Revision of the Alitta virens species complex (Annelida: Nereididae) from the North Pacific Ocean

Zootaxa ◽  
2018 ◽  
Vol 4483 (2) ◽  
pp. 201 ◽  
Author(s):  
TULIO F. VILLALOBOS-GUERRERO ◽  
TORKILD BAKKEN
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
Species Complex ◽  
North Pacific Ocean ◽  
Valid Species ◽  
Distinctive Features ◽  
The North ◽  
The Status ◽  
First Time ◽  
The North Pacific

Alitta virens species complex encompasses elongate nereidids appreciated commercially both in the fishing and aquaculture industries. This complex has been well studied in biological and ecological terms. Nevertheless, detailed taxonomic analyses have scarcely been addressed, to the extent that only a few species in the complex have been recognized as valid but with some difficulties: Alitta brandti Malmgren, 1865 (Sea of Okhotsk), A. grandis (Stimpson, 1853) (northeastern USA) and A. virens (Sars, 1835) (Norway). Whereas, other several species have typically been regarded as synonyms, including those originally described from the North Pacific Ocean: Nereis (Alitta) virens plenidentata Moore, 1909 (California, USA), Nereis dyamusi Izuka, 1912 (Japan) and Nereis foliata Baird, 1863 (Vancouver, Canada). In this study, an examination of the immature and epitoke type and non-type material available for the A. virens species complex from the North Pacific was carried out. Herein, the status of A. brandti as a valid species is reinforced being clearly distinct from A. virens and related species. Alitta dyamusi n. comb., A. plenidentata n. comb. and A. williami nom. nov. are reinstated and transferred to Alitta, the specific epithet of the latter species is a replacement name for Nereis foliata Baird, 1863, which is a junior, primary homonym of Nereis foliata Dalyell, 1853. Lectotypes for A. plenidentata n. comb. and A. williami nom. nov. are designated. The North Pacific species of the A. virens complex, excluding A. plenidentata n. comb. which has several distinctive features that differ from all the Alitta species, are characterized by having homogomph spinigers in both supracicular and subacicular neurochaetae, oral ring with a larger number of rows and paragnaths, and epitoke males with unmetamorphosed pygidium and epitoke-modified chaetae in both neuropodial fascicles. The morphology of epitoke females in the A. virens complex is described for the first time. Identification keys to atoke and epitoke species of this complex are also provided. 

Distribution and Morphology of the Medusa, Calycopsis nematophora, from the North Pacific Ocean

1965 ◽  
Vol 22 (3) ◽  
pp. 841-847 ◽  
Author(s):  
R. Ward Renshaw
Keyword(s):  
Pacific Ocean ◽  
Surface Waters ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Original Description ◽  
Morphological Characters ◽  
Radial Canal ◽  
The North ◽  
First Time ◽  
The North Pacific

The medusa, Calycopsis nematophora, is reported from the North Pacific for the first time since its original description. It is restricted to arctic-subarctic surface waters. Radial canal variation and other morphological characters are discussed.

scholarly journals International Dimension in Colonization of the North-West of America and California at the End of the 17-18 th Centuries

2020 ◽  
Vol 13 (5) ◽  
pp. 7-30
Author(s):  
A. Y. Petrov ◽  
V. N. Kostornichenko ◽  
M. M. Koskina
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Local Population ◽  
Northwest Pacific ◽  
The North ◽  
The Pacific ◽  
The Pacific Ocean ◽  
First Time ◽  
The North Pacific

The article reviews the initial period of European colonization of the North Pacific Ocean and California within the context of diplomatic relations between Russia and Spain during the late 17th and early 18th centuries. It tries to understand the policies of European powers in the American Northwest and the reasons for pursuing their colonial interests there. It analyses the history of exploration of these territories, expeditions to the northern part of the Pacific Ocean, and historical maps of this region. For the first time in Russian historiography the authors touch upon the exploration of California in the 18th century.The exploration of the North Pacific Ocean, the northwestern American coast, including certain areas of California, Alaska and the Aleutian Islands has long attracted the attention of European powers. It was a process in which government authorities and private merchant companies took part. The expansion of the Spanish Empire into California was made possible in part because of the concerns of the Madrid court about the strengthening of the Russian and British empires in the North Pacific Ocean. The Spanish documents from the archives of Madrid, Seville and Simancas – the article introduces them into research communication the first time - show the validity of the fears of the Madrid court regarding the inevitable development of Russian colonization in the region. The advance of Russia to the shores of America has economic reasons: Cossacks and merchants reached the Pacific Ocean pursuing the desire to profit from the fur trade. As the economic influence expanded, the state interests of annexing territories and bringing the local population into citizenship followed behind. The territorial advance of the Russians to the Pacific Ocean was facilitated by the ambitious, but at the same time balanced diplomacy of Peter I, which managed to ensure the expansion of the borders of the Russian Empire.Spanish consolidation in certain territories in California was aimed at a possible containment of the Russian advance. Russian-Spanish relations in the Northwest Pacific at the end of the 17th – 18th centuries contributed to the nature of the subsequent development of territories in the North Pacific Ocean.

scholarly journals Neural Network Approach to Retrieving Ocean Subsurface Temperatures from Surface Parameters Observed by Satellites

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 388
Author(s):  
Hao Cheng ◽  
Liang Sun ◽  
Jiagen Li
Keyword(s):  
Neural Network ◽  
Pacific Ocean ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Sea Surface ◽  
Satellite Measurements ◽  
Surface Parameters ◽  
The North ◽  
The North Pacific ◽  
Bpnn Model

The extraction of physical information about the subsurface ocean from surface information obtained from satellite measurements is both important and challenging. We introduce a back-propagation neural network (BPNN) method to determine the subsurface temperature of the North Pacific Ocean by selecting the optimum input combination of sea surface parameters obtained from satellite measurements. In addition to sea surface height (SSH), sea surface temperature (SST), sea surface salinity (SSS) and sea surface wind (SSW), we also included the sea surface velocity (SSV) as a new component in our study. This allowed us to partially resolve the non-linear subsurface dynamics associated with advection, which improved the estimated results, especially in regions with strong currents. The accuracy of the estimated results was verified with reprocessed observational datasets. Our results show that the BPNN model can accurately estimate the subsurface (upper 1000 m) temperature of the North Pacific Ocean. The corresponding mean square errors were 0.868 and 0.802 using four (SSH, SST, SSS and SSW) and five (SSH, SST, SSS, SSW and SSV) input parameters and the average coefficients of determination were 0.952 and 0.967, respectively. The input of the SSV in addition to the SSH, SST, SSS and SSW therefore has a positive impact on the BPNN model and helps to improve the accuracy of the estimation. This study provides important technical support for retrieving thermal information about the ocean interior from surface satellite remote sensing observations, which will help to expand the scope of satellite measurements of the ocean.

scholarly journals Nursery origin and population connectivity of swordfish Xiphias gladius in the North Pacific Ocean

2021 ◽  
Author(s):  
R. J. David Wells ◽  
Veronica A. Quesnell ◽  
Robert L. Humphreys ◽  
Heidi Dewar ◽  
Jay R. Rooker ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Population Connectivity ◽  
The North ◽  
Xiphias Gladius ◽  
The North Pacific

scholarly journals Direct observations of basin-wide acidification of the North Pacific Ocean

2010 ◽  
Vol 37 (2) ◽  
pp. n/a-n/a ◽  
Author(s):  
Robert H. Byrne ◽  
Sabine Mecking ◽  
Richard A. Feely ◽  
Xuewu Liu
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
North Pacific Ocean ◽  
The North ◽  
Direct Observations ◽  
The North Pacific
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