Largemouth black bass Micropterus salmoides

The largemouth bass is a North American sunfish that entered aquaculture backwards. For decades it was reared only as a hatchery sport fish; it became a farmed food fish once producers learned to feed-train it, and output reached 941,653 tonnes in 2024. FishBase records 97 cm total length, 10.1 kg and 23 years. Production turns on one window in development: at about 1.5 to 2 inches, as fry switch from zooplankton to larger prey, they can be crowded in flow-through tanks and taught to take freeze-dried krill and then a 40 to 48 per cent protein salmonid pellet, with 80 to 90 per cent accepting the diet in roughly a week. Males fan and guard nests and spawn from one year old at ten inches; grow-out ponds carry 5,000 to 6,000 fish per acre to about 0.9 pounds. Veterinarily the species is defined by that training phase - crowding drives columnaris and external parasites, and handling below 55 degrees Fahrenheit causes saprolegniasis. Pale fatty livers and winter mortality point back to nutrition, because the diets are borrowed from salmonids rather than formulated for bass. Largemouth bass virus, an iridovirus, was identified after a 1995 reservoir die-off.