Some species of sturgeon are the largest and most long-lived freshwater fishes. In 1953, a lake sturgeon was caught that was estimated to be 154 years old. The largest is the Russian sturgeon (Huso huso), or beluga. It can reach a length of 8.5 meters and has been known to weigh over 1500 kilograms.
To view video of lake sturgeons, visit this site: http://www.greatlakesfishes.com/.
Perception Channels: tactile ; chemical
Lake sturgeon populations have declined in the last century. This is due partly to overfishing, pollution of rivers, and to some extent because river damming has destroyed spawning runs. (Rodgers 1990)
Lake sturgeon used to be one of the most important fish in the Great Lakes. Heavy fishing and pollution from newly developed land around the lakes has caused it to become very rare. (Evans 1994) Lake sturgeons are listed as threatened by the state of Michigan.
US Federal List: no special status
CITES: appendix ii
State of Michigan List: threatened
IUCN Red List of Threatened Species: least concern
The lake sturgeon does not appear to present any negative attributes concerning the environment or humans.
The lake sturgeon is best known as a food fish. Their unfertilized eggs, carried inside the female, are considered a delicacy. These eggs are the luxury food known as caviar. The meat of this fish is also eaten. Lake sturgeon have been fished for their flesh and their oil as well as for their caviar. Steamboats in North America once used their oil as fuel. They have also supplied isinglass. Isinglass is a form of gelatin and is obtained from the sturgeon's swimbladder and vertebrae. It was traditionally used to clarify wines and as a gelling agent in jams and jellies. Today, it is used for special cements and water-proofing materials, but its main use is in cleaning white wines. (Evans 1994)
The name sturgeon in several European languages means "the stirrer", from the way the fish rummages among the mud for food. It finds its food largely by touch, using its sensitive barbels. As the lake sturgeon cruises over the bottom, the sensitivity of the fleshy whiskers trailing in the sand makes up, to some extent, for the fish's poor eye sight. As soon as the whiskers pass over food, the protrusible mouth drops down with an elevator-like motion and rapidly sucks in its meal. (Herald 1971) Acipenser fulvescens are one of the few fishes to have taste buds on the outside of their mouth. In other fish, they are normally found on the tongue or inside the mouth. The taste buds of the lake sturgeon protrude from the toothless mouth and are used to help in the selection of food.
These fish are slow feeders and can survive several weeks without eating. Moreover, the food it eats is small compared to its own size. The lake sturgeon, in its normal habitat, must devote a great deal of time to feeding. Acipenser fulvescens eat insect larvae, worms, crayfish, snails, and other small fishes. (Rodgers 1990)
Acipenser fulvescens occurs in the freshwaters of North America from the Hudson Bay through the Mississippi River drainages to Alabama. It is found along the Great Lakes - St. Lawrence River drainage and in large lakes in New York and Vermont, including Cayuga Lake and Lake Champlain.
Biogeographic Regions: nearctic (Native )
The lake sturgeon is a fish of temperate waters and is found only in the Northern Hemisphere in North America. Their habitat is usually on the bottom of a riverbed or lake. Acipenser fulvescens prefer a river or lake bottom that has clear sand or gravel. (Herald 1971)
Aquatic Biomes: lakes and ponds; rivers and streams
Average lifespan
Status: wild: 82.0 years.
Average lifespan
Status: wild: 152.0 years.
This fish has a skeleton partly of bone and partly of cartilage. Their slender bodies are covered with rows of bony plates. Beneath the projecting snout there is a small, toothless mouth with thick, sucking lips. There are four barbels (whiskers) in front of the mouth that are used to direct food towards the mouth. Like the body, the head is well protected with plates. A single dorsal fin rises from the back, and the body extends into the long upper part of the tail fin. (World Book Encyclopedia 1998)
The physical characteristics of Acipenser fulvescens vary greatly with age and size. In the young, the body shields are rough and ornamented with hooked spines. As they become adults, the shields grow smoother. Many of them eventually disappear with age. The snout also grows less pointed with age, and the spots of the younger fishes' color pattern disappear. It is common for the lake sturgeon to reach a length of about 1.8 meters and have a mass, on average, of 90 kilograms. (Encyclopedia Americana 1996)
Average mass: 90 kg.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Average mass: 70000 g.
In early summer, lake sturgeons migrate toward the shores of freshwater lakes for spawning purposes. They seek out pebbly habitats with no mud to breed. (Evans 1994) Spawning usually takes place at a depth of 5.4 to 6.0 meters. The females lay a vast number of eggs, anywhere from 2 to 3 million in one season, depending on their size and age. After spawning, the eggs are left to develop on their own. The parents will then return to the lake or river where they spend most of their time. (Rodgers 1990)
The eggs, or roe, are small and sticky. They are encased in a jelly-like substance and use the stickiness to adhere to water plants and stones, or clump together in masses. This allows them to remain stationary and stay in one location despite the current. The eggs are one-fourth of a centimeter in diameter and blackish in color. They will normally hatch in three to seven days. The larvae are 1.25 centimeters long and by the first summer may grow to a length of 20 centimeters. The young grow rapidly until maturity, after which growth continues slowly for several years. (Rodgers 1990)
Although the Russian sturgeon (Acipenser huso) may reach a length of 30 centimeters in one year, the lake sturgeon requires twenty years to attain a length of a little over a meter. Acipenser fulvescens become sexually mature when they are around the age of twenty and at a length of a little over a meter. (Herald 1971)
Average gestation period: 6 days.
Average number of offspring: 350000.
Average age at sexual or reproductive maturity (male)
Sex: male: 2920 days.
Average age at sexual or reproductive maturity (female)
Sex: female: 9490 days.
