Experiments on Rearing the Barnacle Elminius modestus Darwin to the Settling Stage in the Laboratory

1960 ◽  
Vol 11 (1) ◽  
pp. 42 ◽  
Author(s):  
B Wisley
Keyword(s):  
Mass Culture ◽  
Phaeodactylum Tricornutum ◽  
Sea Water ◽  
Main Peak ◽  
Population Densities ◽  
June July ◽  
Food Design ◽  
Liver Powder

Nauplii from freshly collected adults were fed with the diatom Phaeodactylum tricornutum Bohlin and dried liver powder in mass culture tanks. Details of the method of preparation of food, design of the tank, rate of flow of sea-water, and population densities are given. Low but consistent yields (0.02-3.80 per cent.) of settling cyprids were obtained, the total from five consecutive experiments being 3431. At the locality (Menai Straits, Sorth Wales) natural settling of Elminius modestus Darwin took place in the summer months (May-September) with a main peak about June-July. The above experiments were made during winter (December-March) when natural settling was not detected on exposure plates immersed concurrently in the sea amongst adults of this species.

The Variation of the Contents of Pb in Surface Waters in Jiaozhou Bay

2014 ◽  
Vol 651-653 ◽  
pp. 1492-1495 ◽  
Author(s):  
Dong Fang Yang ◽  
Hong Guang Ge ◽  
Feng Min Song ◽  
Chen Li ◽  
Bo Yang
Keyword(s):  
Surface Waters ◽  
Sea Water ◽  
Jiaozhou Bay ◽  
Pollution Prevention ◽  
Quality Standard ◽  
Ocean Current ◽  
Different Seasons ◽  
Grade Ii ◽  
June July ◽  
And Control

This paper analyzed the content and distribution of Pb in surface waters in Jiaozhou Bay in 1982. Results showed that Pb content in April, June, July and October ranged from 0.49-3.25μg.L-1, 0.45-3.35μg.L-1, 0.30-2.67μg.L-1and 0.33-0.67μg.L-1, respectively, complied with Grade I (1.00μg.L-1) or Grade II (5.00μg.L-1) in Sea water quality standard (GB 3097-1997) of China. As a whole, Jiaozhou Bay waters in 1982 was very lightly polluted by Pb. Non-point source was the major source of Pb in this bay, including atmosphere deposition, ocean current from the offshore, and the transportation of the head of the islands. The content, distribution and source of Pb showed significant seasonal variations, and different pollution prevention and control measurements should be took in different seasons.

Enhancement by Glycerol of Phototrophic Growth of Marine Planktonic Algae and its Significance to the Ecology of Glycerol Pollution

1970 ◽  
Vol 27 (2) ◽  
pp. 335-346 ◽  
Author(s):  
Joseph Y. Cheng ◽  
Naval J. Antia
Keyword(s):  
Phaeodactylum Tricornutum ◽  
Sea Water ◽  
Axenic Culture ◽  
Enhancement Effect ◽  
Growth Enhancement ◽  
Prymnesium Parvum ◽  
High Concentration ◽  
Trace Metal Ions ◽  
Ecological Implications ◽  
Phototrophic Growth

The effects of low (0.05 M) and high (0.5–1.0 M) concentrations of glycerol on the growth of 18 species of marine phytoplankters belonging to 7 algal classes were studied. The algae were grown in axenic culture in sea water enriched with nitrate, orthophosphate, silicate, trace-metal ions, vitamin B12, thiamine, biotin, and buffered at pH 7.6–7.8. Apart from a chrysomonad (Prymnesium parvum) and a cryptomonad (Chroomonas salina), none of the species showed any significant growth on glycerol in the absence of light. However, in the presence of light, glycerol enhanced the growth of 16 species, in particular members of the Chrysophyceae and Cryptophyceae, one diatom (Phaeodactylum tricornutum), one rhodophyte (Porphyridium cruentum), and one chlorophyte (Nannochloris oculata). A high concentration of glycerol was required for inducing or asserting growth enhancement of certain species, but was equally effective as the low concentration or was inhibitory to other species. The enhancement effect was observed in the growth rate and in the peak population density, which in many instances was several times that from nonglycerinated cultures and suggested photoheterotrophic growth. Some species showed obvious cytological and metabolic changes from growth on glycerol. The ecological implications of glycerol pollution of sea water are discussed.

