Biomass values for individual turtle species are as high as 586 kg/ha. Typical values are at least an order of magnitude greater than those typical of endotherms, but comparable to ectotherms with aquatic niches. Herbivorous turtle species tend to have higher biomasses than omnivorous or carnivorous species, but the differences are not statistically significant. Semiaquatic species typically have the lowest biomasses. Islands, ponds, and springs harbor species with the highest biomasses. Annual production estimates for two turtle species (three populations) are 1.4 to 14.9 and 6 kg/ha/yr, and are similar to estimates available for most other vertebrate groups except fishes (maximum, 528 kg/ha/yr).