scholarly journals Vorticella and Colacium as epibionts of copepods in Pasig river, Philippines

2020 ◽  
Vol 14 (1) ◽  
Keyword(s):  
Algal Blooms ◽  
Calanoid Copepod ◽  
High Salinity ◽  
Total Dissolved Solids ◽  
The Philippines ◽  
Calanoid Copepods ◽  
Manila Bay ◽  
Laguna De Bay ◽  
The Tropics ◽  
Caudal Rami

The chitinous exoskeleton of copepods serves as a scaffold for microepibionts such as protozoa. Although copepods are highly cosmopolitan, their associated epibionts in the tropics are poorly known. This study presents the first account in the Philippines of the ciliate Vorticella on calanoid copepod Arctodiaptomus dorsalis and both Vorticella and the euglenoid Colacium on the cyclopoid copepods Thermocyclops crassus and Mesocyclops microlasius in the Pasig River. Infestation, however, was low at 0.83% (108 out of 13,039) observed copepods from four collection sites in January-May and July-December 2018. Interestingly, Vorticella and Colacium were frequently observed in cyclopoid than on calanoid copepods, predominantly on the urosome, thorax, cephalosome of copepodites and adult stages of copepods. Colacium was also found attached on the antennules, swimming legs, caudal rami and setae. Prevalence of epibionts was site-related; Vorticella being more abundant in waters near Manila Bay (Site 1) where high salinity, conductivity and total dissolved solids were recorded while Colacium was found more near Laguna de Bay (Site 4). Both were abundantly present in September and absent in May, due to increased inflow of seawater from Manila Bay. Nevertheless, overall low infestation resulted in neither significant spatial nor temporal variation of epibiosis in Pasig River, probably due to heavy loadings of wastewater from nearby tributaries, noticeable algal blooms, detachment of epibionts by predations and changes in water chemistry.

scholarly journals New record of Phyllodiaptomus (Ctenodiaptomus) praedictus sulawensis Alekseev & Vaillant, 2013 (Hexanauplia, Copepoda, Calanoida, Diaptomidae) in the Philippines (Luzon Island)

2018 ◽  
Vol 12 (2) ◽  
Keyword(s):  
New Record ◽  
Calanoid Copepod ◽  
Country Of Origin ◽  
Morphological Characters ◽  
The Philippines ◽  
Freshwater Ecosystems ◽  
Morphological Data ◽  
Calanoid Copepods ◽  
Line Drawings ◽  
Baseline Information

A study originally intended to update the taxonomy and distribution of calanoid copepods in selected freshwater ecosystems of Central Luzon has led to the discovery of a new record of Phyllodiaptomus Kiefer, 1936 in Candaba Swamp, Pampanga. Since 1979, the only calanoid copepods recorded from this area included Filipinodiaptomus insulanus (Wright S., 1928) and Tropodiaptomus australis Kiefer, 1936. Later studies on calanoid copepods in the region have since been non-existent. Analyses of pertinent key morphological characters revealed that the specimens at hand belonged to Phyllodiaptomus (Ctenodiaptomus) praedictus sulawensis Alekseev & Vaillant, 2013, a freshwater diaptomid calanoid copepod subspecies discovered and known to be endemic only in Indonesia. Provided in this paper are baseline information on the morphological characters of the Philippine members of the subspecies accompanied by line drawings as well as a comparison between the recorded morphological data presented by Alekseev, Haffner, Vaillant & Yusoff (2013) and the current dataset to support the identification of the specimen. The discovery of P. (C.) praedictus sulawensis in the Philippines, which was thought to be endemic in Indonesia, presents a new record of this species in the country and the first such record outside of its country of origin.

scholarly journals Chance long-distance or human-mediated dispersal? How Acacia s.l. farnesiana attained its pan-tropical distribution

2017 ◽  
Vol 4 (4) ◽  
pp. 170105 ◽  
Author(s):  
Karen L. Bell ◽  
Haripriya Rangan ◽  
Manuel M. Fernandes ◽  
Christian A. Kull ◽  
Daniel J. Murphy
Keyword(s):  
The Philippines ◽  
Historical Sources ◽  
Long Distance ◽  
Old World ◽  
South Central ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Spanish Explorers ◽  
The Tropics ◽  
Old World Tropics

Acacia s.l. farnesiana , which originates from Mesoamerica, is the most widely distributed Acacia s.l. species across the tropics. It is assumed that the plant was transferred across the Atlantic to southern Europe by Spanish explorers, and then spread across the Old World tropics through a combination of chance long-distance and human-mediated dispersal. Our study uses genetic analysis and information from historical sources to test the relative roles of chance and human-mediated dispersal in its distribution. The results confirm the Mesoamerican origins of the plant and show three patterns of human-mediated dispersal. Samples from Spain showed greater genetic diversity than those from other Old World tropics, suggesting more instances of transatlantic introductions from the Americas to that country than to other parts of Africa and Asia. Individuals from the Philippines matched a population from South Central Mexico and were likely to have been direct, trans-Pacific introductions. Australian samples were genetically unique, indicating that the arrival of the species in the continent was independent of these European colonial activities. This suggests the possibility of pre-European human-mediated dispersal across the Pacific Ocean. These significant findings raise new questions for biogeographic studies that assume chance or transoceanic dispersal for disjunct plant distributions.

