New taxa and new synonymy in Muricidae (Neogastropoda: Pagodulinae, Trophoninae, Ocenebrinae) from the Northeast Pacific

The results of an extensive examination of northeast Pacific muricid gastropods ranging from Aleutian Islands, Alaska, to mid-Baja California, is presented. Two new genera and 26 new species are described: In Pagodulinae: Abyssotrophon fusiformis n. sp., A. newmani n. sp., Boreotrophon cascadiensis n. sp., B. cordellensis n. sp., B. cortesianus n. sp., B. obesus n. sp., B. subapolyonis n. sp., B. vancouverensis n. sp., B. aleuticus n. sp., B. pseudotripherus n. sp., B. santarosensis n. sp., B. tannerensis n. sp. In Trophoninae: Warenia, n. gen., Scabrotrophon buldirensis n. sp, S. kantori n. sp., S. lima n. sp., S. macleani n. sp., S. moresbyensis n. sp., S. norafosterae n. sp., S. trifidus n. sp., Nipponotrophon exquisitus n. sp. In Ocenebrinae: Paciocinebrina n. gen., Nucella angustior n. sp., Paciocinebrina benitoensis n. sp., P. macleani n. sp., P. neobarbarensis n. sp., P. pseudomunda n. sp., P. thelmacrowae n. sp. New synonymy: Boreotrophon kamchatkanus Dall, 1902 (+ Trophonopsis nanus Ergorov, 1994); Paciocinebrina atropurpurea (Carpenter, 1865) (+ Tritonalia interfossa var. clathrata Dall, 1919, Ocinebra rubra Baker, 1891, Tritonalia tracheia Dall, 1919); P. barbarensis (Gabb, 1865) (+ Tritonalia interfossa var. beta Dall, 1919, Ocenebra keenae Bormann, 1946); P. circumtexta (Stearns, 1871) (+ Ocinebra circumtexta var. aurantia Stearns, 1895, Tritonalia circumtexta var. citrica Dall, 1919, Tritonalia lurida var. rotunda Dall, 1919); P. foveolata (Hinds, 1844) (+Tritonalia epiphanea Dall, 1919, Tritonalia fusconotata Dall, 1919); P. gracillima (Stearns, 1871) (+ Tritonalia gracillima var. obesa Dall, 1919, Ocinebra stearnsi Hemphill, 1911); P. interfossa (Carpenter, 1864) (+ Tritonalia interfossa alpha Dall, 1921); P. lurida (Middendorff, 1848) (+ Vitularia aspera Baird, 1863), P. sclera (Dall, 1919) (+ Coralliophila (Pseudomurex) kincaidi Dall, 1919). Generic assignments are changed for the following taxa: Boreotrophon kamchatkanus Dall, 1902; Warenia elegantula (Dall, 1907); Scabrotrophon stuarti (E.A. Smith, 1880); Paciocinebrina atropurpurea (Carpenter, 1865), P. barbarensis (Gabb, 1865), P. circumtexta (Stearns, 1871), P. crispatissima (Berry, 1953), P. foveolata (Hinds, 1844), P. fraseri (Oldroyd, 1920), P. gracillima (Stearns, 1871), P. grippi (Dall, 1911), P. interfossa (Carpenter, 1864), P. lurida (Middendorff, 1848), P. minor (Dall, 1919), P. munda (Carpenter, 1864), P. seftoni (Chace, 1958), P. sclera (Dall, 1919). Boreotrophon alborostratus Taki, 1938, is reinstated. Abyssotrophon Egorov, 1993 and Nodulotrophon Habe & Ito, 1965 are here assigned to Pagodulinae Barco et al., 2012, based on radula morphology

Local genomic adaptation of coral reef-associated microbiomes to gradients of natural variability and anthropogenic stressors

