Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Polish Journal of Ecology

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: freshwater mussels

Sortuj według:

Ogranicz wyniki do:

Shells of Unio tumidus (Bivalvia, Unionidae) from an archeological site and contemporary population inhabiting the same lake

Ożgo M., Bogucki Z., Nowakowska M.

Polish Journal of Ecology

2012

Vol. 60, nr 4

839--844

Mollusc shells from archaeological excavations are often well preserved and allow for species identification and measurements. Large shell assemblages can provide information for environmental reconstruction and investigation of anthropogenic impacts. In this study we compare freshwater mussel shells from a shell midden excavated on a lake island in northern Poland, dated 2,700–2,600 BP, with contemporary populations from that lake. No changes in species composition occurred, with only Unio tumidus and Anodonta sp. present in the prehistoric sample, and Unio tumidus and Anodonta anatina in the contemporary one. In both the archaeological and contemporary samples, shells of Unio tumidus were relatively small (mean shell length 49.3 ± 5.2 mm, max 64 mm, and 46.0 ±5.9 mm, max 61 mm, respectively). However, the values of all measured characteristics (length, height, mass, and thickness) were significantly lower in the contemporary compared to prehistoric shells. In modern times, in the region of the study largescale forest clearing and conversion of land into agricultural areas occurred; presently areas of intensive agriculture directly adjoin the lake. Dwarfing of the shells likely results from anthropogenic deterioration of mussel habitat.

The importance of peat excavation water bodies for biodiversity and conservation : a case of three Unionidae (Bivalvia) mussel species

Ożgo M., Abraszewska A.

Polish Journal of Ecology

2009

Vol. 57, nr 4

793-798

This paper presents populations of Anodonta cygnaea (L.), Anodonta anatina (L.) and Unio pictorum (L.) inhabiting an artificial pond (area 0.3 ha, depth 4 m) formed at a peat excavation site 13 years prior to the collection of the data. The mussels probably colonized the pond as glochidia attached to host fish introduced for angling or migrating with flood waters. The mussel populations were characterized by high densities, high average and maximum shell lengths and high proportions of young individuals. Our study shows that man-made ponds can become favorable habitats for freshwater mussels, and that relatively short time is needed to establish their viable populations. Active conservation of unionid mussels in man-made habitats may require human help at the dispersal stage.