Post date: Monday, March 5, 2012 - 21:01
Updated date: 4/5/18
Black redhorse - Moxostoma duquesnei

 

The black redhorse is a small, torpedo-shaped redhorse that is very similar to the golden redhorse. It is found throughout the central part of the upper Mississippi basin, the southern Great Lakes basin. It occurs in clean, swift flowing creeks and rivers with bottoms of gravel, rock, or sand - usually where the water is clear and clean. The Black Redhorse has a low tolerance for pollution, siltation, or turbidity, and also suffers whenever stream connectivity is impaired.

 

Other Names:  Dusky Redhorse*, Slender Redhorse, Blackhorse, Black Mullet, Finescale Mullet, Finescale Redhorse

*This is the new proposed common name for this species, not yet commonly is use

 

 

 


Description

Oddly enough, the black redhorse is not black. At all. Some have described it as "dusky" but I think this is not easy to see in the live specimens that fishermen typically handle. It's very difficult to distinguish from the Golden Redhorse. Therefore, some identification tips are in order! (Thanks to Joshua Knuth for all of the illustrations)

Identification

When you're thinking that a fish might be a black redhorse, first look at the tail. It should not be bright red. Then, make sure it doesn't have an arched back and a large, fan-shaped dorsal - in which case it would be a silver. Having narrowed it down to golden or black (depending on your region), you then need to dig a little deeper.

Tubercules

Tubercules are hard, toothlike bumps that redhorse develop on their bodies. Male Golden Redhorse develop very large, pointed tubercules on their head during the springtime while spawning. Black Redhorse do not develop these structures - they may get some tiny, pepper-grain-sized tubercules or none at all. Therefore, if you see a bunch of large white bumps on the nose of the fish, then it's not a black redhorse. Check out the Golden redhorse Page to see some good shots of tuberculate male goldens.

Scales

OK, if you don't see any large tubercules, then it's time to count some scales. Black redhorse have 44 to 47 pored scales between the cliethrum and the hypeural plate, along the lateral line (versus 39 to 42 for the golden); typically I look for 45 or more scales before going any further.

 

 

Remember, you're only counting the large scales that are not deformed and have a lateral line pore. Beware of deformed or regenerated scales - redhorse can often have weird, twisted-looking (helical) scale patterns that can mess up the scale counting. This can make the lateral line count invalid - at least on one side of the fish. You'll end up counting a straight line of scales right down the side of the fish, skipping any compressed or non-pored scales at the head as well as any thin and compressed scales right at the tail.

In addition, the caudal peduncle of the black redhorse is very narrow in comparison to the golden redhorse; this really stands out when you step back and look at the fish as a whole. This diagram shows the correct proportions.

Caudal Peduncle Proportions

A reliable indicator that many use is the length versus depth proportion of the caudal peducle. Measure the length of the caudal peducle - this is the distance from the posterior edge of the base of the anal fin to the posterior edge of the hypural plate. Then measure the depth or height of the caudal peduncle at its center. This is easy to do in photographs as long as the fish is laying flat. These measurements are taken and then divided, length over depth. Black redhorse typically have depth that is 59.9% or less and Golden redhorse have a depth of 62% or more. Once you get used to looking for this, it really starts to jump out at you.

Other Characteristics

Black Redhorse also tend to have a more cylindrical, long-bodied shape, as opposed to the stockier, more arched look of the golden redhorse. Certain specimens of the black redhorse also show a weird, almost translucent green coloration that can be striking - epecially during the breeding season.

 

 

 


Habitat

 

The black redhorse occurs in clean, swift flowing creeks and rivers with bottoms of gravel, rock, or sand and has a low tolerance for pollution, siltation, or turbidity. They are a small-stream fish, seldom encountered in large or medium rivers. This is the redhorse most often found in creeks less than 20 feet wide. In Minnesota, Black Redhorse have been found mainly in pools with woody debris and deep runs with cobble and boulder substrates.

 

Range Map

Notable Catches

RoughFish 10/14/17
Graceclaw 7/31/16
Iris 4/25/16
D.T. 4/15/16
Corey 4/8/12


Lifelist Entries

Post date: Sunday, July 31, 2016 - 02:26
A galaxy far, far away
Post date: Sunday, July 13, 2014 - 08:30
Root River
Post date: Monday, July 10, 2017 - 14:00
Grand River, Ingham Co, MI
Post date: Thursday, March 29, 2012 - 10:49
Current River, Missouri
Post date: Friday, August 11, 2017 - 08:32
Post date: Saturday, March 17, 2012 - 21:20
Post date: Saturday, May 31, 2014 - 20:40
Post date: Tuesday, March 13, 2012 - 20:12
SE MN
Post date: Wednesday, April 10, 2013 - 12:05
Little River, Tennessee
Post date: Sunday, July 1, 2012 - 00:15
Post date: Thursday, March 22, 2012 - 22:43
Root River, MN
Post date: Wednesday, January 25, 2017 - 21:10
Pennsylvania
Post date: Friday, April 15, 2016 - 18:35
Root River, Mn.
Post date: Saturday, September 30, 2017 - 21:23
NE Iowa
Post date: Monday, April 25, 2016 - 17:35
Illinois River tributary, Grundy County, IL
Post date: Thursday, May 18, 2017 - 18:45
Yo mama, boiii
Post date: Thursday, April 12, 2012 - 02:23
Post date: Thursday, April 26, 2012 - 22:17
Post date: Saturday, April 7, 2012 - 19:51
Root River, Minnesota
Post date: Friday, April 13, 2012 - 16:17
MN
Post date: Saturday, October 14, 2017 - 22:25
Post date: Sunday, April 26, 2015 - 21:48
Nunyo Creek
Post date: Thursday, June 30, 2016 - 10:51
Grundy County, IL
Post date: Monday, June 17, 2013 - 16:41