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Zootaxa ◽  
2022 ◽  
Vol 5091 (4) ◽  
pp. 587-597
Author(s):  
MASAYUKI OSAWA ◽  
TAIGI SATO

The new porcellanid crab Polyonyx deezi n. sp. is described on the basis of two specimens from Okinawa Island, Ryukyu Islands, southwestern Japan. The new species belongs to the P. sinensis group and may be closest to P. socialis Werding & Hiller, 2019 in the comparatively broad proportions of the carpi of the chelipeds and meri of the ambulatory legs. However, P. deezi n. sp. is immediately distinguished from all other congeners by the median branchial margins of the carapace being bluntly angular and produced laterally and the dorsal surfaces of the carapace and chelipeds with distinct protuberances. The occurrence of P. deezi n. sp. from coral reefs may be unusual in species of the P. sinensis group because many of the known species have been recorded from estuaries or coastal embayments. An identification key to the Indo-West Pacific species of the Polyonyx sinensis group is provided.  


2021 ◽  
Vol 47 (3) ◽  
pp. 77-78
Author(s):  
Khoiril Anwar Maryunani

Recent global warming has been addressed due to human activity that causes increased greenhouse gases. However, there are inherent uncertainties in the statement, one of them is the level of natural variability inherent in the climate system. Climate data from measuring instruments are not long enough to evaluate climate variability and current climate evolution. Therefore, we need climate data that has a long back span. To get adequate past climate data, we need natural phenomena which are climate dependent. This natural phenomenon provides a proxy record of the climate. This study of proxy data is the foundation of palaeoclimatology and paleoceanography. Microfossils (i.e., foraminifera, palynomorphs, nannofossils) which in geology are used as a standard tool in biostratigraphy for both age determination and paleoenvironment and correlation, can also be used as a proxy for obtaining paleoclimate and paleoceanography data. Using microfossil as a proxy to study past climate and paleoceanography, we need an understanding of the type of proxy data available and methods used in their analysis.In addition to the dating method (biostratigraphy), there are many climate and oceanography parameters that can be obtained from microfossil proxies such as: sea surface temperature (SST), sea surface salinity, (SST) climate (warm, cold, dry, wet), precipitation, productivity, oxygen content and organic carbon level, deep sea current and ventilation/upwelling, thermocline and mixed layer, variability deep water properties, CCD, bathymetry, sea level change and dissolution. The methods to obtain data fall into some categories e.g., faunal/floral displacement, morphology changes, transfer function/modern analog and isotopic content. Another method that can be used is observing microfossil assemblages and link them to ecological changes associated with climate change and its paleoceanography.A paleoclimate and paleoceanography study using microfossil proxies has been conducted in the Cendrawasih bay, Papua, Indonesia. The study shows that climate in the tropical west Pacific margin (Cendrawasih bay) during Late Pleistocene to Holocene shows high variability. There are nineteen climate changes occurred during Holocene. Early Holocene dated as ca. 11,800-year BP marked by rapid warming with SST differences to last glacial is about 4oC. Early to Middle Holocene (ca. 5960-year BP) marked by increasing temperature up to 2oC, interrupted by cooling at ca. 11230-, 8310- and 7120-years BP. At Middle Holocene temperature decreased rapidly and reached its peak at around ca. 3150-year BP. After cooling at ca. 3150-year BP, temperature increased and then decreased with its peak at ca. 1710-year BP. Since ca. 1710-year BP to Recent, temperature shows warming trend. SST from MAT indicates warming environment near to 1.5oC. The warming trend was interrupted by rapid cooling and warming at ca. 300-year BP. This last warming trend indicates that global warming had started before industrial era and rapid cooling, or warming can occur without anthropogenic gases influence. The typical Holocene climate of warm-wet, dry-cold reverse and become warm-dry, cold-wet during ca. 790-370-year BP and then reversed back to preceding state.Semi-restricted basin occurred since last glacial with anaerobic condition and estuarine circulation system. Warming during interstadial 1e-1a, causing reverse water circulation and basin become sub-aerobic with anti-estuarine circulation. A lot of terrestrial organic matter flow to the bay and increase acidity and carbonate dissolution. High sedimentation found occurred during glacial period especially at the end of glacial period. Rapid warming during late glacial to middle Holocene, rising relative sea level and the bay become more open marine with well oxygenated bottom water and high marine productivity. Warm temperature and deeper thermocline depth (~ 250 m) in west Pacific occurred up to ca. 5960-year BP. Decreasing Sea surface temperature at ca. 5960-year BP and drop of relative sea level causing sub-aerobic condition inside bay. The semi-restricted state with sub-aerobic condition occurred up to Recent.Distribution of Sphaeroidinella group in the tropical west Pacific shows strong correlation with thermocline depth and reflect El Niño frequency event. Early middle Holocene dominated by La Niña-like condition and since Middle Holocene (ca. 5960-year BP) frequent El Niño event began to occur. 


