• Extensive sampling and thorough taxonomic assessment of Afrotropical Rhyssinae (Hymenoptera, Ichneumonidae) reveals two new species and demonstrates the limitations of previous sampling efforts

      Hopkins, T; Roininen, H; van Noort, S; Broad, G; Kaunisto, K; Sääksjärvi, IE (Pensoft Publishers, 2019-10-07)
      Tropical forest invertebrates, such as the parasitoid wasp family Ichneumonidae, are poorly known. This work reports some of the first results of an extensive survey implemented in Kibale National Park, Uganda. A total of 456 individuals was caught of the subfamily Rhyssinae Morley, 1913, which in the Afrotropical region was previously known from only 30 specimens. Here, the six species found at the site are described and the Afrotropical Rhyssinae are reviewed. Two new species, Epirhyssa johanna Hopkins, sp. nov. and E. quagga sp. nov., are described and a key, diagnostic characters, and descriptions for all 13 known Afrotropical species are provided, including the first description of the male of Epirhyssa overlaeti Seyrig, 1937. Epirhyssa gavinbroadi Rousse & van Noort, 2014, syn. nov. is proposed to be a synonym of E. uelensis Benoit, 1951. Extensive sampling with Malaise traps gave an unprecedented sample size, and the method is recommended for other poorly known tropical areas.
    • Reduction of eyes in last-instar beetle larvae: a special observation in Trictenotomidae, based on Trictenotoma formosana Kriesche, 1919

      Telnov, D; Hu, F-S; Pollock, DA; Lin, Z-R (2019-10-03)
      Recently, Lin & Hu (2018, 2019) unraveled the biology of Trictenotoma formosana Kriesche, 1919. For the first time since Gahan (1908) there is fresh immature stages material available for Trictenotomidae.
    • Phylogenomics resolves major relationships and reveals significant diversification rate shifts in the evolution of silk moths and relatives

      Hamilton, CA; St Laurent, RA; Dexter, K; Kitching, I; Breinholt, JW; Zwick, A; Timmermans, MJTN; Barber, JR; Kawahara, AY (BioMed Central, 2019-09-18)
      Background: Silkmoths and their relatives constitute the ecologically and taxonomically diverse superfamily Bombycoidea, which includes some of the most charismatic species of Lepidoptera. Despite displaying spectacular forms and diverse ecological traits, relatively little attention has been given to understanding their evolution and drivers of their diversity. To begin to address this problem, we created a new Bombycoidea-specific Anchored Hybrid Enrichment (AHE) probe set and sampled up to 571 loci for 117 taxa across all major lineages of the Bombycoidea, with a newly developed DNA extraction protocol that allows Lepidoptera specimens to be readily sequenced from pinned natural history collections. Results: The well-supported tree was overall consistent with prior morphological and molecular studies, although some taxa were misplaced. The bombycid Arotros Schaus was formally transferred to Apatelodidae. We identified important evolutionary patterns (e.g., morphology, biogeography, and differences in speciation and extinction), and our analysis of diversification rates highlights the stark increases that exist within the Sphingidae (hawkmoths) and Saturniidae (wild silkmoths). Conclusions: Our study establishes a backbone for future evolutionary, comparative, and taxonomic studies of Bombycoidea. We postulate that the rate shifts identified are due to the well-documented bat-moth “arms race”. Our research highlights the flexibility of AHE to generate genomic data from a wide range of museum specimens, both age and preservation method, and will allow researchers to tap into the wealth of biological data residing in natural history collections around the globe.
    • Cranial osteology and molecular phylogeny of Argyrogena fasciolata (Shaw, 1802) (Colubridae: Serpentes)