Outdoor mass culture of Spirulina maxima in sea-water

1986 ◽  
Vol 24 (1) ◽  
Author(s):  
MarioR. Tredici ◽  
Teresa Papuzzo ◽  
Luisa Tomaselli
Keyword(s):  
Mass Culture ◽  
Sea Water ◽  
Spirulina Maxima ◽  
Outdoor Mass Culture

scholarly journals A preliminary survey of the epidemiology of bluetongue in Kenya

1971 ◽  
Vol 69 (1) ◽  
pp. 47-60 ◽  
Author(s):  
A. R. Walker ◽  
F. G. Davies
Keyword(s):  
Bluetongue Virus ◽  
Dominant Species ◽  
Light Trap ◽  
Preliminary Survey ◽  
Population Densities ◽  
Potential Vector ◽  
Larval Habitats ◽  
C 23 ◽  
Species Composition And Distribution ◽  
June July

SUMMARYA survey of the species composition and distribution of the Culicoides midge populations at a range of sites where bluetongue is enzootic isolated a group of dominant species: C. cornutus, C. grahamii, C. magnus, C. milnei, C. pallidipennis and C. 23.† Monthly light-trap sampling of Culicoides showed that the population densities of the dominant species greatly increased after the rain seasons and that these species concentrated around flocks of sheep and cattle. The larval habitats of C. cornutus and C. pallidipennis were found associated with stock pens. Precipitin tests on blood-fed Culicoides showed that most of the dominant species regularly feed on sheep and cattle. Bluetongue virus was isolated from C. milnei, C. pallidipennis and C. 23. Serological surveys of wild and domestic bovids from the enzootic area showed a high proportion with antibody to bluetongue virus. The colonization of C. cornutus, a potential vector, is described briefly. A causal relationship between peak rainfall in April-May, peak numbers of Culicoides in May-June and peak bluetongue incidence in June-July is postulated. The vector status of the above species and C. austeni was evaluated.

Therapeutic Treatment for Epibiotic Fouling on Dungeness Crab (Cancer magister) Larvae Reared in the Laboratory

1977 ◽  
Vol 34 (3) ◽  
pp. 432-436 ◽  
Author(s):  
William S. Fisher ◽  
Richard T. Nelson
Keyword(s):  
Phaeodactylum Tricornutum ◽  
Sea Water ◽  
Chemotherapeutic Agent ◽  
Larval Survival ◽  
Antibiotic Activity ◽  
Dungeness Crab ◽  
Cancer Magister ◽  
Larval Stages ◽  
Reasonable Evidence ◽  
Egg Stages

This study shows that larvae of the Dungeness crab (Cancer magister Dana) reared in the laboratory are susceptible to epibiotic microbial infestation similar to that described for eggs of the same species. Larval survival in the laboratory was increased by increased additions of antibiotics to the sea water; however, the chemotherapeutic agent, malachite green, was unsuccessful due to its toxicity to the sensitive larval stages. The addition of the diatom Phaeodactylum tricornutum was beneficial to larval survival in the light but detrimental in dark conditions, supporting the suggestion of a photosynthetic excretion from the algae capable of antibiotic activity. Chronic antibiotic treatment was observed to reduce the size of the larvae. Demonstration of larval susceptibility to epibiotic microbial infestation in the laboratory coupled with its occurrence on egg stages in nature provides reasonable evidence that the disease can occur on larval stages in nature.

scholarly journals Correlation of Some of the Physical and Chemical Properties of the Sea With the Chemical Constitution of the Algae

1949 ◽  
Vol 28 (3) ◽  
pp. 673-699 ◽  
Author(s):  
W. A. P. Black ◽  
E. T. Dewar
Keyword(s):  
Sea Water ◽  
Inorganic Nitrogen ◽  
Vertical Mixing ◽  
Chemical Properties ◽  
Inshore Waters ◽  
Set Up ◽  
Reduced Rate ◽  
June July ◽  
Physical And Chemical ◽  
And Chemical Properties

Monthly samples of the Laminariaceae, L. saccharina and L. cloustoni, from three localities on the Argyllshire coast have been taken from March 1948 to March 1949, and analysed for dry matter, ash, mannitol, laminarin, crude proteins, inorganic nitrogen and alginic acid, and the seasonal variation in these constituents correlated with the changes in composition of the sea water.The results show that a correlation does exist and that a period of rapid photosynthesis occurs from March to June/July, but is restricted in July/August when nitrate is undetectable in the water and phosphate is as low as 0·16–0–20 mg. atom/m.3. The replenishment of the photosynthetic layer with nutrients is retarded in July/August, apparently due to the warming of the inshore waters, which may set up a thermocline restricting vertical mixing.The autumn cooling of the uppermost waters facilitates vertical mixing, regenerating the nutrients in the photosynthetic region, and a second burst of photosynthesis at a reduced rate from the spring ‘outburst’ occurs in October/November.

scholarly journals Seasonal Changes in the Phosphate Content of Sea Water in relation to the Growth of the Algal Plankton during 1923 and 1924

1925 ◽  
Vol 13 (3) ◽  
pp. 700-720 ◽  
Author(s):  
W. R. G. Atkins
Keyword(s):  
Seasonal Changes ◽  
Marked Effect ◽  
Sea Water ◽  
English Channel ◽  
Phosphate Content ◽  
Rate Of Development ◽  
Average Value ◽  
June July ◽  
The Tropics ◽  
Average Consumption

