Photo by cottonmanifesto. Location: Ward's Pond, Olmsted Park, Boston.
Urban species #150: Pumpkinseed Lepomis gibbosus
There are several reasons that the pumpkinseed, a member of the freshwater sunfish family, is well suited to urban bodies of water. They are small, and breed prolifically: each female lays around 1500 eggs. The are predators of the most abundant prey animals: insect larvae, snails, worms. And perhaps most importantly, they are tolerant of low oxygen levels in water, a condition caused by the feeding behavior of carp and Canada geese. Pumkinseed males clear a nest near the shore by digging a bowl in the soil with their fins and removing rocks with their mouths. The female abandons the nest after laying the eggs, and the male guards it. When the fry are born, the males continue to aggressively defend them, and even catch them with their mouths to return them to the nest if they wander too far.
Pumpkinseeds are fed upon by herons, mergansers, and cormorants, as well by larger fish, and snapping turtles. Humans prey upon them as well, for sport and occasionally for food.
As a boy I infrequently fished, and caught almost exclusively pumpkinseeds. Catching them is not nearly as challenging as removing them from the hook, as they can erect their dorsal spines in defense. The pumpkinseed can be distinguished from their close relative the bluegill (also an inhabitant of urban waters) by the red spot on its gill cover. My hopefully humorous essay on my ambivalent feelings toward fishing can be read here.