Fishes of Canada's National Capital Region
Species Accounts
Fundulidae - Topminnows - Fondules
Topminnows or Killifishes are found in fresh, brackish and coastal marine waters of North and Central America where there are about 48 species. There are 3 species in Canada, 1 on the Atlantic coast and in Atlantic drainages, 1 in Arctic and Atlantic drainages including brackish waters of the Atlantic coast, and 1 in freshwaters of the Atlantic drainage.
These small fishes are distinguished by a series of osteological characters such as the autopalatine bone projecting anterior to the lateral ethmoid and the anteriorly directed ventral arms of the maxillary bones of the upper jaw often have strong hooks. Scales are cycloid and extend onto the top of the head. The snout is pointed and elongate compared to related families. The head is flattened on top and the mouth upturned and protrusible. Lateral lines are absent on the body but can be well-developed on the head. The caudal fin is truncate and fins lack spines. Pelvic fins are abdominal. The swimbladder lacks a duct to the gut.
"Killifish" is derived from a Dutch word for a creek or channel in reference to their habitat.
Topminnows lay eggs. Food is usually surface items taken by the oblique mouth. The flattened head may be an adaptation to poor oxygen conditions enabling topminnows to live as close to air-water interface as possible in oxygen-rich conditions. Some are colourful and their tolerance of warm temperatures and wide salinities make them attractive aquarium fishes. Others have been used extensively as experimental animals.
Banded Killifish / Fondule barré
Fundulus diaphanus (Le Sueur, 1817)
Taxonomy
Other common names include Freshwater Mummichog, Freshwater Killy, Grayback, Topminnow, Eastern and Western Banded Killifish, Menona Killifish, Barred Minnow, Hardhead and Petit barré. There are two subspecies, Fundulus diaphanus diaphanus found eastwards from eastern Lake Ontario and Fundulus diaphanus menona Jordan and Copeland in Jordan, 1877 found westwards from Lake Erie. These two subspecies intergrade in the upper St. Lawrence River and Lake Ontario. NCR fish have not been investigated to determine their subspecies.
Key Characters
This species is the only topminnow in the NCR and is distinguished by having an upturned mouth and scales on the head and cheeks.
Description
Dorsal fin rays 10-15, anal rays 9-13 and pectoral rays 14-19. Scales in lateral series 35-53, no lateral line pores. Gill rakers small, numbering 4-7. Males have larger dorsal and anal fins than females. The 2 subspecies are distinguished by the western subspecies having fewer lateral scales, fewer dorsal, anal and pectoral fin rays, and a stripe through the bars on the caudal peduncle.
Colour
Back brown to olive-green or olive-yellow, silvery on the flanks and white or yellow on the belly. There are 8-22 green-brown bars along the flank. Males have more and wider bars than females. Breeding males develop a green-gold dorsal fin with faint black bars, stronger, wide, green flank bars, a yellow throat and have an intense blue-green back. Faber (1984c) illustrates a larva.
Size
Attains 11.4 cm total length.
Distribution
Found in Arctic and Atlantic drainages of Canada including brackish waters of the Atlantic coast. It is found from southwestern and southeastern Newfoundland, Anticosti Island, rarely on the north shore of the Gulf of St. Lawrence, and from the southern Gulf of St. Lawrence south to South Carolina. It extends up the St. Lawrence valley, across southern Ontario and in the southern Great Lakes basin but not north of Lake Superior, and is in Lake of the Woods and southern Manitoba and as far west as eastern Montana.
Origin
This species entered the NCR from possibly an Atlantic coastal refugium, a Mississippian or a Missourian refugium (Mandrak and Crossman, 1992). The presence of this species in Gatineau Park may be from discarded bait fish brought in by anglers (Rubec, 1975a).
Habitat
In fresh waters, Banded Killifish are found in schools in quieter parts of lakes and slow rivers over bedrock, boulders, sand, gravel, silt, mud or detritus near aquatic plants. Water clarity is important as this fish feeds visually. It tolerates low oxygen and high temperatures (above 38°C, although preferred temperature is 21.0°C in Nova Scotia and 28.6°C in Pennsylvania). When disturbed this fish will dive into the substrate at an angle of 45°, burying itself by vigorous lateral body movements. It may remain wholly or partially buried for less than a minute to more than 2 hours.
Age and Growth
Life span is up to 4 years with maturity as early as 1 year.
Food
Food is taken at all levels in the water column despite the dorsally positioned mouth and includes insect larvae, crustaceans, molluscs, flatworms, and flying insects at the surface. Feeding occurs mainly in the afternoon with a shorter period starting just before dawn. Surface feeding causes ripples. It is eaten by various fishes and birds.
Reproduction
Spawning occurs in spring and summer, with females in spawning condition noted in the Ottawa River in June when temperatures were around 23°C (McAllister and Coad, 1975). In Québec spawning occurs in mid-July to August when fish are 2 years old and water temperatures are 21-25°C. Elsewhere maturity at 1 year has been recorded. Males establish territories in weedy areas and fight off other males. The male pursues a female until she extrudes an egg which hangs from her body by a filament. The male redoubles his pursuit and drives the female into vegetation, presses against the female using his dorsal and anal fins, and the female extrudes 5-10 more eggs. The male quivers, bends his body and fertilises the eggs. The eggs separate from the main thread and each other and become tangled in weeds by their own threads. This mating takes only 15-30 seconds and is repeated several times over 5 minutes until about 50 eggs are deposited. Egg diameters are up to 2.1 mm and a female can contain 426 yellow-orange to orange eggs. Eggs hatch in 11-12 days at 22-27°C and larvae are 5.0-6.0 mm long.
Importance
The Banded Killifish has been used as bait in the Maritimes since it is easily transported, reputedly for days packed only in leaves or moss in a can. It is not classified as a bait fish in Ontario and so it is illegal to use it as one (Houston, 1990). This species was placed in the "Not at Risk" category in 1989 by the Committee on the Status of Endangered Wildlife in Canada.
© Brian W. Coad (www.briancoad.com)