ABSTRACT

Adult black redhorse (Moxostoma duquesnei), were seined from the Grand River, Ontario and artificially spawned in May 2007 and May 2008. Eggs hatched after 9-16 days at a mean temperature of 20° C, and after 11 - 25 days at a mean temperature of 17° C.  Eggs did not develop fully at temperatures <11° C. Eggs and larval development of 9 – 22 mm specimens are described. Ontogeny of larval black redhorse was compared to that of other Moxostoma and Minytrema species found in Canada from previously published studies, including greater redhorse (M. valenciennesi), river redhorse (M. carinatum), golden redhorse (M. erythrurum), shorthead redhorse (M. macrolepidotum), copper redhorse (M. hubbsi) and spotted sucker (Minytrema melanops). There was significant overlap between most meristic variables that were compared. However, the majority of black redhorse (up to 18 mm) have higher myomere counts (34 - 39 pre-anal myomeres, 6 -11 postanal myomeres and 40 - 47 total myomeres) that are different from other redhorse species in Canada, and may allow identification of black redhorse as small as 9 mm.

Developmental Stages of Black Redhorse (Moxostoma duquesnei)
Drawings by John Cooper

Protolarval Black Redhorse

Mesolarval Black Redhorse

Metalarval Black Redhorse

Juvenile Black Redhorse

GREATER REDHORSE (Moxostoma valenciennesi) ONTOGENETIC DEVELOPMENT