Aspects of ecology of the threatened ringed sawback turtle, Graptemys oculifera

The ringed sawback turtle, Graptemys oculifem, is endemic to the Pearl River system of Louisiana and Mississippi in southern USA. In 1986 the species was placed on the U.S. Federal List of Endangered and Threatened Species with status designation of 'threatened'. Existing museum specimens were examined to determine geographic distribution, food, growth and reproduction. Caddisflies, dipteran flies, mayflies, beetles and plant material were the most important food. Many stomachs contained small pieces of wood, suggesting that fallen tree trunks were a "grazing" substrate. Males ranged from 3.2-8.6 cm plastron length, and attained sexual maturity during the third or fourth year at lengths of about 6.0-7.0 cm. Adult males experienced recrudescence of testes, with maximum testis lengths during August and September indicating the probable time of spermatogenesis. Females ranged from 3.3-18.9 cm plastron length, and appeared to attain sexual maturity during the seventh or eighth year at lengths greater than 10.0 cm. The data suggested that ovulation occurs from May through July, nesting during June and ,July, and hatching at least during August. Clutch size appeared to be just two or three eggs.