Salinity Relations of Chelydra serpentina in a Long Island Estuary

Abstract

I examined the use of saline habitats by the common snapping turtle (Chelydra serpentina) in a Long Island estuary, where salinities range from fresh water (0 ppt) to approximately 70% seawater (100% seawater = 35 ppt). Movements, blood osmotic concentration, feeding habits, and leech infestation were monitored. Salinity data and field observations of distribution offer circumstantial evidence that snapping turtles are restricted to salinities hypoosmotic to the blood plasma (308 milliosmolal). Turtles were placed in enclosures at capture sites in a saline tidal creek in an attempt to test the possibility that other factors might be important in determining range extension into saline waters