scholarly journals Genetic diversity and connectivity of the megamouth shark (Megachasma pelagios)

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4432 ◽  
Author(s):  
Shang Yin Vanson Liu ◽  
Shoou Jeng Joung ◽  
Chi-Ju Yu ◽  
Hua-Hsun Hsu ◽  
Wen-Pei Tsai ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Based ◽  
The Philippines ◽  
Connectivity Pattern ◽  
Tissue Samples ◽  
Global Migration ◽  
Megamouth Shark ◽  
Satellite Tagging ◽  
The Kuroshio ◽  
Kuroshio Region

The megamouth shark (Megachasma pelagios) was described as a new species in 1983. Since then, only ca. 100 individuals have been observed or caught. Its horizontal migration, dispersal, and connectivity patterns are still unknown due to its rarity. Two genetic markers were used in this study to reveal its genetic diversity and connectivity pattern. This approach provides a proxy to indirectly measure gene flow between populations. Tissues from 27 megamouth sharks caught by drift nets off the Hualien coast (eastern Taiwan) were collected from 2013 to 2015. With two additional tissue samples from megamouths caught in Baja California, Mexico, and sequences obtained from GenBank, we were able to perform the first population genetic analyses of the megamouth shark. The mtDNA cox1 gene and a microsatellite (Loc 6) were sequenced and analyzed. Our results showed that there is no genetic structure in the megamouth shark, suggesting a possible panmictic population. Based on occurrence data, we also suggest that the Kuroshio region, including the Philippines, Taiwan, and Japan, may act as a passageway for megamouth sharks to reach their feeding grounds from April to August. Our results provide insights into the dispersal and connectivity of megamouth sharks. Future studies should focus on collecting more samples and conducting satellite tagging to better understand the global migration and connectivity pattern of the megamouth shark.

Interacting Legal Norms and Cross-Border Divorce: Stories of Filipino Migrant Women in the Netherlands

2019 ◽  
Vol 16 (4) ◽  
pp. 521-529
Author(s):  
Asuncion Fresnoza-Flot
Keyword(s):  
The Netherlands ◽  
The Philippines ◽  
Migrant Women ◽  
Structured Interviews ◽  
Legal Norms ◽  
Global Migration ◽  
Cross Border ◽  
Filipino Women ◽  
Transnational Social Spaces ◽  
Filipino Migrants

The Philippines is one of only two states in the world in which absolute divorce remains largely impossible. Through its family laws, it regulates the marriage, family life and conjugal separation of its citizens, including its migrants abroad. To find out how these family laws interact with those in the receiving country of Filipino migrants and shape their lives, the present paper examines the case of Filipino women who experienced or are undergoing divorce in the Netherlands. Drawing from semi-structured interviews and an analysis of selected divorce stories, it unveils the intertwined institutions of marriage and of divorce, the constraints but also possibilities that interacting legal norms bring in the life of Filipino women, and the way these migrants navigate such norms within their transnational social spaces. These findings contribute interesting insights into cross-border divorces in the present age of global migration.

scholarly journals Transcriptomic resources for prairie grass (Bromus catharticus): expressed transcripts, tissue-specific genes, and identification and validation of EST-SSR markers

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ming Sun ◽  
Zhixiao Dong ◽  
Jian Yang ◽  
Wendan Wu ◽  
Chenglin Zhang ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Ssr Markers ◽  
Large Scale ◽  
Genetic Research ◽  
High Yield ◽  
Yield Strain ◽  
Tissue Samples ◽  
Prairie Grass ◽  
The Future ◽  
Genomic Resource

