Estimates of the number of glochidia produced by clams (Anodonta grandis simpsoniana Lea), attaching to yellow perch (Perca flavescens), and surviving to various ages in Narrow Lake, Alberta

Abstract

Between May 1986 and March 1989, the density, breeding cycle, and glochidia production of the unionid clam Anodonta grandis simpsoniana, and the population size and intensity of glochidia infestation of yellow perch, Perca flavescens, were evaluated in Narrow Lake, Alberta. The total number of glochidia produced was compared with the number of glochidia infesting yellow perch, and clam recruitment to age 2 and adulthood was estimated. Clams carried eggs and glochidia between July and, dependent on the prevailing water temperature, May or June of the following year. A total of 2.9 × 106 clams 2 years and older, of which approximately 50% were mature, produced 38.1 × 1012 glochidia in 1987. Of these, 2.6 × 106 (0.007%) glochidia attached to perch, predominantly (>92%) to 1- and 2-year-old fish. Once attached to perch, glochidia had a relatively high survival: 27% to 2 years of age and 9–18% to maturity. These results suggest that the parasitic phase in the life cycle of unionids is most critical.

Variation in fecundity and other reproductive traits in freshwater mussels

“…In Margaritifera margaritifera, an average of 64% of females reproduces in a given year with the remainder of females in a resting stage (Bauer, 1987). For North American unionids, a number of studies reported high female participation in reproduction (>85% of females reproducing in a given year) (Yokely, 1972;Trdan, 1981;Jansen & Hanson, 1991;Bruenderman & Neves, 1993;Woody & Holland-Bartels, 1993;Haggerty & Garner, 2000), whereas in others, the percentage of gravid females during the peak brooding period ranged from 64 to 75% (Yeager & Neves, 1986;Haggerty et al, 1995;Garner et al, 1999). It is unclear whether the low numbers found in these latter studies are indicative of lower female participation in reproduction, or simply a result of a protracted brooding period with low brooding synchrony among individuals.…”

Assessment of biomarkers for contaminants of emerging concern on aquatic organisms downstream of a municipal wastewater discharge

“…A well-studied population in Narrow Lake (near source of mussels for this study) of this species was assumed to be hermaphroditic by Jansen and Hanson (1991) based on the proportions of gravid specimens in various months and years in the population. A larger sample size of non-gravid mussels would have been preferred in the present study to confirm whether the changes observed in the levels of Vtg-like protein reflect exposure to CECs with estrogenic activity in wastewater.…”

Non‐annual external annuli in the freshwater mussels Anodonta grandis grandis and Lampsilis radiata siliquoidea*

“…Coker et al, 1922;Sebastyen, 1942;Crowley, 1957;Negus, 1966;Heard, 1975;Coon, Ekblad & Trygstad, 1977;Haukioja & Hakala, 1978;McCuaig & Green, 1983;Mitchell, 1984;Hinch, Bailey & Green, 1986;Bauer, 1987;Hanson, Mackay & Prepas, 1988;Jansen & Hanson, 1990;Heller, 1990;Huebner, Malley & Donkersloot, 1990). The assumption that external annuli are laid down yearly is only rarely checked, and recent tests yield equivocal results.…”