During the fall, we tend to see changes in the behavior of animals as they react to cooling temperatures and in preparation for winter. This includes iconic Chesapeake Bay species like rockfish, bluefish, and white perch which become more active. It also includes species like bluegill and pumpkinseed fish, both of which belong to the Sunfish family. Because these species interbreed to create hybrid offspring, it’s easier to just refer to them by family, as opposed to a specific species.
Sunfish belong to the phylogenetic family, Centrarchidae, and include the more common species mentioned above, along with the blackbanded sunfish and the redbreast sunfish which are less common. In fact, blackbanded sunfish were almost extinct in Maryland, with only a single, highly interbred population found during state-wide survey attempts [1]. However, recent collaborative efforts resulted in the first ever release of captive bred blackbanded sunfish in 2025.
All four of these fish species (henceforth referred to as sunfish spp.) prefer freshwater but bluegill and pumpkinseeds can be found in low salinity brackish water. The reason we are talking about sunfish spp for the month of September is because the fall is when we tend to see these fish entering our oyster cages at Easton Point Park on the Tred Avon River.
This may be because the breeding season occurs April through September and egg laying and guarding happens in fresh water [2]. Once the male is done guarding the eggs, they may leave the freshwater region and explore more brackish territories in search of food before moving into deeper water in the winter.
All four of these sunfish spp. have condensed bodies, which means they are almost as tall as they are long, unlike elongated fish that have long, sleek bodies designed for speed. None of these species get particularly large, with bluegill, pumpkinseed fish, and redbreast sunfish having an average size of around 4 inches but growing up to 12 inches long [2]. The blackbanded sunfish is even smaller, with 4 inches being their maximum size.
At various times through the years, we’ve had sunfish spp. in our care and onboard the Fishmobile. Typically, we have referred to the fish we had in our care as bluegills but they may have been hybrids. At least one (pictured) had the orange spot behind the gills we’d typically associate with a pumpkinseed fish but the rest of the markings were more like a bluegill, so again, it’s hard to say which species they are exactly.
Regardless of their ability to interbreed and our ability to tell them apart, bluegill are a fun species to have on the Fishmobile, our traveling aquarium, because this is a species of fish most anglers are familiar with. Numerous kids who come through the bus are familiar with bluegill, these critters having been one of the first species of fish they ever caught while fishing with their families.
Bluegill and other sunfish spp. are important consumers in the Chesapeake Bay, feeding on a variety of small organisms including worms, insects, and other invertebrates as well as aquatic plants. In turn, they are food for higher level predators like larger fish, birds, and mammals. You can think of Sunfish spp. as a stepping stone to the larger fish you may be more familiar with eating from the Chesapeake Bay.
