Meeting Abstract
P3.87 Wednesday, Jan. 6 Visual phases of egg development in Malayan box turtle (Cuora amboinensis) as observed with ultrasound technology HAYES, T. N.*; KALB, H. J.; Georgia Southern University, Statesboro GA hjkalb@gmail.com
Little information is currently known about reproduction in Malayan box turtles in their native environment. In this presentation we will describe three visual phases that can be observed with ultrasound technology of oviducal eggs from ovulation to oviposition. The development of ovarian follicles and oviducal eggs were monitored using an Aloka ultrasound. Information was collected on the number and appearance of oviducal eggs. Newly ovulated eggs (phase 1) have bright white (echoic) yolks with a crisp white shell and more than 50% of the albumin layer appears a solid black (anechoic). During phase 2, less than 50% of the albumin is clear but the yolk is still observable. In phase 3, it is no longer possible to visualize the yolk. Since ultrasound exams were conducted on an irregular schedule, we don’t have good data as to exactly how long each phase lasts. On ten occasions during this study period we were able to calculate an approximate gestation length (the nesting date minus the date an oviducal egg was first observed in phase 1). Based on that information, then phase 1 was observed to last 5.7 ±3.5% (2.3-11.8%), phase 2 was 3.6 ±8.2% (0-26%), and phase 3 was 64.9 ±16.5% (32.6-91.3%) of the observed gestation periods. Neither phase 1 or 2 were observed for more than 6 days, while phase 3 was observed lasting from 6 to 103 days. It appears that changes in the duration of phase 3 are responsible for changes in the total gestation length. Information was collected from 13 females who produced 36 eggs, but similar trends have been observed during prior research. There was only 1 instance in which an egg appeared to regress to an earlier phase. These visual phases should be useful to researchers in both captive and wild populations who are trying to predict when females will nest or to track individual clutches.
