BISC 204 Lecture Notes - Lecture 19: Viviparity, Spatial Ecology, Species Richness
12 Dec 2017
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Extinction risk and spatial ecology of sharks and rays: What are characteristics of the class chondricthyans: vertebrates made of cartilage, shed their teeth, paired fins, skin is dermal denticles, take in oxygen through gills. What ecological characteristics of marine species are thought to buffer them from extinction risk: depth refuges, larger range sizes. Why is it thought that marine species are less likely to go extinct: it will not be profitable to fish for a species if it is not abundant, less human history/impacts in the ocean. Vulnerability of a species to extinction = ____intrinsic___ characteristics + Give an example of an intrinsic characteristic: biological characteristics. Body size, larger body = more risk of extinction. Geographic range size = smaller range, if all in that area get wiped out, theres no other area for them. Life history = longer age of maturity, gestation, less litter size. Give an example of an extrinsic threatening pressure: over fishing.
