The Museum’s vast collections of vertebrates, invertebrates, plants and microbes support our staff's unique expertise in evolutionary biology, biodiversity and systematics.

Recent Submissions

  • Novel molecular approach to define pest species status and tritrophic interactions from historical Bemisia specimens

    Tay, WT; Elfekih, S; Polaszek, Andrew; Court, LN; Evans, GA; Gordon, KHJ; De Barro, PJ (Nature Research, 2017-03-27)
    Museum specimens represent valuable genomic resources for understanding host-endosymbiont/parasitoid evolutionary relationships, resolving species complexes and nomenclatural problems. However, museum collections suffer DNA degradation, making them challenging for molecular-based studies. Here, the mitogenomes of a single 1912 Sri Lankan Bemisia emiliae cotype puparium, and of a 1942 Japanese Bemisia puparium are characterised using a Next-Generation Sequencing approach. Whiteflies are small sap-sucking insects including B. tabaci pest species complex. Bemisia emiliae’s draft mitogenome showed a high degree of homology with published B. tabaci mitogenomes, and exhibited 98–100% partial mitochondrial DNA Cytochrome Oxidase I (mtCOI) gene identity with the B. tabaci species known as Asia II-7. The partial mtCOI gene of the Japanese specimen shared 99% sequence identity with the Bemisia ‘JpL’ genetic group. Metagenomic analysis identified bacterial sequences in both Bemisia specimens, while hymenopteran sequences were also identified in the Japanese Bemisia puparium, including complete mtCOI and rRNA genes, and various partial mtDNA genes. At 88–90% mtCOI sequence identity to Aphelinidae wasps, we concluded that the 1942 Bemisia nymph was parasitized by an Eretmocerus parasitoid wasp. Our approach enables the characterisation of genomes and associated metagenomic communities of museum specimens using 1.5 ng gDNA, and to infer historical tritrophic relationships in Bemisia whiteflies.
  • 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.
  • Synopsis of the pelidnotine scarabs (Coleoptera, Scarabaeidae, Rutelinae, Rutelini) and annotated catalog of the species and subspecies

    Moore, MR; Jameson, ML; Garner, BH; Audibert, C; Smith, ABT; Seidel, M (Pensoft, 2017-04-06)
    The pelidnotine scarabs (Scarabaeidae: Rutelinae: Rutelini) are a speciose, paraphyletic assemblage of beetles that includes spectacular metallic species (“jewel scarabs”) as well as species that are ecologically important as herbivores, pollinators, and bioindicators. These beetles suffer from a complicated nomenclatural history, due primarily to 20th century taxonomic and nomenclatural errors. We review the taxonomic history of the pelidnotine scarabs, present a provisional key to genera with overviews of all genera, and synthesize a catalog of all taxa with synonyms, distributional data, type specimen information, and 107 images of exemplar species. As a result of our research, the pelidnotine leaf chafers (a paraphyletic group) include 27 (26 extant and 1 extinct) genera and 420 valid species and subspecies (419 extant and 1 extinct). Our research makes biodiversity research on this group tractable and accessible, thus setting the stage for future studies that address evolutionary and ecological trends. Based on our research, 1 new species is described, 1 new generic synonym and 12 new species synonyms are proposed, 11 new lectotypes and 1 new neotype are designated, many new or revised nomenclatural combinations, and many unavailable names are presented.
  • 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.
  • 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.
  • International Code of Nomenclature for algae, fungi, and plants (Shenzhen Code) adopted by the Nineteenth International Botanical Congress Shenzhen, China, July 2017.

