Meeting Abstract
P2.101 Saturday, Jan. 5 A comparison of larval and post-metamorphic growth and development between island and mainland populations of Fowler\’s toad BARRILE, G.M.**; BOWER, C.D.; DOWNS, L.K.; KLINGER, J.M.; MOORE, J.T.; KLINGER, T.S.; HRANITZ, J.M.; Bloomsburg University, Bloomsburg gmb98296@huskies.bloomu.edu
Previous research documents island dwarfism in Fowler’s Toad, Anaxyrus (formerly Bufo) fowleri, persists on Assateague Island for at least 22 years. Because of the scarcity of freshwater habitats on Atlantic Coast barrier islands, only a subset of the mainland amphibian communities inhabits these islands. Life history traits often adapt to local conditions within the range of the species. In 2011, we conducted pilot studies of several life history traits, including larval and post-metamorphic growth rates. We continued these studies of life history traits of A. fowleri in 2012, conducting a common garden experiment to investigate island and mainland larval growth rates under common conditions. We monitored tadpoles for growth rate, developmental rate, size at developmental stage, time to metamorphosis, and size at metamorphosis. Island and mainland tadpoles raised primarily in June did not show differences in growth and development. However, mainland tadpoles reared primarily in July significantly differed from the island and mainland tadpoles reared in June. We believe the temperature differences between June and July influenced tadpole growth and development. Since island and mainland eggs did not differ in size after fertilization, maternal effects were not coincident with source population. Since island and mainland toadlets grow and develop similarly to metamorphosis, we conclude that environmental factors contribute strongly to the dwarf body size in island toads. Toadlet post-metamorphic body sizes support this finding because body size differences are already apparent by July of the post-metamorphic growth season. Factors in either the larval or post-metamorphic environments may be responsible for the smaller body sizes of island toads.
