broad and flattened = Cottidae (Sculpins/Chabots) Cottus bairdii (Mottled Sculpin/Chabot tacheté) [widespread]
Body scaled; pectoral fin not as large; head not broad and flattened --> 22
22. One to two anal fin spines; two dorsal fins at most slightly joined at base = Percidae (Perches/Perches et Dards)
Three or more anal fin spines; one dorsal fin (comprising joined spiny and soft parts except almost divided in two at base in Micropterus salmoides) = Centrarchidae (Sunfishes/Achigans et Crapets)
Key to Adult Petromyzontidae (Lampreys/Lamproies)
Adults have teeth in a sucking disc which is lined around the rim by fimbriae (short, thread-like filaments), and they have well-developed eyes. They swim free, or are attached as external parasites to other fish, or may hide under rocks and debris.
1. Two distinct dorsal fins; trunk myomeres (muscle blocks) 63-74 = Lampetra appendix (American Brook Lamprey/Lamproie de l'est) [Ottawa and Gatineau rivers]
Dorsal fin single with at most a slight dip at mid-point, dip not reaching body; trunk myomeres 47-58 --> 2
2. Teeth small and blunt; lateral line organs lacking pigmentation; gut shrivelled, diameter minute; small, length up to about 25.4 cm and often 15 cm or less = Ichthyomyzon fossor (Northern Brook Lamprey/Lamproie du nord)[Ottawa River]
Teeth large, sharp and curved; lateral line organs obviously pigmented; gut well-developed (but atrophies at spawning); larger, length up to about 38 cm --> 3
3. Circumoral teeth usually unicuspid; trunk myomeres 47-55 (usually 49-52, mode 51) = Ichthyomyzon unicuspis (Silver Lamprey/Lamproie argentée) [Ottawa and Gatineau rivers]
Circumoral teeth usually bicuspid; trunk myomeres 49-56 (usually 51-54, mode 53) = Ichthyomyzon castaneus (Chestnut Lamprey/Lamproie brune) [Brewery Creek]
Key to Larval Petromyzontidae (Lampreys/Lamproies)
Note that this key may not work for smaller ammocoetes (<105 mm for the Chestnut Lamprey, i.e. presence of the black lateral line organs means the ammocoete is a Chestnut Lamprey but absence in smaller specimens does not mean it is not), and the distinction of unicuspis and fossor is not possible on pigmentation patterns, at least for Great Lakes fish (Neave, 2004).
Larval lampreys or ammocoetes lack teeth and have a fleshy hood enclosing the oral opening and eyes are weakly developed. They live buried in sediment with the head protruding and are not usually free-swimming.
1. Two distinct dorsal fins; trunk myomeres 63-74 = Lampetra appendix (American Brook Lamprey/Lamproie de l'est)
Dorsal fin single with at most a slight dip at mid-point, dip not reaching body; trunk myomeres 47-58 --> 2
2. Lateral line organs black = Ichthyomyzon castaneus (Chestnut Lamprey/Lamproie brune)
Lateral line organs unpigmented --> 3
3. Caudal fin and head heavily pigmented; a whitish band above the gill openings is about 3 mm deep = Ichthyomyzon unicuspis (Silver Lamprey/Lamproie argentée)
Caudal fin and head weakly pigmented; a whitish band above the gill openings is about 1 mm deep = Ichthyomyzon fossor (Northern Brook Lamprey/Lamproie du nord)
Key to Cyprinidae (Carps/Carpes)
1. Dorsal and anal fins with a strong, serrated, anterior spine-like ray; dorsal fin branched rays 14-23 --> 2
Dorsal and anal fins without a spine-like ray; dorsal fin branched rays 6-8 --> 3
2. Two pairs of barbels; total gill rakers 21-27; pharyngeal teeth in three rows with usually 1,1,3 teeth on each side = Cyprinus carpio (Common Carp/Carpe) [Ottawa and Rideau rivers]
No barbels; total gill rakers 37-50; pharyngeal teeth in one row with usually 4 teeth on each side = Carassius auratus (Goldfish/Carassin) [various ponds in Ontario]
3. No groove between the snout and lip (premaxillaries not protractile, frenum present); snout projects far over ventral mouth; barbel at mouth corner (note spawning male Pimephales notatus develop a barbel-like structure at the rear tip of the upper jaw) = Rhinichthys cataractae (Longnose Dace/Naseux de rapides) [widespread]
A groove between the snout and lip (premaxillaries protractile); snout not markedly projecting and mouth at head tip; no barbel at mouth corner --> 4
4. Small, short, flat, and often triangular barbel present in the groove between upper lip and snout, just anterior to mouth corner (often absent on one or both sides in Margariscus margarita, absent on both sides in 23% of over 1000 individuals from across North America; usually present in the other two species and in some fish from large samples of all species; if the barbel is absent on both sides, Margariscus margarita is distinguished by the high scale count in a complete lateral line, short s-shaped gut, pharyngeal teeth in main rows 5-4, silvery peritoneum (lining of body cavity, belly must be cut open to see), small mouth and lack of unique characters listed for other carp family members) --> 5
