Session 13: ASIH Stoye General Herpetology IRoom: Ballroom 111A2022-07-29 08:15 - 09:15 |
| Moderator: Sean Reilly |
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1. 08:15 Integrative Approach to Determine Species Boundaries of the Sri Lankan TreefrogsPseudophilautus popularis and Pseudophilautus regius. Himidu Pitigala_Arachchilage*, Rajarata University of Sri Lanka; Nayana Wijayathilake, University of Sri Jayawardanapura; Kanishka Ukuwela, Rajarata University of Sri Lanka hpitiga@okstate.edu
Accurate species identification is the first step in developing conservation action plans. In Sri Lanka, many frogs in the genus Pseudophilautus(Rhacophoridae) have been categorized as threatened due to habitat loss. Pseudophilautus popularis, the most wide-spread and abundant of all congeners, is considered least threatened. However, Pseudophilautusregiusis restricted to certain parts of the dry zone of the country. There have recently been concerns about whether P. popularis and P. regius are in fact different species, due to the lack of morphological differences. Thus, we employed an integrative approach to evaluate the evidence that these two groups are distinct species. We collected morphological and acoustic data across four geographically distinct locations where they are known to occur naturally, including their type localities. Eighteen morphological features and thirty morphometric measurements were taken from each specimen, including the type specimens. The mitochondrial 16S rRNA gene was sequenced from tissue samples obtained from the specimens. The results displayed no clear distinction in morphology or male advertisement call properties between the two species. The Maximum Likelihood and Bayesian phylogenies supported the lack of reciprocal monophyly of the two species. The pairwise genetic distance between all individuals sampled was very low and ranged between 0.51-1.59%. Thus, the classification of P. popularis and P. regius as two separate species was not supported by the integrative evidence, andP. regius should be taxonomically referred to as P. popularis, emphasizing the importance of a holistic approach for species delimitation. |
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2. 08:30 Life History Aspects of the Three-lined Salamander (Eurycea guttolineata). Brittany Maldonado*, Southeastern Louisiana University; Christopher Beachy, Southeastern Louisiana University brittany.maldonado@selu.edu
For organisms with large ranges, describing life history from only a small area may underrepresent existing variation. The Three-lined Salamander (Eurycea guttolineata) is found in forested wetlands, streams, and seepages throughout the southeastern United States. Accounts of larval period duration, size of larvae, timing of metamorphosis, and other life history aspects for this species are most heavily described for populations in the southern Appalachian Mountains. Anecdotal descriptions exist for Louisiana, but a detailed year-long study was warranted to examine possible variation in life history aspects. I sampled at two sites in southeastern Louisiana intensively throughout an entire year with a total of 24 site visits. I used both active (searching natural refugia, using dip nets) and passive (leaf litter bags, cover boards) techniques to capture individuals. I measured each individual, noted life stage, and noted reproductive condition if possible. I found that populations in southeast Louisiana had a larval period of 4-6 months without evidence of overwintering. Metamorphosis occurred from April to June, but likely continues into early fall and size at metamorphosis ranged from 21-25 mm snout-girdle length (SGL). Knowing more about life history variation within a species provides baseline data that can inform management, conservation, and ecosystem function in a rapidly changing landscape. |
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3. 08:45 Geographic Variation in the Larval Development and Skeletal Remodeling Sequence of the Southern Two-lined Salamander. Claire Crookston*, Southeastern Louisiana University claire.crookston@selu.edu
The larvae of the Southern Two-lined salamander inhabit low-order streams with dense, overhanging canopies providing allochthonous material to the stream ecosystem. This source of nutrients becomes assimilated into the biomass of aquatic invertebrates and inevitably, the salamanders that prey upon them. Dietary phosphorus and calcium are taken up into bone during larval development and even more so at metamorphic climax when remodeling is at its peak. Larvae were collected from four localities in Louisiana and Mississippi with two being considered sterile (low streambed coverage of leaf litter) and two being productive (high area coverage); specimens and environmental data were collected at each site in the Fall, Spring and Summer seasons. Larvae were cleared and stained to visualize the skeleton for use in the creation of a remodeling and ossification sequence. These larvae can fall into up to three distinct size-age classes that can delineate between post hatching, mid-larval and pre-metamorphic periods of development. Preliminary findings show unusual relationships between size (age) and ossification of structures such as the urohyal (os thyroideum) and appendicular skeleton (long bones and digits). Analysis of the environmental data shows minute differences in concentrations of calcium ions, ammonia, nitrate, and pH values between sites and across seasons that may be associated with human activity and streambed geology. Developmental data collection needs to be completed before comparisons are made to the environmental data. These initial findings give further insight into intrapopulational variation of the developing Plethodontid skeleton and how detrital ecosystems can produce bottom-up effects. |
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4. 09:00 Discussion |