Terminalia catappa (Singapore almond).

2021 ◽  
Author(s):  
Julissa Rojas-Sandoval
Keyword(s):  
Indian Ocean ◽  
Plant Communities ◽  
Western Indian Ocean ◽  
Agroforestry Systems ◽  
The Philippines ◽  
Vital Role ◽  
South East Asia ◽  
Edible Fruit ◽  
Tree Component ◽  
The Tropics

Abstract T. catappa is a hardy, fast-growing, deciduous multipurpose tree, reaching 25 (-40) m tall and producing an edible fruit. It plays a vital role in coastline stabilization as a tree component of strandline plant communities in the western Indian Ocean, South-East Asia and the South Pacific. Under suitable conditions it is a well-formed tree and has been widely planted throughout the tropics for shade, ornament and nuts, especially along sandy seashores (Heinsleigh and Holaway, 1988; Little and Skolmen, 1989). It is much used in agroforestry systems in the Philippines.

Application of Miscible Ethane Foam for Gas EOR Conformance in Low-Permeability Heterogeneous Harsh Environments

SPE Journal ◽  
2020 ◽  
Vol 25 (04) ◽  
pp. 1871-1883
Author(s):  
Mohamad Salman ◽  
Konstantinos Kostarelos ◽  
Pushpesh Sharma ◽  
Jae Ho Lee
Keyword(s):  
Oil Recovery ◽  
High Salinity ◽  
Total Dissolved Solids ◽  
Harsh Environments ◽  
Low Permeability ◽  
Type I ◽  
Fracture Networks ◽  
Operational Conditions ◽  
Minimum Miscibility Pressure ◽  
Carbon Dioxide Co2

Summary Unconventional plays pose a challenging set of operational conditions, including high temperature, high salinity, low permeability, and fracture networks. Aggressive development of these plays and the low primary recovery factors present an opportunity for using enhanced oil recovery (EOR) methods. This work presents a laboratory investigation of miscible ethane (C2H6) foam for gas EOR conformance in low-permeability, heterogeneous, harsh environments [<15 md, 136,000 ppm total dissolved solids (TDS) with divalent ions, 165°F]. The use of C2H6 as an alternative to carbon dioxide (CO2) offers several operational and availability strengths, which might expand gas EOR applications to depleted or shallower wells. Coupling gas conformance also helps improve displacement efficiencies and maximize overall recovery. Minimum miscibility pressure (MMP) displacement tests were performed for dead crude oil from the Wolfcamp Spraberry Trend area using C2H6 and CO2. Aqueous stability, salinity scan, and static foam tests were performed to identify a formulation. Subsequent foam quality and coreflood displacement tests in heterogeneous carbonate outcrop cores were conducted to compare the recovery efficiencies of three processes: gravity-unstable, miscible C2H6 foam; gravity-stable, miscible C2H6; and gravity-unstable, miscible C2H6 processes. Slimtube tests comparing C2H6 to CO2 resulted in a lower MMP value for C2H6. We identified a stable surfactant blend capable of Type I microemulsion and persistent foams in the presence of oil. Corefloods conducted with gravity-unstable miscible C2H6 foam, gravity-stable miscible C2H6, and gravity-unstable miscible C2H6 recovered 98.4, 61.9, and 42.6% oil originally in place, respectively. Our work shows that miscible C2H6 injection processes achieved significant recoveries even under gravity-unstable conditions. The addition of foam provides better conformance control, enhancing overall recovery at the laboratory scale, showing promise for field applications.

scholarly journals Breeding Temperate Japonica Rice Varieties Adaptable to Tropical Regions: Progress and Prospects

Agronomy ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2253
Author(s):  
Myrish Pacleb ◽  
O-Young Jeong ◽  
Jeom-Sig Lee ◽  
Thelma Padolina ◽  
Rustum Braceros ◽  
...  
Keyword(s):  
The Philippines ◽  
Tropical Region ◽  
Japonica Rice ◽  
Rice Varieties ◽  
Temperate Japonica ◽  
Tropical Regions ◽  
Tropical Environments ◽  
Increasing Demand ◽  
Northeast Asian ◽  
The Tropics