L'esturió groc (Acipenser fulvescens) és una espècie de peix pertanyent a la família dels acipensèrids.[5]
És depredat per Ichthyomyzon unicuspis[13] i, als Estats Units, per la llampresa de mar (Petromyzon marinus).[14][15]
És un peix d'aigua dolça i salabrosa, demersal, potamòdrom i de clima temperat (60°N-32°N).[6][16]
Es troba a Nord-amèrica: conques dels rius Mississippí i Sant Llorenç, els Grans Llacs d'Amèrica del Nord i la badia de Hudson.[6][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34]
Pot assolir els 152 anys d'edat.[35]
Es troba amenaçat d'extinció per la sobrepesca, la pèrdua del seu hàbitat i la contaminació.[36][37][38][39]
La construcció de preses és el seu principal problema per facilitar la seua recuperació als Grans Llacs. A més, les àrees de posta i cria poden veure's afectades per l'erosió, la sedimentació i els abocaments contaminants. Altres raons de preocupació als Grans Llacs són la canalització dels rierols, la sobrepesca o la captura il·legal, el desinterès de les administracions públiques i els efectes adversos dels lampricides.[40]
És inofensiu per als humans.[6]
L'esturió groc (Acipenser fulvescens) és una espècie de peix pertanyent a la família dels acipensèrids.
Der See-Stör (Acipenser fulvescens) ist eine Fischart aus der Gattung der Störe (Acipenser), die in Nordamerika in Flüssen und Seen vorkommt. Sie wird kommerziell und von Sportfischern befischt.
Der See-Stör weist den typischen langgestreckten Körperbau der Störe auf. Die Schnauze trägt vier glatte Barteln und ist bei Jungtieren zugespitzt, wird aber mit zunehmendem Alter immer stumpfer und breiter. Entlang des Körpers verlaufen fünf Reihen von Knochenplatten, eine entlang des Rückens, je eine auf mittlerer Höhe der Flanke und je eine am Rand des Bauches. Bei Jungtieren sind die Platten groß und zu scharf zugespitzten Haken ausgebildet, die Haut ist rau. Mit zunehmendem Alter stumpfen die Schuppen ab und schrumpfen bis zum fast völligen Verschwinden, die Haut wird glatter. Die erste Platte der Rückenreihe berührt die Kopfplatte. Die Rückenreihe weist 9 bis 15 Platten auf, die Seitenreihen 29 bis 42 und die ventralen Reihen 7 bis 12. Ein bis zwei Knochenplatten finden sich auch hinter der Rücken- und Afterflosse, beide sind aber nicht von Knochenplatten flankiert. Jungtiere sind rötlichbraun und weisen unregelmäßige schwarze Flecken auf. Erwachsene Tiere sind grünlich-olivbraun oder gräulich ohne Zeichnung. Die Rückenflosse weist 35 bis 45, die Afterflosse 25 bis 30 Weichstrahlen auf. Die Bögen der Kiemenreuse tragen 25 bis 40 Strahlen. Ausgewachsene Tiere erreichen eine Länge von durchschnittlich ein bis 1,80 Metern und maximal 2,7 Meter und ein Gewicht von bis zu 125 kg.[1] Das Höchstalter soll bis zu 152 Jahre betragen.[2][3][4]
Der See-Stör kommt im Sankt-Lorenz-Strom, den Großen Seen, im Lake Champlain, der Hudson Bay, dem Saskatchewan River und dem Flusssystem des Mississippi River bis Nord-Louisiana und Süd-Süd-Dakota vor. Zwischen den Beständen in den großen Seen und West-Kanada und denen des Mississippi findet wahrscheinlich kein Austausch statt.[5]
Die Art lebt am Grund von Seen und großen Flüssen. Sie dringt gelegentlich ins Brackwasser, aber nicht ins Salzwasser vor. Nahrung wird am Grund mit Hilfe der Barteln aufgespürt. See-Störe sind wenig wählerische Allesfresser, die unter anderem Insekten, Weichtiere, Fische und Würmer fressen. Zwischen verschiedenen Fress- und Laichgründen werden teilweise Wanderungen von mehr als 1000 Kilometern unternommen.[3]
Die Paarungszeit beginnt im Frühjahr, wenn die Wassertemperatur 9 bis 15 °C erreicht. Während sich die Männchen alle zwei bis vier Jahre fortpflanzen, laichen die Weibchen nur alle drei bis sieben jahre ab. Die bis zu 7.000.000 Eier pro Weibchen werden in steinigen Uferbereichen von Seen und Flüssen abgelegt. Die Geschlechtsreife wird von Männchen mit 14 bis 16 Jahren und etwa 114 cm Länge erreicht, von Weibchen erst mit 24 bis 26 Jahren und 140 cm Länge.[5]
Während der Fang des See-Störs in den USA zu kommerziellen Zwecken verboten ist, wird die Art in Kanada wegen ihres Fleisches und Kaviars befischt. Die sportliche Befischung ist in einigen US-Bundesstaaten zu bestimmten Zeiten gestattet. Auf Grund der langen Generationszeiten gilt die Art als störungsanfällig. Im Washingtoner Artenschutz-Übereinkommen ist der See-Stör in Anhang II gelistet, die IUCN schätzt den Bestand derzeit als nicht gefährdet (Least Concern) ein.[5]
Der See-Stör wird vom Namao-Virus parasitiert.
Der See-Stör (Acipenser fulvescens) ist eine Fischart aus der Gattung der Störe (Acipenser), die in Nordamerika in Flüssen und Seen vorkommt. Sie wird kommerziell und von Sportfischern befischt.
The lake sturgeon (Acipenser fulvescens), also known as the rock sturgeon,[6] is a North American temperate freshwater fish, one of about 25 species of sturgeon. Like other sturgeons, this species is a bottom feeder and has a partly cartilaginous skeleton, an overall streamlined shape, and skin bearing rows of bony plates on the sides and back.
