bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative Morphology and Biology of Three Species of Eurycercus (Chydoridae, Cladocera) with a Description of Eurycercus macrocanthus sp. nov.
Authors: Frey David G.
Published: February 2007

Comparative studies of the three known species of Eurycercus (including the new species macrocanthus from Eastern Siberia described herein) demonstrate that macrocanthus is much more closely related to lamellatus than to glacialis in many details of morphology, ontogeny, and biology. Its most distinctive character is a great enlargement of the middle clasping hook on the first trunk limb, with the front end of the animal being completely restructured to accomodate its function. Both macrocanthus and lamellatus become reproductive at a small size and have a high reproductive potential, enabling them to survive heavy predation, as by fish, selective for large individuals, which the size‐frequency distributions of the populations suggest is occurring. On the other hand, glacialis does not become reproductive until a much larger size, and its reproductive potential is smaller than in the other species, making it extremely vulnerable to predation concentrated on large individuals. Significantly, where it occurs in the coastal North Sea region, Iceland, and Greenland it is virtually restricted to water bodies without fish. The taxon lamellatus sens. lat. appears to be a complex of closely related species.
Benthic Community Metabolism on the Continental Terrace and in the Deep Sea in the North Pacific
Authors: Pamatmat Mario M.
Published: February 2007

The rates of total oxygen uptake, residual oxygen consumption after poisoning with formaldehyde, and respiration of undisturbed sediment cores from the continental terrace, the abyssal plains, and Aleutian Trench of the North Pacific were measured aboard ship. These measurements, together with determinations of organic carbon, sand, silt, and clay content, of concentrations of reduced substances, and of dissolved oxygen and nutrient salts in interstitial and overlying bottom water, give indications of the level of community metabolism, both aerobic and anaerobic, in the different study areas.
Polychaetes of Truncated Reef Limestone Substrates on Eastern Indian Ocean Coral Reefs: Diversity, Abundance, and Taxonomy
Authors: Kohn Alan J. , Lloyd Margaret C.
Published: February 2007

This study provides the first evaluation of abundance and diversity of polychaete annelid assemblages of coral reefs. Quantitative analyses of the polychaete fauna of truncated coral reef limestone platforms off Sumatra and Thailand revealed a total of 76 species (13 reported for the first time from the tropical Indian Ocean) and average population densities of 49,000/m2. The number of species in a single sample ranged from 16 to 32, and species diversity (H) ranged from 1.9 to 2.5. Three species of Syllidae, Palola siciliensis, and Dodecaceria laddi occurred in all samples. The syllids dominated numerically in all samples but were quite small, mainly 2–10 mm long and 0.01–0.04 mg dry weight. Samples from the same station were essentially identical in species composition and relative abundance. Similarity decreased with increasing distance between stations. With respect to number of species, population density, and dominance of syllids, the assemblages studied resemble those associated with limestone substrates in marine caves in the Mediterranean.
Chlorophyll and Primary Productivity of Some Green, Freshwater Sponges
Authors: Gilbert John J. , Allen Harold L.
Published: February 2007

Relationships between ash‐free dry weight, viable chlorophyll a and pheopigments a were examined by linear regression analysis for non‐gemmulating and gemmulated Spongilla lacustris and for an unidentified, non‐gemmulating species. The primary productivity of S. lacustris was determined by both oxygen and 14C techniques and expressed on a biomass, chlorophyll a, and area basis, and the photosynthetic efficiency was calculated. The proportion of algal photosynthate excreted by the sponge was investigated, and the transfer of algal photosynthate to the sponge was examined by autoradiography.
Some Observations on the Chlorophyll Maximum and Primary Production in the Eastern North Pacific
Authors: Revelante Noelia , Gilmartin Malvern
Published: February 2007

