Freshwater drum

Freshwater drum are the only North American member of their family to exclusively inhabit freshwater (freshwater family members in genera Pachypops, Pachyurus, Petilipinnis and Plagioscion are from South America, while Boesemania is Asian). Their great distribution range goes as far north as the Hudson Bay, and reaches as far south as Guatemala. Their longitudinal distribution goes as far east as the eastern Appalachians and stretches as far west into Texas, Kansas, and Oklahoma. Freshwater drum are considered to be one of the most wide-ranging species in North America. == Description ==

The drum typically weighs . The world record was caught on Nickajack Lake in Tennessee, and weighed in at . The freshwater drum is frequently gray or silvery but may be more bronze or brown colored, common in the Lake Erie population. It is a deep-bodied fish with a divided dorsal fin consisting of 10 spines and approximately 30 rays. The pectoral fins are elongated and pointed, and the lateral line extends into the caudal fin, which has a rounded or pointed margin. The eye of the freshwater drum contains a tapetum lucidum within the retinal pigmented epithelium, as in other sciaenids. In other sciaenids this structure has been found to contain packed lipid spherules which contribute to its reflective properties. Extensive pharyngeal tooth pads are present in upper and lower sets, with cardiform and villiform teeth gradually being replaced by molariform teeth as the fish grows larger. ==Ecology==

The freshwater drum prefers clear water, but it is tolerant of turbid and murky water. They prefer the bottom to be clean sand and gravel substrates. The diet of the freshwater drum is generally benthic and composed of macroinvertebrates (mainly aquatic insect larvae and bivalve mussels), as well as small fish in certain ecosystems. Freshwater drum show distinct seasonal differences in their diet. In April and May, the drum feeds on dipterans. During these months, dipterans make up about 50 percent of the freshwater drum's diet. In August through November, they tend to eat fish (which are primarily young-of-the-year Gizzard shad). The percentage of fish in their diet at this time ranges from 52 to 94 percent. During its adult lifetime, it competes with yellow perch and silver chub in deep water, and competes with black bass in the shoal areas. Commercial fisheries are present for this species, although market price tends to be quite low. Thus, many freshwater drum are harvested as bycatch from targeted higher-value species. There has been some research on the freshwater drum's impact on the invasive zebra mussel in northern lakes and rivers. Zebra mussels are consumed by freshwater drum once they reach a length of , but drum under in length only eat small mussels and reject the larger ones. The fish larger than exhibit less selectivity and consume mussels relative to their availability in lakes. These larger fish are not restricted by their ability to crush zebra mussels, but they are restricted by the size of the clumps that they can remove. The drums' eating of zebra mussels contributes to a high mussel mortality, but not enough to have an impact on their spread, or control the population. ==Life history==

, Alabama During the summer, freshwater drums move into warm, shallow water that is less than deep. The freshwater drum then spawn during a six to seven-week period from June through July when the water reaches a temperature of about . During the spawn, females release their eggs into the water column and males release their sperm. Fertilization is random. Though they can reach very old age, the average age of a freshwater drum is between 6 and 13 years. ==Current management==

There are few management practices for the species, and in many regions daily bag limits are unlimited. The freshwater drum is not federally or state listed by any states. Although the commercial harvest is up to 1 million pounds per year, they are in no danger of overharvest. Due to its abundance, many states allow bowfishing and other non-conventional means to harvest the fish. ==See also==