The lake sturgeon uses its elongated, spade-like snout to stir up the substrate and sediments on the beds of rivers and lakes to feed. Four sensory organs (barbels) hang near its mouth to help the sturgeon locate bottom-dwelling prey. Lake sturgeons can grow to a large size for freshwater fish, topping 7.25 ft (2.2 m) long and 240 lb (108 kg).[7]
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 insect larvae, worms (including leeches), and other small organisms (primarily metazoan) it finds in the mud. Some populations consume fish as a significant component of their diet, particularly since the introduction in the early 1990s of the invasive round goby.[8][9] Given that it is a large species surviving by feeding on very small species, its feeding ecology has been compared to that of large marine animals, like some whales, which survive by filter-feeding.[10]
This species occurs in the Mississippi River drainage basin south to Alabama and Mississippi. It occurs in the Great Lakes and the Detroit River, east down the St. Lawrence River to the limits of fresh water. In the west, it reaches Lake Winnipeg and the North Saskatchewan and South Saskatchewan Rivers. In the north, it is found in the Hudson Bay Lowland.[11] In the east, the species lives in Lake Champlain and in some Vermont rivers, including the Winooski, Lamoille and Missisquoi rivers, and Otter Creek. This distribution makes sense in that all these areas were linked by the large lakes that formed as the glaciers retreated from North America at the end of the last ice age (e.g., Lake Agassiz, Lake Iroquois).
These sturgeon often migrate in search of food or suitable spawning locations, or in response to seasonal environmental conditions. Juveniles typically inhabit pools greater than about 6 feet in depth, and adults typically live deep in large lakes. They are not often far from suitable spawning locations. The abundance of prey also plays a large factor in finding a suitable habitat.[12]
Lake sturgeon have a very long lifespan. Males typically live for 55 years and females can live for 80 to 150 years.[13] They grow quickly during a lengthy juvenile stage.[12]
Lake sturgeon eggs begin yellowed and are attached to a fatty ovarian mass. When the eggs are mature, they become olive green, grey or black. The eggs typically hatch after 8 to 14 days. Observations suggest lake sturgeon and other fish and invertebrates likely consume some fertilized eggs while on the spawning grounds.
At hatching, the larvae are barely discernible and are about 10 mm long. The larvae soon become pelagic, remaining far from the surface and bed, and negatively phototactic, or attracted to darkness, while searching for rocky places to hide. About two weeks after hatching, they disperse downstream with the current for several miles until settling back down upon the river bottom.
As juveniles, all definitive adult structures, except for gonads, form. They are thought to feed on benthic invertebrates like adults. It is thought that during late summer, yearlings gather in large schools in shallow river mouths and bays. The juveniles can be found in the same habitats as adults after a year.[12]
Male lake sturgeon typically reach sexual maturity at 8 to 12 years, but may take up to 22 years. Females reach sexual maturity at 14 to 33 years, most often from 24 to 26 years of age. These sturgeon spawn on clean, gravel shoals and stream rapids, usually from April to June. They prefer to spawn in temperatures between 55 and 64 degrees Fahrenheit.[13] Lake sturgeon reproduce by swimming around each other in circles and shaking violently; the male stops circling when he has released his fertilizer and the female then lays her eggs.[14] Males spawn every 2 to 7 years while females spawn every 4 to 9 years. Only 10 to 20 percent of adult lake sturgeon are sexually active during a season[13]
Lake sturgeon are polygamous, maximizing genetic diversity.[15]
These fish were once killed as a nuisance by catch because they damaged fishing gear. When their meat and eggs became prized, commercial fishermen targeted them. Between 1879 and 1900, the Great Lakes commercial sturgeon fishery brought in an average of 4 million pounds (1800 metric tons) per year. Such unsustainable catch rates were coupled with environmental challenges such as pollution and the construction of dams and other flood control measures. Sturgeon, which return each spring to spawn in the streams and rivers in which they were born, found tributaries blocked and spawning shoals destroyed by silt from agriculture and lumbering. In the 20th century, drastic drops in sturgeon catches, increased regulations, and the closure of viable fisheries occurred. Currently, 19 of the 20 states within the fish's original U.S. range list it as either threatened or endangered.[16][17] It is considered "Vulnerable" by NatureServe.[18]
This sturgeon is a valuable gourmet food fish, as well as a source of specialty products including caviar and isinglass. "In 1860, this species, taken on incidental catches of other fishes, was killed and dumped back in the lake, piled up on shore to dry and be burned, fed to pigs, or dug into the earth as fertilizer."[19] It was even stacked like cordwood and used to fuel steamboats. Once its value was realized, "They were taken by every available means from spearing and jigging to set lines of baited or unbaited hooks laid on the bottom to trap nets, pound nets and gillnets."[19] Over 5 million lb were taken from Lake Erie in a single year. The fishery collapsed, largely by 1900. It has never recovered. Like most sturgeons, the lake sturgeon is rare now and is protected in many areas.[16][17]
In addition to overharvesting, it has also been negatively affected by pollution and loss of migratory waterways. It is vulnerable to population declines through overfishing due to its extremely slow reproductive cycle; most individuals caught before 20 years of age have never bred and females spawn only once every four or five years. The specific harvesting of breeding females for their roe is also damaging to population size. Few individuals ever reach the extreme old age or large size that those of previous generations often did.[20]
In 2001, transmitters placed into ten sturgeon and egg mats placed in the Detroit River documented spawning of sturgeon for the first time in many decades.[21] This discovery followed the 2001 discovery of spawning runs under the Blue Water Bridge in the St. Clair River.[22][23]
The Little River Band of Ottawa Indians (Manistee, MI) Sturgeon Program began in 2001. In 2002 they successfully documented natural reproduction of lake sturgeon by capturing larvae (newly hatched fish) from the Big Manistee River. The Streamside Rearing Facility for lake sturgeon on the Big Manistee River became operational in the spring of 2004 and marked the first time this technique had ever been used for this species. Since that time there have been five SRFs operated within the Lake Michigan Basin built on the same LRBOI design. Many agencies now collaborate on this effort including the U.S. Fish and Wildlife Service, States of Michigan and Wisconsin, and many other partners. The LRBOI Nmé Stewardship Plan, created by biologists and Tribal members, was published in 2005 as a guiding document for the LRBOI sturgeon program and sturgeon restoration. New York State has also had a successful recovery program, using eggs and sperm collected from a spawning area on the St. Lawrence River. In early June 2017, aquatic biologists conducted the annual assisted propagation effort, through which 130,000 fertilized eggs were sent to hatcheries.[24]
Several populations of lake sturgeon have begun to be restored by the U.S. Fish and Wildlife Service in cooperation with locally managed fisheries from North Carolina to the Great Lakes. To better understand their life cycle, USFWS tags individual sturgeon and records abundance, distribution, age, growth and health of the population. While strict regulations have been put in place to monitor harvests, hatcheries are a key component of restoration efforts.[25]
Wolf Lake State Fish Hatchery in Kalamazoo, MI, raises and releases lake sturgeon. The lake sturgeon are produced mainly for inland waters, although a few are stocked in Great Lakes waters.
