. The Rio Grande cooter ( Pseudemys gorzugi ), the westernmost species of the genus Pseudemys , is a riverine turtle native to the lower Rio Grande River basin and its tributaries. Currently, P. gorzugi is under review by the US Fish and Wildlife Service for federal protection. However, very little is known about any aspect of this species' ecology and natural history, posing challenges to the assessment of its conservation status. To fill in these knowledge gaps, we studied female size at maturity, clutch size and mean egg size, correlation between reproductive output and female size, and reproductive seasonality of P. gorzugi from mid-May to mid-August 2018. We captured P. gorzugi on the Black River, New Mexico, using traditional hoop net traps and snorkeling. Of 155 females, 28 contained oviductal follicles and 16 contained shelled eggs. We observed a high proportion of gravid females at the end of May through mid-June, although the egg development cycle may extend into August. Our findings allow for a better understanding of this poorly studied species. Knowledge on seasonality of egg development and deposition can aid management planners in determining appropriate times for implementing protection for nesting females and nesting sites.
Using 8 polymorphic microsatellite loci, we explored genetic variability in Texas spiny softshell turtles ( Apalone spinifera emoryi ) in the region of Big Bend National Park (BBNP) and the Lower Rio Grande Valley (LRGV), which are located in western and southern regions, respectively, of the distribution of the subspecies in Texas. The presence of multiple anthropogenic stressors, such as river flow alterations, human population expansion, and direct harvest, motivated us to evaluate whether genetic consequences of these stressors have become apparent in this species. A low but significant level of genetic differentiation was detectable between these 2 regions. There was also detectable isolation by distance among the turtles in LRGV but not among turtles in BBNP, possibly because the LRGV localities were discontinuous ponds, whereas the BBNP localities were continuously joined stretches of the Rio Grande. We detected no evidence of a recent population bottleneck in BBNP or the LRGV. However, turtles are generally long-lived and, because harvest activity peaked in the 1990s, it is likely that detecting harvest-related changes would be challenging. Continuous long-term sampling is necessary to evaluate the genetic consequences of anthropogenic pressures.