Hove, M., D. Heath, R. Benjamin, M. Endris, R. Kenyon, and J. Kurth. 2002. Brooding behaviors and hosts of Quadrula fragosa and other Amblemines. St. Croix River Research Rendezvous. October 15, 2002, Marine on St. Croix, Minnesota.
 
 

The federally endangered winged mapleleaf (Quadrula fragosa) once ranged throughout the upper Mississippi River watershed, and is now thought to occur only in the St. Croix River, bordering Wisconsin and Minnesota, and possibly in the Ouachita River, Arkansas.

Objectives of this study include describing the brooding period and reproductive behavior, and determining suitable glochidial hosts.  We used SCUBA to sample nine species of amblemines biweekly from spring through fall in 1997-01.  Unlike most amblemines, which brood glochidia during spring and summer, winged mapleleaf brood their young during a relatively short period in September and October.  Demibranchs of gravid winged mapleleaf were usually only slightly swollen making non-lethal gravidity determinations difficult.  Consistent with other amblemines, all four demibranchs served as marsupia.  White, thin conglutinates released were roughly 5 mm wide by 10 mm long and tapered at both ends.  A surprising behavior exhibited by brooding and some non-brooding individuals was the presence of a swollen excurrent siphon.  The siphon protruded approximately 10 mm from the shell margin, had black-ridged crenulations overlaying the gray mantle.

Seventy-five host suitability trials (53 species tested) were conducted.  Glochidia grew while attached to yellow, black, and brown bullheads, and channel and flathead catfish. We collected juvenile winged mapleleaf from channel catfish. A variety of Ictalurids serve as hosts for other amblemines.

In 2003 we will describe environmental variables surrounding the winged mapleleaf brooding period, conduct additional host suitability tests, and attempt to collect fishes naturally infested with winged mapleleaf glochidia.
 
 

[ Mark Hove's UMN F&W Page | Dept. of Fish., Wild., & Cons. Biol. Home Page | University of Minnesota Home Page ]

Copyright: 1998-2002 by the Regents of the University of Minnesota, Department of Fisheries, Wildlife, and Conservation Biology. All rights reserved. Images may be reproduced for non-commercial, educational purposes. Original content by Mark Hove. Please contact me if you would like to use any material and read my use policy. This page was supported in part by: Minnesota Department of Natural Resources, National Park Service, U.S. Fish and Wildlife Service, and University of Minnesota. The University of Minnesota is an equal opportunity educator and employer. The views and opinions expressed in this page are strictly those of the page author. The contents of this page have not been reviewed or approved by the University of Minnesota. Thanks for dropping by!

Last modified on April 7, 2002
Please submit web page suggestions to Mark.Hove@fw.umn.edu