scholarly journals Preliminary observations on living <i>Krithe praetexta praetexta</i> (Sars, 1866), <i>Sarsicytheridea bradii</i> (Norman, 1865) and other marine ostracods in aquaria

1995 ◽  
Vol 14 (2) ◽  
pp. 96-96 ◽  
Author(s):  
Stefan Majoran ◽  
Stefan Agrenius
Keyword(s):  
Water Content ◽  
Water Depth ◽  
West Coast ◽  
Dominant Species ◽  
Research Station ◽  
Sediment Layer ◽  
Marine Research ◽  
Morphological Variations ◽  
Sieve Fraction ◽  
Mode Of Life

Abstract. More than fifty years ago, Elofson (1941) showed that it is fully possible to maintain living cultures of marine ostracods in aquaria. He concentrated particularly on determining the generation length of several species. In this study, we provide some preliminary observations on the mode of life and morphological variations of marine ostracods kept in aquaria. They derive from a water depth of 40m in the Gullmar Fjord (58°17′N and 11°29′E), west coast of Sweden. The dominant species are Krithe praetexta praetexta (Sars, 1866) and Sarsicytheridea bradii (Norman, 1865). Other species housed in the aquaria are: Jonesia acuminata (Norman, 1865), Palmoconcha guttata (Norman, 1865), Palmoconcha laevata (Norman, 1865), Cytheropteron latissimum (Norman, 1865), Pterygocythereis jonesii (Baird, 1850), Acanthocythereis dunelmensis (Norman, 1865), Robertsonites tuberculatus (Sars, 1866), Elofsonella concinna (Jones, 1857) and Argilloecia conoidea (Sars, 1923).MATERIAL AND METHODSThe study was carried out at the Kristineberg Marine Research Station, west coast of Sweden, from July of 1992 to June of 1994. Sediment from a depth of 40 m in the Gullmar Fjord was sieved to remove the macrofauna and frozen, then thawed to constitute a 10–20 mm thick sediment layer in two 501 aquaria. The sediment consisted of 8 % sand (>63 μm), 44 % silt (>3.9 μm) and 49 % clay (<3.9 μm), and with a water content of 71 % ± 5% (σ = 2.4). Ostracods from the ≥250 μm sieve fraction of the dredge sample (from a depth of 40 m) were added to the aquaria. They were kept. . .

The study of the effectiveness of corrosion protection of zinc-rich coating on the base of water sodium silicate

2020 ◽  
Vol 25 (4) ◽  
Keyword(s):  
Corrosion Protection ◽  
Sodium Silicate ◽  
Electrochemical Impedance ◽  
Paint Film ◽  
Salt Spray ◽  
Salt Spray Test ◽  
Test Method ◽  
Liquid Sodium ◽  
Research Station ◽  
Marine Research

The study is examines the assessment of the corrosion-protective properties of zinc-rich coating based on water sodium silicate (ZRC) using the Electrochemical Impedance Spectra (EIS) with AutoLAB PGSTAT204N. The system consists of three electrodes: Ag/AgCl reference electrode in 3 M solution of KCl, auxiliary electrode – Pt (8x8 mm) and working electrodes for determination potential (Ecorr) and impedance measurement, salt spray test method and natural teszzt method at Dam Bay Marine Research Station, Nha Trang, Khanh Hoa, Viet Nam. ZSC can provide good cathodic protection when zinc content is 70% by weight or more. ZSC with a mixing ratio of High Modulus Liquid Sodium Glass / Zinc Powde : 25/75 by weight (working title – TTL-VN) has good corrosion protection after 16 cycles salt spray test and after 18 months natural test in seawater. The paint film has basic parameters as adhesion – 4,41 MPa, flexural strength – 2 mm, pendulum hardness – 0,62 conventional units and initial coating potentia l – 0,96 V Ag/AgCl.

Iospilids (Polychaeta: Iospilidae) from the northwest Caribbean Sea, with observations on reproductive structures

Zootaxa ◽  
2006 ◽  
Vol 1211 (1) ◽  
pp. 53 ◽  
Author(s):  
SOLEDAD JIMÉNEZ-CUETO ◽  
EDUARDO SUÁREZ-MORALES ◽  
SERGIO I. SALAZAR-VALLEJO
Keyword(s):  
Caribbean Sea ◽  
Common Species ◽  
Eastern Coast ◽  
Reproductive Process ◽  
Morphological Variations ◽  
Reproductive Structures ◽  
Morphological Adaptations ◽  
The Family ◽  
Mode Of Life ◽  
The Caribbean

