Southern and Northern Great Plains (United States) Paddlefish Stocks Within Frameworks of Acipenseriform Life History and the Metabolic Theory of Ecology

Sampling conducted in 2008–2010 on a southern Great Plains stock of paddlefish Polyodon spathula inhabiting the Neosho River, Spring River, and Grand Lake, Oklahoma, is characterized (1) in terms of the Acipenseriform life history framework outlined for the Yellowstone–Sakakawea stock of the Northern Plains and (2) in relation to the framework metabolic theory of ecology and associated latitudinal and environmental correlations with lifespan. In the Grand Lake stock, male fish typically mature at ages 6–7, and females mature at ages 8–9. The five stages of the lifespan (immature, maturing, growth and reproduction, prime reproduction, senescence to death) are compressed into a period of 15–20 years; the prime reproduction period occurs from ages 12 to 16 years for females. This lifespan compares to one of 40–50 years (and occasionally longer), and a prime reproduction period for females from ages 25 to 40 years, for the Yellowstone–Sakakawea stock. The more compressed lifespan of the Grand Lake stock and lower energy storage, as indicated by weights of gonadal fat bodies, are consistent with the framework metabolic theory of ecology. Over the course of a year, fish in Grand Lake are under a much higher metabolic demand than those in Lake Sakakawea. The distinct differences detailed between these two stocks from the southern and northern plains may exist between other paddlefish stocks, other Acipenseriform species, and other fish taxa separated by large latitudinal and climatic differences. The results have specific implications for harvest management and effects of climate change on Acipenseriform life histories and lifespan.