Save to Library Save. Create Alert Alert. Share This Paper. Background Citations. Results Citations. Citation Type. Has PDF. Publication Type. More Filters. Jumping sturgeon in the Suwannee River. To the Editor: The following is presented to illustrate a unique outdoor injury that the wilderness provider may encounter.
The Gulf Coast sturgeon Acipenser oxyrinchus desotoi is a large fish that … Expand. View 1 excerpt, cites background. What do Gulf sturgeon eat? Gulf sturgeon feed on tiny aquatic insect larvae and other small aquatic invertebrates during the first few months of their life. However, after their first year of life in the river, Gulf sturgeon do not eat while in fresh water.
Intensive feeding occurs in estuarine waters or in nearshore marine waters of the Gulf during winter. By feeding on small shrimp, crabs, worms, and mollusks during the winter, Gulf sturgeon increase greatly in weight. Then, from March-April through October-November, they do not feed. Instead, they use energy stored in their body fat and muscle. During the summer-fall period of fasting, sturgeon may lose up to 20 percent of their body weight.
This weight loss is more than compensated for during the next round of winter feeding, when Gulf sturgeon may increase their body weight by as much as 50 percent. Do sturgeon form schools? Unlike many coastal and river-dwelling fishes, Gulf sturgeon do not school but congregate. Behaving more like herd animals, they gather loosely during the winter feeding period and during the summer fasting period. They may also move in loosely-organized groups during the spring and fall migration.
Can sturgeon bite? No, as sturgeon have no teeth. They feed by sucking in their food. Prey is detected by taste and touch by four sensitive barbells in front of the mouth, and by a system of sensors on the underside of their long, flat snout. Why do large male sturgeon netted in spring and fall have red, raw snouts? During spawning, which takes place at night, several males may compete for one female.
Spawning males repeatedly rub their snouts against the flanks of the female. Their snouts become red, raw, and sometimes bloody from abrasion against the bony scutes of the female. The abdomen of the female also becomes pink or red from the same rubbing behavior.
When captured in large mesh nets made of multi-filament twine instead of monofilament , they are rarely injured in any way. Since a few fish may spawn in fall, red snouts and flanks may also be observed then. Researchers have discovered why sturgeon jump. There are two reasons for this activity. Jumping helps the fish equalize pressure in their swim bladder. When the ambient pressure changes during a high or low front, or when the fish move to a different depth in the river, their bladder will expand or shrink.
By jumping, they can gulp in air needed to maintain neutral buoyancy. The other reason they jump is to communicate with other sturgeon. When do sturgeon jump? Sturgeon are generally observed jumping during the summer and fall months May-October. Jumping occurs most frequently in mid-summer May-early August in rivers when sturgeon are fasting.
Therefore, jumping has nothing to do with feeding. Jumping occurs intensely at dawn and dusk and less frequently in between. Where do sturgeon jump? Gulf sturgeon are known to jump in a few Florida rivers, including the Suwannee River. While it is possible for sturgeon to jump anywhere in the river, sturgeon in the Suwannee River are more commonly observed jumping in certain parts of the river where sturgeon gather, referred to as 'holding' areas.
There are a number of less important holding areas. Do sturgeon attack boats? As part of their natural behavior in summer holding areas, sturgeon frequently jump straight out of the water, turning sideways and landing with a loud noise. Much like deer hit by cars, jumping sturgeon are sometimes struck by boats.
A large sturgeon can weigh more than pounds, so impact with a fast-moving boat can cause serious injury to both boat passengers and the sturgeon alike. Have people been injured by jumping sturgeon?
Yes, people have sustained injuries related to jumping sturgeon. Injuries have resulted when jumping sturgeon have come into direct contact with people and when people have responded to avoid collisions with jumping sturgeon. Additionally, there was one reported strike in on the Choctawhatchee River resulting in one injury and two reported strikes in on the Santa Fe River resulting in three injuries. Lake sturgeon migrate to shores of freshwater lakes in early summer for spawning.
Female lay anywhere from two to three million eggs per season. Sturgeon may not begin spawning until they are 15 to 25 years old, and only spawn every four years on average. These fish can live for decades. Males may reach 55 years, while females have been recorded living for years. Lake sturgeon were once abundant throughout the Great Lakes system until overfishing in the s and early s decimated their populations. In , lake sturgeon were designated as a threatened species in Michigan, marking the beginning of recovery programs to attempt to revive the population.
Lake sturgeon, however, have reproductive traits that make rehabilitation of the species difficult, including delayed maturation and periodic interrupted spawning cycles. To make matters worse, this species is now faced with further negative impacts by pollution, the destruction of main food sources, and invasive aquatic species—impacts that are likely to be exacerbated by climate change.
Climate change is expected to further threaten this fish as rising water temperatures greatly decrease the quality and quantity of spawning and nursery habitats. Climatic variability could also disrupt the timing of sturgeon reproduction and length of optimal fish growth periods as environmental cues shift and warming waters affect stream ecological processes and ecosystem health.
Sturgeon have been observed swimming upside down on their backs. Research suggests this might be to feed on insects on the surface of the water. Given the location of the sturgeon mouth, that is the only way it could feed at the surface. In the aquarium, sturgeon like to swim through the filter air bubbles, perhaps cleaning their gills.
You may also see sturgeon lying on top of each other in tanks. Unlike other fish such as trout , sturgeon tend to have their own unique personalities and behaviours. These behaviours may be feeding strategies or just playfulness. Lake Sturgeon Acipenser fulvescens are descendants of a prehistoric fish, and look much the same as fossils from the Upper Cretaceous Period million years ago, when dinosaurs roamed the earth.
The age of a sturgeon cannot be determined externally. Much like a tree, you can tell how old it is by counting the growth rings on the bones of its pectoral fins. Back to top How they look From their prehistoric days, sturgeon have an outer armour of bony plates, a skeleton made of cartilage, and a shark-like tail. Scutes have little hooked spurs that make the young sturgeon hard-to-swallow and unappealing, protecting them from predators like walleye and pike.
Young sturgeon often have black blotches on their sides, back, and snout to help them camouflage with the lake or river bottom. These blotches will lighten or disappear when they are about 60 cm long — too large for most natural predators.
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