1. The seasonal changes in the sea water of the English Channel and. of Plymouth Sound have now been followed for almost two years, and the second year's results closely resemble those of the first, and again confirm the earlier surface results obtained by Matthews. For 1923 the average consumption at Station El, surface to bottom, 70 metres, was 29·6 mg. of P2O5 per cubic metre, leaving a balance of 7·4 mg. out of the original 37 mg. For 1924 the corresponding figures were, used up 28·3 mg., balance 8·7 mg., winter concentration 37 mg. The minimum average value was obtained in June and July in 1924, in July only in 1923. During June, July, and August, 1924, the surface water was almost entirely denuded of phosphate, values from 1·5 to 2·5 mg. per cubic metre being obtained. These figures would be milligrams per metric ton if fresh water were being considered, as it is they are milligrams per 1027 kg. for. water of S35·3% at 11°C, so it may be appreciated that very little phosphate remains unutilized by the phytoplankton.2. Owing probably to the high sunshine record for March the year 1924 was over a month ahead of 1923 in the spring as regards phosphate consumption, and, therefore, it may be presumed in the multiplication of the phytoplankton. At the same time, in the attainment of definite temperatures 1924 lagged about a month behind. 1923 in spring. Since temperature has such a marked effect upon the rate of development of the plankton as a whole it appears that the zooplankton must have been retarded in 1924 as compared with 1923.3. Samples obtained from the tropics show that even in winter phosphate may be much diminished, for the light is bright. The periodic alterations in phosphate content are, therefore, suppressed or much reduced as compared with the temperature zones. It is indicated that in arctic latitudes the sea becomes even richer in phosphate during winter than it does here, accordingly the summer development of phytoplankton is all the. more abundant.

Studies on the Growth of Phaeodactylum Tricornutum VI. the Relationship to Sodium, Potassium, Calcium and Magnesium

1970 ◽  
Vol 50 (2) ◽  
pp. 293-299 ◽  
Author(s):  
J. Hayward
Keyword(s):  
Phaeodactylum Tricornutum ◽  
Sea Water ◽  
Ionic Composition ◽  
Sodium Potassium ◽  
Major Cations ◽  
Water Media ◽  
Salinity Levels ◽  
Half Strength ◽  
The Media ◽  
Calcium And Magnesium

The growth of certain unicellular marine algae has been shown to occur in culture solutions whose total ionic content and chemical composition departs markedly from that of natural sea water. In fact, some of these algae apparently grow more rapidly in half-strength sea water media than in a medium of salinity equal to 35‰. This ability, on the part of the algae, to grow at widely different salinities suggests that the algal cells are able to maintain an internal ionic composition despite wide variation in the external composition of the surrounding culture medium in which they are growing. Droop (1958) has shown that the major cations present in sea water can be varied within wide limits and it was decided to concentrate on the cations, sodium, potassium, calcium and magnesium. A series of analyses of Phaeodactylum tricornutum has been carried out to determine the concentrations of the four cations present in the cells and also to determine whether these concentrations vary during the growth of cells in culture over a period of time. In addition the analyses have been carried out on cells which have been grown at two different salinities, to compare internal cellular concentrations at different salinity levels of the media.

scholarly journals Studies on the growth of marine phytoplankton II. Isochrysis galbana Parke

1958 ◽  
Vol 37 (3) ◽  
pp. 781-788 ◽  
Author(s):  
Joanna M. Kain ◽  
G. E. Fogg
Keyword(s):  
Organic Matter ◽  
Phaeodactylum Tricornutum ◽  
Sea Water ◽  
Isochrysis Galbana ◽  
Good Deal ◽  
Point Of View ◽  
Marine Phytoplankton ◽  
Prymnesium Parvum ◽  
General Study ◽  
Growth Requirements

A good deal is known about the growth in culture of Phaeodactylum tricornutum Bohlin (Nitzschia closterium W. Sm. forma minutissima Allen & Nelson) (see Spencer, 1954; Harvey, 1955; Provasoli, McLaughlin & Droop, 1957). This organism, however, is a somewhat aberrant member of the Chrysophyta, and other marine and brackish-water representatives of the group, e.g. Syracosphaera carterae Braarud & Fagerland (Braarud & Fagerland, 1946; Provasoli, McLaughlin & Pintner, 1954), Prymnesium parvum Carter (Reich & Kahn, 1954; Droop, 1954), and certain other species (Droop, 1954, 1955 a, b) have been studied much less intensively from this point of view. It has therefore seemed worth while making a general study, similar to that reported in the first paper of this series for the diatom Asterionella japonica Cleve & Müller ex Gran, of the growth requirements of a representative of the Chrysophyceae. Isochrysis galbana Parke, a flagellate of some importance as a food organism of the oyster, has been selected for this purpose. Johnston (1955) has used unialgal cultures of this species in studies of dissolved organic matter in sea water and, since the investigation being described was carried out, Droop (1957) has reported that it has a requirement for cobalamin.

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