There is also a streamside rearing facility near Onaway, Michigan on the Black River, a tributary of the Cheboygan River, then Lake Huron. The facility is run and managed by the Michigan Department of Natural Resources, Michigan State University, and Tower Kliber. Each year hundreds to thousands of sturgeon are raised and released into Black Lake, and other surrounding areas. Adult sturgeon are caught in the river, their eggs and sperm are extracted and then taken back to the hatchery for fertilization, and left to incubate. Hatched larvae are also caught in the river with drift nets. The hatchery is open to the public, and people can also watch the hatchery workers catch the fish.
Today, limited sturgeon fishing seasons are permitted in only a few areas, including some locations in Minnesota, Wisconsin, and Michigan. Fishing for sturgeon is allowed on Black Lake in Michigan, for example, but the fishery is limited to five total fish taken each year, each over 36 in (910 mm) and taken through the ice with spears.
Anglers in Minnesota have the opportunity to harvest one lake sturgeon per calendar year between 45 and 50 in on the Rainy River, and Lake of the Woods on the Canada–US border. The early season runs from April 24 to May 7 each year with the late season running from July 1 to September 30. Anglers must have a valid Minnesota fishing license and purchase a sturgeon tag to harvest a lake sturgeon.
An annual sturgeon spearing season is open on Lake Winnebago in Wisconsin. It has changed from a 16-day season in the past to a season with a marked quota, but the season can still run for the full 16 days. If 90–99% of the quota is reached on any day, the season is over at 1:00 pm the following day. If 100% (or more) of the quota is reached, the Wisconsin Department of Natural Resources can enable an emergency stoppage rule.[26] In 2012, the largest sturgeon ever caught on Lake Winnebago (a female) was 125 years old, weighed 240 lb., and measured 87.5 in. in length. It was tagged and released by scientists from the Wisconsin Department of Natural Resources.[27]
The sturgeon is also present in Quebec in the St. Lawrence River, where it is targeted by commercial fisheries. It is also a game fish with a harvest limit of one per day.
The sturgeon was and is a major figure in Menominee culture. For example, one of their clans is the Sturgeon Clan. There was also special celebration, the Sturgeon Festival, in which the spiritual and economic aspects of the fish were celebrated. Among the spiritual aspects are the sturgeon's role as protector of wild rice. Sturgeon were taken not just for their meat but also for the eggs (caviar) and other parts, especially the isinglass, which was traditionally used as a paint adhesive and later as a trade item with Europeans. [28]
The fish was also a key economic factor among the Anishinaabe. In fact, members of this tribe living in the sturgeon-rich Winnipeg River watershed were known as "Sturgeon Indians" during the fur trade era. Devices used in fishing sturgeon included spear, weir, net, and less commonly hook and line.[29]
_2.JPG)
Lake sturgeon, Batchawana Bay, Lake Superior (live released).
Lake sturgeon.
_2.JPG)
Juvenile lake sturgeon
Goulais Bay, Lake Superior.
_3.JPG)
Juvenile lake sturgeon
Goulais Bay, Lake Superior.
.jpg)
A very juvenile lake sturgeon.
The lake sturgeon (Acipenser fulvescens), also known as the rock sturgeon, is a North American temperate freshwater fish, one of about 25 species of sturgeon. Like other sturgeons, this species is a bottom feeder and has a partly cartilaginous skeleton, an overall streamlined shape, and skin bearing rows of bony plates on the sides and back.
The lake sturgeon uses its elongated, spade-like snout to stir up the substrate and sediments on the beds of rivers and lakes to feed. Four sensory organs (barbels) hang near its mouth to help the sturgeon locate bottom-dwelling prey. Lake sturgeons can grow to a large size for freshwater fish, topping 7.25 ft (2.2 m) long and 240 lb (108 kg).