No such barbel --> 7
5. Lateral line scales 43-50; flank scales each with an anterior patch of pigment but overall colour is bright silvery = Semotilus corporalis (Fallfish/Ouitouche) [widespread]
Lateral line scales 46-79, usually 52-75; flank scales without an anterior patch of pigment, overall colour not bright silvery --> 6
6. Lateral line scales 47-66, usually 52-63; distinctive black spot at anterior dorsal fin base; body not spotted, scales outlined with pigment; mouth large, corner at level of front of eye or behind = Semotilus atromaculatus (Creek Chub/Mulet à cornes) [widespread]
Lateral line scales 46-79, usually 65-75; no black spot at anterior dorsal fin base; body usually appears spotted or speckled black and brown; mouth small, corner not reaching level of front of eye = Margariscus margarita (Pearl Dace/Mulet perlé) [widespread]
7. Lateral line scales 63 or more --> 8
Lateral line scales 57 or less --> 9
8. Peritoneum black (if silvery with dark speckles, flap-like barbel may have been missed or is absent --> 5), mouth small, extending to, or just past, the nostrils; 2 extra major loops in the gut; a stripe or series of spots between a dark upper flank stripe and the back; pharyngeal teeth in one row = *Phoxinus eos (Northern Redbelly Dace/Ventre rouge du nord) [widespread]
Peritoneum black (if silvery with dark speckles, flap-like barbel may have been missed or is absent --> 5), mouth large, extending to, or just past, the anterior eye margin; short s-shaped gut; no second stripe or spots as above; pharyngeal teeth in two rows = *Phoxinus neogaeus (Finescale Dace/Ventre citron) [widespread]
* Note: These two species commonly hybridize and diploid and triploid hybrids are reported from the NCR in Hawley (= Holly) Lake, Québec. Hybrids may occur in the absence of one parent species and are mostly female clones (Dawley et al., 1987; Dawley and Goddard, 1988). Character states in the key may not allow distinction of species.
9. Lateral line strongly decurved with 39-57 scales; naked fleshy keel between the pelvic fins and the anus on the belly midline; anal fin branched rays 7-18, usually 11-13 = Notemigonus crysoleucas (Golden Shiner/Méné jaune) [widespread]
Lateral line not strongly decurved; belly scaled at midline, no naked fleshy keel; anal fin branched rays usually 10 or less --> 10
10. Second dorsal fin unbranched ray short and stout, separated from next ray by a relatively wide membrane in adults (first ray is minute and difficult to see); back flattened; dark to dusky blotch at anterior dorsal fin above base in adults; scales in front of dorsal fin on back smaller and more crowded than flank scales, not in regular rows --> 11
Second dorsal fin unbranched ray thin and splint-like, closely attached to next ray; back more rounded; no blotch above anterior dorsal fin base; scales in front of dorsal fin on back usually large and distinct, more like flank scales and in regular rows --> 12
11. Lateral line usually incomplete, not extending along whole flank; mouth at tip of body; caudal fin base spot faint to absent; body deep, depth less than 4.0 times in standard length (tip of snout to end of vertebral column or tail base); dorsal fin origin above or slightly anterior to pelvic fin origin; gill rakers 14 or more = Pimephales promelas (Fathead Minnow/Tête-de-boule) [widespread]
Lateral line complete; mouth under snout; caudal fin base spot well-developed; body more slender, more than 4.5 times in standard length; dorsal fin origin posterior to pelvic fin origin; gill rakers 11 or fewer = Pimephales notatus (Bluntnose Minnow/Ventre-pourri) [widespread]
12. Gut long with numerous coils; mouth almost horizontal, below tip of head, with a long diagonal fold above and below its corner --> 13
Gut short with an s-shaped loop; mouth oblique, at tip of head (below tip in Notropis hudsonius but without long diagonal fold --> 14
13. Colour brassy in adult, dull silver in young; dorsal fin margin rounded; 14-20 radii (rarely 11-12) on adult scales (radii are grooves radiating from the scale centre); usually 5-6 scales between lateral line and pelvic fin; no thin black line along flank = Hybognathus hankinsoni (Brassy Minnow/Méné laiton) [widespread]
