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    Reptile Systematics, etc.

    2021-07-23   09:15 - 11:15

    Moderator: Mark Merchant



    1.  09:15  IN-PERSON    Is Science Weighing Lizards Down? Effects of Transmitter Size on a Small Desert Lizard (Phrynosoma mcallii). Anthony Pawlicki*, University of Arizona; Mickey Parker, Texas A&M University; Matt Goode, University of Arizona   anthonypawlicki12@gmail.com

    Potential effects of radio transmitters on lizards are seldom studied. We investigated effects of transmitter size on Flat-tailed Horned Lizard (Phrynosoma mcallii; FTHL) body condition, space use, movement, and survival. We studied FTHL in the Lower Colorado Subdivision of the Sonoran Desert near Yuma, Arizona from 2011-2014. We affixed radio transmitters, varying in size from 0.75 – 2.00 g, to lizards, and some individuals were outfitted with multiple transmitter sizes. We relocated lizards an average of three to four times per week. We radio tracked 354 individuals for a total of 7,345 fixes. We radio tracked until they either shed the transmitter during ecdysis, were predated, we replaced the transmitter, or they were removed from the study. We calculated percent body mass of transmitters by dividing the mass of the transmitter by the mass of the lizard at initial capture. We assessed body condition using linear models, and we assessed space use and movement rates using mixed effects models. We ranked all candidate models using Akaike’s Information Criterion (AIC). Results revealed that transmitter size had a significant negative effect on body condition only during the summer wet season; however, the change in body condition was negligible. Transmitter size did not influence space use, but it did have a significant negative effect on movement rates. We tested the potential effect of transmitter size on survivorship using an extended Cox proportional hazards model. Results revealed that females with large transmitters exhibited decreased survival rates.


    2.  09:30  IN-PERSON    Characterization of the McFaddin National Wildlife Refuge Snake Community. Mark Merchant*, McNeese State University; Andrew Austin, Texas A&M University; Sarah Baker, McNeese State University   mmerchant@mcneese.edu

    Coastal saltmarsh environment is one of the most imperiled habitat types in Texas. To determine best management practices for wildlife that inhabit coastal marshes, we must first document the communities that are present. Snakes are often under-sampled in these efforts due to their cryptic behavior. We surveyed a 6.72-km section of road on McFaddin National Wildlife Refuge (southeast Texas coast near the Louisiana border) from April 23 to October 21, 2020. We were particularly interested in documenting the presence of the Gulf Saltmarsh Snake (Nerodia clarkii), as this species occurs only in coastal marshes and thus is vulnerable to becoming threatened due to habitat loss. On 56 evening field trips (124 hours total search time), we documented 399 snake encounters, which included 7 species(Nerodia cyclopian(n=130), Nerodia clarkii(n=112), Agkistrodon piscivorous(n=54), Thamnophis proximus(n=38), Storeria dekayi(n=27), Lampropeltis holbrooki (n=3), Pantherophis obsoletus (n=1)).Capture times revealed strong crepuscular behavior patterns of aquatic snakes (N. cyclopian, N. clarkii, and A. piscivorous). Most N. cyclopian (72.8%) and N. clarkii (85.7%) were captured between 20 and 40 minutes after sunset, and A. piscivorous(82.9%) was shifted later, to between 30 and 90 minutes after sunset. Of 383 live snake encounters, only 3 snakes were observed before sunset. PIT tags were inserted under the skin of 216 aquatic snakes; only 13 snakes were recaptured and thus more data is needed to generate meaningful population estimates.


    3.  09:45  IN-PERSON    Inhibitory activities of n-hexane fraction of Moringa oleifera leaves(Lam.) against phospholipases isolated from Naja haje and Naja nigricollisvenoms. Akindele Adeyi*, Animal Physiology Unit, Department of Zoology, University of Ibadan; Abideen Omobayo Jimoh, Animal Physiology Unit, Department of Zoology, University of Ibadan; Babafemi Siji Ajisebiola, Department of Zoology, Osun State University,; Olubisi Esther Adeyi, Department of Biochemistry, Federal University of Agriculture; Samuel Metibemu Damilohun, Department of Biochemistry Adekunle Ajasin University,   delegenius@yahoo.com

    Phospholipases are one of the principal toxic components of snake venom inducing a wide variety of pharmacological activities after envenomation.Natural inhibitors are known to inhibit toxic effects of snake venom enzymes. In this study, ethanol crude extract of M. oleifera was partitioned using n-hexane and ethyl acetateafter which fractionation was done using column and thin layer chromatography. Subsequently,the inhibitory activities of the crude extract and sub-fractions of M. oleiferawere investigated against phospholipase enzymes isolated from Naja haje and Naja nigricollis venoms in vitroandin-silicowhile EchiTab-PLUSpolyvalent antivenom was used as the standard drug. The molecular weight of isolated N. Haje phospholipase (NH-PL) and N. nigricollisphospholipase (NN-PL)were24.11 and 35.22 kDa respectively while NH-PL enzymes had specific activity of 2.70 ?M/min/mg substrate, NN-PL activity was 2.10?M/min/mgsubstrate.Furthermore, Kmof NH-PL was 0.330 ?M with Vmaxof 0.085 ?M/mL.min while NN-PL had Vmaxof 0.198 ?M/mL.minand Kmof 0.670 ?M.M. oleiferan-hexane sub-fraction 5 (MOLH5)displayed a complete inhibition of NN-PL enzyme athigh concentrations and achieved total inhibition against NH-PL enzyme activity at all concentrations used. Molecular docking of the phytoconstituents of n-hexane sub-fraction(MOLH5) against venom phospholipase A2 showed 2-Hydrazino-8-hydroxy-4-phenylquinoline, the lead with a docking of -6.789 kcal/mol. Further in-silico studies revealed the lead as a potential drug candidate.Results indicated that the presence of natural inhibitors of phospholipases in M. oleiferan-hexane sub-fraction could assist in the development of alternative therapy in the treatment of snake envenoming.