      Das, S; Campbell, P; Roy, S; Mukherjee, S; Pramanick, K; Biswas, A; Raha, S; Fritz, U (Museum of Zoology, Dresden (Senckenberg Gesellschaft für Naturforschung), 2019-08-15)
      Descriptive accounts of the cranial osteology of snakes is important for systematics, functional morphology and also, to some extent, palaeontology. In the present study, we describe the skull of Argyrogena fasciolata, a south Asian colubrid snake, in detail. Bones of the snout unit of this snake are adapted for a fossorial mode of life whereas the braincase lacks any adaptations related to such an existence. We also compared its skull with other snakes belonging to sixteen other genera which together form the large clade containing Afrotropical, Palaearctic and Saharo-Arabian racers/whip snakes. The comparison shows that the cranium of A. fasciolata bears more similarity with that of Platyceps spp, differing mostly in three characteristics pertaining to premaxilla, nasal and pterygoid bones, than it does with crania of other genera. This suggests a closer relationship between those two genera. We also performed molecular phylogenetic analyses on three mitochondrial loci using Maximum Likelihood and Bayesian Inference optimality criteria. The resultant phylogenies indeed recover A. fasciolata as sister to Platyceps spp.
    • Warm Temperatures, Cool Sponges: The Effect of Increased Temperatures on the Antarctic Sponge Isodictya sp

      González-Aravena, M.; Kenny, N.J.; Osorio, M.; Font, A.; Riesgo, A.; Cárdenas, C.A. (bioRxiv, 2019-08-06)
      Although the cellular and molecular responses to exposure to relatively high temperatures (acute thermal stress or heat shock) have been studied previously, only sparse empirical evidence of how it affects cold-water species is available. As climate change becomes more pronounced in areas such as the Western Antarctic Peninsula, it has become crucial to understand the capacity of these species to respond to thermal stress. Here we use the Antarctic sponge Isodictya sp. to investigate how sessile organisms (particularly Porifera) can adjust to acute short-term heat stress, by exposing this species to 3 and 5 °C for 4 hours, corresponding to predicted temperatures under high-end 2080 IPCC-SRES scenarios. Assembling a de novo reference transcriptome (90,188 contigs, >93.7% metazoan BUSCO genes) we have begun to discern the molecular response employed by Isodictya to adjust to environmental insult. Our initial analyses suggest that TGF-β, ubiquitin and hedgehog cascades are involved, alongside other genes. However, the degree and type of response changed little from 3 to 5 °C, suggesting that even moderate rises in temperature could cause stress at the limits of this organism’s capacity. Given the importance of sponges to Antarctic ecosystems, our findings are vital for discerning the consequences of increases in Antarctic ocean temperature on these and other species.
    • Clinical Pathology of Plastic Ingestion in Marine Birds and Relationships with Blood Chemistry.

      Lavers, JL; Hutton, I; Bond, AL (American Chemical Society, 2019-07-15)
      Pollution of the environment with plastic debris is a significant and rapidly expanding threat to biodiversity due to its abundance, durability, and persistence. Current knowledge of the negative effects of debris on wildlife is largely based on consequences that are readily observed, such as entanglement or starvation. Many interactions with debris, however, result in less visible and poorly documented sublethal effects, and as a consequence, the true impact of plastic is underestimated. We investigated the sublethal effects of ingested plastic in Flesh-footed Shearwaters (Ardenna carneipes) using blood chemistry parameters as a measure of bird health. The presence of plastic had a significant negative effect on bird morphometrics and blood calcium levels and a positive relationship with the concentration of uric acid, cholesterol, and amylase. That we found blood chemistry parameters being related to plastic pollution is one of the few examples to date of the sublethal effects of marine debris and highlights that superficially healthy individuals may still experience the negative consequences of ingesting plastic debris. Moving beyond crude measures, such as reduced body mass, to physiological parameters will provide much needed insight into the nuanced and less visible effects of plastic.
    • Symbiosis, Selection, and Novelty: Freshwater Adaptation in the Unique Sponges of Lake Baikal

