Proximate Causes of Alternative Reproductive Tactics in Blue Ridge Two-Lined Salamanders (Eurycea cf. wilderae)

Alternative reproductive tactics (ARTs) refer to discrete variation in reproductive behavior between members of a sex and within a species. ARTs are present in Blue Ridge two-lined salamanders (Eurcyea cf. wilderae) in the form of male polymorphism. Two male morphs exist: “searching” males and “guarding” males. Each phenotype has a unique reproductive ecology and associated discrete morphological differences. Another trait that shows discrete variation in E. cf. wilderae is the larval period, which may be one or two years in length. This thesis explores the proximate causes of ARTs in a population of E. cf. wilderae from the Blue Ridge of North Carolina. The first chapter of this thesis surveys for a genetic cause for these ARTs. In this chapter, I use genomic data to evaluate population structure, identify sex-linked and ART-linked genetic markers, and estimate effective population size and kinship. The results suggest that E. cf. wilderae follow an XY sex determination system wherein alternative haplotypes of the Y chromosome determine male ARTs. The effective population size was found to be consistent with estimates from other studies on closely related taxa and the kinship coefficients within the sample were found to be low. The second chapter of this thesis assesses the relationship between ARTs and the length of the larval period, another axis of discrete life history variation in E. cf. wilderae. In this chapter, I use the ART-specific genetic markers identified in the first chapter to identify the reproductive phenotypes of 200 larvae belonging to two age classes and calculate the relative frequencies of phenotypes within the population. The results suggest no relationship between ARTs and larval period. However, I found an even sex ratio and that searching males are almost twice as abundant as guarding males in the population. Overall, this thesis not only contributes to the body of knowledge on genetically determined ARTs and the evolutionary ecology of E. cf. wilderae by: 1) identifying an XY sex determination system; 2) identifying that ARTs are linked to alternative Y chromosome haplotypes; and 3) demonstrating that larval period is not associated with ARTs; but also addresses broader topics such as: 1) the causes of alternative phenotypes with discrete life history differences; 2) the genomic bases of polymorphism and sex determination in species; and 3) the relationship between genotype, phenotype, and environmental factors

Citizen science and online data: Opportunities and challenges for snake ecology and action against snakebite

The secretive behavior and life history of snakes makes studying their biology, distribution, and the epidemiology of venomous snakebite challenging. One of the most useful, most versatile, and easiest to collect types of biological data are photographs, particularly those that are connected with geographic location and date-time metadata. Photos verify occurrence records, provide data on phenotypes and ecology, and are often used to illustrate new species descriptions, field guides and identification keys, as well as in training humans and computer vision algorithms to identify snakes. We scoured eleven online and two offline sources of snake photos in an attempt to collect as many photos of as many snake species as possible, and attempt to explain some of the inter-species variation in photograph quantity among global regions and taxonomic groups, and with regard to medical importance, human population density, and range size. We collected a total of 725,565 photos—between 1 and 48,696 photos of 3098 of the world's 3879 snake species (79.9%), leaving 781 “most wanted” species with no photos (20.1% of all currently-described species as of the December 2020 release of The Reptile Database). We provide a list of most wanted species sortable by family, continent, authority, and medical importance, and encourage snake photographers worldwide to submit photos and associated metadata, particularly of “missing” species, to the most permanent and useful online archives: The Reptile Database, iNaturalist, and HerpMapper.ISSN:2590-171

On the taxonomy and systematics of the recently described Lycodon deccanensis Ganesh, Deuti, Punith, Achyuthan, Mallik, Adhikari, Vogel, 2020 (Serpentes, Colubridae) from India

Lycodon deccanensis Ganesh, Deuti, Punith, Achyuthan, Mallik, Adhikari, Vogel, 2020 was recently described from the Mysore plateau of Karnataka based solely on morphology but lacking in-depth descriptions and comparisons. A scrutiny of the description reveals that the type series, of two specimens, comprise specimens of two different species along with discrepancies throughout the paper. Surveys conducted near the type locality of the species led to the discovery of additional specimens, which allow us to provide an elaborate description of the species and present data on its phylogenetic relationship with members of the genus and comments on the systematics of Lycodon of India. Results from molecular phylogenetics suggest that Lycodon deccanensis is a member of the L. aulicus clade based on molecular data for mitochondrial cytochrome b gene and shows an un-corrected p-distance (sequence divergence) of 14–17% from other members of the Lycodon aulicus clade