A new species of Cythere (Ostracoda) from the Middle Eocene McIntosh Formation, Doty Hills, Washington State, USA, and its significance for the evolutionary history of the genus

2010 ◽  
Vol 84 (4) ◽  
pp. 709-719
Author(s):  
Tatsuhiko Yamaguchi ◽  
James L. Goedert
Keyword(s):  
Evolutionary History ◽  
Middle Eocene ◽  
Washington State ◽  
Northwestern Pacific ◽  
The Pacific ◽  
Northeastern Pacific ◽  
History Of ◽  
The Pacific Ocean ◽  
Western Washington ◽  
A New Species

Cythere ikeyanoriyukii n. sp., an extant phytal ostracode genus, was obtained from the Middle Eocene McIntosh Formation in the Doty Hills, western Washington State, USA. It was associated with eleven taxa, which are extant phytal and shelfal genera such as Loxocorniculum, Xestoleberis, Ambostracon, Coquimba, and Acanthocythereis. The presence of Cythere in this assemblage is surprising and indicates that the first appearance of this genus was middle Eocene time at the latest, or at least 20 Ma earlier than previously thought. Cythere did not originate in the Pacific Ocean around Japan as previously thought, but instead must have migrated from the northeastern Pacific to the northwestern Pacific between middle Eocene and early Miocene time.

scholarly journals Eggs of echinoids separated by the Isthmus of Panama harbor divergent microbiota

2020 ◽  
Vol 648 ◽  
pp. 169-177
Author(s):  
TJ Carrier ◽  
HA Lessios ◽  
AM Reitzel
Keyword(s):  
Community Composition ◽  
Bacterial Communities ◽  
Evolutionary History ◽  
Isthmus Of Panama ◽  
The Pacific ◽  
Species Pairs ◽  
History Of ◽  
The Pacific Ocean ◽  
The Caribbean ◽  
Bodies Of Water

Relationships between animals and their associated microbiota are dependent on both the evolutionary history of the host and on the environment. The majority of studies tend to focus on either one of these factors but rarely consider how both determine the community composition of the associated microbiota. One ‘natural experiment’ to test how evolutionary history, shared environments, and the interaction between these factors drive community composition is to compare geminate species pairs. Echinoids separated by the Isthmus of Panama are suitable for this comparison due to their known evolutionary history and differences in the oceanographic characteristics of the Caribbean Sea and the Pacific Ocean. By comparing the bacterial communities of the eggs of Echinometra and Diadema geminate species pairs, we show that each pair of geminate species associates with a distinct bacterial community in a pattern consistent with phylosymbiosis, and that the interaction between the evolutionary history of the host and the environment best explains differences in these communities. Moreover, we found that the relative abundance of particular bacterial taxa differed considerably between the 2 bodies of water and that the 2 Caribbean Echinometra species were dominated by unclassified bacterial taxa within the phototrophic Oxyphotobacteria. Taken together, data presented here support the hypothesis that the bacterial communities associated with geminate species are another characteristic of these species that have diverged in ~2.8 million years of isolation.

scholarly journals Proposal of two new genera of the family Zosimeidae Seifried (Copepoda: Harpacticoida): Heterozosime gen. nov. and Acritozosime gen. nov.

2021 ◽  
Vol 760 ◽  
Author(s):  
Jong Guk Kim ◽  
Jimin Lee
Keyword(s):  
Evolutionary History ◽  
Northwestern Pacific ◽  
Exopodal Segment ◽  
New Genera ◽  
Morphological Examination ◽  
Korean Waters ◽  
The Pacific ◽  
The Family ◽  
The Pacific Ocean ◽  
Thoracic Legs