El esturión de lago (Acipenser fulvescens) es una especie de pez acipenseriforme de la familia Acipenseridae, de agua dulce, de las zonas templadas de América del Norte, y forma parte de una de las 20 especies pertenecientes a la familia de los esturiones. Al igual que los esturiones, esta especie es uno de los eslabones evolutivos más antiguos, con una parte del esqueleto cartilaginoso y su piel con hileras de placas óseas. Para alimentarse, este pez utiliza su alargado hocico en forma de espada para agitar la arena y el limo en los lechos de los ríos y lagos. Los bigotes que rodean la boca, por lo general cuatro, son meramente un órgano sensorial para ayudarle a encontrar su alimento. El esturión del lago puede llegar a pesar más de 100 kilogramos y a tener una longitud de 2 metros durante su larga vida, que puede llegar a los 100 años de edad. Generalmente alcanzan la madurez sexual durante la tercera década de vida.
El esturión del lago tiene paladar y alrededor de la boca unos labios similares a los del barbo y los extiende para aspirar suavemente alimento vivo entre el lodo. Debido a su falta de dientes, traga los alimentos enteros. Su dieta está constituida por insectos, larvas, gusanos, sanguijuelas, peces pequeños y otros organismos pequeños, principalmente metazoos que se encuentran en el barro.
Antiguamente su aceite se utilizaba para alimentar los barcos de vapor. Es también un valioso manjar para la cocina gourmet por su codiciado caviar y por la “cola de pescado”.
Como la mayoría de los esturiones, el esturión del lago es bastante poco común ahora, y está protegido en muchas áreas. Ha sido sobre explotado para sus diferentes productos, y ha sucumbido a la contaminación y la pérdida de vías migratorias. Es vulnerable a la disminución de la población debido a la sobre pesca, ya que su ciclo reproductivo es muy lento. La mayoría de los individuos capturados antes de los veinte años de edad nunca se han reproducido y las hembras desovan sólo una vez cada cuatro o cinco años. La recolección específica de hembras reproductoras en su madurez, para la recolección del caviar, también es muy perjudicial para el tamaño de la población. El esturión de lago, que una vez fue una especie muy abundante en los Grandes Lagos, que era capturado y descartado por los pescadores, que buscaban otras especies, ahora raramente es visto. A diferencia de las generaciones anteriores, hoy muy pocos ejemplares llegan a la vejez o a desarrollar su tamaño máximo.
Hoy en día, existen temporadas de pesca limitadas de esturión, y se permite sólo en pocas áreas incluyendo algunos lugares en Minnesota, Wisconsin y Míchigan. La pesca de esturión se permite por ejemplo, en el Lago Negro (Michigan); pero se limita tan solo a cinco ejemplares por año, cada uno de más de 91 cm y solo puede ser cazado a través del hielo con lanzas. Unos 25 pescadores son elegidos por sorteo cada día y se da una indicación cuando se han cogido un pez. Cuando cinco banderas se han plantado en el hielo la temporada se cierra hasta el próximo año. Algunas temporadas de pesca han durado tan solo unas horas.
Los pescadores en Minnesota tienen la oportunidad de pescar un esturión de lago por año, cuando las lluvias anuales llegan a los 1100 mm sobre los ríos y lagos de los bosques en la frontera canadiense. El comienzo de la temporada se extiende desde el 24 de abril hasta el 7 de mayo de cada año, con un posible retraso para el 1 de julio al 30 de septiembre. Los pescadores deben tener una licencia válida de pesca de Minnesota y comprar una etiqueta especial para la pesca del esturión de lago.
También hay una temporada anual de cacería de esturiones en Lago Winnebago en Wisconsin. Esta temporada antes era de 16 días de duración; pero ahora cierra cuando se cumple el cupo máximo permitido de ejemplares cazados. Sin embargo, si la temporada aún no cumple su cuota y se vencen los 16 días puede extenderse el plazo hasta las 12:30 horas del día siguiente. Si el 100% (o más) de la cuota se alcanza antes de los 16 días, el Departamento de Recursos Naturales aplica una regla de paro de emergencia, que pone fin a la temporada de casa de ese día a las 12:30 horas. Protegiendo así este valioso recurso. Para pescar estos ejemplares los pescadores miran por un agujero que se corta en el hielo con motosierras durante 6 hora al día. Y el total de los agujeros no deben superar los 4.5 m². Solo se pueden cazar esturiones de más de 91 cm.[2]
El esturión más grande atrapado, del que se tiene registros, ocurrió en el Lago Winnebago, con un peso de 188 libras, capturado por el Sr. Dave Piechowski en 2004[3]
Este esturión también se encuentra en el río San Lorenzo en Quebec pero en peligro de extinción.
Juvenil
Goulais Bay, Lago Superior
Juvenil
Goulais Bay, Lago Superior
El esturión de lago (Acipenser fulvescens) es una especie de pez acipenseriforme de la familia Acipenseridae, de agua dulce, de las zonas templadas de América del Norte, y forma parte de una de las 20 especies pertenecientes a la familia de los esturiones. Al igual que los esturiones, esta especie es uno de los eslabones evolutivos más antiguos, con una parte del esqueleto cartilaginoso y su piel con hileras de placas óseas. Para alimentarse, este pez utiliza su alargado hocico en forma de espada para agitar la arena y el limo en los lechos de los ríos y lagos. Los bigotes que rodean la boca, por lo general cuatro, son meramente un órgano sensorial para ayudarle a encontrar su alimento. El esturión del lago puede llegar a pesar más de 100 kilogramos y a tener una longitud de 2 metros durante su larga vida, que puede llegar a los 100 años de edad. Generalmente alcanzan la madurez sexual durante la tercera década de vida.
El esturión del lago tiene paladar y alrededor de la boca unos labios similares a los del barbo y los extiende para aspirar suavemente alimento vivo entre el lodo. Debido a su falta de dientes, traga los alimentos enteros. Su dieta está constituida por insectos, larvas, gusanos, sanguijuelas, peces pequeños y otros organismos pequeños, principalmente metazoos que se encuentran en el barro.
