The effects of UVB lighting on growth in captive juvenile diamondback terrapins (Malaclemys terrapin)

Conservation efforts for diamondback terrapins (Malaclemys terrapin), considered a vulnerable species, include head-start programs in which juvenile terrapins are raised in captivity until they are large enough to be released safely into the wild. As part of these efforts, we have been investigating various aspects of terrapin husbandry to help develop optimal conditions to raise terrapins in the laboratory. In this study we examined the effects of UVB lighting, which has been linked to the promotion of shell growth through vitamin D₃ synthesis. Our results indicate no significant difference in mass or carapace length between terrapins exposed to UVB lighting and the control group, although we noted three terrapins from the blocked-UVB group and one terrapin in the UV group exhibited abnormal carapace scutes. Our findings that while UVB lighting may have significant effects on growth, these effects may not be seen early on. Further studies will be needed to determine whether UVB exposure, early in life, has effects on growth in older terrapins.