Shell morphology, growth and longevity of Unio tumidus (Bivalvia: Unionidae) from an archaeological site and contemporary population inhabiting the Oder estuary

Abstract Mussel shells are often found in archaeological excavations and can provide information useful for ecological reconstruction assessment of anthropogenic impact on waters. In this study, two sample groups swollen river mussel ( Unio tumidus ) which occurred during the Early Middle Ages (EMS) currently (MS) Oder estuary (Baltic basin) were compared. Allometric shell growth, morphological characteristics (length, width, height thickness), age structure growth mussels analysed using von Bertalanffy equation. All three types allometric (isometry both positive negative allometry) observed studied mussels. groups, typical values length, thickness recorded. However, higher these recorded EMS group. Moreover, group, compared with MS group U. , was characterised by a longevity (12 10 years, respectively) asymmetric length L ∞ (93.09 83.23 mm, respectively). Both had similar rate k ). Larger sizes probably caused differential preservation and/or recovery, resulted from differences structure, especially mortality amongst individuals older than 6 years