Colour bright silvery; dorsal fin margin falcate (sickle-shaped) and pointed; 12 or less radii on adult scales (range 5-12); usually 4 scales between lateral line and pelvic fins; thin black line along flank lying partly over dark stripe = Hybognathus regius (Eastern Silvery Minnow/Méné d'argent) [Ottawa and Rideau rivers]
14. Barbel distinct, slender and present at angle of upper and lower jaw = Nocomis biguttatus (Hornyhead Chub/Tête à taches rouges)
No barbel --> 15
15. Anal fin branched rays 8-11, rarely 7 (sometimes 7 in Luxilus cornutus but this species has anterior lateral line scales more than twice as high as wide); pharyngeal tooth formula usually 2,4-4,2 --> 16
Anal fin branched rays 6-7, rarely 8; pharyngeal tooth formula usually 1,4-4,1 or 4-4 (2,4-4,2 in Notropis hudsonius but this species has a distinctive black spot on the caudal fin base) --> 18
16. Exposed part of anterior lateral line scales more than twice as high as wide; dorsal fin origin over or in front of the level of the pelvic fins insertion (posteriomost point of attachment of fin base) = Luxilus cornutus (Common Shiner/Méné à nageoires rouges) [widespread]
Exposed part of anterior lateral line scales about equal in width and depth (about twice as high as wide in Notropis volucellus but this species has black pigment around anus and anal fin base); dorsal fin origin behind the level of the pelvic fins insertion --> 17
17. Pectoral fin rays usually 15-17; snout length less than orbit (bony eye socket) diameter; anterior lateral line pores not outlined by pigment; predorsal stripe weak; flank pigment ends above lateral line anteriorly; distal anal fin margin concave; dorsal fin pointed, anterior ray tip reaching well beyond posterior ray tip when fin depressed = Notropis atherinoides (Emerald Shiner/Méné émeraude) [widespread]
Pectoral fin rays usually 11-14; snout length greater than orbit diameter in fish longer than 3.5 cm standard length; anterior lateral line pores outlined above and below by pigment spots giving a "stitched" appearance; predorsal stripe distinct; flank pigment ends at or below lateral line anteriorly; distal anal fin margin straight; dorsal fin not as pointed, anterior ray tip not reaching posterior ray tip when fin depressed = Notropis rubellus (Rosyface Shiner/tête rose) [widespread]
18. Dorsal fin with black blotch on last 2-4 membranes (may be weakly expressed or absent in young); snout pointed; eye small, less than one-quarter head length in adults (at least less than one-third) = Cyprinella spiloptera (Spotfin Shiner/méné bleu) [Bear Creek, Ottawa River]
Dorsal fin without posterior blotch; snout rounded; eye more than one-quarter head length in adults --> 19
19. Black spot at base of caudal fin large and obvious (may be obscured by silvery scales in live fish); dorsal and anal fins falcate = Notropis hudsonius (Spottail Shiner/Queue à tache noir) [widespread]
No obvious spot at caudal fin base; dorsal and anal fins convex or straight --> 20
20. Flank stripe strongly developed, extending onto head and to snout --> 21
Flank stripe weakly developed, not extending onto snout --> 22
21. Chin black (as is snout); mid-flank stripe often a strong black zig-zag; usually 2 rows of pharyngeal teeth = Notropis heterodon (Blackchin Shiner/Menton noir) [widespread]
Chin not black (but snout black); anterior mid-flank stripe composed of a series of crescents, tips pointing rearwards; usually 1 row of pharyngeal teeth = Notropis heterolepis (Blacknose Shiner/Museau noir) [widespread]
22. Area around anus and base of anal fin weakly pigmented; anal fin branched rays usually 6 (range 5-7); flank pigment not extending below lateral line; thin stripe on mid-line of back = Notropis stramineus (Sand Shiner/Méné paille) [Ottawa, Jock and Mississippi rivers]
Area around anus and base of anal fin black; anal fin branched rays usually 7 (range 7-8); flank pigment extends below lateral line; no distinct stripe on mid-line of back = Notropis volucellus (Mimic Shiner/Méné pâle) [widespread]
Key to Catostomidae (Suckers/Catostomes)
Adults
1. Dorsal fin long, with 22-32 major rays; anterior rays elongated into a high, sickle-shape = Carpiodes cyprinus (Quillback/Couette) [Ottawa and Gatineau rivers]
Dorsal fin short, with 9-18 major rays; anterior rays not markedly elongated --> 2
2. Scales small numbering 53 or more (usually 58 or more) in the lateral line; body rounded in cross section --> 3
Scales large numbering 48 or less in the lateral line; body compressed in cross section --> 4
3. Scales in lateral line 91-120 = Catostomus catostomus (Longnose Sucker/Meunier rouge) [Ottawa River, rare to absent]
Scales in lateral line 53-85 (usually 58-68) = Catostomus commersonii (White Sucker/Meunier noir) [widespread]