Abstract Background Prairie grass (Bromus catharticus) is a typical cool-season forage crop with high biomass production and fast growth rate during winter and spring. However, its genetic research and breeding has remained stagnant due to limited available genomic resources. The aim of this study was to generate large-scale genomic data using high-throughput transcriptome sequencing, and perform a preliminary validation of EST-SSR markers of B. catharticus. Results Eleven tissue samples including seeds, leaves, and stems were collected from a new high-yield strain of prairie grass BCS1103. A total of 257,773 unigenes were obtained, of which 193,082 (74.90%) were annotated. Comparison analysis between tissues identified 1803, 3030, and 1570 genes specifically and highly expressed in seed, leaf, and stem, respectively. A total of 37,288 EST-SSRs were identified from unigene sequences, and more than 80,000 primer pairs were designed. We synthesized 420 primer pairs and selected 52 ones with high polymorphisms to estimate genetic diversity and population structure in 24 B. catharticus accessions worldwide. Despite low diversity indicated by an average genetic distance of 0.364, the accessions from South America and Asia and wild accessions showed higher genetic diversity. Moreover, South American accessions showed a pure ancestry, while Asian accessions demonstrated mixed internal relationships, which indicated a different probability of gene flow. Phylogenetic analysis clustered the studied accessions into four clades, being consistent with phenotypic clustering results. Finally, Mantel analysis suggested the total phenotypic variation was mostly contributed by genetic component. Stem diameter, plant height, leaf width, and biomass yield were significantly correlated with genetic data (r > 0.6, P < 0.001), and might be used in the future selection and breeding. Conclusion A genomic resource was generated that could benefit genetic and taxonomic studies, as well as molecular breeding for B. catharticus and its relatives in the future.

scholarly journals Distribution of ultraphytoplankton in the western part of the North Pacific subtropical gyre during a strong La Niña condition: relationship with the hydrological conditions

2013 ◽  
Vol 10 (9) ◽  
pp. 5947-5965 ◽  
Author(s):  
M. Girault ◽  
H. Arakawa ◽  
A. Barani ◽  
H. J. Ceccaldi ◽  
F. Hashihama ◽  
...  
Keyword(s):  
El Niño ◽  
North Pacific ◽  
El Nino ◽  
Subtropical Gyre ◽  
La Niña ◽  
North Pacific Subtropical Gyre ◽  
Heterogeneous Distribution ◽  
La Nina ◽  
The Kuroshio ◽  
Kuroshio Region

Abstract. The distribution of ultraphytoplankton was investigated in the western North Pacific Subtropical Gyre (NPSG) during La Niña, a cold phase of El Niño Southern Oscillation (ENSO). Observations were conducted in a north-south transect (33.6–13.25° N) along the 141.5° E meridian in order to study the ultraplankton assemblages in various oligotrophic conditions. Analyses were performed at the single cell level by analytical flow cytometry. Five ultraphytoplankton groups (Prochlorococcus, Synechococcus, picoeukaryotes, nanoeukaryotes and nanocyanobacteria-like) defined by their optical properties were enumerated in three different areas visited during the cruise: the Kuroshio region, the subtropical Pacific gyre and a transition zone between the subtropical Pacific gyre and the Warm pool. Prochlorococcus outnumbered the other photoautotrophs in all the investigated areas. However, in terms of carbon biomass, an increase in the relative contribution of Synechococcus, picoeukaryotes and nanoeukaryotes was observed from the centre of the subtropical gyre to the Kuroshio area. In the Kuroshio region, a peak of abundance of nanoeukaryotes observed at the surface suggested an increase in nutrients likely due to the vicinity of a cold cyclonic eddy. In contrast, in the salinity front along the isohaline 35 and anticyclonic eddy located around 22.83° N, the mainly constant distribution of Prochlorococcus from the surface down to 150 m characterised the dominance by these microorganisms in high salinity and temperature zone. Results suggested that the distribution of nanocyanobacteria-like is also closely linked to the salinity front rather than low phosphate concentration. The maximum abundance of ultraphytoplankton was located above the SubTropical Counter Current (STCC) at depths > 100 m where higher nutrient concentrations were measured. Finally, comparison of the ultraphytoplankton concentrations during El Niño (from the literature) and La Niña (this study) conditions seems to demonstrate that La Niña conditions lead to higher concentrations of Synechococcus in the Subtropical gyre and a lower abundance of Synechococcus in the Kuroshio region. Our results suggest that the west part of NPSG is a complex area, where different water masses, salinity fronts and eddies lead to a heterogeneous distribution of ultraphytoplankton assemblages in the upper layer of the water column.