      Kenny, Nathan J.; Plese, Bruna; Riesgo, Ana; Itskovich, Valeria B. (Oxford Academic, 2019-06-27)
      Freshwater sponges (Spongillida) are a unique lineage of demosponges that secondarily colonized lakes and rivers and are now found ubiquitously in these ecosystems. They developed specific adaptations to freshwater systems, including the ability to survive extreme thermal ranges, long-lasting dessication, anoxia, and resistance to a variety of pollutants. Although spongillids have colonized all freshwater systems, the family Lubomirskiidae is endemic to Lake Baikal and plays a range of key roles in this ecosystem. Our work compares the genomic content and microbiome of individuals of three species of the Lubomirskiidae, providing hypotheses for how molecular evolution has allowed them to adapt to their unique environments. We have sequenced deep (>92% of the metazoan “Benchmarking Universal Single-Copy Orthologs” [BUSCO] set) transcriptomes from three species of Lubomirskiidae and a draft genome resource for Lubomirskia baikalensis. We note Baikal sponges contain unicellular algal and bacterial symbionts, as well as the dinoflagellate Gyrodinium. We investigated molecular evolution, gene duplication, and novelty in freshwater sponges compared with marine lineages. Sixty one orthogroups have consilient evidence of positive selection. Transporters (e.g., zinc transporter-2), transcription factors (aristaless-related homeobox), and structural proteins (e.g. actin-3), alongside other genes, are under strong evolutionary pressure in freshwater, with duplication driving novelty across the Spongillida, but especially in the Lubomirskiidae. This addition to knowledge of freshwater sponge genetics provides a range of tools for understanding the molecular biology and, in the future, the ecology (e.g., colonization and migration patterns) of these key species.
    • Stability in Lepidoptera names is not served by reversal to gender agreement: a response to Wiemers et al. (2018)

      van Nieukerken, EJ; Karsholt, O; Hausmann, A; Holloway, JD; Huemer, P; Kitching, IJ; Nuss, M; Pohl, GR; Rajaei, H; Rennwald, E; et al. (Pensoft Publishers, 2019-06-26)
      In a recent paper in ZooKeys, Wiemers et al. (2018) provided an updated list of European butterfly names. In this list the authors follow gender agreement for species names, when interpreted as adjectival in derivation, in contrast to the common practice among most lepidopterists. Here we comment on this aspect of the paper, and voice our concern that this reversal does not benefit the stability of Lepidoptera names and is, indeed, inimical to their stability. Modern zoological science needs the communities of taxonomists and users to agree on the names that are used to communicate information about the taxa we study and cherish. In this age, such collegiate acceptance is more important than ever, given that the number of users of scientific names has increased enormously. Agreement is particularly important when considering the numerous online databases, observation sites, Wikipedia, etc. Several global and local initiatives over the last several decades have begun to compile authoritative lists of taxonomic names to serve the community and build towards a greater stability, including Species 2000 / Catalogue of Life (Roskov et al. 2018; Roskov et al. 2019), Global Biodiversity Information Facility (GBIF Secretariat 2019) and Fauna Europaea (de Jong et al. 2014; Fauna Europaea 2017). Unfortunately, the current (and likely future) funding situation for most of these projects is poor, to say the least, and populating these databases relies heavily on a diminishing number of taxonomists, who rarely receive recognition for their work. The Fauna Europaea database, which is of special importance as Europe’s main zoological taxonomic index, has suffered particularly, being an EU-supported project that was only funded by the European Commission between 2000 and 2004. Subsequently, updating was carried out at the Zoological Museum of Amsterdam (de Jong et al. 2014), first under the umbrella of the PESI project (PESI 2011; de Jong et al. 2015), then later without funding, until the Amsterdam museum was merged with Naturalis Biodiversity Center in Leiden in 2011. Since then, the Fauna Europaea database has been run by the Museum für Naturkunde, Leibniz-Institute for Research on Evolution and Biodiversity, Berlin, Germany. Recently, however, updating has come to a stand-still, very much to the frustration both of taxonomists who wish to update their lists and of users who need an up-to-date and authoritative nomenclature. Given these circumstances, we enthusiastically applaud the initiative that several specialists of European butterflies have taken separately to publish an update for butterflies (superfamily Papilionoidea) in an open access journal, to produce a new list for the use of the scientific community (Wiemers et al. 2018).
    • A revision of the Morelloid Clade of Solanum L. (Solanaceae) in North and Central America andthe Caribbean

