Reproductive Energetics of the African Reed Frogs, Hyperolius viridiflavus and Hyperolius marmoratus

We investigated the reproductive energetics of two reed frogs, Hyperolius viridiflavus ommatostictus and Hyperolius marmoratus taeniatus. Rates of CO₂ release of calling male H. viridiflavus ommatostictus reached values of 0.28-1.05 mL/g · h equivalent to an O₂ consumption of 038-1.44 mL O₂/g · h. Mean estimated O₂ consumption was 1.40 mL/g · h at an average call rate of 5,400 calls/h. The estimated net cost of calling was 33J/h for a 1.5·g male. Lactate levels were higher after calling than after resting, but this was due to higher lactate concentrations in the limbs than in the rest of the body containing the trunk muscles used for calling. Thus, anaerobic metabolism does not contribute significantly to calling energetics. Assimilation efficiencies of juvenile H. marmoratus taeniatus and adult males and females of both species were 81.4% -87. 7%. The energy content of an average clutch was 3.73 kJ and 2.84 kJ for H. viridiflavus ommatostictus and H. marmoratus taeniatus, respectively. Net conversion efficiencies of females of both species measured directly as the actual proportion of energy invested in eggs were about 29% and are the first measurements of this kind in amphibians. Whole-body lipid content decreased significantly over the course of a simulated breeding season in male but not in female H. marmoratus taeniatus, suggesting that males may have difficulties replenishing fat stores while engaging in reproductive activity even under ad lib. feeding conditions.