Schools of Juvenile Largemouth Bass Learning to Survive

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.

Damselflies and Small Fish
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.

Juvenile Largemouth Bass
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 on Spawning Bed
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.
Juvenile Largemouth Bass
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.
Juvenile Largemouth Bass
The juvenile fish are then ready to leave the nest and begin feeding on zooplankton.
Juvenile Largemouth Bass
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.