    4.  10:00  VIRTUAL    Comprehensive phylogenetic assessments of the highly-endemic herpetofauna of Sibuyan: disentangling the history of community origins to assess conservation implications. Camila Meneses*, Department of Ecology and Evolutionary biology and Biodiversity Institute, University of Kansas; Cameron Siler, Department of Biology and Sam Noble Oklahoma Museum of Natural History, University of Oklahoma; Phillip Alviola, Institute of Biological Sciences, Animal Biology Division, University of the Philippines Los Baños; Juancho Balatibat, Department of Forest Biological Sciences College of Forestry and Natural Resources, University of the Philippines Los Baños; Juan Carlos Gonzalez, Institute of Biological Sciences, Animal Biology Division, University of the Philippines, Los Baños; Cheryl Natividad, Institute of Biological Sciences, Genetics and Molecular Biology Division, University of the Philippines Los Baños; Rafe Brown, Department of Ecology and Evolutionary Biology and Biodiversity Institute, University of Kansas   cgmeneses23@ku.edu

    Visualizinghistorical,dry land connectionsthat were once shared bymodern islands has been crucial for understanding the distribution of biodiversity in the Philippines, an archipelago in which sealevel oscillations during the Pleistocene undoubtedly influenced the assembly of regionalized floras and faunas. Sibuyan Island, separated by deep-water channels form neighboring landmasses, harborsdistinct communities of amphibians and reptiles, many species of which are island endemics. Based onafew phylogenetic studies, several biogeographic origins for Sibuyan Island endemics have been postulated. However, despite these formative works,species diversityandthebiogeographical affinitiesof the herpetofauna of Sibuyan and the surrounding islands of the Romblon Island Groupremain less well understood.We undertook this study to provide a taxonomy-free, phylogenetic perspective onevolutionary processes of herpetofaunal assemblages based onpreliminary taxonomic studies of species diversity in the region—all in the context of their evolutionary relationships to the surrounding biogeographic species pools. A species-by-species systematic approach alleviates obstacles for understanding the amalgamate biogeography of the island’s fauna, obviates further taxonomic subjectivity, and allows us to re-assess and take stock of the conservation “value” of Sibuyan’s primary protected areas (Mt. Guiting-guiting Natural Park). Our contribution emphasizes the critical importance oflong-term, repeated biodiversity survey efforts in the Philippines and application of a multifaceted approach to the collection ofindependent data streams (e.g., vouchered material,genetic information, phylogeny estimation, etc.) for understanding forest community species composition. The results of this meta-analysisemphasizethe urgent needfor acceleratingtheevaluation ofthe evolutionary history of Philippine biodiversity and integratingsuch information into conservation strategy developmentand action.


    5.  10:45  IN-PERSON    NO-SHOW: Using Genomic Data to Delimit Species Within the Cuban Green Anoles, Anolis allisoni and A. porcatus. Javier Torres*, The University of Kansas   metalofis@gmail.com


    6.  11:00  VIRTUAL    Stable isotopes confirm atypical diet of Texas horned lizards (Phrynosoma cornutum) in small towns. Rachel Alenius-Thalhuber*, Texas Christian University; Dean Williams, Texas Christian University   r.alenius@tcu.edu

    The Texas horned lizard (Phrynosoma cornutum)is considered a species of conservation concern in Texas and Oklahoma. Typically, the Texas horned lizard specializes on ants, especially large-bodied harvester ants (Pogonomyrmex spp.). It is believed that this extensive dietary specialization makes horned lizards highly vulnerable to habitat modifications which influence the availability of harvester ants. However, some populations exist in modified habitats where horned lizards exploit alternative prey items. Using stable N and C blood and prey isotopes collected in 2017 and 2018, we examined the diets of horned lizard populations in small towns in Karnes County, Texas. We found that harvester ants were not a major food source of horned lizards in these populations. Tropic position, estimated by ?15 N ratios, did not differ between study sites. However, diets, as determined by ?13 C ratios, differed between sites, and appeared to be related to habitat type. Harvester ant availability was a strong predictor of ?13 C ratios at each site, suggesting that horned lizards modify their diets in response to prey availability. These results were consistent with dissected scat collected at the same locations in 2016. Understanding the degree to which Texas horned lizards can modify their diets provides insight for the management and habitat requirements of this species.




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