Crustaceana ◽  
2021 ◽  
Vol 94 (11-12) ◽  
pp. 1313-1325
Author(s):  
Elisabeth Mock ◽  
Christoph D. Schubart

Abstract The genus Metopograpsus H. Milne Edwards, 1853 is widespread throughout the Indo-West Pacific and currently consists of seven species that can only be separated by minor morphological differences. Therefore, it represents a good example for the usefulness of genetic analyses for identification and classification. In order to obtain phylogenetic information at both lower and higher evolutionary levels, it is best to use a combination of mitochondrial and nuclear molecular markers. Here we present for the first time a molecular phylogeny based on a relative long fragment of the 28S rRNA nuclear gene for the genus Metopograpsus, after application of newly developed primers. Our data suggest an alternative intrageneric speciation order, with M. thukuhar and M. cannicci holding a basal position and a monophyletic grouping of M. frontalis, M. oceanicus and M. quadridentatus, which differs from prior phylogenetic reconstructions. Previously recognized intraspecific phylogeographic patterns in M. latifrons and M. quadridentatus could not be confirmed, due to limited variability of this conserved nuclear gene and due to an incomplete geographic coverage of the corresponding species. In contrast, the previously indicated phylogenetic subdivision within the formerly widespread species M. thukuhar, which led to the recent description of M. cannicci, is here supported.


Crustaceana ◽  
2021 ◽  
Vol 94 (11-12) ◽  
pp. 1395-1405
Author(s):  
Yanrong Wang ◽  
Zhongli Sha ◽  
Xianqiu Ren

Abstract A new species of Eusiridae, Eusirus liui sp. nov. is described from a hydrothermal vent on Okinawa Trough, North-West Pacific. The new species differs from the other 30 congeneric species mainly by the following combination of characters: the acute rostrum reaching to 1/3 the length of peduncular article 1 of antenna 1; the absence of eyes; pleonite 3 without acute protrusion on dorsal margin, and the posterior margin of epimeron 3 with 18 serrations. A key to all known Eusirus species is provided herein. This is the fourth species within the Eusiridae that has been found from vent fields.


ZooKeys ◽  
2021 ◽  
Vol 1076 ◽  
pp. 151-182
Author(s):  
Takato Izumi ◽  
Takuma Fujii

Edwardsianthus England, 1987 is a genus of Edwardsiidae, a family of burrowing and worm-like sea anemones characterized by lacking four mesenteries in the first cycle and containing only one type of nematocysts in nemathybomes. Until now, this genus has accommodated only two species since its establishment and has been recorded only from Indo-West Pacific regions. In this study, six species are reported from Japan: two are previously known species, E. pudicus (Klunzinger, 1877) and E. gilbertensis (Carlgren, 1931); four are new species, E. carbunculussp. nov., E. sapphirussp. nov., E. smaragdussp. nov., and E. amethystussp. nov. Based on these results, the diagnostic features of the genus are revised.


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