An oceanographic transect between Central California and the Hawaiian Islands delimited a continuous subsurface chlorophyll maximum associated with an oxygen maximum at 1% to 0.1% light penetration depths. The phytoplankton community consisted primarily of nannoplankton with a prominent diatom component, and was photosynthetically active as measured in „low light level”︁ incubators, contributing an estimated 20–30% to total water column production. Functioning as a nutrient trap blocking the vertical movement of nutrients into the upper euphotic zone, the chlorophyll maximum apparently required an overlying pycnocline for development.
Methods for Measuring the Primary Productivity and Standing Crops of an Epiphytic Algal Community Attached to Scirpus validus VAHL
Authors: Hickman Michael , Klarer David M.
Published: February 2007

Methods for measuring the primary productivity and the standing crops of an epiphytic algal community attached to Scirpus validus VAHL. are described. Experimental designs to show the accuracy of these methods are discussed and the components of variation are calculated for these designs. Primary productivity is measured using the carbon‐14 technique and liquid scintillation counting while the standing crops are measured using cell counts and chlorophyll a content.
Plankton Studies in a Mangrove Environment. VIII. Further Investigations on Primary Production, Standing‐Stock of Phyto‐ and Zooplankton and Some Environmental Factors
Authors: Tundisi J. , Tundisi T. M. , Kutner Myriam B.
Published: February 2007

The present paper describes and discusses the seasonal cycle of primary production, standing‐stock, climatological and environmental factors, and their interrelationships in a mangrove swamp of the estuarine type (25°S, South Latitude, Cananéia, Brasil). Comparisons with values of primary production for other tropical and temperate environments have been made. Further lines of work are indicated.
Untersuchungen des CO2–Stoffwechsels submerser höherer Wasserpflanzen im Fließgewässer unter Einsatz eines fahrbaren Infrarot‐Gasanalysator‐Labors
Authors: Horbach W. , Hornig L. , Weise G.
Published: February 2007

Investigations on the CO2 Balance of Submerged Water Plants in Running Water By Means of a Motile Laboratory for Infrared Gas Analysis

The CO2‐balance of the submerged water mosses Hygrohypnum ochraceum f. obtusifolia, Amblystegium riparium, Amblystegium riparium f. fontinaloides and of Potamogeton trichoides (Potamogetonaceae) was investigated by means of a transportable laboratory for infrared gas analysis. The experiments were carried out in the river Zwickauer Mulde by means of glass vessels exposed to the water body. The device for continuous measuring CO2 exchange was operated by pumping air through the vessels containing 4 l of water. The water plants exhibited a distinct day night rhythm of CO2 turnover. In some cases river water alone, which had percolated a tampon of Perlon fibres, also showed a considerable day night rhythm of CO2 turnover which had to be attributed to phytoplankton and suspended periphyton organisms, the activity of which is superimposed above the photosynthetic activity of the macrophytes. Measurement of the CO2 balance of submerged plants in water containing microphytes can only be attributable to the macrophytes if the time of exposition does not exceed one day.
A Preliminary Approach to the Use of the Isotopic Ratio 13C/12C for the Evaluation of Mineralization in Aquatic Environments
Authors: Bertoni R. , Melchiorri‐Santolini U. , Létolle R. , Lugrin M. , Olive Ph.
Published: February 2007

12C/13C ratio is used as natural tracer for the estimation of the mineralizing activity of pelagic bacteria.

Attention is particularly given to the variations of the isotopic ratio of the inorganic carbon produced by the microbial oxidation in comparison with the ratio of the dissolved organic matter.
The Effects of Hydrostatic Pressure on Living Aquatic Organisms III. Behavior and Tolerance of Euplanktonic Organisms to Increased Hydrostatic Pressure
Authors: George Robert Y. , Marum James P.
Published: February 2007

In the habitat temperature, northern cold planktonic species seem more resistant to pressure than related southern warm species. Generally, a prolonged “hyperactivity phase” was recognized between moderate and high hyperbaric levels in most planktonic species. Descriptions of reactions of various planktonic species to increasing pressure are given with reference to stimulated activity (R1), onset of tetany (T), and inactivity (I). On the basis of LD50 levels, the 16 planktonic species show high, moderate, low or extremely low tolerance to one hour stress conditions of high hydrostatic pressure.
The Effects of Hydrostatic Pressure on Living Aquatic Organisms VI. Organic Complexity and Hydrostatic Pressure Sensitivity
Authors: Menzies Robert J. , Selvakumaran M.
Published: February 2007