Iospilids are a small, inconspicuous group of holopelagic polychaetes that dwell in the upper layers of tropical, temperate, and cold waters of the world. Representatives of this interesting and infrequent group were collected during four oceanographic cruises off the eastern coast of the Yucatan Peninsula, northwest Caribbean Sea. Three of the four species currently known in the family were recorded: Iospilus phalacroides Viguier, 1886, Phalacrophorus pictus Greeff, 1879, and P. uniformis Reibisch, 1895. The latter was the most common species in the area; it occurred during the four cruises and represented more than 92% of the total iospilid specimens caught; it was slightly more abundant in nighttime samples. New observations of reproduction-related morphological variations and sexual dimorphism are presented for P. uniformis. These may be regarded as morphological adaptations to the planktic mode of life thus favouring the efficiency of the reproductive process in the water column. These are the first records of the family Iospilidae in the Caribbean Basin. Revised generic and species diagnoses, taxonomic illustrations and notes, and an identification key are given here for the species recorded in the Caribbean.

Characteristics of neutralized mine drainage sediment depending to the depth in semi-active treatment

2020 ◽  
Author(s):  
Dong-Kil Lee ◽  
Young-Wook Cheong ◽  
Gil-Jae Yim ◽  
Won hyun Ji ◽  
Sanghyun Cho
Keyword(s):  
Water Content ◽  
Active Treatment ◽  
Treatment Process ◽  
Mine Drainage ◽  
Sediment Layer ◽  
Drainage Flows ◽  
Treatment Facilities ◽  
Depth Water ◽  
Over Time ◽  
Sedimentary Layer

&lt;p&gt;In the semi-active treatment process of mine drainage, neutralized mine drainage flows into settling pond to form sedimentary layer. The sedimentation layer is increased in thickness over time by the continuous inflow of sediment, and the bottom &amp;#160;of the sediment layer is compressed by the load of the upper layer. Thus, the physical characteristics of the sedimentary layers change depending on the depth over time. In this study, the sedimentation layers of four semi-active treatment facilities in South Korea were sampled by depth to measure physical properties and chemical composition. As a result of the analysis, the density and water content of the sludge did not change significantly, while the particle size distribution and viscosity were different according to the depth. As a result of statistical analysis, there was a significant correlation between depth, water content, and viscosity of the sediments. In addition, the content of Mn and Fe contained in the sediments was correlated with the content of Ca and Mg.&lt;/p&gt;

The effects of synoptic and local meteorological condition on CO2, CH4, PM10 and PM2.5 at Bachok Marine Research Station (BMRS) in Peninsular Malaysia

2020 ◽  
Vol 132 (6) ◽  
pp. 845-868
Author(s):  
Noraini Mohyeddin ◽  
Azizan Abu Samah ◽  
Sheeba Nettukandy Chenoli ◽  
Matthew J. Ashfold ◽  
Mohammed Iqbal Mead ◽  
...  
Keyword(s):  
Meteorological Condition ◽  
Peninsular Malaysia ◽  
Research Station ◽  
Marine Research ◽  
Pm10 And Pm2.5

scholarly journals The Effect of Earthworm (Lumbricus terrestrisL.) Population Density and Soil Water Content Interactions on Nitrous Oxide Emissions from Agricultural Soils

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Andrew K. Evers ◽  
Tyler A. Demers ◽  
Andrew M. Gordon ◽  
Naresh V. Thevathasan
Keyword(s):  
Population Density ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Agricultural Soils ◽  
Lumbricus Terrestris ◽  
Nitrous Oxide Emissions ◽  
Research Station ◽  
Significant Difference ◽  
The Relationship

Earthworms may have an influence on the production ofN2O, a greenhouse gas, as a result of the ideal environment contained in their gut and casts for denitrifier bacteria. The objective of this study was to determine the relationship between earthworm (Lumbricus terrestrisL.) population density, soil water content andN2Oemissions in a controlled greenhouse experiment based on population densities (90 to 270 individualsm−2) found at the Guelph Agroforestry Research Station (GARS) from 1997 to 1998. An experiment conducted at considerably higher than normal densities of earthworms revealed a significant relationship between earthworm density, soil water content andN2Oemissions, with mean emissions increasing to 43.5 gha−1day−1at 30 earthworms 0.0333 m−2at 35% soil water content. However, a second experiment, based on the density of earthworms at GARS, found no significant difference inN2Oemissions (5.49 to 6.99 gha−1day−1) aa a result of density and 31% soil water content.