Holobionts are species-specific associations between macro- and microorganisms. On coral reefs, the benthic coverage of coral and algal holobionts varies due to natural and anthropogenic forcings. Different benthic macroorganisms are predicted to have specific microbiomes. In contrast, local environmental factors are predicted to select for specific metabolic pathways in microbes. To reconcile these two predictions, we hypothesized that adaptation of microbiomes to local conditions is facilitated by the horizontal transfer of genes responsible for specific metabolic capabilities. To test this hypothesis, microbial metagenomes were sequenced from 22 coral reefs at 11 Line Islands in the central Pacific that together span a wide range of biogeochemical and anthropogenic influences. Consistent with our hypothesis, the percent cover of major benthic functional groups significantly correlated with particular microbial taxa. Reefs with higher coral cover had a coral microbiome with higher abundances of Alphaproteobacteria (such as Rhodobacterales and Sphingomonadales), whereas microbiomes of algae-dominated reefs had higher abundances of Gammaproteobacteria (such as Alteromonadales, Pseudomonadales, and Vibrionales), Betaproteobacteria, and Bacteriodetes. In contrast to taxa, geography was the strongest predictor of microbial community metabolism. Microbial communities on reefs with higher nutrient availability (e.g., equatorial upwelling zones) were enriched in genes involved in nutrient-related metabolisms (e.g., nitrate and nitrite ammonification, Ton/Tol transport, etc.). On reefs further from the equator, microbes had more genes encoding chlorophyll biosynthesis and photosystems I/II. These results support the hypothesis that core microbiomes are determined by holobiont macroorganisms, and that those core taxa adapt to local conditions by selecting for advantageous metabolic genes

Evolution of whole-body enantiomorphy in the tree snail genus Amphidromus

Diverse animals exhibit left–right asymmetry in development. However, no example of dimorphism for the left–right polarity of development (whole-body enantiomorphy) is known to persist within natural populations. In snails, whole-body enantiomorphs have repeatedly evolved as separate species. Within populations, however, snails are not expected to exhibit enantiomorphy, because of selection against the less common morph resulting from mating disadvantage. Here we present a unique example of evolutionarily stable whole-body enantiomorphy in snails. Our molecular phylogeny of South-east Asian tree snails in the genus Amphidromus indicates that enantiomorphy has likely persisted as the ancestral state over a million generations. Enantiomorphs have continuously coexisted in every population surveyed spanning a period of 10 years. Our results indicate that whole-body enantiomorphy is maintained within populations opposing the rule of directional asymmetry in animals. This study implicates the need for explicit approaches to disclosure of a maintenance mechanism and conservation of the genus

Produktie van TAME via reactieve distillatie

Document uit de collectie Chemische ProcestechnologieDelftChemTechApplied Science

Produktie van TAME via reactieve distillatie

Document uit de collectie Chemische ProcestechnologieDelftChemTechApplied Science

From Europe to America: Pliocene to Recent trans-Atlantic expansion of cold-water North Atlantic molluscs

Data on the geographical distribution, phylogeny and fossil record of cool-temperate North Atlantic shell-bearing molluscs that live in waters shallower than 100 m depth belong to two biogeographic provinces, one in eastern North America north of Cape Cod, the other in northern Europe. Amphi-Atlantic species, which are found in both provinces, comprise 30.8% of the 402 species in the northeastern Atlantic and 47.3% of the 262 species in the northwestern Atlantic. Some 54.8% of these amphi-Atlantic species have phylogenetic origins in the North Pacific. Comparisons among fossil Atlantic faunas show that amphi-Atlantic distributions became established in the Middle Pliocene (about 3.5 million years ago), and that all represent westward expansions of European taxa to North America. No American taxa spread eastward to Europe without human assistance. These results are in accord with previous phylogeographic studies among populations within several amphi-Atlantic species. Explanations for the unidirectional expansion of species across the Atlantic remain uncertain, but may include smaller size and greater prior extinction of the North American as compared to the European fauna and biased transport mechanisms. Destruction of the European source fauna may jeopardize faunas on both sides of the Atlantic