Spawning Fish
With spring comes birds singing and nesting, baby animals of all kind being born, and a general feeling of refreshment and excitement. But what about under the water? What are fish up to after months of surviving under the frozen surfaces of lakes and rivers?
Well, generally speaking, fish are getting ready to spawn. Spawning refers to when a female fish deposits eggs and then a male (or multiple males) swims over the eggs and fertilizes them. There can be quite a lot of variation with regards to spawning behaviours in fish all over the world, but here in Sudbury, as spring is gearing up above water, the fish are having a grand ol’ time below.
Spawning behaviours in fish can start as early as mid-April, like with perch and walleye. Some, like the brown bullhead (catfish) may only start in June and continue into July. One of the reasons for this is that the brown bullheads like warmer water, so they wait until the water has warmed up to about 21 degrees Celsius. In comparison, most bass species spawn between 16-18 degrees Celsius and perch like it colder at temperatures between 9-12 degrees Celsius—Brrrrrrr!
The bass, or sunfish, family have nest-making and parental care down to an art form. Pumpkinseeds, rock bass, and smallmouth bass are some of the species found in Ramsey Lake and all of them make a nest. The male is the caregiver. Nests are usually shallow, cleared areas with a sandy, gravel or muddy bottom near shore. The male will guard his nest from other males in hopes that a female will come along to admire his hard work. Sometimes multiple females will visit one male’s nest and deposit eggs. Depending on the species, the eggs will hatch 3-10 days after spawning. But the male’s job isn’t done yet: he will actually stick around for several days to protect his young.
This male pumpkinseed is actively protecting his nest. Other pumpkinseeds and a rock bass would occasionally come too close and he would chase them away and return to diligently to his post. There were many nests visible in a small area of shoreline where this photo was taken.
Some other species like the perch family have a more hands-off approach. They don’t make nests, nor do they provide any parental care. The males will go into shallow areas, followed by the females. Spawning happens at night or early morning. Little is known about the actual spawning act, but a large female can average about 23,000 eggs in one spawning event. You can see the evidence of these spawning events if you take a walk on the boardwalk at Science North. Until about mid-summer you can see thousands of small perch schooled together near the docks.
