Throughout the lower Susquehanna basin, four commonly encountered Lepomis sunfishes are gathering in the shallows of lakes and ponds and in the pools of the regions streams and rivers to spawn. As water temperatures surge into the upper sixties and seventies, you’ll see them from the shoreline as the colorful male sunfish clears a nest depression to attract and court one or more egg-laying females. After the eggs are laid and fertilized, the male relentlessly guards the nest against trespassers, which can include other males protecting their scrapes located just a few feet away. A colony of nesting sunfish can include multiple species—hybridization does occur.
So grab a pair of close-focusing binoculars or a camera and go take a look. Because they generally thrive in clean, warmwater streams, you might be able to find all four of these Lepomis sunfishes in the waters near you.
Fishwatching 101- These four species of Lepomis sunfishes are found throughout the lower Susquehanna watershed. The Pumpkinseed and the Redbreast Sunfish, both natives to the river and its tributaries, may be the most beautiful fish found in our region. Click the image to see an enlarged version marked with key field identification points.While you’re searching for sunfish, don’t be surprised to find Largemouth Bass, another native transplant introduced from the Mississippi River drainage basin, lurking in the shallows. Their spawning period began as water temperatures reached the low sixties. Soon, they and their young will be feeding on the newly-hatched sunfish produced in nearby nests.
Yesterday, while photographing damselflies on a rehabilitated segment of a warmwater lower Susquehanna valley stream, we noticed some oddly chunky small fish gathered on the surface of a pool along the shoreline.
Perched damselflies and some sort of robust little fish feeding nearby.
Upon further inspection, they appeared to be fingerlings of some type of sunfish or bass. Time for a closer look.
At just one inch in length, these juvenile Largemouth Bass (Micropterus salmoides) are already showing signs of the dark lateral stripe that so easily identifies the adult fish.Adult Largemouth Bass began spawning among nearby beds of Spatterdock and other emergent and submerged aquatic vegetation about one month ago, just as water temperatures stabilized to a minimum of the low sixties for several days and nights. Each female can lay thousands of eggs. Only those that are successfully fertilized by the attending male have a chance to hatch.Largemouth Bass eggs can hatch as soon as ten days after being deposited in the nest by the female and fertilized by the male. The fry linger in the nest for another week consuming the nutrition contained in their attached yolk sac.The juvenile fish are then ready to leave the nest and begin feeding on zooplankton.Young largemouths often gather in schools to feed in waters near their birthplace. As they grow, they soon begin consuming small invertebrates and tiny fish. But for young bass, the hazards are many. These juveniles can become victims of a host of predatory insects, crayfish, piscivorous birds, and bigger fish. Then too, Largemouth Bass, like most other species of fishes, are cannibalistic and will consume others of their own kind. Of the thousands of eggs produced by a mating pair, natural selection determines which, if any, of their progeny will survive to reproduce and sustain their genetic line.
In the Lower Susquehanna River Watershed, the Largemouth Bass is an introduced species, a native transplant from the Mississippi watershed and Atlantic Slope drainages south of the Chesapeake.