scholarly journals Phytoplankton Increase Along the Kuroshio Due to the Large Meander

2021 ◽  
Vol 8 ◽  
Author(s):  
Daniel Andres Lizarbe Barreto ◽  
Ricardo Chevarria Saravia ◽  
Takeyoshi Nagai ◽  
Takafumi Hirata
Keyword(s):  
Chlorophyll A ◽  
Mixed Layer Depth ◽  
Local Environment ◽  
Trophic Levels ◽  
Large Meander ◽  
The Mean ◽  
Western Side ◽  
The Kuroshio ◽  
Cold Core ◽  
Kuroshio Region

The Kuroshio Large Meander (LM) is known to be highly aperiodic and can last from 1 to 10 years. Since a stationary cold core formed between the Kuroshio and the southern coast of Japan off Enshu-Nada and approaching warm saltier water on the eastern side of the LM changes the local environment drastically, many commercially valuable fish species distribute differently from the non-LM period, impacting local fisheries. Despite this importance of the LM, the influences of the LM on the low trophic levels such as phytoplankton and zooplankton have still been unclear. In this study, satellite daily sea surface chlorophyll data are analyzed in relation to the LM. The results show positive anomalies of the chlorophyll-a concentration along the Kuroshio path during the LM periods, 2004–2005 and 2017–2019, from the upstream off Shikoku to the downstream (140°E). These positive anomalies are started by the triggering meander generated off south of Kyushu, which then slowly propagates to the downstream LM region in both the LM periods. Even though the detailed patterns along the Kuroshio region in the two LM periods were different, similar formations of the positive anomalies on the western side of the LM with shallower mixed layer depth are observed. Furthermore, we found clear relationships between the minimum distance from several stations along the coast to the Kuroshio axis and the mean chlorophyll-a anomaly, with significant correlations with the distance from different stations.

scholarly journals Blending coral restoration science and practice: A novel approach to Acropora population enhancement.

2018 ◽  
Author(s):  
Jessica S Levy ◽  
Kayla J Ripple ◽  
Ken Nedimyer ◽  
Scott R Winters
Keyword(s):  
Genetic Diversity ◽  
Population Based ◽  
Acropora Cervicornis ◽  
Recovery Plan ◽  
Innovative Methods ◽  
Novel Approach ◽  
Restoration Techniques ◽  
Caribbean Coral Reefs ◽  
Reef Tract ◽  
Restoration Strategies

Florida and Caribbean coral reefs are in a state of unprecedented decline. Reefs once dominated by branching, hard-coral species, Acropora cervicornis and A. palmata, have lost upwards of 98% of Acroporid cover in recent decades. This decline is attributed to multiple, compounding factors. As these threats continue, there is a clear need for innovative methods to bolster remaining populations thus signaling to managers that intervention is needed to support recovery of the species. The urgency around coral decline has prompted practitioners to try a variety of restoration techniques. While promising, efforts need to incorporate best-practices of supporting genetic diversity, ecological function, and resiliency for successful coral restoration outcomes. Herein we present novel approaches to coral population enhancement (coral restoration) that blend science and practice. Guided by NOAA’s Acropora Recovery Plan, we have implemented an ambitious restoration plan to outplant 50,700 corals using both Acropora species across eight reefs along the Florida Reef Tract. The restoration strategies presented here are designed to meet several population-based recovery objectives and criteria identified in the Acropora Recovery Plan including: increasing abundance, promoting genetic diversity, promoting recruitment, and disease mitigation (as informed by monitoring).

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