Historical connections between early marine science research and dissemination: the case study of aquarium Vasco Da Gama (Portugal) from late 19th century to mid-20th century

2017 ◽  
Vol 74 (6) ◽  
pp. 1522-1530 ◽  
Author(s):  
Bruno Pinto
Keyword(s):  
19Th Century ◽  
Road Construction ◽  
Science Research ◽  
Research Station ◽  
Marine Science ◽  
Late 19Th Century ◽  
Marine Research ◽  
Marine Station ◽  
Portuguese Society ◽  
Marine Science Research

Abstract In the late 19th century, there was a bloom of public aquariums throughout Europe. Some of them were built for entertainment purposes, whereas others were connected to marine science stations. This article explores the origins and development of the aquarium/marine research station Vasco da Gama (Portugal) as an example of this duality. Initially, the aquarium was created in 1898 by the Portuguese Society of Geography, in a political context of national affirmation. In the first years, a deficient establishment, lack of financial resources, and scarce technical knowledge contributed for its degradation. Therefore, the Navy took over the aquarium in the early 1900s, delivering its management some years later to the Portuguese Society of Natural Sciences. After improvements and modifications, it became one of the first marine biological stations in 1919. This was important for the development of national marine science research at a time of scarce resources. Despite many years of a symbiotic relation between science research and dissemination, the demolition of part of the aquarium/marine station due to a road construction in 1940 brought issues of disequilibrium between both functions. This eventually led to the separation of aquarium and marine station in 1950. Other themes such as connections to national and international institutions are also discussed.

scholarly journals Komposisi Fitoplankton Pada Tambak Kerang

2017 ◽  
Vol 20 (1) ◽  
pp. 65
Author(s):  
Ken Suwartimah ◽  
Ika Desie Wulandari ◽  
Retno Hartati ◽  
Sri Redjeki
Keyword(s):  
Diversity Index ◽  
Environmental Parameters ◽  
Research Area ◽  
Research Station ◽  
Total Period ◽  
Marine Research ◽  
Shellfish Farming ◽  
Sampling Locations ◽  
Anadara Granosa

This study aims to determine to determine the species composition, abundance and community structure of phytoplankton in shellfish aquaculture ponds blood (Anadara granosa) in Menco, District Wedung, District Demak.Metode used in this study is Diskriptif method, determination of the location of the study is purposive sampling Methods, namely the determination of the sampling locations should be based on consideration, the station I to III of the sampling stations representing keseluruan research area. Marine research station is Blood Shellfish Farming in Hamlet Menco. Station is divided into three stations, with making four periods. Environmental parameters taken include: salinity, temperature, pH, DO, nitrate, phosphate, dissolved oxygen, organic materials. The results of the study, found 19 genera of phytoplankton. Phytoplankton abundance 2596-18844 cells / L. Diversity index (H ') based on the total period ranged from 1.098 to 1.837. On January 18-March 3, 2014, categorized into the diversity index medium. Uniformity index (e) the entire period ranged from 0.616 to 0.999. Keywords: composition, phytoplankton, cockle pond  Fitoplankton atau mikroalga merupakan makanan utama kerang di tambak. Penelitian ini bertujuan untuk mengetahui komposisi jenis, kelimpahan, dan struktur komunitas fitoplankton pada tambak budidaya kerang darah (Anadara granosa) di Menco, Kecamatan Wedung, Kabupaten Demak. M etode yang digunakan dalam penelitian ini adalah metode Deskriptif. Sampel fitoplankton diambil dari Tambak Kerang Darah selama empat periode. Parameter lingkungan sebagai data penunjang adalah salinitas, suhu, pH, DO, nitrat, fosfat, oksigen terlarut, bahan organik. Hasil penelitian menjunjukkan terdapat 19 genus fitoplankton, dengan kelimpahan 2.5-18.8x103sel.L-1. Indeks keanekaragaman (H’) berdasarkan total keseluruhan periode berkisar antara 1,098-1,837. Pada tanggal 18 Januari-3 Maret 2014, dikategorikan masuk dalam indeks keanekaragaman sedang. Indeks keseragaman (e) keseluruhan periode berkisar antara 0,616–0,999. Kata Kunci : Fitoplankton; Tambak Kerang Darah

scholarly journals Cryopreservation of mature coconut embryos by desiccation method

CORD ◽  
2005 ◽  
Vol 21 (01) ◽  
pp. 34
Author(s):  
Anitha Karun ◽  
K.K. Sajini ◽  
V.A. Parthasarathy
Keyword(s):  
Water Content ◽  
Silica Gel ◽  
West Coast ◽  
Shoot Meristem ◽  
Zygotic Embryos ◽  
Irreversible Damage ◽  
Mature Embryos ◽  
Optimum Duration

Mature embryos of West Coast Tall variety of coconut could be cryopreserved after desiccation pretreatments and retrieved into plantlets. The desiccation pretreatment and optimum duration for dehydration of zygotic embryos were standardized.  The maximum retrieval of healthy plantlets was obtained from the embryos subjected to 18 hours silica gel or 24 hours laminar airflow desiccation pretreatment. Irreversible damage caused by desiccation to the death of the shoot meristem was noticed when the water content reduced to 20%. 

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