Habitat Pumpkinseeds typically live in warm, calm lakes, ponds, and pools of creeks and small rivers with plenty of vegetation. They prefer clear water where they can find shelter to hide. They tend to stay near the shore, and can be found in numbers within shallow and protected areas. They will feed at all water levels from the surface to the bottom in the daylight, and their heaviest feeding will be in the afternoon. Pumpkinseed sunfish usually travel together in schools that can also include bluegills and other
sunfish. Pumpkinseeds are more tolerant of low oxygen levels than bluegills are, but less tolerant of warm water. Groups of young fish school close to shore, but adults tend to travel in groups of two to four in slightly deeper yet still covered waters. Pumpkinseeds are active throughout the day, but they rest at night near the bottom or in shelter areas in rocks or near
submerged logs.
Reproduction and life cycle Once water temperatures reach in the late spring or early summer, the male pumpkinseeds begin to build nests. Nesting sites are typically in shallow water on sand or gravel lake bottoms. The males use their caudal fins to sweep out shallow, oval-shaped nesting holes that stretch about twice the length of the pumpkinseed itself. The fish remove debris and large rocks from their nests with their mouths. Nests are arranged in colonies consisting of about three to 15 nests each. Often, pumpkinseeds build their nests near bluegill colonies, and the two species interbreed. Male pumpkinseeds are vigorous and aggressive, and defend their nests by spreading their opercula. Because of this aggressive behavior, pumpkinseeds tend to maintain larger territories than bluegills. Females arrive after the nests are completed, coming in from deeper waters. The male then releases
milt and the female releases eggs. Females may spawn in more than one nest, and more than one female may use the same nest. Also, more than one female will spawn with a male in one nest simultaneously. Females are able to produce 1,500 to 1,700 eggs, depending on their size and age. Once released, the eggs stick to gravel, sand, or other debris in the nest, and they hatch in as few as three days. Females leave the nest immediately after spawning, but males remain and guard their offspring. The male guards them for about the first 11 days, returning them to the nest in his mouth if they stray from the nesting site. The young fish stay on or near the shallow breeding area, and grow to about in their first year.
Sexual maturity is usually achieved by age two. Pumpkinseeds have lived to be 12 years old in
captivity, but in nature most do not exceed six to eight years old.
Diet Pumpkinseeds are
carnivorous and feed on a variety of small prey both at the water surface and at the bottom. Among their favorites are insects, small
molluscs and
crustaceans (such as small
crawfish), worms,
minnow fry, small frogs or
tadpoles, and even
cannibalizing other smaller pumpkinseeds. They are effective at destroying
mosquito larvae and even occasionally consume small pieces of
aquatic vegetation and
detritus. They also will readily consume human food scraps, most notably
bread which is commonly used for bait. The pumpkinseed sunfish has a terminal mouth, allowing it to open at the anterior end of the snout.
Adaptations The pumpkinseed sunfish has adapted in many ways to the surroundings where it lives. Its skin reflects camouflage for its habitat. The pattern that appears on the pumpkinseed resembles that of the sunlight patterns that reflect on the shallow water of bays and river beds. The pumpkinseed sunfish has developed a specific method of protection. Along the
dorsal fin are 10 to 11 spines, and there are three additional spines on the anal fin. These spines are very sharp, which aid the fish in defense. The pumpkinseed has the ability to anticipate approaching predators (or prey) via a
lateral line system, allowing it to detect changes or movements in the water using different mechanical receptors. The brightly colored gill plates of the pumpkinseed sunfish also serve as a method of protection and dominance. Also known as an
eye spot, the dark patch at the posterior of the gill plate provides the illusion that the eye of the fish is larger and positioned further back on the body, thus making the fish seem up to four times larger than it actually is. When a pumpkinseed feels threatened by a predator, it flares its gills to make it seem larger in size, and shows off the flashy red coloration. Males of the species also flare their gills in the spring spawning season in a show of dominance and territoriality. In the southernmost regions of its distribution, the pumpkinseed has developed a larger mouth opening and abnormally large jaw muscles to aid in feeding; its forage is small crustaceans and mollusks. The larger bite radius and enhanced jaw muscles allow the pumpkinseed to crack the shells of their prey to attain the soft flesh within, thus providing one common name of 'shellcracker'. ==Conservation status==