      Knapp, S; Barboza, GE; Bohs, L; Sarkinen, T (Pensoft Publishers, 2019-05-30)
      The Morelloid Clade, also known as the black nightshades or “Maurella” (Morella), is one of the 10 major clades within the mega-diverse genus Solanum L. The clade is most species rich in the central to southern Andes, but species occur around the tropics and subtropics, some extending well into the temperate zone. Plants of the group are herbaceous or short-lived perennials, with small white or purplish white flowers, and small juicy berries. Due to the complex morphological variation and weedy nature of these plants, coupled with the large number of published synonyms (especially for European taxa), our understanding of species limits and diversity in the Morelloid Clade has lagged behind that of other major groups in Solanum. Here we provide the second in a three-part series of revisions of the morelloid solanums treating the species occurring in North and Central America and the Caribbean (for the Old World see PhytoKeys 106, the third part will treat species of South America). Synonymy, morphological descriptions, distribution maps, and common names and uses are provided for all 18 species occurring in this region. We treat 10 of these species as native, and eight as putatively naturalised, introduced and/or invasive in the region. We provide complete descriptions with nomenclatural details, including lecto- and neotypifications, for all species. Keys to all species occurring in the whole region and for each area within it (i.e., North America, Central America and Mexico, and the islands of the Caribbean), illustrations to aid identification both in herbaria and in the field, and distribution maps are provided. Preliminary conservation assessments are provided for all species. Details of all specimens examined are provided in three Supplementary Materials files.
    • Genome-wide SNP data reveal an overestimation of species diversity in a group of hawkmoths.

      Hundsdoerfer, AK; Lee, KM; Kitching, IJ; Mutanen, M (Oxford University Press, 2019-05-29)
      The interface between populations and evolving young species continues to generate much contemporary debate in systematics depending on the species concept(s) applied but which ultimately reduces to the fundamental question of “when do nondiscrete entities become distinct,mutually exclusive evolutionary units”? Species are perceived as critical biological entities, and the discovery and naming of new species is perceived by many authors as a major research aim for assessing current biodiversity before much of it becomes extinct.However, less attention is given to determining whether these names represent valid biological entities because this is perceived as both a laborious chore and an undesirable research outcome. The charismatic spurge hawkmoths (Hyles euphorbiae complex, HEC) offer an opportunity to study this less fashionable aspect of systematics. To elucidate this intriguing systematic challenge, we analyzed over 10,000 ddRAD single nucleotide polymorphisms from 62 individuals using coalescent-based and population genomic methodology. These genome-wide data reveal a clear overestimation of (sub)species-level diversity and demonstrate that the HEC taxonomy has been seriously oversplit. We conclude that only one valid species name should be retained for the entire HEC, namely Hyles euphorbiae, and we do not recognize any formal subspecies or other taxonomic subdivisions within it. Although the adoption of genetic tools has frequently revealed morphologically cryptic diversity, the converse, taxonomic oversplitting of species, is generally (and wrongly in our opinion) accepted as rare. Furthermore, taxonomic oversplitting is most likely to have taken place in intensively studied popular and charismatic organisms such as the HEC.
    • Progress on bringing together raptor collections in Europe for contaminant research and monitoring in relation to chemicals regulation.

      Movalli, P; Duke, G; Ramello, G; Dekker, R; Vrezec, A; Shore, RF; García-Fernández, A; Wernham, C; Krone, O; Alygizakis, N; et al. (Springer-Verlag, 2019-05-27)
    • Population substructure and signals of divergent adaptive selection despite admixture in the sponge Dendrilla antarctica from shallow waters surrounding the Antarctic Peninsula

      Leiva, Carlos; Taboada, Sergi; Kenny, Nathan J.; Combosch, David; Giribet, Gonzalo; Jombart, Thibaut; Riesgo, Ana (Wiley, 2019-05-24)
      Antarctic shallow‐water invertebrates are exceptional candidates to study population genetics and evolution, because of their peculiar evolutionary history and adaptation to extreme habitats that expand and retreat with the ice sheets. Among them, sponges are one of the major components, yet population connectivity of none of their many Antarctic species has been studied. To investigate gene flow, local adaptation and resilience to near‐future changes caused by global warming, we sequenced 62 individuals of the sponge Dendrilla antarctica along the Western Antarctic Peninsula (WAP) and the South Shetlands (spanning ~900 km). We obtained information from 577 double digest restriction site‐associated DNA sequencing (ddRADseq)‐derived single nucleotide polymorphism (SNP), using RADseq techniques for the first time with shallow‐water sponges. In contrast to other studies in sponges, our 389 neutral SNPs data set showed high levels of gene flow, with a subtle substructure driven by the circulation system of the studied area. However, the 140 outlier SNPs under positive selection showed signals of population differentiation, separating the central–southern WAP from the Bransfield Strait area, indicating a divergent selection process in the study area despite panmixia. Fourteen of these outliers were annotated, being mostly involved in immune and stress responses. We suggest that the main selective pressure on D. antarctica might be the difference in the planktonic communities present in the central–southern WAP compared to the Bransfield Strait area, ultimately depending on sea‐ice control of phytoplankton blooms. Our study unveils an unexpectedly long‐distance larval dispersal exceptional in Porifera, broadening the use of genome‐wide markers within nonmodel Antarctic organisms.
    • Uncovering the sub-lethal impacts of plastic ingestion by shearwaters using fatty acid analysis.

