Threadfin shad (Dorosoma petenense) are a member of the herring family - Clupeidae. They occur naturally in many rivers and reservoirs throughout the southeast and are often stocked as a forage fish in sport fish ponds in the southern latitudes. A mature threadfin shad is usually 5 to 6 inches in length; however, we have observed them up to 7 inches in highly-fertile ponds. The caudal fin of threadfin shad is often distinctly yellow; hence the local name "yellow-tails." Threadfin shad can often be seen feeding just below the surface early in the morning and late in the evening in open water areas. They are filter feeders, primarily feeding on plankton. Threadfin shad are prolific spawners, capable of spawning before the end of their first growing season. Spawning typically peaks in the spring when the water temperature reaches 65-70 degrees and may continue at intervals throughout the summer and into early fall, depending on population size, health, and other environmental conditions. Another peak in reproduction is often observed in early fall in ponds with light to moderate densities of shad.
Threadfin Shad in Sport Fish Ponds
There are several benefits to stocking threadfin shad as a supplemental forage species in sport fish ponds. First, their relatively small adult size and high reproductive capabilities equates to the perfect food for largemouth bass. Results will be observed in improved growth rates for all size groups of bass. Second, by partially shifting bass predation from bluegill to shad, more bluegill reach the intermediate size-range which helps in maintaining a healthy, balanced fish population. Third, threadfin shad compete slightly with bass fry. This competition reduces bass "recruitment." In other words, fewer bass fingerlings survive each year. This decreases the need to remove as many small bass. The bass fry that do survive will have ample forage fish as prey. This translates into faster growth rates and a larger maximum size for the bass. Finally, due to their offshore schooling nature, threadfin shad create an exciting topwater fishery as the bass "bust" them on the surface.
We have established threadfin shad populations in many small impoundments in Louisiana, Mississippi, Alabama, Georgia, and Florida. We have also successfully stocked threadfin shad in the southern parts of Arkansas and Tennessee. However, ponds located in the northern latitudes of this range are more susceptible to losing a portion or all of their threadfin shad population during unusually cold winters. Each pond within this geographical range is unique in its ability to sustain a healthy threadfin shad population. For example, larger and deeper ponds tend to offer a better refuge for threadfin shad when the air temperature drops considerably. Also, ponds less than 2 acres may have trouble maintaining a threadfin shad population due to bass predation. A healthy plankton bloom throughout the growing season is necessary to support and sustain a threadfin shad population.
When and How Many to Stock
Stocking threadfin shad has become part of the standard stocking program for new ponds with most of our customers. Whether in a new pond, or in a pond with an established fish population, threadfin shad are most often introduced March through April just prior to spawning. However, it is also effective to stock them throughout the summer and fall. We sell threadfin shad by the "load" which is a volumetric unit derived from the capacity of our hauling tanks. A load contains 8,000 to 10,000 fish, depending on their size. Typically, we recommend stocking new ponds with at least 1 load per 10 surface acres of water. However, this recommendation may be higher in ponds with an existing fish population.