Forty species of aquatic animals belonging to 14 phyla of various levels of organic complexity were examined with reference to their ability to survive increasing hydrostatic pressure. The results of these experiments lead us to seriously question the commonly stated and often quoted hypothesis that there is an inverse relationship between pressure resistance and the complexity of organisms.
The Effects of Hydrostatic Pressure on Living Aquatic Organisms VII. Size and Pressure Effects
Authors: Selvakumaran M. , Hodson Robert , Menzies Robert J.
Published: February 2007

A survey of the pressure resistance of aquatic animals in different stages of their life cycle shows that adults generally are more tolerant of pressure than the egg and nauplii, but older adults appear less pressure resistant than younger adults. Data on many species of aquatic animals of different size shows no correlation between size and pressure resistance. It is concluded that size is not a special determinant in the successful deep‐sea colonization of shallow‐water animals and this is consonant with the fact of occasional large deep‐sea species whereas the average size is quite small in comparison with littoral species.
The Dual Origin of the Black Sea Foraminifera
Authors: Tufescu Mircea
Published: February 2007

Evidence is given supporting the possibility of survival in the modern Black Sea of descendents of Miocene Pontic foraminiferal populations. This evidence includes the present existence of Foraminifera in the Aral and Caspian Seas, the existence of pockets of species in the Paratethys area in waters long isolated from any seas, the existence in the Golovitza Lagoon of Foraminifera living at salinities lower than those that are thought to have existed in the Pontic Basin during its lacustrine period, and evidence from zoogeography. It is shown that there are morphological, ecological and physiological modifications in these aboriginal populations as compared to populations of the same species living in the Mediterranean. In addition to these aboriginal populations, evidence is given for three invasions of Foraminifera from the Mediterranean during geological periods when the Black and Mediterranean Seas were merged.
Der frühlarvale Köcherbau von Micrasema longulum McL. (Trichoptera, Brachycentridae)
Authors: Bohle Hans Wilhelm
Published: February 2007

Case Construction of Young Larvae of Micrasema longulum McL. (Trichoptera, Brachycentridae)

The method of case building used by the first three larval instars of Micrasema longulum is described. The initial case is constructed above the hatching aperture in the jelly of the egg mass, in the same way as it is done by other species of Brachycentridae. The material of the initial case is caught from drifting particles in running water. From the end of the first larval instar only silk is used for the extension of the case. Two silken layers of a very regular pattern are to be distinguished. The construction of the cloverleaf‐shaped posterior aperture is described. Some of the methods used for the case building show a maturing process during ontogenesis.
Growth and Differentiation of Seedling of an Aquatic Plant, Trapella sinensis Oliv. I. Some Growth Characteristics in the Early Stage
Authors: Yabe Akira , Okuda Masao , Takada Hideo
Published: February 2007

It was shown that the early growth of Trapella sinensis seedlings can be divided into two distinct stages based upon susceptibility for different growth‐regulators, such as gibberellin, kinetin, and the extract of Chlorella cells grown in light. The two stages were observed on the 7th and the 10th days, respectively. Especially the epicotyl showed different sensitivities to the growth regulators mentioned above. The effect of gibberellin (GA3), kinetin and the extract of Chlorella cells grown in light on the growth of T. sinensis seedlings after germination at 23 °C in light at 2000 lux was investigated. Each addition was done at zero time and after 3, 6 and 10 days growth, and the effect was observed subsequent every 3 or 4 days.
Growth and Differentiation of Seedlings of an Aquatic Plant, Trapella sinensis OLIV II. Photosynthesis and Respiration of Seedling in Early Stages
Authors: Yabe Akira , Okuda Masao , Takada Hideo
Published: February 2007

