Academic Year 2014 - 2015

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    Phenotypic Plasticity in the Relative Hind-Limb Growth of Lab-Reared Anolis sagrei: Replication of Experimental Results and a Test of Perch Diameter Preference
    (2014-06) Langford, Gabriel J.; Macedonia, Joseph M.; Bessette, Christopher W.; Matey, Jennifer L.; Raboin, Brittany A.; Schiffmacher, Ashley E.; Reynolds, Brett J.
    Several observational and experimental studies have shown that perch diameter has an impact on the development of hind-limb length (HL) in Anolis species. This 'phenotypic plasticity' in relative hind-limb growth (RHG) has implications for short-term and long-term adaptation to different structural habitats. Our study is the first to replicate research in which hatchling/juvenile Anolis sagrei were reared on narrow-diameter or broad-diameter dowels in a laboratory setting. Although subjects reared on different dowel diameters did not differ significantly in RHG at 5 weeks into the experiment, results at 15 weeks revealed a significant effect of treatment but not of sex: subjects in the broad ( N = 69) treatment group exhibited significantly greater RHG than did subjects in the narrow ( N = 61) treatment group. We extended this research with a novel follow-up study: we placed our lab-reared subjects into outdoor enclosures where they had a choice of narrow- or broad-diameter dowels on which to perch. Results showed that subjects in both treatment groups chose broad-diameter dowels as perches more often than narrow-diameter dowels. We offer several potential explanations for the strong preference of our subjects for broad-diameter dowels irrespective of the dowel diameter on which they were reared.
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    Elucidating the life cycle and life history of Dero hylae (Naididae), a rare parasitic oligochaete from Florida tree frogs.
    (Journal of Parasitology, 2015-03) Andrews, Jessee M.; Childress, Jasmine N.; Iakovidis, Triantafilos J.; Langford, Gabriel J.
    Given their ubiquitous nature, it is surprising that more oligochaete annelid worms (Annelida: Clitellata) have not adopted an endoparasitic lifestyle. Exceptions, however, are the understudied members of the genus Dero (Allodero) that parasitize the ureters of tree frogs and toads. This study experimentally explores the life cycle and host specificity of Allodero hylae, the worm’s use of chemical cues in host searching, and its seasonal prevalence and abundance over a year-long collection period on the Florida Southern College campus. A total of 2,005 A. hylae was collected from the ureter, urinary bladder, or expressed urine of wild Osteopilus septentrionalis; a significant positive correlation was found between host snout–vent length and parasite intensity for female but not male hosts. Monthly prevalence of A. hylae reached a peak of 58% in April, but never dropped below 20% in any month; mean abundance peaked March–May, whereas few worms were recovered in December and January. Confirming a parasitic lifestyle, wildcollected hosts with intense infections, typically .40 worms, showed obvious dilatation of the ureter wall, and some young-of-the-year O. septentrionalis exposed to A. hylae in the laboratory were killed by the apparent rupture of the host’s ureter. The worm has a direct life cycle: worms expelled in the host’s urine are capable of locating and re-infecting other hosts within aquatic microhabitats such as bromeliad tanks, and worms can survive for weeks in a free-living environment, even undergoing a morphological change. Further, chemotaxis assays found a positive response to a tree frog attractant for worms recently removed from hosts. Overall, this study provides the first multifaceted investigation on the life history and ecology of any Allodero spp., which offers new insights into an understudied endoparasitic oligochaete.