The Identity of Some Cyphonautes Larvae (Polyzoa)

1964 ◽  
Vol 44 (3) ◽  
pp. 645-654 ◽  
Author(s):  
J. S. Ryland
Keyword(s):  
Brackish Water ◽  
Membranipora Membranacea ◽  
Electra Pilosa ◽  
European Seas

SUMMARYFive cyphonautes are described in Nordisches Plankton (Lohmann, 1911). Cyphonautes schneideri and C. borealis are larvae of Membranipora membranacea and represent extremes of variation in the shape of the shell. Cyphonautes balticus, like C. compressus which was very inadequately described, is the larva of Electra pilosa. The cyphonautes of these two species are the only ones likely to be encountered in the plankton of normally saline European seas. Cyphonautes barroisi is the larva of the brackish-water Electra crustulenta.Cyphonautes balticus Thorson (1946), not Lohmann, is the larva of M. membranacea.Larval synonymies for M. membranacea and E. pilosa are given.The use of the Cyphonautes names is undesirable, and those of the polyzoan adults should be employed.

Electrophysiology and Co-ordinated Behavioural Responses in the Colonial Bryozoan Membranipora Membranacea (L.)

1975 ◽  
Vol 62 (2) ◽  
pp. 389-404
Author(s):  
J. P. THORPE ◽  
G. A. B. SHELTON ◽  
M. S. LAVERACK
Keyword(s):  
Nervous System ◽  
Conduction Velocity ◽  
Giant Axon ◽  
Nerve Plexus ◽  
Retractor Muscle ◽  
Contraction Rate ◽  
Membranipora Membranacea ◽  
Behavioural Responses ◽  
Electra Pilosa

1. There is a colonial retraction response in the Bryozoans Membranipora membranacea and Electra pilosa. 2. The conduction velocity of the response is about 100 cm sec−1. 3. The colonial response will circumnavigate the end of a cut, but will not cross it. 4. The lophophore retraction time is 60–80 msec. 5. The lophophore retractor muscle with a peak contraction rate of 20 + muscle lengths per second is probably one of the fastest contracting muscles known. 6. The colonial responses to successive stimuli under certain circumstances are similar to those of some corals. 7. Nervous pulses can be recorded travelling across the colony at the same velocity as the colonial response. 8. Increases and decreases in the number and frequency of T1 pulses correspond with increases and decreases in the area and duration of the colonial response and are produced in response to the same stimuli. 9. Other pulses can be recorded which correspond to the retraction of the lophophore retractor muscle. 10. The lophophore retractor muscle is apparently under the control of a giant axon from the zooidal ganglion. 11. The colonial nervous system has many of the properties expected of a nerve plexus.

scholarly journals The cyphonautes larvae of the Plymouth area and the metamorphosis of Membranipora membranacea (L.)

1955 ◽  
Vol 34 (3) ◽  
pp. 441-449 ◽  
Author(s):  
D. Atkins
Keyword(s):  
Membranipora Membranacea ◽  
Electra Pilosa ◽  
Do So

Several cyphonautes larvae (Polyzoa Ectoprocta) have been distinguished and described (Lohmann, 1911; Marcus, 1940; Thorson, 1946), but few have been seen to metamorphose, thus Unking the late larva with the adult. Three, belonging to the suborder Cheilostomata, which have been observed to do so, are Cyphonautes compressus into Electra pilosa L. (Schneider, 1869; Barrois, 1877; Kupelwieser, 1905–6), Cyphonautes occidentalis into Membranipora villosa, (Robertson, 1908; O'Donoghue, 1927) and an unnamed cyphonautes into Nichtina ( = Membranipora) tuberculata (Hastings, 1929, pp. 706–7).

Investigational Studies on Quantity of Salinity in Netravati River Estuary Sand-Coastal Karnataka

2018 ◽  
Vol 6 (6) ◽  
pp. 46
Author(s):  
Raveesha P ◽  
K. E. Prakash ◽  
B. T. Suresh Babu
Keyword(s):  
Brackish Water ◽  
Sea Water ◽  
Salt Water ◽  
Construction Material ◽  
Salt Content ◽  
River Estuary ◽  
Sand Sample ◽  
River Sand ◽  
Natural Aggregates

The salt water mixes with fresh water and forms brackish water. The brackish water contains some quantity of salt, but not equal to sea water. Salinity determines the geographic distribution of the number of marshes found in estuary. Hence salinity is a very important environmental factor in estuary system. Sand is one major natural aggregate, required in construction industry mainly for the manufacture of concrete. The availability of good river sand is reduced due to salinity. The quality of sand available from estuarine regions is adversely affected due to this reason. It is the responsibility of engineers to check the quality of sand and its strength parameters before using it for any construction purpose. Presence of salt content in natural aggregates or manufactured aggregates is the cause for corrosion in steel. In this study the amount of salinity present in estuary sand was determined. Three different methods were used to determine the salinity in different seasonal variations. The sand sample collected nearer to the sea was found to be high in salinity in all methods.  It can be concluded that care should be taken before we use estuary sand as a construction material due to the presence of salinity.

