Rainbow Smelt – Size | Diet | Facts | Habitat | Predators | Lures

Rainbow Smelt
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The rainbow smelt, scientific name Osmerus mordax is a North American species of fish of the household Osmeridae. It was launched to the Great Lakes, and from there has made its method to varied different locations. Walleye, trout, and different bigger fish prey on this smelt. In this article, I am going to talk about Rainbow Smelt size, diet, facts, lure, habitat, predators, etc.

Rainbow Smelt facts

The rainbow smelt prefer juvenile ciscoes, zooplankton resembling calanoid copepods (Leptodiaptomus ashlandi, L. minutus, L. sicilis), and different small organisms, however, are aggressive and can eat virtually any fish they discover.

They are anadromous spring spawners and like clear streams with light movement and light siltation. The rainbow smelt faces a number of boundaries. They are weak swimmers and can’t overcome most fish ladders.

This prevents them from making it previous the dams to the headwater streams the place they spawn. The rise in erosion and dams helped to decimate the smelt inhabitants within the 1980s.

There are present plans to attempt to scale back damming and to assist control erosion. With present efforts to scale back the human effect on this and plenty of different affected species, the inhabitants are back on the rise.

Rainbow Smelt is a predatory fish native to the north Atlantic coastal areas of North America in addition to a couple of lakes within the Ottawa Valley within the St. Lawrence River watershed.

Deliberate stocking in Michigan within the early 20th century led to established Rainbow Smelt populations in Lake Erie, Lake Michigan, Lake Huron, and Lake Superior.

The fish doubtless invaded Lake Ontario from Atlantic coastal areas via the Erie Canal, New York. More just lately, people have illegally launched Rainbow Smelt to inland lakes.

Rainbow Smelt Identification

Rainbow Smelt has a silvery, pale inexperienced back and a white underside. The sides of the fish are iridescent purple, blue, and pink with a vivid silvery stripe.

They have lower than 75 scales on the lateral line, that are simply eliminated. Rainbow Smelt has three attribute fins, a dorsal in the course of the back, and adipose, and a deeply forked rear tail fin.

The snout is pointed with a properly developed, canine-like tooth on the tongue and roof of the mouth. Rainbow Smelt resemble the minnow household (Cyprinidae spp.), Lake Whitefish (Coregonus clupeaformis), and Cisco (C. artedi), nevertheless, minnows lack an adipose fin, and Lake Whitefish and Cisco have deeper bodies than Rainbow Smelt however no tooth on the roof of their mouths or tongues.

In their native habitat, Rainbow Smelt spends most of their lives at sea and migrate into freshwater to spawn. Rainbow Smelt which has invaded Ontario waters can not return to the ocean, however, they nonetheless observe old behavior patterns.

In the spring, they transfer in giant faculties from lakes into streams and alongside shorelines to spawn. Rainbow Smelt eats plankton – small animals and vegetation discovered within the water – in addition to juvenile native fish.


Outside its native vary, the Rainbow Smelt could be discovered within the St. Lawrence River watershed, every of the Great Lakes, different inland lakes, resembling Lake Simcoe, Lake Nipissing, and Lake Nipigon, in addition to many smaller inland lakes.

The fish has additionally been launched to the Hudson Bay watershed, lakes in northwestern Ontario and Manitoba, together with Lake Winnipeg and plenty of American states.

Rainbow Smelt Description

The body of the rainbow smelt is slender and cylindrical. It has a silvery, pale inexperienced back and is iridescent purple, blue, and pink on the edges, with a light underside.

When full-grown, the rainbow smelt is between 7 and 9 inches (18 and 23 cm) long and weighs about three ounces (85 g). Individuals over 12 inches (30 cm) long are recognized.

Rainbow Smelt Distribution and habitat

The rainbow smelt is widespread throughout North American watersheds. The North American native vary of the rainbow smelt extends via the Atlantic drainages between New Jersey and Labrador to Arctic drainages, and the Pacific drainages as far south as Vancouver Island.

The rainbow smelt has been launched into water our bodies within the U.S. states of Colorado, Connecticut, Georgia, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nebraska, New Hampshire, New York, North Carolina, North Dakota, Ohio, Pennsylvania, South Dakota, Tennessee, Vermont, Virginia, and Wisconsin.

Landlocked populations have been traditionally recognized in Maine, and fish from one among these populations have been launched to Crystal Lake, Michigan after which unfold to the Great Lakes.

Rainbow smelt invaded the Great Lakes watershed via an intentional introduction of eggs to Crystal Lake in 1912. This lake drains into Lake Michigan, from which fish escaped into Lake Michigan and unfolds shortly all through the Great Lakes and their tributaries.

Early data documenting the smelt’s vary growth within the Great Lakes embrace Lake Michigan, Lake Erie, Lake Huron, Lake Ontario, and Lake Superior.

Rainbow smelt has been first reported from Lake Ontario in 1929, and doubtless reached it by dispersal alongside natural waterways from the Finger Lakes, New York, the place they have been deliberately launched in 1917.