Acipenser fulvescens Acipenser generoko animalia da. Arrainen barruko Actinopterygii klasean sailkatzen da, Acipenseridae familian.
Acipenser fulvescens Acipenser generoko animalia da. Arrainen barruko Actinopterygii klasean sailkatzen da, Acipenseridae familian.
Järvisampi (Acipenser fulvescens) on sampien heimoon kuuluva kala, jota pidetään joskus akvaariossa.[2]
Järvisammella on leuassaan neljä suurta viiksisäiettä. Selässä on kahdessa rivissä luukilpiä. Evät ovat pyöreäreunaiset. Järvisampi on yleensä noin metrin mittainen, mutta kolme kertaa suurempiakin yksilöitä on tavattu. Kalan paino on suurimmillaan 120 kiloa. Vuonna 1952 pyydystettiin 152 vuoden ikäinen järvisampi.[2]
Lajin elinaluetta ovat Pohjois-Amerikassa ovat Hudsoninlahti ja Mississippi-joki.[3] Järvisampi elää murto- ja makeassavedessä.[2] Lajin uhanalaisuusluokitus on Kansainvälisen luonnonsuojeluliiton mukaan elinvoimainen.[4]
Järvisampi on lähes kaikkiruokainen.[2]
Järvisampi (Acipenser fulvescens) on sampien heimoon kuuluva kala, jota pidetään joskus akvaariossa.
Acipenser fulvescens
L'esturgeon jaune (Acipenser fulvescens) est un esturgeon habitant la côte est nord-américaine.
L'esturgeon jaune est un des plus grands poissons d'eau douce et un de ceux ayant la vie la plus longue[1]. L'esturgeon jaune peut vivre jusqu'à 100 ans et même davantage[réf. nécessaire]. Il se reproduit pour la première fois entre 12 et 20 ans. Ensuite il va se reproduire tous les 2 ou 4 ans en remontant les cours d'eau jusqu'à une frayère propice, normalement sur un fond de gravier dans les eaux rapides d'une rivière. Beaucoup de populations sont sérieusement menacées. Par exemple sa pêche est maintenant interdite en Ontario. Au Québec ce poisson est encore pêché commercialement dans le fleuve Saint-Laurent. C'est un poisson convoité par les pêcheurs à la ligne pour le combat intense qu'il offre et les sauts hors de l'eau. Aux États-Unis il existe une pêche très restrictive au harpon.
L'esturgeon se nourrit d'organismes vivant sur le fond. Les gastéropodes constituent souvent une partie importante de son alimentation. Il consomme également des insectes, des crustacés et des poissons. Comme beaucoup d'autres esturgeons, l'esturgeon jaune est reconnu pour ses sauts spectaculaires en dehors de l'eau sans raison apparente. Longtemps interprété comme une manœuvre pour se débarrasser des parasites ce serait en fait un mode de communication pour indiquer les aires d'alimentation.
Il fait partie des espèces que caractérise leur sénescence négligeable ; l'esturgeon jaune peut ainsi atteindre l'âge de 152 ans[2]. L'espèce ne présente pas de signes de sénescence reproductive : un spécimen capturé au Canada âgé de 150 ans était plein d’œufs[3].
L'esturgeon jaune vit dans les eaux douces et même parfois saumâtres des grands cours d'eau et des lacs des bassins du Saint-Laurent, du Mississippi et de la baie d'Hudson[4].
Acipenser fulvescens
L'esturgeon jaune (Acipenser fulvescens) est un esturgeon habitant la côte est nord-américaine.
Acipenser fluvescens Rafinesque, 1877, conosciuto comunemente come storione di lago, è un pesce osseo appartenente alla famiglia famiglia Acipenseridae.
Questa specie è endemica del Nord America.
Acipenser fluvescens Rafinesque, 1877, conosciuto comunemente come storione di lago, è un pesce osseo appartenente alla famiglia famiglia Acipenseridae.
Acipenser fulvescens is een straalvinnige vissensoort uit de familie van steuren (Acipenseridae).[2] De wetenschappelijke naam van de soort is voor het eerst geldig gepubliceerd in 1817 door Rafinesque.
De soort staat op de Rode Lijst van de IUCN als niet bedreigd, beoordelingsjaar 2004. De omvang van de populatie is volgens de IUCN stijgend.[1]. Zijn Nederlandse naam is meersteur.
Bronnen, noten en/of referenties
Multimedia w Wikimedia Commons Jesiotr jeziorny[3] (Acipenser fulvescens) – gatunek ryby z rodziny jesiotrowatych (Acipenseridae).
Szarozielona ryba o smukłym ciele i charakterystycznych wyrostkach kostnych na bokach. Na pysku ma dwie pary wąsów, służących do odbierania bodźców dotykowych. Dorasta do 2 m długości, waży około 90 kg.
Główne skupiska tych ryb zamieszkują dorzecze Missisipi, słodkie wody wokół Zatoki Hudsona i Wielkie Jeziora Północnoamerykańskie.
Jesiotr jeziorny żywi się drobnymi zwierzętami wodnymi, takimi jak ślimaki, narybek, małże, a także rybia ikra.
Jesiotr żyje przy dnie jezior i dużych rzek (zazwyczaj na głębokości 5-9 m). Samiec dożywa wieku 55 lat, samica może żyć nawet 150 lat.
Ryba poławiana ze względu na smaczne mięso, niegdyś na wielką skalę, obecnie jej połowy są ograniczone ze względu na gwałtowny spadek liczby populacji w XX w. W ostatnich latach liczba osobników znów zaczęła wzrastać.
Jesiotr jeziorny (Acipenser fulvescens) – gatunek ryby z rodziny jesiotrowatych (Acipenseridae).