      Puskic, PS; Lavers, JL; Adams, LR; Grünenwald, M; Hutton, I; Bond, AL (Oxford Academic, 2019-05-16)
      Marine plastic pollution is increasing exponentially, impacting an expanding number of taxa each year across all trophic levels. Of all bird groups, seabirds display the highest plastic ingestion rates and are regarded as sentinels of pollution within their foraging regions. The consumption of plastic contributes to sub-lethal impacts (i.e. morbidity, starvation) in a handful of species. Additional data on these sub-lethal effects are needed urgently to better understand the scope and severity of the plastics issue. Here we explore the application of fatty acid (FA) analysis as a novel tool to investigate sub-lethal impacts of plastic ingestion on seabird body condition and health. Using gas chromatography-mass spectrometry, we identified 37 individual FAs within the adipose, breast muscle and liver of flesh-footed (Ardenna carneipes) and short-tailed (Ardenna tenuirostris) shearwaters. We found high amounts of FA 16:0, 18:0, 20:5n3 (eicosapentaenoic acid), 22:6n3 (docosahexaenoic acid) and 18:1n9 in both species; however, the overall FA composition of the two species differed significantly. In flesh-footed shearwaters, high amounts of saturated and mono-unsaturated FAs (needed for fast and slow release energy, respectively) in the adipose and muscle tissues were related to greater bird body mass. While total FAs were not related to the amount of plastic ingested in either species, these data are a valuable contribution to the limited literature on FAs in seabirds. We encourage studies to explore other analytical tools to detect these sub-lethal impacts of plastic.
    • How has the environment shaped geographical patterns of insect body sizes? A test of hypotheses using sphingid moths.

      Beerli, N; Bärtschi, F; Kitching, IJ; Ballesteros-Mejia, L; Beck, J (Wiley, 2019-05-14)
      Aim: We mapped the geographical pattern of body sizes in sphingid moths and investigated latitudinal clines. We tested hypotheses concerning their possible environmental control, that is, effects of temperature (negative: temperature size rule or Bergmann's rule; positive: converse Bergmann rule), food availability, robustness to starvation during extreme weather and seasonality. Location: Old World and Australia/Pacific region. Methods: Body size data of 950 sphingid species were compiled and related to their distribution maps. Focusing on body length, we mapped the median and maximum size of all species occurring in 100 km grid cells. In a comparative approach, we tested the predictions from explanatory hypotheses by correlating species' size to the average environmental conditions encountered throughout their range, under univariate and multivariate models. We accounted for phylogeny by stepwise inclusion of phylogenetically informed taxonomic classifications into hierarchical random‐intercept mixed models. Results: Median body sizes showed a distinctive geographical pattern, with large species in the Middle East and the Asian tropics, and smaller species in temperate regions and the Afrotropics. Absolute latitude explained very little body size variation, but there was a latitudinal cline of maximum size. Species' median size was correlated with net primary productivity, supporting the food availability hypothesis, whereas support for other hypotheses was weak. Environmental correlations contributed much less (i.e. <10%) to explaining overall size variation than phylogeny (inclusion of which led to models explaining >70% of variability). Main conclusion: The intuitive impression of larger species in the tropics is shaped by larger size maxima. Median body sizes are only very weakly related to latitude. Most of the geographical variation in body size in sphingid moths is explained by their phylogenetic past. NPP and forest cover correlate positively with the body size, which supports the idea that food availability allowed the evolution of larger sizes.
    • Trimitomics: An efficient pipeline for mitochondrial assembly from transcriptomic reads in nonmodel species