4. Scales around caudal peduncle (tail stem in front of tail fin) usually 15-16, rarely 12-13; dorsal fin distal margin usually strongly convex in adults (very slightly concave to straight in young); snout laterally mottled; mouth more terminal (terminal = at tip of snout) than other species = Moxostoma valenciennesi (Greater Redhorse/Chevalier jaune) [Ottawa, Mississippi and Rideau rivers, Bear Creek]
Scales around caudal peduncle usually 12-13, rarely 15-16; dorsal fin distal margin slightly convex (may be obviously convex in adult Moxostoma anisurum), straight, emarginate, or falcate; snout not mottled --> 5
5. Lower lip narrow, posterior margins of each half meet at an acute angle centrally; lower lip with transverse lines on folds or plicae, forming irregular-sized, oblong papillae; lower lip narrows abruptly before joining upper lip; maximum body depth into body length (head tip to end of scales) 3.5 times or less; dorsal fin rays usually 14-15 (range 12-17); caudal fin dusky to silver and all fins without red colour; flank blotches pale to absent = Moxostoma anisurum (Silver Redhorse/Chevalier blanc) [widespread]
Lower lip broader, posterior margins of each half meet at an obtuse angle centrally, may be almost straight (rarely acute at about 80°); lower lip without transverse lines on folds or plicae (large, oval papillae may be found posteriorly on the lower lip of large Moxostoma macrolepidotum); lower lip thick at corners; maximum body depth into body length (head tip to end of scales) 3.7 times or more; dorsal fin rays usually 13 or less; caudal fin pink to blood red (paler in young); 3-4 flank blotches distinct --> 6
6. Pharyngeal arch strongly developed with 6-9, large molar teeth on lower half of tooth row; distal dorsal fin margin rounded, straight, or slightly concave; long head, less than 4.3 times in standard length; mouth large; gill rakers with spots at base or on lower part of raker = Moxostoma carinatum (River Redhorse/Chevalier de rivière) [Ottawa, Gatineau and Mississippi rivers]
Pharyngeal arch not strongly developed, teeth comb- or blade-like and numerous, more than 11 on lower half of tooth row; distal dorsal fin margin falcate, or s-shaped; short head, 4.3-5.4 times in standard length; mouth small, not as wide as head; no gill raker spots = Moxostoma macrolepidotum (Shorthead Redhorse/Chevalier Rouge) [widespread]
Key to young Moxostoma (Redhorses/Suceurs)
(modified after Vachon (2003))
Young or juvenile Moxostoma (total length 35-150 mm) can be identified by the key below. These redhorses are particularly difficult to identify as young and Nathalie Vachon's careful study is based on fish from the Richelieu and St. Lawrence rivers in Québec but should be applicable to fish in the NCR. Characters in brackets are additional ones that will aid in identification but are not always unique to the species.
1. Scales around caudal peduncle (tail stem in front of tail fin) usually 15-16, rarely 12-13; supraorbital canals (pored, bony canals on the head running over the eye) not well-developed and not usually visible [pigmentation present and intense on the latero-ventral body, especially near the pectoral fins; relatively uniform pigmentation of the opercle or mostly concentrated on the upper half with a vertical row anteriorly; a relatively diffuse stripe behind the supratemporal canal across the occiput (top of the head at the back); dorsal fin very slightly concave or straight with 13-14, rarely 12, rays; body depth high to moderate; small melanophores diffusely spread on the body and snout giving a mottled aspect, very rarely forming 4 saddles (pigment in a saddle-shape over the back and down onto the sides); pharyngeal arches delicate with numerous comb-like teeth] = Moxostoma valenciennesi (Greater Redhorse/Chevalier jaune)
Scales around caudal peduncle usually 12-13, rarely 15-16; supraorbital canals moderately to strongly developed and visible --> 2
2. Supraorbital canals strongly developed, visible and straight in the anterior part from the snout to about mid-eye [pigmentation behind the supratemporal canal strong; large lower lip straight or slightly curved with obvious longitudinal ridges or plicae and often with deep transverse grooves; dorsal fin slightly concave with 13 rays, rarely 12, 14 or 15; body depth moderate to low; large melanophores distributed in 3-4 saddles; snout melanophores generally large; pharyngeal arches delicate with numerous comb-like teeth] = Moxostoma macrolepidotum (Shorthead Redhorse/Chevalier rouge)
Supraorbital canals moderately or strongly developed, visible and sinuous --> 3
