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Lake Sturgeon fish identification, its habitats, characteristics, fishing methods.
The lake sturgeon is an evolutionarily ancient bottom feeder with a partly cartilaginous skeleton and skin bearing rows of bony plates, called scutes. The fish uses its elongated, spade-like snout to stir up the sand and silt on the beds of rivers and lakes while feeding. There are 4 barbels surrounding the mouth that are purely a sensory organ to help it find its food. The lake sturgeon is a large freshwater fish, that can grow to an over 200 lb (100 kg) and a length of over 9 ft (3 m) during its long over 100 years lifetime.
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The lake sturgeon (Acipenser fulvescens), also known as rock sturgeon, black sturgeon, brown sturgeon, rubber-nose, and smoothback, is a North American temperate freshwater fish native to Canada and United States and is widely distributed in North America, currently ranging all over the basins of the Mississippi River, Lake Champlain, the St. Lawrence-Great Lakes, Hudson Bay-James Bay, and the Saskatchewan.
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Description
The lake sturgeon has elongated, torpedo-shaped body covered instead of scales with five rows of bony, shell-shaped plates, called scutes: one on top that run along the length of the body and two rows along each side. Each scute comes to a peak with a sharp-pointed spur. Body is angular (5-sided) in young, but round in adults. As the fish grows older, the rows of spine-tipped bony scutes smooth out and the scutes are barely visible.
It has a sharp, cone-shaped flattened snout and slightly upturned, that become shorter and blunter with age, and 4 smooth sensitive barbels underneath on the lower snout just in front of the mouth. Its large, ventral toothless mouth, which it can extend like a tube, is set back from the end of the snout and there are two smooth lobes (vents) on the lower lip. Soft area on the top of the head and black viscera is absent. The anal fin is not opposite the dorsal fin, but rather it is closer to the caudal (tail) fin. The caudal peduncle (between dorsal and caudal fins) is short, stout, and partly naked. The top of its tail is longer than the bottom and pointed without threadlike extension (noticeable in shovelnose sturgeon). Extended upper portion of the caudal fin resemble a shark, also both species have cartilage skeletons instead of bone.
Distinguish Characteristics
- 35-40 dorsal fin rays
- 25-30 anal fin rays
- 9-17 dorsal scutes
- 29-42 lateral scutes
- 7-12 ventral scutes
- Snout is pointed
- Lower lip has a split in the middle
- Max length: over 9 ft (2.7 m)
- Max weight: over 310lbs (141 kg)
- Max age: 152 years
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Young Sturgeon start their life with five rows of razor sharp scutes along its body for protection from predators, as they mature these will become smooth. The dorsal fin is set way back on the sturgeon very close to its caudal fin. Lake sturgeon generally ranges from 5 to 40 pounds and 20 to 55 inches long. But sturgeon may grow to more than 300 pounds and 8 feet long.
Lake Sturgeons are green-yellow to blue-gray to black on a back, and a lighter grey almost white on the belly. Large spots present on anterior half of upper surface of snout and on back. The young are reddish-brown. Like most fish, their color changes as they get older and larger. The dorsal (top) and lateral (side) bony plates are the same color as the body and the fins are dark brown or grey with the single, dorsal fin far back near the caudal fin.
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Habitats
The lake sturgeon is a cold-water species found primarily in shoal areas of large freshwater lakes and rivers usually in 5-9 m depth, but also occurs in the brackish waters and canals with flow. They are bottom dwellers, adapted to feeding on the mud or gravel and mud bottom. Their feeding/home areas include usually depositional and fairly solid silt or silt-sand substrates, with presumed high densities of benthic invertebrates. Generally those areas occur at the lower end of navigation pools near the main channel, the mouths of tributaries and large secondary channels, and at some channel border areas.
Other than spawning migrations, they seasonally move from shallow waters when it is getting warm, into deeper water, a return to the shoals in fall, and a return to moderate depths in winter. While migrating, lake sturgeons use areas of the river with relatively high current velocities including the main channel in the upper and mid reaches of navigation pools, and tributaries.
Sturgeon are bottom feeders and have a vacuum cleaner like mouth set under its head perfectly designed to suck up clams and other food from the bottom. The lake sturgeon has taste buds on and around its barbels near its rubbery, prehensile lips. It extends its lips to vacuum up soft live food which it swallows whole due to its lack of teeth. Its diet consists of almost exclusively small organisms like insect larvae, worms (including leeches), small aquatic insects, crayfish, snails, clams, small fish and other small, primarily metazoan organisms it finds in the mud, and even algae. They are omnivorous (feeding on both animals and plants) and virtually anything edible that enters the mouth is sucked up and consumed. The food is pulled in the mouth, often partly retracted and sucked in again.
Spawning
Mature adults average between 3-5 feet in length and 10-80 pounds in weight. Female became mature when they are 84–140 cm long between 24–26 years of age. Male became mature before they are 76–117 cm long or 14–19 years old. The lake sturgeon has an extremely slow reproductive cycle and females spawn only once every 3-7 years. Males spawn every 1-4 years. They start spawning run to streams as soon as the ice melts, but spawn start from early May to late June when water temperatures rise and reach 48-68°F (9–20 °C). Lake sturgeon is known to move great distances to spawning and feeding habitats. Spawning migrations out of lakes and up rivers to suitable grounds are often as long as 80 miles (128 km).
Lake sturgeons spawn in shallow areas over hard clean large rough substrates, along windswept rocky shores of islands and in rapids in streams with moderate to swift current velocities. Spawning take place in 2-15 feet (0.6-4.5 m) deep water, rapids, or the bases of low falls. Where suitable spawning streams are unavailable, lake sturgeon may spawn in wave action over ledges or around rocky islands. During spawning, sturgeon lay in groups of 1 to 2 males per 1 female. The males are quite active, rolling near the bottom, gather around females, vibrating, leaping out of the water with a loud splash, and thrashing about as she releases her eggs. Females can produce up to 800,000 eggs each spawning season (approximately 4,000 to 5,000 eggs per pound of body weight). No nest is built, female scatter their eggs in the river current while the male swims close to and slightly above the female releasing milt that covers and fertilizes the eggs.
The adhesive eggs are scattered by currents and stick to rocks and logs. Young hatch out in 5-8 days at 59-63°F (15-17°C) and are about 8mm in length. Exogenous feeding begins after 10-14 days. The fry develop very quickly and look like miniature adults at only 2 to 3 cm in length. They grow rapidly, reaching 7.5 inches by the end of the first growing season.
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Lake sturgeon is a source of caviar and isinglass and its oil was once used to fuel steamboats. It is also a valuable gourmet food fish. Limited sturgeon fishing seasons runs from April 24 to May 7 and from July 1 to September 30, and is permitted in only a few areas including some locations in Minnesota, Wisconsin and Michigan. Fishing for sturgeon is allowed on Black Lake in Michigan, on Lake Winnebago in Wisconsin, and on the Rainy River and Lake of the Woods on the Canadian border in Minnesota.
Lake Sturgeon is bottom feeders that use their powerful sense of smell to search out food sources. The stationary baits that give off strong odors are the best for this fish. Look for the deeper holes in the river with a sand or muddy bottom just below a stretch of fast water. Cast your line into the pool just at the edge of the faster water and wait. Use a tackle that can handle hard fighting very big and strong fish.
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