Notes on the reproductive ecology of the rough-footed mud turtle (Kinosternon hirtipes) in Texas, USA

Abstract

Kinosternon hirtipes is among the least-studied North American turtles and little is known concerning reproduction. In the United States, K. hirtipes occurs at < 10 sites within a single creek drainage in Presidio County, Texas where it is considered a threatened species. We investigated the reproductive ecology of one of these populations at Plata Wetland Complex in 2007. We captured nine female K. hirtipes in wire mesh traps and hoop nets baited with fish. Eggs were obtained by injecting females with oxytocin. We recovered 19 eggs from six females captured in May and June. The smallest female that produced eggs was about 7.1 years old. Mean (± 1SD) clutch size, egg length, egg width, egg mass, and clutch mass were 3.1 ± 1.4 eggs, 28.7 ± 1.4 mm, 17.5 ± 0.9, 5.3 ± 0.6 g, and 17.5 ± 0.8 g, respectively. Relative egg mass and relative clutch mass were 0.035 and 0.011, respectively. There was a significant, positive linear relationship between female carapace length (CL) and egg width. The relationship between CL and relative egg mass was negative, and approached statistical significance. Relationships between CL and clutch size, egg length, and egg mass were not significant. Reproductive attributes of K. hirtipes in Texas are similar to those reported from a population in Mexico.