The freshwater pearl mussel (Margaritifera margaritifera) is a highly specialized and sensitive freshwater
bivalve, whose survival in the juvenile phase is indicative of high quality habitats. This contribution investigates
the use of juvenile freshwater pearl mussels as bioindicators, considering the influence of mussel
stock and study stream conditions on juvenile performance, as described by survival and growth rates.
A standardized cross experiment was carried out investigating juvenile performance in four different
pearl mussel stocks originating from the Rhine, Danube and Elbe drainages, representing distinct genetic
conservation units. The juveniles were exposed in five study streams which were selected to integrate
pearl mussel streams with different water qualities and recruitment status of the mussel population. Per
study stream, five standard mesh cages containing an equal number of 20 (10 × 2) juvenile pearl mussels
per stock in separate chambers were installed. Survival and growth rates of juveniles were checked
after three months (i.e. before their first winter) and after nine months (i.e. after their first winter). Mussel
stock and study stream conditions significantly influenced juvenile performance. Growth rates were
determined by study stream conditions and increased with stream water temperature, organic carbon
and C/N ratios. Survival rates varied stock-specifically, indicating different levels of local adaptation to
their native streams. Due to the detection of stream-specific differences in juvenile performance,freshwater
pearl mussels appear suitable as bioindicators. However, a careful consideration of stock-specificity is
necessary to avoid false interpretation of bioindication results. The comparison of stock-specific survival
in native versus non-native streams implicates that exposure of juveniles outside their native habitats is
able to increase breeding success or else serve for risk spreading in breeding programs.
The freshwater pearl mussel (Margaritifera margaritifera) is a highly specialized and sensitive freshwater
bivalve, whose survival in the juvenile phase is indicative of high quality habitats. This contribution investigates
the use of juvenile freshwater pearl mussels as bioindicators, considering the influence of mussel
stock and study stream conditions on juvenile performance, as described by survival and growth rates.
A standardized cross experiment was carried out investigating juvenile performance in four different
pearl mussel stocks originating from the Rhine, Danube and Elbe drainages, representing distinct genetic
conservation units. The juveniles were exposed in five study streams which were selected to integrate
pearl mussel streams with different water qualities and recruitment status of the mussel population. Per
study stream, five standard mesh cages containing an equal number of 20 (10 × 2) juvenile pearl mussels
per stock in separate chambers were installed. Survival and growth rates of juveniles were checked
after three months (i.e. before their first winter) and after nine months (i.e. after their first winter). Mussel
stock and study stream conditions significantly influenced juvenile performance. Growth rates were
determined by study stream conditions and increased with stream water temperature, organic carbon
and C/N ratios. Survival rates varied stock-specifically, indicating different levels of local adaptation to
their native streams. Due to the detection of stream-specific differences in juvenile performance,freshwater
pearl mussels appear suitable as bioindicators. However, a careful consideration of stock-specificity is
necessary to avoid false interpretation of bioindication results. The comparison of stock-specific survival
in native versus non-native streams implicates that exposure of juveniles outside their native habitats is
able to increase breeding success or else serve for risk spreading in breeding programs.
การแปล กรุณารอสักครู่..
