Spring Pygmy Sunfish, One of Alabama's Rare Fishes
Keith B. Floyd
Alabama is blessed with an abundance of streams and rivers. This large amount of fresh water provides a home to over 306 native freshwater species. Alabama is second only to Tennessee in the number of freshwater fish species found in a state. These diverse aquatic habitats also support thirteen species of fish that only occur within the state of Alabama. These unique species are found in limited areas of river basins, particular watersheds, or springs. One of the fish species that is unique to Alabama is the spring pygmy sunfish.
The spring pygmy sunfish is found only in two locations, both in the Tennessee Valley region of north Alabama. The Beaverdam Creek watershed that drains into Wheeler Reservoir contains spring pygmy sunfish, and Pryor Spring contains a re-established population of the species. Biologists stocked the fish in Pryor Spring during the 1980s, and the spring pygmy sunfish are doing well. Both of these populations are in Limestone County. The first spring pygmy sunfish was discovered in Cave Spring, Lauderdale County. Spring pygmy sunfish were feared to be extinct after Pickwick Reservoir filled and changed the habitat.
The Fisheries Section of the Division of Wildlife and Freshwater Fisheries studied the spring pygmy sunfish for several years during the early 1990s. Unlike some rare species that are difficult to find even in their preferred habitat, spring pygmy sunfish are often abundant. Their preferred habitat consists of thick concentrations of aquatic vegetation such as parrot’s feather and coontail. Often 10 spring pygmy sunfish can be collected from a vegetated area the size of a basketball net. High densities of these unique fish also occur in shallow, heavily vegetated margins of the spring run below a lake on Beaverdam Creek. Recent sampling efforts extended the known range downstream in Beaverdam Creek to the impounded section of Wheeler Reservoir. These populations are spotty and restricted to dense vegetation.
The close association to vegetation serves two purposes. Vegetation provides a ready source of food -- insect larvae and tiny crustaceans such as copepods and daphnia. The vegetation also acts as a refuge from predators. Spring pygmy sunfish in aquaria experiments lose their association with vegetation in the absence of predators.
Spring pygmy sunfish rarely grow larger than an inch. Males and females of the spring pygmy sunfish exhibit substantially different color patterns, a condition known as sexual dimorphism. Breeding males are generally dark brown with five to seven narrow silver or gold vertical bars along their sides. The dorsal and anal fins have darkened areas. Females are brown on the back, mottled brown and white on the sides, and white on the bottom. The spring pygmy sunfish is also unusual in that it lives little more than a year. Spawning occurs in March and April with eggs being laid on vegetation. Few adults are seen after spring.
The spring pygmy sunfish is one of Alabama’s unique fish. Agreements with Limestone County landowners have been successful in preserving and extending the finite habitat for this special fish. Knowledge and awareness of rare species and their preferred habitats assist in conserving this fish for many more years.
Photographs by Doug Darr
Date Published: November 1999