      Plese, Bruna; Rossi, Maria Eleonora; Kenny, Nathan James; Taboada, Sergi; Koutsouveli, Vasiliki; Riesgo, Ana (Wiley, 2019-05-09)
      Mitochondrial resources are of known utility to many fields of phylogenetic, population and molecular biology. Their combination of faster and slower‐evolving regions and high copy number enables them to be used in many situations where other loci are unsuitable, with degraded samples and after recent speciation events.The advent of next‐generation sequencing technologies (and notably the Illumina platform) has led to an explosion in the number of samples that can be studied at transcriptomic level, at relatively low cost. Here we describe a robust pipeline for the recovery of mitochondrial genomes from these RNA‐sequencing resources. This pipeline can be used on sequencing of a variety of depths, and reliably recovers the protein coding and ribosomal gene complements of mitochondria from almost any transcriptomic sequencing experiment. The complete sequence of the mitochondrial genome can also be recovered when sequencing is performed in sufficient depth. We show the efficacy of our pipeline using data from eight nonmodel invertebrates of six disparate phyla. Interestingly, among our poriferan data, where microbiological symbionts are known empirically to make mitochondrial assembly difficult, this pipeline proved especially useful. Our pipeline will allow the recovery of mitochondrial data from a variety of previously sequenced samples, and add an additional angle of enquiry to future RNA‐sequencing efforts, simplifying the process of mitochondrial genome assembly for even the most recalcitrant clades and adding these data to the scientific record for a range of future uses.
    • Recommended best practices for plastic and litter ingestion studies in marine birds: Collection, processing, and reporting

      Provencher, JF; Borrelle, SB; Bond, AL; Lavers, JL; van Franeker, JA; Kühn, S; Hammer, S; Avery-Gomm, S; Mallory, ML (Canadian Science Publishing, 2019-05-09)
      Marine plastic pollution is an environmental contaminant of significant concern. There is a lack of consistency in sample collection and processing that continues to impede meta-analyses and largescale comparisons across time and space. This is true for most taxa, including seabirds, which are the most studied megafauna group with regards to plastic ingestion research. Consequently, it is difficult to evaluate the impacts and extent of plastic contamination in seabirds fully and accurately, and to make inferences about species for which we have little or no data. We provide a synthesized set of recommendations specific for seabirds and plastic ingestion studies that include best practices in relation to sample collection, processing, and reporting, as well as highlighting some “cross-cutting” methods. We include guidance for how carcasses, regurgitations, and pellets should be handled and treated to prevent cross-contamination, and a discussion of what size class of microplastics can be assessed in each sample type. Although we focus on marine bird samples, we also include standardized techniques to remove sediment and biological material that are generalizable to other taxa. Lastly, metrics and data presentation of ingested plastics are briefly reviewed in the context of seabird studies.
    • An annotated type catalogue of seven genera of operculate land snails (Caenogastropoda, Cyclophoridae) in the Natural History Museum, London

      Sutcharit, C; Ablett, J; Panha, S (Pensoft, 2019-05-07)
      The collection of the seven cyclophorid snail genera housed in the Natural History Museum, London (NHM), includes 95 available species-level names belonging to the genera Pterocyclos Benson, 1832, Cyclotus Swainson, 1840, Myxostoma Troschel, 1847, Rhiostoma Benson, 1860, Scabrina Blanford, 1863, Crossopoma Martens, 1891, and Pearsonia Kobelt, 1902. Lectotypes are here designated for twelve available species-level names to stabilise existing the nomenclature. A complete catalogue of these types, including colour photographs, is provided for the first time. After examining these type specimens, an unpublished manuscript name was found and is described herein as Pterocyclos anamullayensis Sutcharit & Panha, sp. n.
    • Early consequences of allopolyploidy alter floral evolution in Nicotiana (Solanaceae)