    Turland, NJ; Wiersema, JH; Barrie, FR; Greuter, W; Hawksworth, DL; Herendeen, PS; Knapp, S; Kusber, W-H; Li, D-Z; Marhold, K; et al. (Koeltz Botanical BooksGlahutten, Germany, 2018-06-26)
    The rules that govern the scientific naming of algae, fungi, and plants are revised at the Nomenclature Section of an International Botanical Congress (IBC). This edition of the International Code of Nomenclature for algae, fungi, and plants embodies the decisions of the XIX IBC, which took place in Shenzhen, China in July, 2017. This Shenzhen Code supersedes the Melbourne Code (McNeill & al. in Regnum Veg. 154. 2012), published six years ago after the XVIII IBC in Melbourne, Australia, and like its five predecessors, it is written entirely in (British) English. The Melbourne Code was translated into Chinese, French, Italian, Japanese, Korean, Portuguese, Spanish, and Turkish; it is anticipated that the Shenzhen Code, too, will become available in several languages. In questions about the meaning of provisions in translated editions of this Code, the English edition is definitive.
  • Nomenclatural notes on Anthicidae and Pyrochroidae (Coleoptera). 6

    Telnov, Dmitry (Baltijas Koleopterologijas Instituts/Baltic Institute of Coleopterology, 2018-12-23)
    Five new combinations, three new synonyms and two new statuses for the Anthicidae are proposed. New distributional data or corrections are provided on 65 taxa of Pyrochroidae and Anthicidae. Eighteen new species and subspecies are described: Anthelephila panayensis sp. nov., Anthicus (s. str.) chitwanus sp. nov., A. (s. str.) lepcha sp. nov., A. (s. str.) vicinor sp. nov., Aulacoderus muehlei sp. nov., Clavicomus garze sp. nov., C. kham sp. nov., Cyclodinus phragmiteticola sp. nov., Macratria dotyali sp. nov., M. kopetzi sp. nov., M. leprieuri gasconica ssp. nov., Macratriomima casuarius sp. nov., M. chandleri sp. nov., Notoxus reuteri sp. nov., Rimaderus bonadonai sp. nov., R. sahyadri sp. nov., Stenidius obliquesetosus sp. nov., and Tomoderus schmidti sp. nov. Additional description is given for Anthelephila kresli Kejval, 2007 and Yunnanomonticola Telnov, 2002.
  • Descriptions of two new Australian genera of Anthicidae (Insecta: Coleoptera)

    Telnov, Dmitry (Baltijas Koleopterologijas Instituts/Baltic Institute of Coleopterology, 2018-12-23)
    Two new Australian Anthicidae genera, Australosteropes gen. nov. (Steropinae) and Sahulanthicus gen. nov. (Anthicinae: Anthicini) are described, diagnosed, and illustrated. Some critical morphological characters of these new groups and the subfamilies to which they belong are discussed. New combinations are made for the following 18 taxa: Australosteropes davidsonae (Armstrong, 1948) comb. nov. (from Macratria Newman, 1838), Sahulanthicus abundans (Lea, 1922) comb. nov., S. apicalis (King, 1869) comb. nov., S. baudinensis (Champion, 1895) comb. nov., S. brevicollis (King, 1869) comb. nov., S. cavifrons (Champion, 1895) comb. nov., S. crassipes (LaFerté-Sénectère, 1849) comb. nov., S. crassus (King, 1869) comb. nov., S. discoideus (Champion, 1895) comb. nov., S. immaculatus (King, 1869) comb. nov., S. inglorius (Lea, 1896) comb. nov., S. laticollis (MacLeay, 1872) comb. nov., S. luridus (King, 1869) comb. nov., S. monostigma (Champion, 1895) comb. nov., S. obliquefasciatus (King, 1869) comb. nov., S. permutatus (Pic, 1897) comb. nov., S. scutellatus (Lea, 1896) comb. nov. (all from Microhoria Chevrolat, 1877), and S. dilatipennis (Pic, 1900) comb. nov. (from Anthicus Paykull, 1798). Lectotype is designated for Sahulanthicus dilatipennis (Pic, 1900).
  • New, north-easternmost locality for Bembidion monticola Sturm, 1825 (Coleoptera: Carabidae) in Europe: relict of ancient distribution or a result of range expansion?