Trapella sinensis seedlings were examined to determine whether the effect of growth regulators such as gibberellin (GA3), kinetin and the extract of Chlorella cells on chlorophyll formation, photosynthetic activity and cytochrome oxidase activity depend upon the developmental stage. Each addition promoted the growth on both the basis of dry weight and of fresh weight. Among these regulators, only Chlorella extract promoted growth as a result of an activated rate of photosynthesis through increased chlorophyll formation. There also was an increased respiratory rate through increased cytochrome oxidase activity.
Einige histologische und histochemische Untersuchungen epidermaler Proliferationen bei postlarvalen Aalstadien
Authors: Bremer Heinz
Published: February 2007

Some Histological and Histochemical Investigations on Epidermal Proliferations of Postlarval Stages of the Eel (Anguilla anguilla L.)

The development of fish‐pox on the skin of post‐larval eels is described as an epithelial folding in the sense of a hyperplastic proliferation. It is supposed that this is correlated with an osmotic overburdening.
Enumeration of Bacteria in Sea Water
Authors: Lewin Ralph A.
Published: February 2007

The choice of methods to be used for the enumeration of bacteria in sea water must depend on the objectives of the investigators. Comparisons of data based on different methods may be invalid. An operational definition is given for a colony‐generating unit (CGU) which, under some conditions, may be a single viable bacterium. Such units can conveniently be enumerated by a modification of the “minimum probable number” method currently employed in aquatic bacteriology. Counts of “viable bacteria” (CGU) in surface sea water samples from the region of the North Pacific Gyre (28° N, 155°W) were estimated to range from 10,000 to 200,000 per litre.
A System for the Quantitative Sampling of Shallow Water Benthos
Authors: Kritzler H. , Hiskey R. M. , Thomas P. J.
Published: February 2007

An air lift, operated by a diver‐boatman team and permitting rapid excision and automatic sieving of uniform portions of mud, sand, and fine to medium shell hash bottoms, is described. The apparatus can be deployed from a very small boat. It is inexpensive to make and to operate and has been used with great success at depths of not more than five meters.
A Seasonal Quantitative Study of the Littoral Cladocera and Copepoda in a Bog Pond and an Acid Marsh in Newfoundland
Authors: Daggett Rollin F. , Davis Charles C.
Published: February 2007

A quantitative study was made of the littoral microcrustaceans in a bog pond and an acid marsh located on the Avalon Peninsula, Newfoundland, from May, 1972 to May, 1973. A total of 17 species of Cladocera and 7 species of Copepoda were found in La Manche Marsh, while 21 species of Cladocera and 5 species of Copepoda were collected in Round Pond. The maximum standing stocks were similar in the two localities. The dominant forms in the summer and fall in La Manche Marsh were Cladocera: Acantholeberis curvirostris, Biapertura intermedia, Chydorus sphaericus, and Ilyocryptus spinifer. In the winter the copepod, Macrocyclops albidus, was dominant, while Cyclops varicans rubellus was the most abundant species in the spring. Round Pond also was dominated by Cladocera in the summer and fall; namely, Acroperus alonoides, Alona rustica, Alonella excisa, Chydorus sphaericus, and Sida crystallina. The copepods, Eucyclops agilis and Macrocyclops albidus, were dominant in the winter and early spring.
Benthic Invertebrates in Delaware Bay: Animal‐Sediment Associations of the Dominant Species
Authors: Kinner Peter , Maurer Don , Leathem Wayne
Published: February 2007

The purpose of this study was to determine the composition of the benthic fauna near the mouth of Delaware Bay. One hundred and five species were collected and identified from 277 grab samples. A sediment sample was also collected at each of the stations. Faunal density was low with the number of individuals rarely exceeding 10/0.1 m2. Species were ranked according to number of individuals; the nine top species comprised 83.4% of the fauna. The top three species, Tellina agilis, Gemma gemma, and Nucula proxima, comprised 65.2% of all the individuals collected. A high percentage of the species (41.9%) occurred in two samples or less. The six most frequently collected species were compared with six sediment classes based on weight percentage of siltclay. Protohaustorius wigleyi and Trichophoxus epistomus were found mainly in less than 10% silt‐clay. Tellina agilis and Ampelisca verrilli were transitional between the pure sand and mud facies. Nucula proxima and Heteromastus filiformis were members of a high silt‐clay facies (<50% silt‐clay). Diversity values were significantly greater (.05) in the low silt‐clay sediments (0–25% silt‐clay) than in the high silt‐clay sediments (> 25% silt‐clay). The relative dominance (redundancy) was not significantly different in any of the sediment types.
Rotorua Phytoplankton Reconsidered (North Island of New Zealand)
Authors: Thomasson Kuno
Published: February 2007

As early as in 1888, NORDSTEDT published some information about the algal flora of Rotorua lakes, on the North Island of New Zealand. He studied samples from the lakes Rotomahana and Tarawera, and made some notes on the algae in Lake Taupo. Since then a number of minor contributions with additional information about the algal flora of the Rotorua district have been published. The present paper describes the composition of phytoplankton in nine of the lakes in Rotorua district, and in Lake Taupo. These are all monomictic soft water lakes. The plankton is fairly rich in desmids, quantitatively as well as qualitatively. The study is based on random sampling by the author in March, 1968.
Limnological Studies of a Subarctic Lake System
Authors: Alexander Vera , Barsdate Robert J.
Published: February 2007

A limnological study was carried out on a pair of lakes within the taiga forest of interior Alaska. These lakes, Ace and Deuce Lakes, are irregular in that one of them (Deuce Lake) is meromictic, never undergoing complete circulation, and the other (Ace Lake) has a spring circulation which is confined to the surface layers and autumnal mixing is attenuated. The ionic composition is similar to lakes in the surrounding area, with somewhat higher levels of dissolved ions. The unique features of the lake system are related to the meromictic tendencies and highly colored water with rather high ionic content. Primary productivity rates are relatively high by interior Alaskan standards, and nutrient levels are high. Primary productivity is confined to the surface meter, but even so annual productivity amounts to more than 70 g C/m2‐yr.
Light‐dependent Synthesis of δ‐aminolaevulinic Acid Dehydratase During the Developmental Period of Trapella Seedlings
Authors: Yabe Akira , Takada Hideo
Published: February 2007

Mature seeds of Trapella sinensis, after removal of receptacles, were germinated for 10 days at 23°C in the dark and then were illuminated. After illumination, the activity of δ‐aminolaevulinic acid (ALA) dehydratase was determined in relation to chlorophyll synthesis, and increases in dry weight of the whole or of parts of a developing seedling. Internal programming of development was related to changes in ALA dehydratase activity on the basis of porphobilinogen synthesis. Exogenously added ALA as well as an extract of Chlorella cells promoted this activity. There was an enhancement of chlorophyll formation resulting in an enhancement of the photosynthetic rate and in an increase of growth promotion by addition of Chlorella extract.
The effect of thermal effluent upon the standing crop of an epiphytic algal community
Authors: Klarer David M. , Hickman Michael
Published: February 2007

The investigation of the epiphyton associated with Scirpus validus VAHL. in Lake Wabamun commenced in May 1971 and continued until the end of August 1972. Seven stations encompassing heated, partially and non‐heated areas of the lake were investigated. From July 1971 until the termination of the investigation water temperature, dissolved oxygen and water chemistry were monitored. There were no large variations in these parameters except for water temperature and dissolved oxygen levels among the stations. However, there were increases in the dissolved silica, nitratenitrogen and phosphate‐phosphorus levels during the autumn and winter months at the heated stations while at a partially heated station only dissolved silica and nitrate‐nitrogen increased. The epiphyton at all stations showed a spring maximum, a summer minimum, and a maximum in the late summer/early autumn. The spring dominants at all stations were Fragilaria capucina and Diatoma elongatum. During the late summer/early autumn maximum diatoms were dominant at the non‐heated stations while chlorophycean species were dominant at the heated stations. The heated water caused a decrease in the number of species and a corresponding increase in the importance of a few species at the heated stations. The major impact of the heated water, however, was an extension of the period of open water and the corresponding increase in mean yearly standing crop size in the heated areas.
Primary productivity, phytoplankton and limiting nutrient factors in labrador lakes
Authors: Ostrofsky Milton L. , Duthie H. C.
Published: February 2007

The primary productivity of some lakes and reservoirs in western Labrador was measured by the 14C method in order to determine the range of productivities and the effects of impoundment. No primary productivity data previously existed for this part of Canada. Both the primary productivity and standing crops of phytoplankton were found to be low in a newly impounded lake but later rose to levels greater than in surrounding natural lakes. In nutrient enrichment experiments, carbon was never found to be limiting but phosphorus stimulated primary productivity when added alone or in combination with nitrogen.
Abundance, growth and production of the roach (Rutilus rutilus [L.]) population in the Klíčava reservoir during the years 1964 and 1967–1972
Authors: Pivnička Karel
Published: February 2007

During the years 1964 and 1967–1972 the relationship between abundance, growth and production of the roach population in the Klíčava reservoir (Central Bohemia) was studied. Significant values for correlation coefficients were found for all variables. Noticeable variations in abundance were accompanied by similar variations in growth rate. Only the ascending part of the production‐abundance relationships was examined.
Notonemouridae of Australia (Plecoptera, Ins.)
Authors: Illies Joachim
Published: February 2007

A revision of the Australian and Tasmanian members of the family Notonemouridae is given, studying the abundant material from several Australian and European collections and additional material obtained during the author's collecting trip to Australia and Tasmania in 1966. The family of Notonemouridae was hitherto only poorly known from this area (6 species). The following text gives descriptions of 16 species, 10 of them, and 4 genera, being new to science. The larvae of this family in Australia and Tasmania live in cold springs and rivers, especially on seepage areas in high mountains, where they climb on vertical rock surfaces; the adults are able to jump by means of their hind femora.
Man‐made eutrophication in a newfoundland (Canada) harbour
Authors: Frecker Maxine F. , Davis Charles C.
Published: February 2007

A comparative study in 1969‐1970 of the phytoplankton and certain other parameters in St. John's Harbour and Aquaforte Harbour, located on the southeast coast of Newfoundland, led to the conclusion that St. John's Harbour which receives untreated sewage as a prime source of nutrients was by far the more eutrophic. Evidence for the eutrophic state was especially observed in the central basin (Station 1) of the harbour. Here the bottom waters were deficient in oxygen especially during the summer months. Secchi disc readings were generally lower at this station, and the annual standing crop of phytoplankton was almost three times that at unpolluted Aquaforte Harbour. Also the proportion of the biomass contributed by the nannoplankton was greater in St. John's Harbour. One euglenoid occurred in bloom concentrations throughout the summer months and may possibly be considered as an indicator of organically‐polluted waters.
Über den Einfluß der Wasserstoffionenkonzentration und des Hydrogenkarbonatgehaltes auf die Ausbildung von Bergbachbiozönosen
Authors: Ziemann Horst
Published: February 2007

On the basis of investigations of the diatom flora and the Plecoptera, Ephemeroptera and Trichoptera fauna in two mountain brooks with different chemisms the different effects of the regional factors of the water chemism and the extraregional factors, current and temperature, on the biocoenosis is discussed. The zoocoenotic division of mountain streams is affected by the extraregional factors; the structure of the diatom associations and the distribution of individual species of the insect fauna are dependent on the regional effect of the water chemism. The correlation of the halobic indices as ecological characteristics of the diatom flora with the factors of the water chemism, pH and alkalinity, and their relationship with the distribution of some species of the insect fauna suggest that the halobic index is a useful criterion for the ecological classification of waters. Also for the judgement of the trophic conditions and the self‐purification of waters the halobic index can be regarded as an additional criterion.
The disappearance of four leaf leachates in a hard and soft water stream in South Western Ontario, Canada
Authors: Lock Maurice A. , Noel Hynes H. B.
Published: February 2007

The disappearance of ‘dissolved’ organic carbon (D. O. C.) leached from maple, aspen, cedar and pine leaves was followed in hard and soft stream water and hard and soft stream water plus sediment. Differences were found in the rates and extent of the disappearance of D. O. C. between the leaves and the water types. These are discussed in relation to the productivity of two extreme stream types.
Notes on the systematics and ecology of Daphnia pulex LEYDIG in Northern Canada
Authors: Meijering M. P. D.
Published: February 2007

Daphnia populations from the region of Yellowknife (N. W. T.) on the Great Nave Lake, from Tuktoyaktuk (N. W. T.) on the coast of the Beaufort Sea east of the Mackenzie‐Delta, and from Shingle Point (Y. T.) west of the Mackenzie‐Delta were described. Population diagrams were given for the beginning of September 1974. The populations found at the above mentioned sites were compared with Daphnia pulex from Spitsbergen and the German island of Spiekeroog. Though some characteristics of Daphnia middendorffiana FISCHER occurred, mainly in individuals from very northern ponds, these were always found in individuals which also possessed some of the characteristics of Daphnia pulex. In every pond, specimens with characteristics of Daphnia middendorffiana lived together with other individuals resembling Daphnia pulex. Males were found in three out of the four visited ponds on the shore of the Arctic Sea, and were apparently Daphnia pulex. All the material sampled in northern Canada was regarded as belonging to Daphnia pulex LEYDIG 1860 emend. RICHARD 1896. There was evidence, that characteristics of Daphnia middendorffiana develop under the influence of environmental conditions, such as food supply. Daphnia magna STRAUS was found far north of the arctic circle.
Chloridzellen der Larven von Caenis diminuta WALKER (Ephemeroptera, Caenidae) bei unterschiedlicher Salinität
Authors: Wichard Wilfried , Tsui Philip T. P. , Maehler‐V. Dewall Anne
Published: February 2007

The larvae of Caenis diminuta WALKER (Ephemeroptera, Caenidae) have coniform chloride cells which are involved in osmoregulation. The number of chloride cells varies according to salinity conditions of the surrounding waters. The larvae from brackish water have less chloride cells than the larvae from fresh water.
Egg size and duration of embryonic development in Crustacea
Authors: Steele D. H. , Steele V. J.
Published: February 2007

The duration of embryonic development is inversely correlated with egg size in Crustacea. Development is faster in amphipods and mysids than in decapods, isopods and cumaceans of the same size. The relationships are of considerable significance in the ecology of these animals.
Some Effects of a Power Plant Effluent on Estuarine Epibenthic Organisms
Authors: Young James S. , Frame Ann B.
Published: February 2007

A study using the submerged test panel method was conducted at the Oyster Creek Nuclear Generating Station near Barnegat Bay, New Jersey to investigate effects of the heated effluent on epibenthic communities. Test panels were placed in the intake and discharge canals and collected using SCUBA at 28, 84, 168 and 335‐day intervals between October 1970 and October 1971. Exposed panels were replaced by clean panels upon collection.

Faunal resemblance, both between stations during a sampling date and within stations from one sampling date to the next, was low. Numbers of species were higher at the discharge station than at the intake station from late fall to early summer and lower from midsummer to early fall. Overall differences in diversity at the two stations could not be detected. The optimum temperature for growth of Balanus sp. was approached more closely during winter in the discharge canal than in the intake canal where growth was retarded by cold water. Balanus eburneus appeared to have an extended breeding season. Because of dilution of the discharged water with cooler intake water through a plant bypass system during the summer, the effluent was not seriously harmful to amphipod reproduction. Season abundances of numerous invertebrates at both stations are reported and possible power plant effects are discussed.
Biohydrodynamics and Ecology of Life Forms of Pelagial
Authors: Aleyev Yu. G.
Published: February 2007