      McCarthy, EW; Landis, JB; Kurti, A; Lawhorn, AJ; Chase, MW; Knapp, S; Le Comber, SC; Leitch, AR; Litt, A (BMC, 2019-04-27)
      Background: Polyploidy has played a major role in angiosperm evolution. Previous studies have examined polyploid phenotypes in comparison to their extant progenitors, but not in context of predicted progenitor phenotypes at allopolyploid origin. In addition, differences in the trends of polyploid versus diploid evolution have not been investigated. We use ancestral character-state reconstructions to estimate progenitor phenotype at allopolyploid origin to determine patterns of polyploid evolution leading to morphology of the extant species. We also compare trends in diploid versus allopolyploid evolution to determine if polyploidy modifies floral evolutionary patterns. Results: Predicting the ancestral phenotype of a nascent allopolyploid from reconstructions of diploid phenotypes at the time of polyploid formation generates different phenotype predictions than when extant diploid phenotypes are used, the outcome of which can alter conclusions about polyploid evolution; however, most analyses yield the same results. Using ancestral reconstructions of diploid floral phenotypes indicate that young polyploids evolve shorter, wider corolla tubes, but older polyploids and diploids do not show any detectable evolutionary trends. Lability of the traits examined (floral shape, corolla tube length, and corolla tube width) differs across young and older polyploids and diploids. Corolla length is more evolutionarily labile in older polyploids and diploids. Polyploids do not display unique suites of floral characters based on both morphological and color traits, but some suites of characters may be evolving together and seem to have arisen multiple times within Nicotiana, perhaps due to the influence of pollinators. Conclusions: Young polyploids display different trends in floral evolution (shorter, wider corolla tubes, which may result in more generalist pollination) than older polyploids and diploids, suggesting that patterns of divergence are impacted by the early consequences of allopolyploidy, perhaps arising from genomic shock and/or subsequent genome stabilization associated with diploidization. Convergent evolution in floral morphology and color in Nicotiana can be consistent with pollinator preferences, suggesting that pollinators may have shaped floral evolution in Nicotiana.
    • The chemical basis of a signal of individual identity: shell pigment concentrations track the unique appearance of Common Murre eggs.

      Hauber, ME; Bond, AL; Kouwenberg, A-L; Robertson, GJ; Hansen, ES; Holford, M; Dainson, M; Luro, A; Dale, J (Royal Society, 2019-04-26)
      In group-living species with parental care, the accurate recognition of one's own young is critical to fitness. Because discriminating offspring within a large colonial group may be challenging, progeny of colonial breeders often display familial or individual identity signals to elicit and receive parental provisions from their own parents. For instance, the common murre (or common guillemot: Uria aalge) is a colonially breeding seabird that does not build a nest and lays and incubates an egg with an individually unique appearance. How the shell's physical and chemical properties generate this individual variability in coloration and maculation has not been studied in detail. Here, we quantified two characteristics of the avian-visible appearance of murre eggshells collected from the wild: background coloration spectra and maculation density. As predicted by the individual identity hypothesis, there was no statistical relationship between avian-perceivable shell background coloration and maculation density within the same eggs. In turn, variation in both sets of traits was statistically related to some of their physico-chemical properties, including shell thickness and concentrations of the eggshell pigments biliverdin and protoporphyrin IX. These results illustrate how individually unique eggshell appearances, suitable for identity signalling, can be generated by a small number of structural mechanisms.
    • Detection of ultrafine plastics ingested by seabirds using tissue digestion.

      Lavers, JL; Stivaktakis, G; Hutton, I; Bond, AL (Elsevier, 2019-04-06)
      Plastic debris is a major global threat to marine ecosystems and species. However, our knowledge of this issue may be incomplete due to a lack of a standardized method for quantifying ingested ultrafine particles (1 μm - 1 mm) in wildlife. This study provides the first quantification of ultrafine plastic in seabirds using chemical and biological digestion treatments to extract plastic items from seabird gizzards. The alkaline agent, potassium hydroxide, outperformed the enzyme corolase, based on cost and efficiency (e.g., digestion time). Ultrafine plastics were observed in 7.0% of Flesh-footed Shearwater (Ardenna carneipes) gizzards collected from Lord Howe Island, Australia and accounted for 3.6% of all plastic items recovered (13 out of 359 items). Existing methods for extracting ingested plastic from seabirds do not account for ultrafine particles, therefore our results indicate current seabird plastic loads, and the associated physical and biological impacts, are underestimated.