Meeting Abstract

23.2  Monday, Jan. 4  Do larger females produce more fit hatchlings? Effect of female age and size on egg size and hatchling growth in the Mississippi diamondback terrapin, Malaclemys terrapin pileata COLEMAN, Andrew T*; WIBBELS, Thane; HUANG, Yu-hui; MARION, Ken; DINDO, John; Univ. of Alabama at Birmingham; Univ. of Alabama at Birmingham; Univ. of Alabama at Birmingham; Univ. of Alabama at Birmingham; Dauphin Island Sea Lab colemana@uab.edu

Throughout their range, populations of diamondback terrapins, Malaclemys terrapin , are experiencing declines from historic levels due to a number of threats. Along the Gulf Coast of Alabama, only isolated remnant aggregations exist in areas where once a large terrapin farm existed. To address the high amount of nest predation by raccoons, which represents a major threat, a head starting program was initiated at U.A.B. The ultimate goal of the head starting program is to ensure the future survival of diamondback terrapins in Alabama. However, obtaining terrapin hatchlings have offered an opportunity to further study the species’ biology, including relationships between female and hatchling physiology and fitness. In the summer of 2009, fourteen clutches for a total of 103 eggs (average of 7.4 eggs/clutch) were obtained from females that subsequently were measured, weighed, and tagged. The length, width, and mass of every egg were measured. After hatching, carapace length and width, plastron length, and mass of every hatchling were measured once a week. Each clutch was fed the same amount twice a week. The effect of female age and size on both egg size and hatchling growth was examined. Rate of hatchling growth was treated as an indicator of hatchling fitness, but other potential indicators were also evaluated. So do larger females produce more fit hatchlings? The answer to this evolutionary question has obvious conservation implications for populations facing extirpation.