The silver redhorse (''

Moxostoma ''Moxostoma'', the redhorses or jumprocks, is a genus of North American ray-finned fish in the family Catostomidae. Redhorses are variable in size, geographic location, and other ecological traits such as spawning substrate. Several redhorses ar ...

anisurum'': Moxostoma= mouth to suck; anisurum = unequal tail) is a species of

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mi ...

fish endemic to

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

and the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

. It is the longest-lived redhorse known (a group of 25 extant species), with a maximum reported age of 41 years. Sometimes called redhorse or sucker for short, it is in the family Catostomidae with other suckers. The species is distributed from

Quebec Quebec is Canada's List of Canadian provinces and territories by area, largest province by area. Located in Central Canada, the province shares borders with the provinces of Ontario to the west, Newfoundland and Labrador to the northeast, ...

Alberta Alberta is a Provinces and territories of Canada, province in Canada. It is a part of Western Canada and is one of the three Canadian Prairies, prairie provinces. Alberta is bordered by British Columbia to its west, Saskatchewan to its east, t ...

and is also in the

Mississippi River The Mississippi River is the main stem, primary river of the largest drainage basin in the United States. It is the second-longest river in the United States, behind only the Missouri River, Missouri. From its traditional source of Lake Ita ...

St. Lawrence River The St. Lawrence River (, ) is a large international river in the middle latitudes of North America connecting the Great Lakes to the North Atlantic Ocean. Its waters flow in a northeasterly direction from Lake Ontario to the Gulf of St. Lawren ...

Ohio River The Ohio River () is a river in the United States. It is located at the boundary of the Midwestern and Southern United States, flowing in a southwesterly direction from Pittsburgh, Pennsylvania, to its river mouth, mouth on the Mississippi Riv ...

, and the

Great Lakes The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes spanning the Canada–United States border. The five lakes are Lake Superior, Superior, Lake Michigan, Michigan, Lake Huron, H ...

basins. The current world record is , caught by Chris Stephenson on Pickwick Lake in Alabama, April 1995 and certified by National Freshwater Fishing Hall of Fame. This species is of growing interest to rod-and-line anglers. The long-lived and late-maturing silver redhorse is also a sportfish pursued by kill-and-dump

bowfishing Bowfishing is a fishing technique that uses specialized archery equipment to impale and retrieve fish. A bowfisher will use a bow or crossbow to shoot fish through the water surface with a barbed arrow tethered to a line, and then manually retr ...

, a 21st century unregulated sport that produces tons of wanton waste, and thus management and conservation are in need of updating.

Morphology

The silver redhorse is silver on both sides and has a dark gray-brown back and a slate gray tail. The caudal fin is large and moderately forked. Each lobe of the fin is pointed and equal in size. On the silver sides there are 41–42 cycloid lateral line scales. The single dorsal fin does not have any dorsal spines, but instead contains 14–17 soft rays. Their dorsal fin is slightly convex (rounded outward) and is located approximately in the middle of the back. There is no adipose fin (unstructured fin found behind the rayed dorsal fin) present on the back of the fish. The mouth of the silver redhorse is in the inferior position, as it is a bottom feeder. The rear edge of the silver redhorse lips forms a deep "V". Because of extreme similarities, the silver red horse is commonly confused with the Black redhorse and the Golden redhorse. However, both of these redhorses have slightly concave dorsal fins (curves in toward body) with only 12–14 fin rays. Additionally the Silver red horse is more deep-bodied than the golden or black redhorse. It typically weights and measures long, but it can reach up to and .

Geographic distribution

The native range of the silver red horse is the Great Lakes and the St. Lawrence and Mississippi River basins. However, there have been instances in which the fish was found in Clayton lake and the New River Drainage in North Carolina. The silver redhorse is also widely distributed in eastern North America from Missouri to Quebec with most residing in the southeastern United States. It is typically found in lakes and in small to large rivers, where it often lives in undercut banks or protruding tree roots. They are also found in deep pools with little to no current and a sand substrate at the bottom of the pool useful for burying their eggs. They are a good indicator of water quality as they cannot tolerate murky water.

Diet

Due to its inferior mouth position, this fish is a bottom feeder. It feeds on

mollusks Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The num ...

alga Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular microalgae, suc ...

detritus In biology, detritus ( or ) is organic matter made up of the decomposition, decomposing remains of organisms and plants, and also of feces. Detritus usually hosts communities of microorganisms that colonize and decomposition, decompose (Reminera ...

, immature

insects Insects (from Latin ') are hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of jointed ...

, and other small invertebrates.

Monogenea Monogeneans, members of the class Monogenea, are a group of ectoparasitic flatworms commonly found on the skin, gills, or fins of fish. They have a direct lifecycle and do not require an intermediate host. Adults are hermaphrodites, meaning they ...

parasites have been found in the gills of the silver redhorse.

Life history

The silver redhorse generally spawns in the spring in or around April or May when the water temperatures reach around . They take advantage of the shallow landforms flowing channels, also known as riffles, and spawn at the top and the bottoms of the riffles at night. One study in Quebec, Canada found that the silver redhorse is abundant in what they call V-males, as they outnumber the females considerably. For every female on the spawning bed, there is a minimum of 2 males that are used to successfully reproduce. The common methodology includes two males pressing a female between them, causing a vibration to occur while the egg and the sperm are released. The females bury their eggs in the gravel and offer no further parental care. Reproduction maturity for the species happens late in its life usually around four to five years of age. The species thrives in deep bottomed lakes and river systems which promote optimal nest succession year in and year out. The lifespan for the species is several decades, with 41 years being the maximum age reported.

Relationship with humans

The species is quite abundant in southeastern rivers including the Mississippi,

Missouri Missouri (''see #Etymology and pronunciation, pronunciation'') is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it border ...

, and Ohio river systems. The silver redhorse is increasingly recreationally fished for throughout most of the areas in which it inhabits. This includes bowfishing, a sport which disposes whole-bodied native fish by the ton, including silver redhorse. In Minnesota, 21st century tournament bowfishing of redhorse exceeds the commercial harvest level by more than 200 times. Currently, this long-lived, late-maturing, and variably-reproducing species is of conservation concern and urgently requires new management. The silver redhorse is listed as threatened in the Strawberry River basin in Arkansas. The

IGFA The International Game Fish Association (''IGFA'') is the leading authority on angling pursuits and the keeper of the most current world record fishing catches by fish categories. Fishermen who are sport fishers and anglers are careful to follow ...

all-tackle record is tied at , with one being caught from Plum Creek in

Wisconsin Wisconsin ( ) is a U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest of the United States. It borders Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michig ...

in 1985, and the other from the

Chagrin River The Chagrin River is located in Northeast Ohio. The river has two branches, the Aurora Branch and East Branch. Of three hypotheses as to the origin of the name, the most probable is that it is a corruption of the name of a Frenchman, Sieur de Seg ...

, Ohio on 19 March 2024.

References

* {{Taxonbar, from=Q1144405 Moxostoma Fish of Canada Freshwater fish of North America Fish described in 1820 Taxa named by Constantine Samuel Rafinesque