BIOL 1070 Lecture Notes - Fish Gill, Zebra Mussel, Glochidium
Document Summary
Biodiversity is the variety of genes, species and ecosystems. Shaped by billions of years of evolutionary history of interaction between environments and life forms (natural phenomenon, other species, etc. ) Human activity can have lasting impacts at large scales that are difficult to predict. What factors contribute to the threats to native freshwater mussel biodiversity in the great lakes region: mass propagation of mussels, pollution, human impacts, invasive species, pollution, overfishing, temperature fluctuation. Bivalves develop in 3 ways (ontogenic variation; not all freshwater mussels develop in the same way) By passing early development as a parasitic stage on a host (unionids) By producing veliger larvae ( in dreissena polymorpha) By releasing fully developed young mussels (rare) Glochidia which attach to a fish gills by clamping down onto the finger-like gill extensions, suck nutrients out of the blood of the fish; eventually leave the fish and grow till the become a full sized adult) Sometimes release a few million of these glochidia.