3. Lower lip thin with an acute angle (90° or less) and with very fine longitudinal ridges [pigmentation behind the supratemporal canal not strong; supraorbital canal moderately or strongly developed, visible and sinuous especially in the anterior part with very visible pores; dorsal fin slightly concave or straight in larger fish with 14-16 rays, very rarely 13 or 17; body depth high or moderate; small melanophores evenly distributed on the body; pharyngeal arches delicate with numerous comb-like teeth] = Moxostoma anisurum (Silver Redhorse/Chevalier blanc)
Lower lip thin with an obtuse angle (>90°) and with realtively perceptible longitudinal ridges [pigmentation behind the supratemporal canal generally moderate; supraorbital canal moderately developed, visible and sinuous in the anterior part and occasionally in the posterior part; dorsal fin slightly concave with 12-14 rays, rarely 15; body elongate; small melanophores evenly distributed on the body, very rarely forming 3-4 saddles; black spot"(s) present at the base of the first gill raker; pharyngeal arches heavy with molariform lower teeth] = Moxostoma carinatum (River Redhorse/Chevalier de rivière)
Key to Ictaluridae (North American Catfishes/Barbottes et Barbues)
1. Adipose fin long, closely associated with the caudal fin, and attached to the back; small fishes, maximum size 11.5-31.2 cm, usually 17.3 cm or less --> 2
Adipose fin short, remote from the caudal fin, and posteriorly free from the back; large fishes, maximum size 46.5-120.2 cm --> 4
2. Premaxillary band of teeth (in anterior roof of mouth) with lateral processes extending backwards; posterior teeth of pectoral fin spine-like ray weaker than anterior teeth; back with pale areas behind head and at posterior end of dorsal fin; pectoral fin radials (bones in fin base - dissection or x-ray required) never fused = Noturus flavus (Stonecat/Barbotte des rapides) [Rideau River]
Premaxillary band of teeth without lateral processes extending backwards; posterior teeth of pectoral fin spine-like ray longer than anterior teeth or absent; back a uniform grey; pectoral fin radials usually fused --> 3
3. Body short, stout and tadpole-shaped; mouth terminal; pectoral spine-like ray without posterior teeth; branched pectoral rays 4-9 but usually 5-7 and modally 6; branched pelvic rays 4-9 but usually 7; typically 10 preoperculomandibular canal pores (canal runs from lower jaw onto the preopercle bone); dorsal, caudal and anal fins without a black distal margin; dark streak along mid-flank at intersection of dorsal and ventral muscle blocks = Noturus gyrinus (Tadpole Madtom/Chat-fou brun) [widespread]
Body elongate and slender; mouth subterminal; pectoral spine-like ray with posterior teeth; branched pectoral rays usually 8; branched pelvic rays usually 8; 11 preoperculomandibular canal pores; dorsal, caudal and anal fins with a black distal margin; no flank streak = Noturus insignis (Margined Madtom/Chat-Fou Liséré) [Gatineau Park and Gatineau River]
4. Caudal fin with a strong fork; almost continuous surface bony ridge on back between back of head and dorsal fin origin; mouth corner barbels more than 3 times longer than nostril barbels = Ictalurus punctatus (Channel Catfish/Barbue de rivière) [Ottawa, Gatineau and Mississippi rivers]
Caudal fin not forked, but truncate (square-cut) to rounded; back more fleshy, soft, depressible area before dorsal fin; mouth corner barbels about 2 times longer than nostril barbels --> 5
5. Chin barbels yellow to white or pinkish, upper barbels yellow to grey; anal fin touches caudal fin when pressed to the body; total anal rays 24-28; distance between lower jaw notch and tip of lower jaw much greater than distance between lower jaw notch and isthmus; fins (except pelvics and adipose) with black distal margins = Ameiurus natalis (Yellow Bullhead/Barbotte jaune) [Ottawa River]
All barbels brown to black (bases of lower ones may be pale in young); anal fin not reaching caudal fin when pressed to body; total anal rays 19-24; distance between lower jaw notch and tip of lower jaw about equal to distance between lower jaw notch and isthmus; no fins with black distal margins = Ameiurus nebulosus (Brown Bullhead/Barbotte brune) [widespread]
Key to Esocidae (Pikes/Brochets)
1. Submandibular pores 9-11 (usually 5 on each lower jaw); cheeks (the area between the eye and the preoperculum) fully scaled; flanks dark with lighter, wavy bars in young, or rows of light, bean-shaped spots in adults; no mid-dorsal light stripe (or a discontinuous one in young) = Esox lucius (Northern Pike/Grand brochet) [widespread]