In the Pacific Ocean, the taxonomy of the family Zosimeidae Seifried, 2003 is poorly understood and to date only five species of the genus Zosime Boeck, 1873 are known. During oceanographic cruises exploring the species diversity of harpacticoids, two undescribed zosimeid copepods were sampled from shallow Korean waters and the deep northwestern Pacific. A detailed morphological examination has led us to propose two new genera, Heterozosime gen. nov. for the Korean zosimeid H. tenuis gen. et sp. nov. and Acritozosime gen. nov. for the deep-sea zosimeid A. spinesco gen. et sp. nov. Both new genera exhibit a distinctive feature in that the first thoracic leg has a two-segmented exopod, in contrast to the three-segmented exopod of this leg in all known zosimeid genera. Furthermore, Acritozosime gen. nov. can also be discriminated from other genera by the two-segmented endopod in second to fourth thoracic legs and the reduced setal armatures of the second exopodal segment of antenna, the first endopodal segment of first to third thoracic legs and the third exopodal segment in second to fourth thoracic legs. A comparison of the fundamental structures of appendages suggests that A. spinesco gen. et sp. nov. experienced a unique evolutionary history within the Zosimeidae.

THE TECTONIC HISTORY OF THE PACIFIC OCEAN BASIN SINCE CHRON 34Y (83 MA)

2017 ◽  
Author(s):  
Nicky M. Wright ◽  
◽  
Maria Seton ◽  
Simon E. Williams ◽  
R. Dietmar Müller
Keyword(s):  
Pacific Ocean ◽  
Ocean Basin ◽  
Tectonic History ◽  
The Pacific ◽  
History Of ◽  
The Pacific Ocean

scholarly journals A Novel Rubi-Like Virus in the Pacific Electric Ray (Tetronarce californica) Reveals the Complex Evolutionary History of the Matonaviridae

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 585
Author(s):  
Rebecca M. Grimwood ◽  
Edward C. Holmes ◽  
Jemma L. Geoghegan
Keyword(s):  
Evolutionary History ◽  
Mammalian Species ◽  
Virus Transmission ◽  
Health Concern ◽  
Virus Species ◽  
Vast Number ◽  
The Pacific ◽  
Positive Sense ◽  
History Of ◽  
Fish Viruses

Rubella virus (RuV) is the causative agent of rubella (“German measles”) and remains a global health concern. Until recently, RuV was the only known member of the genus Rubivirus and the only virus species classified within the Matonaviridae family of positive-sense RNA viruses. Recently, two new rubella-like matonaviruses, Rustrela virus and Ruhugu virus, have been identified in several mammalian species, along with more divergent viruses in fish and reptiles. To screen for the presence of additional novel rubella-like viruses, we mined published transcriptome data using genome sequences from Rubella, Rustrela, and Ruhugu viruses as baits. From this, we identified a novel rubella-like virus in a transcriptome of Tetronarce californica—order Torpediniformes (Pacific electric ray)—that is more closely related to mammalian Rustrela virus than to the divergent fish matonavirus and indicative of a complex pattern of cross-species virus transmission. Analysis of host reads confirmed that the sample analysed was indeed from a Pacific electric ray, and two other viruses identified in this animal, from the Arenaviridae and Reoviridae, grouped with other fish viruses. These findings indicate that the evolutionary history of the Matonaviridae is more complex than previously thought and highlights the vast number of viruses that remain undiscovered.

scholarly journals Extreme secondary sexual dimorphism in the genus Florarctus (Heterotardigrada: Halechiniscidae)

2021 ◽  
Vol 51 (3) ◽  
Author(s):  
Piotr Gąsiorek ◽  
David Møbjerg Kristensen ◽  
Reinhardt Møbjerg Kristensen
Keyword(s):  
Sexual Dimorphism ◽  
Pacific Ocean ◽  
Barrier Reef ◽  
Queensland Museum ◽  
The Pacific ◽  
Secondary Sexual Dimorphism ◽  
The Pacific Ocean ◽  
A New Species ◽  
Lines Of Evidence ◽  
Secondary Sexual

