The under-appreciated members of the minnow, perch and stickleback families offer great fish-watching opportunities
Peterborough Examiner – June 14, 2024 – by Drew Monkman
As a child, there was nothing I enjoyed more than pursuing frogs and turtles along Jackson Creek or at my grandparents’ cottage on Clear Lake. However, when I’d try to scoop them up with a net, I’d sometimes inadvertently catch small fish. Some had bright scarlet bellies while others sported a row of spines along the back. I remember being amazed that such exotic-looking species even existed. These redbelly dace and brook sticklebacks were my first window into the world of non-game fish and just how fascinating they are.
Many of our non-game species belong to the minnow family (Cyprinidae) which also includes carp. They make up the largest family of freshwater fish in the world, and about two dozen species can be found right here in the Kawarthas. Most any bridge or culvert on a shallow, slow-moving stream provides opportunities for minnow-watching. Polarized glasses come in handy as they reduce water surface glare.
The May through early July spawning season is a great time to observe and even catch non-game fish before returning them to the water. All you need is a minnow net, preferably with a telescopic handle, and a clear plastic container for optimal viewing or to take a photo. Alternatively, you can briefly hold the fish in your open palm to snap a picture. You can then use the iNaturalist app to identify the species. “A Field Guide to Freshwater Fishes of Ontario”, published by the Royal Ontario Museum Press, is also an excellent resource for fish identification and ecology. I also recommend the website https://ontariofishes.ca/fish_list.php
To find locations to look for fish – or any other species – go to iNaturalist.ca, click on Explore and enter the species name and the location (e.g., Peterborough, ON). A map will appear showing where the species has been observed. Just click on the marker. I’ve used this tool to suggest some locations for the species below.
Fallfish
Of our native minnows, the fallfish (Semotilus corporalis) is not only the largest but also one of the most intriguing in its nesting behaviour. Olive to gold-brown above, bright silver on the side, and sometimes up to a foot long at maturity, breeding males develop a pinkish cast around the gill coverings. Using their mouth to carry stones, they build piles measuring as much as a metre high and two metres wide. It is the largest stone mound nest built by any fish.
Spawning occurs in or over a trough on the side or top of the mound. The male positions himself over the trough and “trembles.” The trembling is a signal to the female to swim to the side of the male and deposit her eggs. After spawning, males cover the pit and eggs with stones.
If you are out walking along a creek or small river when water levels are low – often in late summer or fall – keep an eye open for these stone mounds. You’ll understand why First Nations people of the Hudson Bay region called the fallfish “Awadosi” or “stone carriers.” Locations to try: Eel’s Creek, Indian River
Creek and hornyhead chub
Another common minnow of local creeks and streams is the common creek chub (Semotilus atromaculatus). Usually less than 20 cm in length, this species is a popular bait minnow. Throughout most of the year creek chubs appear blackish above and silvery below. However, during the spring spawning season, the male acquires a rosy color and develops four large tubercles on each side of its head. Creek chub also have a black spot at the anterior base of the dorsal fin.
Being a close evolutionary cousin the fallfish, the male creek chub also builds a mound-like nest of stones. It’s possible to observe the male guarding the eggs from predators. Locations to try: Jackson Creek, Bear’s Creek, Cavan Creek, Thompson Creek
Keep an eye out, too, for hornyhead chub (Nocomis biguttatus) – a great name for a breeding fish! It is similar to the creek chub but has a barbel (a whiskerlike sensory organ) at the posterior end of the jaw. Male hornyheads move small pebbles with their mouths to make conical piles where the female deposits her eggs. Locations to try: Jackson Creek, Indian River, Cavan Creek
Dace
One of the most beautiful members of the minnow family is the northern redbelly dace (Chrosomus eos). Only about 3 to 7 cm in length, males sport a vibrant scarlet belly during the mating season, while the breeding female develops an equally-attractive green belly stripe. Redbelly dace inhabit ponds and creek pools, most often in or near beds of emergent and floating plants. A group of males will chase a female into a mass of algae where she will lay several dozen eggs. These are then fertilized by the males. Afterwards, the female heads off to another algal mass to do the same thing. Locations to try: Preston Road west of Peterborough, Mount Pleasant Road
Darters
Minnows aren’t our only non-game fish. Darters, which belong to the perch family, are another interesting group. They are ideal species for fish-watching because they spawn so close to shore. Measuring up to 18 cm in length, the logperch (Percina caprodes) is the largest darter in Canada and quite common in the Kawarthas. Look for them in the shallow waters of sandy or rocky beaches in lakes and over similar substrates in creeks and rivers.
Logperch spawn numerous times during the spring and summer, laying adhesive eggs that stick between the rocks and substrate of rocky shoals. They feed on invertebrates they find by flipping over stones with their snout. Locations to try: Otonabee River, Meade Creek, Cavan Creek
Sticklebacks
In quiet, vegetated ponds and backwaters of creeks, watch for the brook stickleback (Culaea inconstans). Belonging to its own separate family, the stickleback has a series of spines or “stickles” down the back. What is most unique about this fish, however, is how it reproduces. In the spring and summer, the male establishes a territory and actually turns black in colour. Using a secretion from the kidney, he then glues fragments of vegetation to the stems of aquatic plants and builds a three-dimensional nest about the size and shape of a golf ball. He even fashions an entrance with no exit.
The male stickleback then proceeds to make a series of darting movements along with nips and nudges to coax the female into the nest. After she lays her eggs by shaking violently, she pushes her way through the wall of the nest to exit. The male then enters the nest himself to fertilize the eggs. The hard-working dad guards the eggs until they have hatched and the young have grown to about a centimetre in size. Should any of the young wander away from the nest prematurely, the male gathers them into his mouth and deposits them back in the protective enclosure. Locations to try: Jackson Creek, Harper Creek at Fisher Drive, Mount Pleasant Road
Other opportunities
One of the best fish-watching destinations in Ontario is Corbett’s Dam in Port Hope. From mid-August to early October thousands of chinook and coho salmon swim from Lake Ontario up the Ganaraska River to their spawning grounds. Lock 19 in Peterborough is a great spot to see spawning walleye in April and the foot bridge just north of the Holiday Inn is excellent for watching greater redhorse, a type of sucker, in May.
I’d like to thank Scott Gibson, a senior MNRF fish biologist, for help in preparing this article.
Climate crisis update
Earth’s record-breaking temperatures have continued for a full year now, with May marking the 12th consecutive month for which the average temperature set a new record for that month. The global average temperature for the last 12 months is the highest on record, at 1.63 C above the 1850-1900 pre-industrial average. Unsurprisingly, atmospheric carbon dioxide continues to climb. The reading for the week ending June 9 was 427.64 parts per million (ppm), compared to 424.46 ppm just one year ago.