Submandibular pores 12-20 (usually 6-10 on each lower jaw); cheeks only scaled on upper half; flanks light to silvery with darker spots, blotches or oblique bars; prominent mid-dorsal, light stripe in young = Esox masquinongy (Muskellunge/Maskinongé) [widespread]
Key to Osmeridae (Smelts/Éperlans)
1. Total gill rakers 32-36 (usually 33-36); orbit diameter 4.4-6.5% of standard length; small, standard length less than 135 mm = Osmerus spectrum (Pygmy Smelt/Éperlan nain) [Meech Lake]
Total gill rakers 26-37 (usually 28-32); orbit diameter 7.0-11.3% of standard length; larger, standard length can exceed 200 mm = Osmerus mordax (Rainbow Smelt/Éperlan arc-en-ciel) [widespread]
Key to Salmonidae (Salmons/Saumons)
1. Teeth in lower jaw absent except in youngest fish; mouth small, lower jaw short, not extending back to mid-eye; scales large, 13 or less from dorsal fin origin to lateral line; caudal fin clearly forked; overall colour silvery to white --> 2
Teeth in lower jaw strong and conical; mouth large, lower jaw long, extending back to or past mid-eye; scales small, 19 or more from dorsal fin origin to lateral line; caudal fin usually truncate (obvious fork only in Salvelinus namaycush and Salmo salar); overall colour darker with spots and vermiculations --> 3
2. Mouth at tip of head; gill rakers 14-18 on upper arch; upper lip profile slopes forward in line with forehead (snout tip pointed viewed laterally) = Coregonus artedi (Cisco/Cisco de lac) [Québec lakes]
Mouth overhung by snout; gill rakers 7-12 on upper arch; upper lip profile vertical or bent back from line of forehead (snout tip rounded viewed laterally) = Coregonus clupeaformis (Lake Whitefish/Grande corégone) [Québec lakes]
3. Head and body with black spots (Salmo salar has red flank spots when young); pelvic and anal fins without white anterior margin; scales stand out; vomer bone (in centre of roof of mouth) flat, with teeth in 2 rows on shaft --> 4
Body with light spots of white, cream, pink, or red; pelvic and anal fins with conspicuous white anterior margin; scales inconspicuous; vomer bone deeper, without teeth on shaft --> 7
4. Caudal fin with radiating rows of black spots; body without red spots --> 5
Caudal fin lacking spots, if present not in rows; body may have red spots --> 6
5. Orange to red mark on each inner lower jaw (the "cutthroat"); small teeth on tongue base; no pink flank stripe (or if present, faint and copper-orange) = Oncorhynchus clarkii (Cutthroat Trout/Truite fardée) [Québec lakes and rivers]
No cutthroat mark; no basal tongue teeth; usually pink (or red to orange) flank stripe = Oncorhynchus mykiss (Rainbow Trout/Truite arc-en-ciel) [Québec lakes and rivers]
6. Opercular area with only 2-3 large spots; upper jaw not extending back much beyond eye (centre of eye in young); teeth on vomer bone weak; adipose fin without red or orange, adults lack red on flank (red present in young between parr marks and as a halo around dark spots in spawning fish); dark blotches on caudal fin if present not restricted to upper lobe; caudal fin deeply forked, medial rays less than half length marginal rays = Salmo salar (Atlantic Salmon/Saumon Atlantique) [Québec lakes]
Opercular area with many spots; upper jaw extending back well beyond eye (posterior half of eye in young); teeth on vomer bone strong; adipose fin often margined red or orange, adults often with rust-red flank spots with a blue halo; blotches on caudal fin if present only on upper lobe; caudal fin slightly forked, medial rays more than half the length of marginal rays = Salmo trutta (Brown Trout/Truite brune) [Québec lakes and rivers]
7. Caudal fin deeply forked; spots on flank sometimes irregular, bean-shaped whitish or cream (rarely orange); pyloric caeca (finger-like blind sacs attached to the junction of the stomach and intestine - see below) about 90-200; 7-12 parr marks (dark bars on flank of young fish), irregular, often interrupted, and narrow = Salvelinus namaycush (Lake Trout/Touladi) [Québec lakes, Gatineau River]
Caudal fin emarginate or square when spread out (may be forked in some Salvelinus alpinus populations); orange, pink or red spots on flank; pyloric caeca 13-75 --> 8
8. Dorsal and caudal fins and back with vermiculations (dark wavy lines); pelvic and anal fins with snow white leading edge set off by black behind; tip of lower jaw and roof of mouth black; flank spots usually surrounded by a blue halo; basibranchial teeth usually absent (on floor of mouth between gills); 8-10 regularly arranged parr marks along flank in young = Salvelinus fontinalis (Brook Trout/Omble de fontaine) - [widespread in Québec]