The capacity of rainbow smelt to disperse is set by the connectivity of lakes, the flexibility of smelt to maneuver via connecting streams, and the suitability of linked lakes as habitat. Rainbow smelt is weak swimmers so they can’t make it over fish ladders. This has helped to stop a fair wider unfold of their vary.

Rainbow smelt happens in rivers, coastal areas, and ponds. In their anadromous territories, they spend the summers alongside the coast, usually in waters no more than 20 ft (6.1 m) deep and no more than 1 mile (1.6 km) from shore.

They overwinter below the ice in estuaries, producing an antifreeze protein and glycerol. In the spring, they spawn at nighttime in small streams, typically ones that go dry in the summertime.


Rainbow Smelt Ecology

In 1883 Stedman and Argyle discovered that the rainbow smelt consumed bloaters (Coregonus hoyi) and alewives (Alosa pseudoharengus). However, in addition, they acknowledged that this predator had not affected the inhabitants of bloaters however that effect may very well be a chance.

A 2003 research by Horppila et al. reveals that smelt densities can exceed 40,000 people per hectare and should create big predation stress on the lake. Horppila et al. additionally states {that a} single smelt can eat between 0.12 grams and 0.14 grams.

Another research confirmed that in Lake Ontario the first meal sources for rainbow smelt have been slimy sculpins (Cottus cognatus) and opossum shrimp (Mysis relicta), however, nothing was stated on whether or not this predation had a vital effect on the populations. In 1973 Havey reported that there was elevated development in landlocked Atlantic salmon populations after the introduction of the smelt.

It was additionally proven by Brandt and Madon in 1986 that grownup lake trout (Salvalinus namaycush) may very well be a keystone predator species for the smelt.

It is discovered proof of competitors for meals between launched rainbow smelt and native yellow perch (Perca flavescens) in Wisconsin lake habitats, and smelt could also be partially liable for the decline of Great Lakes whitefish (Coregonus spp.).

The U.S. EPA acknowledged in 2008 that they consider the smelt contributed to the extinction of the blue pike (Stizostedion vitreum glaucum) by outcompeting for meals.

Acidity could alter smelt distributions as a result of they weren’t present in small lakes with a pH lower than 6.Zero in a number of surveys. Because of snowmelt, rainbow smelt eggs may be uncovered to deadly pH decreases in poorly buffered lakes.

Life history

Rainbow smelt is anadromous, ascending from saltwater to freshwater to spawn. Smelt are additionally able to finish their life history solely in freshwater.

Landlocked grownup rainbow smelt spawns shortly after ice-off at night time within the decrease reaches of streams. Shaw present in his analysis that no shoreline spawning had ever occurred.

McKenzie states that the variety of eggs extruded by a feminine is positively associated with its dimension and Nellbring acknowledged in his 1989 analysis that the eggs are adhesive and fasten to substrates resembling gravel, sand, mud, or submerged vegetation.

Eggs are left unattended and hatch in 1–4 weeks, relying on water temperature. The time to sexual maturity relies on meals provide and water temperature and plentiful meals and hotter temperatures encourage sooner development.

Crossman and Scott state that in optimum situations and huge lakes, rainbow smelt could attain 35.6 centimeters (14.Zero in) and might stay for over seven years.

Rainbow Smelt Fishing

Rainbow smelt is fished commercially and for sport. Commercial harvests are down from historic ranges; for instance, around 1880 an annual harvest from the Charles River alone was around 9 million fish, whereas as we speak few smelt are discovered within the Charles River.

They are generally processed into animal feed, however are additionally eaten by people. They are a preferred winter recreation fish and the spring smelt run is a practice in lots of components of their distribution. Fishing for rainbow smelt utilizing a gill web is a well-liked exercise alongside the city of Chicago’s lakefront.

Other Recommended Reading

How to Identify Rainbow Smelt

Adult Rainbow Smelt has long, slim bodies averaging 19 cm in size. Their bodies are olive-green on the back, with purple, pink, and blue iridescence on the edges, with a silvery stomach.

The mouth is giant, relative to the fish, with a protruding decrease jaw and huge canine tooth on the roof of the mouth and the tongue.

Rainbow Smelt has a single dorsal fin in the course of its back and a small fleshy fin close to the tail referred to as an adipose fin. Scales are small and simply detach throughout dealing with the fish, very similar to our native shiners.

Rainbow Smelt could also be confused with fish within the minnow household (Cyprinidae sp.), Lake Whitefish (Coregonus clupeaformis), and Cisco (C. artedi). Unlike Rainbow Smelt, fish within the minnow household shouldn’t have an adipose fin, nor giant tooth.

Whereas Lake Whitefish and Cisco are silvery fish with an adipose fin, very similar to a Rainbow Smelt, however, their bodies are deeper than the Rainbow Smelt and they don’t have a tooth on the tongue and roof of the mouth. Learn more about humpback anglerfish.

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