0000000000236628
AUTHOR
Mari Saarinen-valta
Effect of substrate particle size on burrowing of the juvenile freshwater pearl mussel Margaritifera margaritifera
AbstractJuveniles of the endangered freshwater pearl mussel (FPM,Margaritifera margaritifera) live burrowed in stream substrate for the first years of their life. Fine sediments block water exchange within substrate and may cause juvenile mortality and recruitment failure. To better understand the connection between success of juvenile FPM and substrate particle size, it would be important to understand behavioural responses of FPM to varying substrate sizes at this critical life stage. We placed newly detached FPM juveniles in a 7-mm layer of sieved sand sorted into five sizes (< 120, 120–200, 200–250, 250–500 and 500–650 µm) each with 10 replicate dishes, 10 juveniles per dish, with bu…
Effect of pH, iron and aluminum on survival of early life history stages of the endangered freshwater pearl mussel, Margaritifera margaritifera
Glochidium larvae and juveniles of the endangered freshwater pearl mussel Margaritifera margaritifera may be sensitive to low pH and metal exposure, but to our knowledge, no tolerance tests have been performed. Therefore, we exposed glochidia, fish-attached glochidia, and juveniles of the pearl mussel to low pH and increased iron (Fe) and aluminum (Al) by using realistic pH (6.0–4.5), Fe (0.5–2.0 mg L−1), and Al (0.25–1.0 mg L−1) levels periodically observed in this study site. Survival of glochidia decreased with decreasing pH, increasing Fe, and increasing Al, as well as with increasing Fe + Al concentration in a 72 h exposure. All glochidia died within 24 h in pH 4.5 and Fe 2.0 mg L−1. W…