Dorsal and caudal fins without vermiculations; white leading edge not usually set off by black behind; tip of lower jaw and roof of mouth whitish; no blue halos around flank spots; basibranchial teeth present and numerous; 10-15 parr marks in young irregular and not clearly defined = Salvelinus alpinus (Arctic Char/Omble chevalier) [Québec lakes]
Key to young Salmonidae (Salmons/Saumons)
Key to Gasterosteidae (Sticklebacks/Épinoches)
1. Short dorsal fin spines 7-12 (usually 9), alternately sloping left and right = Pungitius pungitius (Ninespine Stickleback/Épinoche à neuf épines) [Québec lakes]
Short or long dorsal fin spines 3-7, in median line --> 2
2. Short dorsal fin spines 4-7; short pelvic spines (both less than eye diameter); scutes weakly developed = Culaea inconstans (Brook Stickleback/Épinoche à cinq épines) [widespread]
Long dorsal fin spines 3; long pelvic spines (both exceeding eye diameter); scutes (vertical bony plates on flanks) large = Gasterosteus aculeatus (Threespine Stickleback/Épinoche à trois épines) [widespread in Québec]
Key to Centrarchidae (Sunfishes/Crapets)
1. Dorsal fin spines 6-9, usually 7-8; length of whole anal and dorsal fin bases about equal = Pomoxis nigromaculatus (Black Crappie/Marigane noire) [Ottawa, Gatineau and Rideau rivers]
Dorsal fin spines 9-13; length of whole anal fin base 1.5-3.3 times in whole dorsal fin base length --> 2
2. Anal fin spines 5-7, usually 6, folding into a groove; length of anal fin base about 1.5 times in whole dorsal fin base length; 7-11 distinctive horizontal rows of spots below the lateral line; eye red = Ambloplites rupestris (Rock Bass/Crapet de roche) [widespread]
Anal fin spines 3, no basal groove; length of anal fin base 2.1-3.3 times in whole dorsal fin base length; no horizontal rows of spots below the lateral line --> 3
3. Lateral line scales small, 58-81; body rounded in cross section and elongate, maximum body depth 2.5-5.0 (usually 3.0 or more) times in body length from snout tip to end of scales --> 4
Lateral line scales large, 35-50; body compressed in cross section and deep, maximum body depth 1.7-3.0 (usually 2.5 or less) times in body length from snout tip to end of scales --> 5
4. Upper jaw extends back to about mid-pupil but not behind eye; lateral line scales 67-81; scales present on the bases of the soft dorsal and anal fin bases; young fish with 3 strong bars on caudal fin, an orange bar at the fin base, a black bar on the fin, and broad white to yellow bar on fin tips; caudal spot weak to absent in young; flank in young with many bronze spots, often forming 8-16 distinct bar = Micropterus dolomieu (Smallmouth Bass/Achigan à petite bouche) [widespread]
Upper jaw extends back to a level behind eye; lateral line scales 58-77 (usually less than 70 in Canada); no scales on the bases of the soft dorsal and anal fin bases; caudal fin in young not clearly barred, yellowish to reddish at base, black distally and only extreme distal margin of fin white; well-developed caudal spot in young; young fish with a flank stripe, sometimes in separate blotches = Micropterus salmoides (Largemouth Bass/Achigan à grande bouche) [widespread]
5. Opercular or "ear" flap black with a red spot at posterior edge (white in preserved fish, rarely absent and flap all black); opercular flap stiff and inflexible at its bony edge; cheeks with wavy blue streaks; gill rakers short and rounded, longest raker not reaching second adjacent raker when appressed (in adults, longer in young but not as long as in young bluegills; length of longest raker less than two times its base width in adults, 3-4 times in young-of-the-year); no black blotch at posterior base of second dorsal fin = *Lepomis gibbosus (Pumpkinseed/Crapet-soleil) [widespread]
Opercular flap all black; flap thin and flexible at its bony edge; head without blue streaks but a blue sheen ventrally; gill rakers relatively long and slender, longest raker reaching base of second or third adjacent raker when appressed (in adults, shorter in young; compare young fish of similar size in these two species; length of longest raker 4-5 times its base width in adults); black blotch at posterior base of second dorsal fin on last 5 rays = *Lepomis macrochirus (Bluegill/Crapet arlequin) [Ottawa and Rideau rivers]
* Note: These two species are known to hybridize freely in Canada, and hybrids breed with parents, giving a continuous range in characters between the two species. Hybridization is not recorded for the NCR but should it occur, identification to species would not be possible.
