Buying Time for Endangered Species
sunfish nests, following suit. The end result was that 100 adult shiners produced more than 22,000 young.
Pallid, lake and shovelnose sturgeons are the three types of sturgeon found in Missouri. These fish evolved millions of years ago and were still common in the big river systems only a century ago. The federally endangered pallid sturgeon can live 40 years, weigh up to 65 pounds and attain a length of up to 6 feet. The state-endangered lake sturgeon can live up to 150 years and has the potential to top 300 pounds and reach 8 feet in length. The shovelnose is the smallest of the three and is still abundant.
The Department’s Blind Pony Hatchery, located at Sweet Springs, Mo., is one of only six hatcheries in the U.S. that raises pallid sturgeon. In fact, Blind Pony pioneered the spawning techniques for pallid sturgeon. In 1991, staff used techniques developed for spawning white sturgeon on shovelnose sturgeon. After success with the shovelnose sturgeon, Blind Pony started with pallid sturgeon in 1992.
The hunt for pallid sturgeon adults to serve as brood stock begins in March by biologists on the Missouri and Mississippi rivers. These fish are so rare that finding mature adults can be a problem. The males become mature at 5 to 7 years of age and the females at 12 to 15 years of age. Once the fish are captured, they are transported to Blind Pony.
Once the fish are brought into the hatchery for spawning, the adults are injected with a hormone. Approximately 15 hours after the injections, the fish are ready to spawn. The milt from the males is collected and stored in sterile, refrigerated containers until it is needed. The eggs from the females are collected by applying gentle pressure to the fish’s abdomen, causing the eggs to flow out of the fish and into a collecting bowl.
Once the eggs are collected (up to 100,000 out of a single fish) they are fertilized with the milt. After fertilization, the eggs are incubated in hatching jars. Incubation takes approximately six to eight days depending on the water temperature.
The newly hatched fish (fry) are placed in hatchery tanks for rearing to the stocking size of 9 inches or larger. Throughout their time at the hatchery, the fish are fed a diet of frozen brine shrimp. By October, these fish are large enough to be tagged and released into the Missouri and