Successful reproduction is critical to the persistence of at-risk species; however, reproductive characteristics are understudied in many wild species. New Zealand’s endemic tuatara (Sphenodon punctatus), the sole surviving member of the reptile order Rhynchocephalia, is restricted to 10% of its historic range. To complement ongoing conservation efforts, we collected and characterized mature sperm from male tuatara for the first time. Semen collected both during mating and from urine after courting contained motile sperm and had the potential for a very high percentage of viable sperm cells (98%). Scanning electron microscopy revealed a filiform sperm cell with distinct divisions: head, midpiece, tail, and reduced end piece. Finally, our initial curvilinear velocity estimates for tuatara sperm are 2–4 times faster than any previously studied reptile. Further work is needed to examine these trends at a larger scale; however, this research provides valuable information regarding reproduction in this basal reptile.

28Aim: This paper aims to inform our knowledge of common baby's breath's (Gypsophila 29 paniculata) current population structure and invasion status using a combination of 30 contemporary genetic methods and historical herbarium data. 31 Taxon: Gypsophila paniculata (Angiosperms: Eudicot, Caryophyllaceae) 32 Location: Samples were collected from seven locations spanning a portion of the plant's North 33 American range: Washington, North Dakota, Minnesota, and Michigan, United States. 34 Methods: To analyze contemporary population structure, individuals of G. paniculata from 7 35 distinct sampling locations were collected and genotyped at 14 microsatellite loci. Population 36 structure was inferred using both Bayesian and multivariate methods. To investigate G. 37 paniculata's invasion status, public herbarium databases were searched for mention of the 38 species. Records were combined, resulting in a database of 307 herbarium collections dating 39 from the late 1800's to current day. Using this database, invasion curves were created at different 40 geospatial scales. 41 Results: Results of genetic analyses suggest the presence of at least two genetic clusters 42 spanning our seven sampling locations. Sampling locations in Washington, North Dakota, 43 Minnesota, and northwestern Michigan form one genetic cluster, distinct from our two more 44 southern sampling locations in Michigan, which form a second cluster with increased relative 45 genetic diversity. Invasion curves created for these two clusters show different time periods of 46 invasion. An invasion curve created for North America suggests G. paniculata's range may still 47 be expanding. 48 Main conclusions: Gypsophila paniculata has likely undergone at least two distinct invasions in 49 North America, and its range may still be expanding. Restricted genetic diversity seen across a 50 wide geographic area could be a signature of limited seed distributors present during the early 51 period of this garden ornamental's invasion.52

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The morphological characteristics that impact feeding ecology in ectotherms, particularly reptiles, are poorly understood. We used morphometric measures and stable isotope analysis (carbon-13 and nitrogen-15) to assess the link between diet and functional morphology in an island population of an evolutionarily unique reptile, the tuatara (Sphenodon punctatus). First, we established a significant positive correlation between overall body size, gape size, and fat store in tuatara (n=56). Next, we describe the relationship between stable isotope profiles created from whole blood and nail trim samples and demonstrate that nail trims offer a low-impact method of creating a long-term dietary profile in ectotherms. We used nitrogen-15 values to assess trophic level in the population and found that tuatara on Takapourewa forage across multiple trophic levels. Finally, we found a significant relationship between gape size and carbon-13 (linear regression: P<0.001), with tuatara with large gapes showing dietary profiles that suggest a higher intake of marine (seabird) prey. However, whether body size or gape size is the primary adaptive characteristic allowing for more optimal foraging is yet unknown. This article has an associated First Person interview with the first author of the paper.

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Invasive species provide an opportune system to investigate how populations respond to new environments. While the impacts of invasive species increase annually, gaps in our understanding of how these species adapt to introduced areas remain. Using the perennial forb Gypsophila paniculata, we investigated how invasive species respond to different environments.

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Invasive species provide an opportune system to investigate how populations respond to new environments. Baby's breath (Gypsophila paniculata) was introduced to North America in the 1800s and has since spread throughout the United States and western Canada. We used an RNA‐seq approach to explore how molecular processes contribute to the success of invasive populations with similar genetic backgrounds across distinct habitats. Transcription profiles were constructed from seedlings collected from a sand dune ecosystem in Petoskey, MI (PSMI), and a sagebrush ecosystem in Chelan, WA (CHWA). We assessed differential gene expression and identified SNPs within differentially expressed genes. We identified 1,146 differentially expressed transcripts across all sampled tissues between the two populations. GO processes enriched in PSMI were associated with nutrient starvation, while enriched processes in CHWA were associated with abiotic stress. Only 7.4% of the differentially expressed transcripts contained SNPs differing in allele frequencies of at least 0.5 between populations. Common garden studies found the two populations differed in germination rate and seedling emergence success. Our results suggest the success of G. paniculata in these two environments is likely due to plasticity in specific molecular processes responding to different environmental conditions, although some genetic divergence may be contributing to these differences.