Key to Percidae (Perches/Perches)
1. Mouth large, upper jaw extending to or beyond eye mid-point; lower edges of preopercle (L-shaped bone in front of operculum or gill cover) serrated; caudal fin forked; branchiostegal rays (bony struts on underside of head) 7-8, usually 7 --> 2
Mouth small, upper jaw not extending beyond anterior quarter of eye margin; lower edges of preopercle smooth; caudal fin rounded or weakly emarginate; branchiostegal rays 5-6, usually 6 --> 4
2. Anal fin soft rays 6-9, usually 7-8; lower jaw teeth about equal in size, no canines; body compressed in cross section; flanks with 5-10 distinctive, wide, dark bars = Perca flavescens (Yellow Perch/Perchaude) [widespread]
Anal fin soft rays 10-14, usually 12-13; lower jaw with a pair of canine teeth at jaw tip; body subcylindrical in cross section; vague, interrupted bars only in young --> 3
3. Adults with large black blotch at rear base of spiny dorsal fin, no other spots on spiny fin membranes; no scales on operculum in adults; 5-8 dark saddles over the back; lower lobe of caudal fin usually white at tip; pyloric caeca 3, about equal in length to stomach = Sander vitreus (Walleye/Doré jaune) [widespread]
Adults without large black blotch at rear base of spiny dorsal fin although membranes with small to moderate half-moon black spots; scales on operculum in adults; 3-4 brown saddles over the back; lower lobe of caudal fin not white at tip; pyloric caeca 3-9, usually 5, shorter than stomach = Sander canadense (Sauger/Doré noir) [Ottawa and Gatineau rivers]
4. Anal fin large, its area about equal to or larger than soft dorsal fin; body elongate and rounded; midline of belly between and behind pelvic fins naked (females), or with enlarged scales (males) --> 5
Anal fin small, its area much less than soft dorsal fin; body more compressed than rounded; midline of belly between and behind pelvic fins scaled or not, but no enlarged scales --> 6
5. First dorsal fin spines 12-17, usually 14-16; lateral scale rows (counted along mid-flank from head to tail) 67-103, usually 77 or more; no deep groove between the snout and lip (premaxillaries not protractile) = Percina caprodes (Logperch/Fouille-roche zébré) [widespread]
First dorsal fin spines 9-13, usually 10-12; lateral scale rows 43-61, usually 52 or less; a deep to weak groove between the snout and lip (premaxillaries protractile) = Percina copelandi (Channel Darter/Fouille-roche Gris) [Quyon stream, Gatineau River]
6. Snout and upper lip separated by a groove (premaxillaries protractile); a single thin anal fin spine --> 7
Snout and upper lip joined, not separated by a groove (premaxillaries not protractile); two anal fin spines, the first thick --> 8
7. Infraorbital (under the eye) and supratemporal (over back of head) head canals not continuous; normally 6 pores or fewer on the infraorbital canal; 1-11, usually 9 or fewer, pores in the preoperculomandibular head canal (canal runs from lower jaw onto the preopercle bone); 9-15, usually 12 or fewer, dorsal fin soft rays; cheek (area below and behind the eye) and nape (area behind the top of the head) usually scaleless or with very few scales; usually 3-4 bars on the caudal fin = *Etheostoma nigrum (Johnny Darter/Raseux-de-terre noir) [widespread]
Infraorbital and supratemporal head canals continuous; normally 8 pores or more on the infraorbital canal; 9-13, usually 11, pores in the preoperculomandibular head canal; 10-17, usually 13 or more, dorsal fin soft rays; cheek and nape usually covered with scales; usually 5-8 bars on the caudal fin = *Etheostoma olmstedi (Tessellated Darter/Raseux-de-terre gris) [widespread]
* Note: Head canals and pores are best seen in specimens injected by capillary action with the temporary stain methylene blue. These two species hybridize and some scientists regard them as a single species (Brett, 1985).
8. Cheeks and opercles scaled (may be obscured by skin); dorsal fin spines longer than eye diameter; soft dorsal fin rays 9-13, usually 10-11 = Etheostoma exile (Iowa Darter/Dard à ventre jaune) [widespread]
Cheeks and opercles not scaled; dorsal fin spines short, about eye diameter or less; soft dorsal fin rays 10-15, usually 12-14 = Etheostoma flabellare (Fantail Darter/Dard barré) [Québec streams]
List of Figures (to come)
1. Pictorial key to families (note body form; number, size, position and shape of fins; presence/absence of barbels; eye size and position).
4. Internal anatomy (from McAllister and Coad, 1985).
5. Teeth arrangement (from Encyclopaedia of Canadian Fish).
6. Scale types (ditto).
8. Lamprey disc.
12. Lower lip broad or narrow (couplet 5 in Catostomidae).
14. External characters of a catfish.
© Brian W. Coad (www.briancoad.com)