• 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.
    • Professional fossil preparators at the British Museum (Natural History), 1843-1990*

      Graham, M; Reichenbach, H (Edinburgh University Press, 2019-10-01)
      Since the inception of the British Museum (Natural History) in 1881 (now the Natural History Museum, London), the collection, development and mounting of fossils for scientific study and public exhibition have been undertaken by fossil preparators. Originally known as masons, because of their rock-working skills, their roles expanded in the late nineteenth and early twentieth centuries, when, at the forefront of the developing science of palaeontology, the Museum was actively obtaining fossil material from the UK and abroad to build the collections. As greater numbers of more impressive specimens were put on public display, these preparators developed new and better methods to recover and transport fossils from the field, and technical improvements, in the form of powered tools, enabled more detailed mechanical preparation to be undertaken. A recurring theme in the history of palaeontological preparation has been that sons often followed in their fathers’ footsteps in earth sciences. William and Thomas Davies, Caleb and Frank Barlow, and Louis and Robert Parsons were all father-and-son geologists and preparators.
    • 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.
    • Conserved gene signalling and a derived patterning mechanism underlie the development of avian footpad scales

      Cooper, RL; Lloyd, VJ; Di-Pöi, N; Fletcher, AG; Barrett, PM; Fraser, GJ (BioMed Central, 2019-08-13)
      Background: Vertebrates possess a diverse range of integumentary epithelial appendages, including scales, feathers and hair. These structures share extensive early developmental homology, as they mostly originate from a conserved anatomical placode. In the context of avian epithelial appendages, feathers and scutate scales are known to develop from an anatomical placode. However, our understanding of avian reticulate (footpad) scale development remains unclear. Results: Here, we demonstrate that reticulate scales develop from restricted circular domains of thickened epithelium, with localised conserved gene expression in both the epithelium and underlying mesenchyme. These domains constitute either anatomical placodes, or circular initiatory fields (comparable to the avian feather tract). Subsequent patterning of reticulate scales is consistent with reaction–diffusion (RD) simulation, whereby this primary domain subdivides into smaller secondary units, which produce individual scales. In contrast, the footpad scales of a squamate model (the bearded dragon, Pogona vitticeps) develop synchronously across the ventral footpad surface. Conclusions: Widely conserved gene signalling underlies the initial development of avian reticulate scales. However, their subsequent patterning is distinct from the footpad scale patterning of a squamate model, and the feather and scutate scale patterning of birds. Therefore, we suggest reticulate scales are a comparatively derived epithelial appendage, patterned through a modified RD system.
    • 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.
    • Ngwevu intloko: a new early sauropodomorph dinosaur from the Lower Jurassic Elliot Formation of South Africa and comments on cranial ontogeny in Massospondylus carinatus

      Chapelle, KEJ; Barrett, PM; Botha, J; Choiniere, JN (PeerJ Inc., 2019-08-05)
      Our knowledge of Early Jurassic palaeobiodiversity in the upper Elliot Formation of South Africa has increased markedly in recent years with the discovery of new fossils, re-assessments of previously collected material and a better understanding of Stormberg Group stratigraphy. Here, Ngwevu intloko, a new genus of upper Elliot basal sauropodomorph is named on the basis of a complete skull and partial skeleton (BP/1/4779) previously assigned to Massospondylus carinatus. It can be distinguished from all other basal sauropodomorphs by a combination of 16 cranial and six postcranial characters. The new species is compared to a small ontogenetic series of M. carinatus as well as to a range of closely related taxa. Taphonomic deformation, sexual dimorphism and ontogeny are rejected as possible explanations for the morphological differences present between BP/1/4779 and other taxa. Osteohistological examination reveals that BP/1/4779 had nearly reached adult size at the time of its death at a minimum age of 10 years.

