Abstract

The oxygen consumption rates and the critical partial pressure of oxygen (P_c) at which each species begins to conform their oxygen consumption rate to decreasing environmental oxygen tensions were determined for juvenile Procambarus clarkii and P. zonangulus. P. clarkii had a higher overall oxygen consumption rate (7.63 ± 0.6 (SEM) pmol O₂/(s*mg fresh weight)) than P. zonangulus (4.87 ± 0.35 (SEM) pmol O₂/(s*mg fresh weight)) at resting conditions. Both species regulated oxygen consumption rates to low oxygen levels, however, P. zonangulus was able to regulate normal oxygen consumption rates to lower oxygen levels (2.26 ± 0.27(SEM) kPa) than P. clarkii (4.4 ± 0.28(SEM) kPa). These physiological differences in metabolic rates and P_c which allow each species to exploit their natural habitats, may provide for adaptive advantages in areas where these species occur sympatrically. The ability to regulate oxygen consumption to lower environmental oxygen tensions may increase the survival and subsequent abundance of P. zonangulus. However, at normoxic environmental oxygen tensions the high fecundity of P. clarkii may lead to an increased abundance of juvenile P. clarkii relative to the less fecund P. zonangulus.

Supplemental Documents

• There are no supplementary documents for this article

Cited By

Citations: