Flathead Catfish
Flathead catfish adult female
Catheterizing a few eggs to check their development
Giving an injection of hormone
Spawning pens
Checking cans for eggs
Flathead catfish spawn in spawning container
Flathead catfish spawn in spawning container
Weighing a flathead catfish spawn
Incubating flathead catfish egg
7 day old flathead catfish fry in swim-up tank
Hatching Brine shrimp eggs
90 day old flathead catfish fingerlings
Flathead Catfish are not raised at Lost Valley Hatchery every year. They are produced only when a request is made for them, for a particular body of water, by a fisheries management biologist. Broodstock flathead catfish are not kept at Lost Valley Hatchery. They are collected from Truman Reservoir when the water temperature approaches 75 degrees F. The broodstock are collected by setting trot lines and drop lines. In large reservoirs, it is difficult to collect large enough fish by electro shocking, and hoop nets work best in rivers. Collecting mature fish with trot or drop lines does not injure or stress the fish. It is important to not stress the fish at time of collection. Broodfish that have been excessively stressed are not likely to spawn.
Broodstock are transported to the hatchery and held in outside concrete tanks. One raceway is prepared for spawning by setting up 4' x 4' spawning pens. Spawning containers, such as barrels, are placed in each pen. The fish are sexed and separated to two different tanks. Female flathead catfish are checked for egg development. Females are catheterized to obtain a sample of eggs. In order to induce ovulation, females require hormone injections using Human Chorionic Gonadotropin (HCG).
Once injected, the female is placed in a spawning pen with a male of similar or slightly smaller size.
After 24 hours, the spawning containers are checked daily for eggs (spawns). Spawning usually occurs in 24 - 48 hours.
Spawns are removed and transferred into the hatchery, weighed and placed in hatching baskets. There are 3,000 eggs in a pound of flathead catfish eggs. An average sized spawn for a 10 - 20 pound fish is 6,000 - 10,000 eggs.
Hatching baskets are equipped with a water sprinkler underneath to keep fresh water constantly moving under the eggs. Spawns are kept in these baskets until hatching occurs. Therapeutic treatments are administered as needed to control fungus which will kill the eggs if left untreated.
After hatching, sac fry are removed from the baskets and transferred to swim-up tanks. Feeding begins a few days after hatching as the fry "swim-up" to the water surface. Brine shrimp eggs are hatched daily to feed the fry. The flathead catfish fry are fed this shrimp for seven days. For the next week they are fed brine shrimp and frozen krill (oceanic plankton). After two weeks the fish are graded. The larger fish are started on a high protein dry diet and the smaller fish are kept on the shrimp and krill. By day 26 all fish are on the dry diet. When the fish are totally on the dry diet, automatic feeders are set over the tanks to dispense feed every half hour. The feed size is gradually increased with the increased size of the fish. Weight counts are taken every two weeks to monitor growth and tank density. Fish are divided to other tanks to prevent overcrowding. These fish may be stocked in the fall if a 3 inch - 4 inch fish is desirable. If a larger size is requested, the fish are kept inside, in tanks, during the winter. Feeding will continue in the spring and the fish are stocked when they reach a size of 8 inches.