Temperate japonica rice is mainly cultivated in temperate regions. Many temperate japonica varieties have a superior grain quality that is preferred in Northeast Asian countries such as Japan, Korea, and China. The changes in consumers’ preferences in Southeast Asia and Western countries has contributed to increasing the demand for temperate japonica. Most temperate japonica varieties developed in temperate regions typically exhibit extra-early flowering under the short-day conditions in the tropics, which usually results in severely reduced yields. Since 1992, we have been developing temperate japonica varieties that can adapt to tropical environments to meet the increasing demand for temperate japonica rice, having released six varieties in the Philippines. Especially, the yield of one of the temperate japonica varieties, Japonica 7, was comparable to the yields of leading indica varieties in the Philippines. Here, we discuss the current breeding initiatives and future plans for the development of tropical-region-bred temperate japonica rice.

scholarly journals Species Composition of Algal Epiphyton of Pink Lotus (Nymphaea pubescens Willd) Found in Laguna de Bay (Philippines)

2019 ◽  
Vol 17 (3) ◽  
pp. 237-256
Author(s):  
Eldrin De Los Reyes ARGUELLES
Keyword(s):  
Species Composition ◽  
The Philippines ◽  
Freshwater Ecosystems ◽  
Taxonomic Study ◽  
Habitat Distribution ◽  
Epiphytic Algae ◽  
Freshwater Habitats ◽  
Laguna De Bay ◽  
Root Tissues ◽  
First Time

In spite of the fact that epiphytic algae are considered an important component of freshwater ecosystems, our knowledge of their diversity and distribution is still rather poor. Taxonomic study on the composition of epiphytic algae living on submerged leaf and root tissues of macrophyte Nymphaea pubescens Willd, found at Laguna de Bay (Philippines), was conducted. In total, 21 algal taxa were identified: 10 Cyanophyceae, 6 Trebouxiophyceae, and 5 Bacillariophyceae. The taxa described in this study represent 13 orders, 16 families, 18 genera, and 21 species based on the recent combined taxonomical approach. Of these taxa, the occurrence of a rare cyanobacteria, Chroococcus schizodermaticus West, is reported for the first time in the Philippines. One species is also reported here for the first time in the Philippines, based on current taxonomic nomenclature, and this is Cyanothece aeruginosa (Nägeli) Komárek, which is based on the former name of Synechococcus aeruginosus Nägeli. These taxonomic records are considered important basal information in enriching the knowledge about the diversity and habitat distribution of cyanobacteria and microalgae in macrophytes found in freshwater habitats in the Philippines.

scholarly journals On the evolution and molecular epidemiology of the potyvirus Papaya ringspot virus

2002 ◽  
Vol 83 (10) ◽  
pp. 2575-2585 ◽  
Author(s):  
Marion F. Bateson ◽  
Rosemarie E. Lines ◽  
Peter Revill ◽  
Worawan Chaleeprom ◽  
Cuong V. Ha ◽  
...  
Keyword(s):  
Molecular Epidemiology ◽  
Indian Subcontinent ◽  
Phylogenetic Analyses ◽  
The Philippines ◽  
Ringspot Virus ◽  
Population Variation ◽  
Watermelon Mosaic Virus ◽  
Papaya Ringspot Virus ◽  
Long Distance ◽  
The Tropics

The potyvirus Papaya ringspot virus (PRSV) is found throughout the tropics and subtropics. Its P biotype is a devastating pathogen of papaya crops and its W biotype of cucurbits. PRSV-P is thought to arise by mutation from PRSV-W. However, the relative impact of mutation and movement on the structure of PRSV populations is not well characterized. To investigate this, we have determined the coat protein sequences of isolates of both biotypes of PRSV from Vietnam (50), Thailand (13), India (1) and the Philippines (1), and analysed them together with 28 PRSV sequences already published, so that we can better understand the molecular epidemiology and evolution of PRSV. In Thailand, variation was greater among PRSV-W isolates (mean nucleotide divergence 7·6%) than PRSV-P isolates (mean 2·6%), but in Vietnamese populations the P and W biotypes were more but similarly diverse. Phylogenetic analyses of PRSV also involving its closest known relative, Moroccan watermelon mosaic virus, indicate that PRSV may have originated in Asia, particularly in the Indian subcontinent, as PRSV populations there are most diverse and hence have probably been present longest. Our analyses show that mutation, together with local and long-distance movement, contributes to population variation, and also confirms an earlier conclusion that populations of the PRSV-P biotype have evolved on several occasions from PRSV-W populations.

Sign in / Sign up

Export Citation Format

Share Document