AbstractSecondary sexual dimorphism in florarctin tardigrades is a well-known phenomenon. Males are usually smaller than females, and primary clavae are relatively longer in the former. A new species Florarctus bellahelenae, collected from subtidal coralline sand just behind the reef fringe of Long Island, Chesterfield Reefs (Pacific Ocean), exhibits extreme secondary dimorphism. Males have developed primary clavae that are much thicker and three times longer than those present in females. Furthermore, the male primary clavae have an accordion-like outer structure, whereas primary clavae are smooth in females. Other species of Florarctus Delamare-Deboutteville & Renaud-Mornant, 1965 inhabiting the Pacific Ocean were investigated. Males are typically smaller than females, but males of Florarctus heimi Delamare-Deboutteville & Renaud-Mornant, 1965 and females of Florarctus cervinus Renaud-Mornant, 1987 have never been recorded. The Renaud-Mornant collection was re-examined, and type series were analysed. Florarctus heimi and F. cervinus were always found together in the coralline sand of Heron Island (Great Barrier Reef). The animals were kept alive and surveyed in the laboratory of the Queensland Museum. All studied individuals of the larger F. heimi (up to ca. 400 μm) were females, and all adults of the smaller F. cervinus (about 170 μm) were males. Males of F. cervinus were observed mating with females of F. heimi. Following those morphological and behavioural lines of evidence, we propose that F. cervinus is a junior synonym of F. heimi. Based on the discovery of dimorphism in F. bellahelenae sp. nov. and the strong sex-related morphological disparities in F. heimi, we suggest that extreme secondary dimorphism may be present in other florarctin arthrotardigrades.

scholarly journals Pathogen emergence in changing ecosystems: RAD-seq reveals long evolutionary history of Phellinus noxius in east Asia, Australia, and the Pacific Islands

2021 ◽  
Author(s):  
Olga Kozhar ◽  
Mee-Sook Kim ◽  
Jorge Ibarra Caballero ◽  
Ned Klopfenstein ◽  
Phil Cannon ◽  
...  
Keyword(s):  
East Asia ◽  
Evolutionary History ◽  
Pacific Islands ◽  
Genetic Relationships ◽  
Supervised Machine Learning ◽  
Sequencing Data ◽  
The Pacific ◽  
Recent Emergence ◽  
History Of ◽  
Phellinus Noxius

Emerging pathogens have been increasing exponentially over the last century. The knowledge on whether these organisms are native to ecosystems or have been recently introduced is often of great importance. Understanding the ecological and evolutionary processes promoting emergence can help to control their spread and forecast epidemics. Using restriction site-associated DNA sequencing data, we studied genetic relationships, pathways of spread, and evolutionary history of Phellinus noxius, an emerging root-rotting fungus of unknown origin, in eastern Asia, Australia, and the Pacific Islands. We analyzed patterns of genetic variation using Bayesian inference, maximum likelihood phylogeny, populations splits and mixtures measuring correlations in allele frequencies and genetic drift, and finally applied coalescent based theory using approximate Bayesian computation (ABC) with supervised machine learning. Population structure analyses revealed five genetic groups with signatures of complex recent and ancient migration histories. The most probable scenario of ancient pathogen spread is movement from west to east: from Malaysia to the Pacific Islands, with subsequent spread to Taiwan and Australia. Furthermore, ABC analyses indicate that P. noxius spread occurred thousands of generations ago, contradicting previous assumptions that it was recently introduced in multiple areas. Our results suggest that recent emergence of P. noxius in east Asia, Australia, and the Pacific Islands is likely driven by anthropogenic and natural disturbances, including deforestation, land-use change, severe weather events, and introduction of exotic plants. This study provides a novel example of utilization of genome wide allele frequency data to unravel dynamics of pathogen emergence under conditions of changing ecosystems.

The Pacific Ocean as Highway to Gold Mountain

2017 ◽  
Author(s):  
Elizabeth Sinn
Keyword(s):  
United States ◽  
New Zealand ◽  
Pacific Ocean ◽  
Capital Flows ◽  
The United States ◽  
The West ◽  
New Era ◽  
The Pacific ◽  
History Of ◽  
The Pacific Ocean

This chapter takes a broad look at the Pacific Ocean in relation to Chinese migration. As trade, consumption and capital flows followed migrants, powerful networks were woven and sustained; in time, the networks fanned across the Pacific from British Columbia along the West Coast of the United States to New Zealand and Australia. The overlapping personal, family, financial and commercial interests of Chinese in California and those in Hong Kong, which provide the focus of this study, energized the connections and kept the Pacific busy and dynamic while shaping the development of regions far beyond its shores. The ocean turned into a highway for Chinese seeking Gold Mountain, marking a new era in the history of South China, California, and the Pacific Ocean itself.

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