O esturjão-de-lago (Acipenser fulvescens; em inglês “lake sturgeon”) é um peixe de água doce das regiões temperadas da América do Norte, sendo uma dentre as cerca de 20 espécies de esturjão existentes. Assim como outros esturjões, esta espécie se alimenta no fundo de lagos e rios, e tem um esqueleto parcialmente cartilaginoso e uma pele dotada de fileiras de placas ósseas.
O esturjão-de-lago pode atingir um peso de 100 quilogramas e um comprimento de 3 metros. Ele pode viver até mais de 100 anos e geralmente só atinge a maturidade sexual na terceira década de vida.
A sua dieta consiste de larvas de insetos, vermes (incluindo sanguessugas), pequenos peixes e outros organismos pequenos que encontra no lodo.
O esturjão-de-lago é uma fonte de caviar e isinglass, ou cola de peixe, e o seu óleo já foi utilizado como combustível de embarcações. Ele é também um peixe de alto valor culinário. Assim como a maioria dos esturjões, o esturjão-de-lago atualmente é raro, encontrando-se sob proteção em várias áreas. A espécie foi alvo de pesca excessiva, e sucumbiu à poluição e à perda das suas rotas migratórias. Ele é vulnerável ao declínio populacional devido ao seu ciclo reprodutivo extremamente lento. A maioria dos indivíduos capturados antes dos 20 anos de idade jamais se reproduziu e as fêmeas só desovam uma vez a cada quatro ou seis anos. A captura específica das fêmeas em período de reprodução para a extração da sua ova também contribui para a redução populacional desse peixe. O esturjão-de-lago já foi uma espécie muito abundante nos Grandes Lagos da América do Norte, mas atualmente é raro que se veja algum espécime. Poucos indivíduos chegam à idade extremamente avançada ou alcançam o tamanho que, no passado, frequentemente, eram presenciados nesta espécie. Apesar disso, devido às medidas de proteção e monitoramento, o seu estado de conservação, que em passado recente era vulnerável, atualmente é considerado pouco preocupante.
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|colaboração= ignorado (ajuda) O esturjão-de-lago (Acipenser fulvescens; em inglês “lake sturgeon”) é um peixe de água doce das regiões temperadas da América do Norte, sendo uma dentre as cerca de 20 espécies de esturjão existentes. Assim como outros esturjões, esta espécie se alimenta no fundo de lagos e rios, e tem um esqueleto parcialmente cartilaginoso e uma pele dotada de fileiras de placas ósseas.
O esturjão-de-lago pode atingir um peso de 100 quilogramas e um comprimento de 3 metros. Ele pode viver até mais de 100 anos e geralmente só atinge a maturidade sexual na terceira década de vida.
A sua dieta consiste de larvas de insetos, vermes (incluindo sanguessugas), pequenos peixes e outros organismos pequenos que encontra no lodo.
O esturjão-de-lago é uma fonte de caviar e isinglass, ou cola de peixe, e o seu óleo já foi utilizado como combustível de embarcações. Ele é também um peixe de alto valor culinário. Assim como a maioria dos esturjões, o esturjão-de-lago atualmente é raro, encontrando-se sob proteção em várias áreas. A espécie foi alvo de pesca excessiva, e sucumbiu à poluição e à perda das suas rotas migratórias. Ele é vulnerável ao declínio populacional devido ao seu ciclo reprodutivo extremamente lento. A maioria dos indivíduos capturados antes dos 20 anos de idade jamais se reproduziu e as fêmeas só desovam uma vez a cada quatro ou seis anos. A captura específica das fêmeas em período de reprodução para a extração da sua ova também contribui para a redução populacional desse peixe. O esturjão-de-lago já foi uma espécie muito abundante nos Grandes Lagos da América do Norte, mas atualmente é raro que se veja algum espécime. Poucos indivíduos chegam à idade extremamente avançada ou alcançam o tamanho que, no passado, frequentemente, eram presenciados nesta espécie. Apesar disso, devido às medidas de proteção e monitoramento, o seu estado de conservação, que em passado recente era vulnerável, atualmente é considerado pouco preocupante.
Amerikansk stör (Acipenser fulvescens) är en art av släktet Acipenser som finns i Nordamerika. Till skillnad från många andra störar tillbringar den hela sitt liv i sötvatten.[1]
Den amerikanska stören är en långsmal fisk med spetsig nos och en kropp täckt av 5 rader benplattor. Den saknar fjäll, men har huden försedd med hudtänder som ger den ett sandpapperliknande utseende. Ryggfenan är placerad långt bak, just före den hajliknande stjärtfenan.[3] Nosen är lång, och har en liten, tandlös mun med tjocka läppar som den kan använda till att suga upp föda med. Framför munnen sitter 4 skäggtömmar.[4] Rygg och sidor är mörka, och kontrasterar skarpt mot den vitaktiga buken.[3] Som mest kan den bli 274 cm lång och väga 125 kg, men det är sällan den blir så stor.[5]
Arten är en bottenfisk, som föredrar stora floder och sjöar[6] med ren sand- eller grusbotten.[4] Strömförhållandena kan variera. men den tenderar att undvika helt stillastående vatten.[1] Den har dålig syn, och lokaliserar födan främst med hjälp av skäggtömmarna kring munnen. Den har dessutom smaklökar utanpå munnen, något som hjälper den vid födosöket. Maten består av olika bottenlevande djur som insektslarver, maskar, kräftor, snäckor och småfisk.[4] Arten kan bli gammal, över 100 år. Rekordet hade en individ som fångades 1953 och uppskattades vara 152 år.[1]
Den amerikanska stören mognar sent; hanen blir könsmogen mellan 15 och 20 års ålder, honan vid en ålder på 20 till 25 år.[6] Leken äger rum på våren, när vattnet når upp till en temperatur av 9 till 15 °C. Hanarna leker mellan varje och vart 4:e år, honorna mellan vart 3:e och vart 7:e.[1] Lekplatserna, dit deltagarna vandrar, utgörs av sjöstränder med ren grusbotten, vanligen på ett djup mellan 5,4 och 6 m. Äggen, som är små (0,25 mm), svarta och klibbiga kläcks efter 3 till 7 dygn.[4]
Utbredningsområdet omfattar USA och Kanada i Mississippis, Saint Lawrenceflodens och Saskatchewanflodens avrinningsområden, i floder som mynnar ut i Hudson Bay och James Bay, i Stora sjöarna samt i Champlainsjön.[1]
Arten fiskas framför allt för rommen, som används till kaviar, men också för köttet.[4] Sedan slutet av 1800-talet utsattes den för ett intensivt fiske som gjorde att den var nästan försvunnen i slutet på 1950-talet. Idag har förhållandena förbättrats och populationen växer, och den är därför klassificerad som livskraftig ("LC") av IUCN. Så sent som 1996 betraktades den emellertid ännu som sårbar ("VU").[1]
Amerikansk stör (Acipenser fulvescens) är en art av släktet Acipenser som finns i Nordamerika. Till skillnad från många andra störar tillbringar den hela sitt liv i sötvatten.