      Almeida, NV; Schofield, PF; Geraki, K; Russell, Sara (Lunar and Planetary Institute, 2019-08)
    • A Diverse Array of Fluvial Depositional Systems in Arabia Terra: Evidence for mid-Noachian to Early Hesperian Rivers on Mars

      Davis, Joel; Gupta, S; Balme, M; M. Grindrod, P; Fawdon, P; Dickeson, ZI; Williams, RME (Wiley, 2019-07-22)
      Branching to sinuous ridges systems, hundreds of kilometers in length and comprising layered strata, are present across much of Arabia Terra, Mars. These ridges are interpreted as depositional fluvial channels, now preserved as inverted topography. Here we use high‐resolution image and topographic data sets to investigate the morphology of these depositional systems and show key examples of their relationships to associated fluvial landforms. The inverted channel systems likely comprise indurated conglomerate, sandstone, and mudstone bodies, which form a multistory channel stratigraphy. The channel systems intersect local basins and indurated sedimentary mounds, which we interpret as paleolake deposits. Some inverted channels are located within erosional valley networks, which have regional and local catchments. Inverted channels are typically found in downslope sections of valley networks, sometimes at the margins of basins, and numerous different transition morphologies are observed. These relationships indicate a complex history of erosion and deposition, possibly controlled by changes in water or sediment flux, or base‐level variation. Other inverted channel systems have no clear preserved catchment, likely lost due to regional resurfacing of upland areas. Sediment may have been transported through Arabia Terra toward the dichotomy and stored in local and regional‐scale basins. Regional stratigraphic relations suggest these systems were active between the mid‐Noachian and early Hesperian. The morphology of these systems is supportive of an early Mars climate, which was characterized by prolonged precipitation and runoff.
    • 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).
    • Digital dissection of the head of the rock dove (Columba livia) using contrast-enhanced computed tomography.

      Jones, MEH; Button, DJ; Barrett, PM; Porro, LB (Biomed central (BMC), 2019-06-10)
      The rock dove (or common pigeon), Columba livia, is an important model organism in biological studies, including research focusing on head muscle anatomy, feeding kinematics, and cranial kinesis. However, no integrated computer-based biomechanical model of the pigeon head has yet been attempted. As an initial step towards achieving this goal, we present the first three-dimensional digital dissection of the pigeon head based on a contrast-enhanced computed tomographic dataset achieved using iodine potassium iodide as a staining agent. Our datasets enable us to visualize the skeletal and muscular anatomy, brain and cranial nerves, and major sense organs of the pigeon, including very small and fragile features, as well as maintaining the three-dimensional topology of anatomical structures. This work updates and supplements earlier anatomical work on this widely used laboratory organism. We resolve several key points of disagreement arising from previous descriptions of pigeon anatomy, including the precise arrangement of the external adductor muscles and their relationship to the posterior adductor. Examination of the eye muscles highlights differences between avian taxa and shows that pigeon eye muscles are more similar to those of a tinamou than they are to those of a house sparrow. Furthermore, we present our three-dimensional data as publicly accessible files for further research and education purposes. Digital dissection permits exceptional visualisation and will be a valuable resource for further investigations into the head anatomy of other bird species, as well as efforts to reconstruct soft tissues in fossil archosaurs.
    • Mammalian tolerance to humans is predicted by body mass: evidence from long-term archives.

      Crees, JJ; Turvey, ST; Freeman, R; Carbone, C (Ecological Society of America, 2019-06-08)
      Humans are implicated as a major driver of species extinctions from the Late Pleistocene to the present. However, our predictive understanding of human-caused extinction remains poor due to the restricted temporal and spatial scales at which this process is typically assessed, and the risks of bias due to "extinction filters" resulting from a poor understanding of past species declines. We develop a novel continent-wide dataset containing country-level last-occurrence records for 30 European terrestrial mammals across the Holocene (c.11,500 years to present), an epoch of relative climatic stability that captures major transitions in human demography. We analyze regional extirpations against a high-resolution database of human population density (HPD) estimates to identify species-specific tolerances to changing HPD through the Holocene. Mammalian thresholds to HPD scale strongly with body mass, with larger-bodied mammals experiencing regional population losses at lower HPDs than smaller-bodied mammals. Our analysis enables us to identify levels of tolerance to HPD for different species, and therefore has wide applicability for determining biotic vulnerability to human impacts. This ecological pattern is confirmed across wide spatiotemporal scales, providing insights into the dynamics of prehistoric extinctions and the modern biodiversity crisis, and emphasizing the role of long-term archives in understanding human-caused biodiversity loss. This article is protected by copyright. All rights reserved.
    • 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.