    Kovalenko, YN; Telnov, Dmitry (Entomological Society of Finland, 2018-09-17)
    A new record of a subpopulation of Bembidion monticola Sturm, 1825 from Arkhangelsk region (Northern Europe, Russia) is discussed. The locality of this record is remote, about 700 km to the east from the northernmost previously known locality of this species. Ecology and distribution of B. monticola in northern Europe are reviewed, as well as possible ways of its spread further to northeast are hypothesised.
  • A review of the Helophorus frater-praenanus group of species, with description of a new species and additional faunal records of Helophorus Fabricius from China and Bhutan (Coleoptera: Helophoridae)

    ANGUS, RB; Jia, F-L; Chen, Z-N (Austrian Zoological-Botanical Society and the Vienna Coleopterists Society (Wiener Coleopterologenverein, WCV), 2014)
    The six species of the East Palaearctic Helophorus frater-praenanus group (Coleoptera: Helophoridae) are reviewed and a new species, H. aquila sp.n. is described from China (Qinghai). Habitus, head and pronotum and aedeagophores are figured for all the species and a key for their identification is given. Four further species which could be confused with the H. frater-praenanus group are discussed and illustrated. These are H. croaticus KUWERT, 1886, H. pumilio ERICHSON, 1837, H. pitcheri ANGUS, 1970 and H. shatrovskyi ANGUS, 1985. Additional faunal records of Helophorus FABRICIUS species from the Tibetan Plateau and other areas of China are given. Helophorus tuberculatus GYLLENHAL, 1808 is recorded from Bhutan for the first time
  • 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.
  • Pushing the limits of whole genome amplification: successful sequencing of RADseq library from a single microhymenopteran (Chalcidoidea, Trichogramma)

    Cruaud, A; Groussier, G; Genson, G; Saune, L; Polaszek, A; Rasplus, J-Y (PeerJ, 2018-10-16)
    A major obstacle to high-throughput genotyping of microhymenoptera is their small size. As species are difficult to discriminate, and because complexes may exist, the sequencing of a pool of specimens is hazardous. Thus, one should be able to sequence pangenomic markers (e.g., RADtags) from a single specimen. To date, whole genome amplification (WGA) prior to library construction is still a necessity as at most 10 ng of DNA can be obtained from single specimens (sometimes less). However, this amount of DNA is not compatible with manufacturer’s requirements for commercial kits. Here we test the accuracy of the GenomiPhi kit V2 on Trichogramma wasps by comparing RAD libraries obtained from the WGA of single specimens (F0 and F1 generation, about1 ng input DNA for the WGA (0.17–2.9 ng)) and a biological amplification of genomic material (the pool of the progeny of the F1 generation). Globally, we found that 99% of the examined loci (up to 48,189 for one of the crosses, 109 bp each) were compatible with the mode of reproduction of the studied model (haplodiploidy) and Mendelian inheritance of alleles. The remaining 1% (0.01% of the analysed nucleotides) could represent WGA bias or other experimental/analytical bias. This study shows that the multiple displacement amplification method on which the GenomiPhi kit relies, could also be of great help for the high-throughput genotyping of microhymenoptera used for biological control, or other organisms from which only a very small amount of DNA can be extracted, such as human disease vectors (e.g., sandflies, fleas, ticks etc.).
  • 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.
  • 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.
  • Preliminary survival and movement data for a declining population of Flesh-footed Shearwater Ardenna carneipes in Western Australia provides insights into marine threats

    Lavers, J; Lisovski, S; Bond, A (Cambridge University Press, 2018-08-31)
    Seabirds face diverse threats on their breeding islands and while at sea. Human activities have been linked to the decline of seabird populations, yet over-wintering areas typically receive little or no protection. Adult survival rates, a crucial parameter for population persistence in long-lived species, tend to be spatially or temporally restricted for many seabird species, limiting our understanding of factors driving population trends at some sites. We used bio-loggers to study the migration of Western Australian Flesh-footed Shearwaters Ardenna carneipes carneipes and estimated adult survival over five years. Western Australia is home to around 35% of the world’s breeding Flesh-footed Shearwaters, a population which was up-listed to Vulnerable in 2015. During the austral winter, shearwaters migrated across the central Indian Ocean to their non-breeding grounds off western Sri Lanka. Low site fidelity on breeding islands, mortality of adult birds at sea (e.g. fisheries bycatch), and low annual breeding frequency likely contributed to the low estimated annual adult survival (2011–2015: ϕ = 0.634-0.835).
  • 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.
  • 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.
  • 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.
  • 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.
  • 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.

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