Black Redhorse (Moxostoma duquesnei) - Grand River, Ontario 2007

Ontogeny and Larval Habitat Preferences

We have been working in conjunction with Fisheries and Oceans Canada to study egg development, early life history and larval/juvenile habitat requirements of black redhorse (Moxostoma duquesnei).  Black redhorse is one of several redhorse species native to the Grand River, Ontario and literature is limited.  In 2007, black redhorse were found to closely associate with greater redhorse (Moxostoma valenciennesi), and shared the same spawning riffles. Although they were using the same riffles there was clear habitat partitioning between the two species in terms of the area, current and depth utilized.  Golden redhorse (Moxostoma erythrurum) were observed spawning on separate riffles. 

On May 15 2007, mature brood stock were captured and gametes were collected streamside.  Fertilized eggs were then carefully transported to our hatchery. After 13-14 days the eggs hatched and after another 5 to 6 days larval fish became free-swimming.  Eggs were also collected from spawning redds on May 25 and transported to our hatchery.  They hatched simultaneously with the artificially fertilized eggs. On June 4 the spawning riffle was surveyed and larval redhorse were observed congregating and feeding 20-30m upstream  along the riverbanks in shallow slack water and backwater areas.

We proceeded quickly forward in 2008 and built a fully controlled fifteen tank hatchery with three thermal replicates ranging in temperature between 0 - 30 degrees C. We raised  black redhorse successfully in 2008 for a continuing study of ontogentetic development and larval/juvenile habitat requirements in Canada.

 

Habitat Utilization and Movement by Larval and Juvenile Black Redhorse, Moxostoma duquesnei, in the Grand River, Ontario

Abstract - Black redhorse (Moxostoma duquesnei) larval and juvenile habitat was characterized in the Grand River, Ontario from June to September, with juvenile fish movements to overwintering areas recorded in November using underwater videography. Similar to adult black redhorse and their congeners, larval black redhorse were most likely to be found in clean, clear, stable runs with low to moderate flow, over pebble, gravel and cobble substrate, mixed with sand. Areas (n = 23) where 0+ black redhorse were observed and collected averaged 1.4 ± 0.2 m from shore, in areas with a mean water temperature of 22.0 ± 0.5°C, a mean depth of 0.20 ± 0.02 m and a mean water velocity of 0.12 ± 0.05 m/s. Juvenile black redhorse moved upstream in the early evening and at night to overwintering areas in November when water temperatures approached 5°C.  Larval and juvenile black redhorse occupied riffles, runs, pools and backwater areas; however, there was a strong preference for runs. Water temperature, dissolved oxygen, salinity and pH levels in the Grand River approach the lethal tolerances of other Moxostoma species and there was evidence that persistence of black redhorse populations in the Grand River may be related to the presence of groundwater.

VIEW LARVAL REDHORSE BORN IN 2008

Black Redhorse Ontogeny

Click HERE to see a video of juvenile black redhorse at night

Our old (pilot) hatchery

Incubating eggs with a basic hatchery set-up

Larval black redhorse in 2007

Click here....Biology, ecology and population assessment of black redhorse in Canada

GREATER REDHORSE (Moxostoma valenciennesi) ONTOGENY AND DEVELOPMENT