Metazoan Parasites and Health State of European Eel, Anguilla Anguilla (Anguilliformes, Anguillidae), From Tonga Lake and El Mellah Lagoon in the Northeast of Algeria

2018 ◽  
Vol 52 (4) ◽  
pp. 279-288 ◽  
Author(s):  
F. Bakaria ◽  
S. Belhaoues ◽  
N. Djebbari ◽  
M. Tahri ◽  
I. Ladjama ◽  
...  
Keyword(s):  
Brackish Water ◽  
Parasite Species ◽  
Anguilla Anguilla ◽  
European Eel ◽  
Health State ◽  
Component Community ◽  
Metazoan Parasites ◽  
Parasite Communities ◽  
High Dominance ◽  
Argulus Foliaceus

Abstract The aim of the study was to examine metazoans parasite communities of European eels (Anguilla anguilla) in freshwater (Tonga Lake) and brackish water (El Mellah lagoon) in the northeast of Algeria. Six parasite taxa were collected: one monogenean, Pseudodactylogyrus sp.; two crustaceans, Ergasilus sp. and Argulus foliaceus; two nematodes, Cucullanus sp. and Anguillicola crassus; one cestode, Bothriocephalus claviceps. Th e most prevalent parasite taxa in freshwater were Pseudodactylogyrus sp., A. crassus and Bothriocephalus claviceps; whereas in the brackish water, eels were infected mainly with A. crassus. Th e characteristics of the parasite component community structure revealed low parasite species diversity and high dominance values in eels from the two localities. Both communities were dominated by a single parasite species: Tonga eels by the monogenean Pseudodactylogyrus sp. and El Mellah lagoon eels by the nematode A. crassus, verified by high Berger-Parker dominance values of 0.76 and 0.87 respectively.

Low-Resistance Monovalent-Selective Cation Exchange Membranes for Energy-Efficient Ion Separations

2020 ◽  
Author(s):  
Eyal Wormser ◽  
Oded Nir ◽  
Eran Edri
Keyword(s):  
Cation Exchange ◽  
Brackish Water ◽  
Molecular Layer ◽  
Water Desalination ◽  
Molecular Layer Deposition ◽  
Selective Layer ◽  
Trade Off ◽  
Membrane Selectivity ◽  
Layer Deposition ◽  
Water Energy Nexus

<div> <div> <div> <p>The desalination of brackish water provides water to tens of millions of people around the world, but current technologies deplete much needed nutrients from the water, which is detrimental to both public health and agriculture. A selective method for brackish water desalination, which retains the needed nutrients, is electrodialysis (ED) using monovalent-selective cation exchange membranes (MVS-CEMs). However, due to the trade-off between membrane selectivity and resistance, most MVS-CEMs demonstrate either high transport resistance or low selectivity, which increase energy consumption and hinder the use of such membranes for brackish water desalination by ED. Here, we used molecular layer deposition (MLD) to uniformly coat CEMs with ultrathin layers of alucone. The positive surface charge of the alucone instills monovalent selectivity in the CEM. Using MLD enabled us to precisely control and minimize the selective layer thickness, while the flexibility and nanoporosity of the alucone prevent cracking and delamination. Under conditions simulating brackish water desalination, this compound provides monovalent selectivity with negligible added resistance—the smallest reported resistance for a monovalent-selective layer, to date—thereby alleviating the selectivity–resistance trade-off. Addressing the water–energy nexus, we show that using these membranes in ED will cut at least half of the energy required for selective brackish water desalination with current MVS-CEMs. </p> </div> </div> </div>

SEA CURE

Alloy Digest ◽  
1979 ◽  
Vol 28 (5) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Ferritic Stainless Steel ◽  
High Resistance ◽  
Brackish Water ◽  
Crevice Corrosion ◽  
Heat Treating

Abstract SEA-CURE is a ferritic stainless steel designed to provide high resistance to pitting and crevice corrosion in condensers cooled by saline or brackish water. It is used for condenser tubes and has great potential for many other uses. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-364. Producer or source: Trent Tube.

CRONIFER 1713 LCN

Alloy Digest ◽  
1983 ◽  
Vol 32 (5) ◽  
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Brackish Water ◽  
Heat Treating ◽  
Nitrogen Addition ◽  
Chloride Ions ◽  
Low Carbon ◽  
Good Resistance ◽  
Temperature Performance ◽  
Aqueous Chloride

Abstract CRONIFER 1713 LCN is a fully austenitic low-carbon chromium-nickel-molybdenum stainless steel. It contains a nitrogen addition (0.10-0.20%) which helps to stabilize the austenite. Its molybdenum content (4.0-5.0%) provides good resistance to pitting attack by media containing chloride ions. Thus it has good resistance to brackish water and seawater. Typical applications are bleaching plants and equipment for handling aqueous chloride solutions. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SS-425. Producer or source: Vereingte Deutsche Metallwerke AG.

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