Cá tầm hồ (Acipenser rubicundus hay Acipenser fulvescens) là một loài cá tầm, theo ý kiến của các nhà ngư học Bắc Mỹ thì loài cá tầm này với cá tầm ở miền đông Bắc Mỹ (Acipenser maculosus?) là một loài, trong những năm gần đây đã trở thành khách thể của ngành công nghiệp lớn và nhiều lợi nhuận tại các khu vực khác nhau trên hồ Michigan và hồ Erie; thịt của nó được hun khói sau khi được lạng thành các mảnh và ngâm nước muối nhẹ; Những phần cắt bỏ (đầu, đuôi v.v) và các phần mỏng còn lại được dùng để nấu lấy dầu; gần như toàn bộ trứng cá muối được chuyển sang châu Âu. Một hãng sản xuất trung bình mỗi năm dùng hết khoảng 10.000-18.000 cá tầm, trung bình mỗi con nặng 23 kg (50 lb). Cá tầm hồ không thể di cư ra biển, trong khi các cá thể phía dưới thác Niagara lại có thể tự do di chuyển ra biển; và hoàn toàn có thể là các con cá thuộc loài này mà người ta nói rằng thu được tại vịnh Tay trên thực tế là đánh bắt được tại khu vực ven biển của Scotland.
Cá tầm hồ (Acipenser rubicundus hay Acipenser fulvescens) là một loài cá tầm, theo ý kiến của các nhà ngư học Bắc Mỹ thì loài cá tầm này với cá tầm ở miền đông Bắc Mỹ (Acipenser maculosus?) là một loài, trong những năm gần đây đã trở thành khách thể của ngành công nghiệp lớn và nhiều lợi nhuận tại các khu vực khác nhau trên hồ Michigan và hồ Erie; thịt của nó được hun khói sau khi được lạng thành các mảnh và ngâm nước muối nhẹ; Những phần cắt bỏ (đầu, đuôi v.v) và các phần mỏng còn lại được dùng để nấu lấy dầu; gần như toàn bộ trứng cá muối được chuyển sang châu Âu. Một hãng sản xuất trung bình mỗi năm dùng hết khoảng 10.000-18.000 cá tầm, trung bình mỗi con nặng 23 kg (50 lb). Cá tầm hồ không thể di cư ra biển, trong khi các cá thể phía dưới thác Niagara lại có thể tự do di chuyển ra biển; và hoàn toàn có thể là các con cá thuộc loài này mà người ta nói rằng thu được tại vịnh Tay trên thực tế là đánh bắt được tại khu vực ven biển của Scotland.
Acipenser fulvescens Rafinesque, 1817
Охранный статус
Озёрный осётр[1] (лат. Acipenser fulvescens) — крупная рыба семейства осетровых.
Максимальная длина тела — 274 см, а масса — 125 кг. Максимальная продолжительность жизни — 152 года[2].
Спина и бока туловища черно-серые или оливково — коричневые, брюхо белое или желтоватое. Созревает в 15-25 лет. Встречается в бассейне рек Миссисипи, Святого Лаврентия и Саскачеван, а также в озере Виннипег и Великих озёрах. Интродуцирован в ряд более мелких озёр Северной Америки — Мендота, Монона, Вингра, Большой Кедр и др. У самок массой от 5 до 51 кг плодовитость колеблется в широких пределах — от 50 тыс. до 667 тыс. икринок. Пищу его составляют мелкие донные организмы — моллюски, личинки насекомых, пиявки, амфиподы и другие беспозвоночные, реже рыба.
Озёрный осётр (лат. Acipenser fulvescens) — крупная рыба семейства осетровых.
Максимальная длина тела — 274 см, а масса — 125 кг. Максимальная продолжительность жизни — 152 года.
Спина и бока туловища черно-серые или оливково — коричневые, брюхо белое или желтоватое. Созревает в 15-25 лет. Встречается в бассейне рек Миссисипи, Святого Лаврентия и Саскачеван, а также в озере Виннипег и Великих озёрах. Интродуцирован в ряд более мелких озёр Северной Америки — Мендота, Монона, Вингра, Большой Кедр и др. У самок массой от 5 до 51 кг плодовитость колеблется в широких пределах — от 50 тыс. до 667 тыс. икринок. Пищу его составляют мелкие донные организмы — моллюски, личинки насекомых, пиявки, амфиподы и другие беспозвоночные, реже рыба.