The relation between inertial forces and frictional forces characterizing the pattern of movement of plankton and nekton organisms, respectively, and expressed by the Reynolds number Re may be used as a base for classifying the life forms of the pelagial. The upper limit for the existence of euplanktic forms connected with devices for increasing the hydrodynamic resistance and ensuring passive floating with the least expenditure of energy corresponds to Re values ≦5,0 · 105. The upper boundary of the nektoplankton is in correspondance to Re ≦2,0 · 107. The organization of nekton organisms capable of active directed horizontal movement and with devices for reducing the hydrodynamic resistance is in accordance with Re >5,0 · 103, as a rule is in accordance with Re > 105.
Influence of Sediment Inflow on Phytoplankton Primary Productivity in Lake Tahoe (California‐Nevada)
Authors: Tilzer Max M. , Goldma Charles R. , Richards Robert C. , Wrigley Robert C.
Published: February 2007

Light, nutrient concentrations and phytoplankton photosynthesis were studied in a Lake Tahoe sediment plume during maximum spring runoff. They were compared with conditions in clear lake waters not influenced by inlets. In the plume, nutrient concentrations increased in proportion to sediment density whereas light transmission of water was reduced with little effect on the spectral composition except for red light. Light inhibition of photosynthesis at the lake surface was less pronounced in the plume than in clear water and light limitation occurred more rapidly in deeper layers. Evidence from both lake experiments and laboratory bioassays suggests that iron had the greatest stimulatory effect on both photosynthetic activity and biomass growth at maximum sediment densities near the stream inlet.

Because of less surface inhibition, photosynthetic light energy utilization efficiency was usually higher in the sediment plume which occurred in relatively shallow areas near the shore. In order to estimate overall effects of enhanced turbidity associated with nutrient loading on Lake Tahoe's primary productivity, profiles taken in shallow areas near the lakeshore were extrapolated to the maximum depth of photosynthesis. Light limitation would cause decreasing productivity, but nutrient stimulation would make this effect less pronounced. The overall effect would depend on the extent of sediment loading relative to nutrient loading.
Dynamics of Spatial Pattern for the Gastrotrich Tetranchyroderma bunti in the Surface Sand of High Energy Beaches
Authors: Nixon David E.
Published: February 2007

This paper is a quantitative study of the spatial pattern of the intertidal gastrotrich. Tetranchyroderma bunti, and its migration pattern during a tidal cycle on three high energy beaches of Bogue Banks, North Carolina, USA. Included in the study were the macrodistribution and micro‐distribution. T. bunti is gregarious and forms a clumped spatial pattern in the sand. The four clump sizes found were 2.2, 3.3, 4.4, and 5.5 cm with a ratio of 9: 6: 4: 1, respectively. The spatial pattern of these clumps suggests that the general spatial pattern of the population in its most dense area is aggregated clumped. Field experiments show that this is a stable pattern during at least part of the low tide period, and laboratory experiments suggest that the low water content of the sand at low tide contributes to this stability by decreasing the movement of the gastrotrichs. A significant difference (p<0.05) was found in the density of the gastrotrichs parallel to the shore line, but part of this difference was due to local shifts in the spatial pattern of the population instead of a change in the longshore abundance. T. bunti showed a tidal migration pattern opposite to that of the ground water movement.
A Further Investigation on the Primary Productivity in the Divergence Zone Near the French Mediterranean Coast
Authors: Slawyk Gerd , Minas Hans Joachim , Minas Monique , Packard Theodore T.
Published: February 2007

The present investigation re‐examines hydrological features, the inorganic phosphate distribution and primary productivity near the “Hyères” Islands in the French Mediterranean in the early summer divergence zone as previously studied by MINAS and BLANC (1970). In addition, concentrations of particulate nitrogen, Chl‐a and nitrate have been determined. Uptake rates of 15N‐labelled nitrate (“new production”) and the oxygen consumption (ETS‐activity) by the phytoplankton population have been estimated.
The Ecology of Temporary Streams I. The Faunas of Two Canadian Streams
Authors: Williams D. Dudley , Hynes H. B. Noel
Published: February 2007

This, the first of two papers on the ecology of temporary streams, describes, in detail, the faunas of two such habitats in southeastern Canada. The adaptive mechanisms for coping with the summer drought are documented for a variety of species and faunal succession is shown to occur from the stream stage (fall‐winter) through the pool stage (spring) to the terrestrial (summer).
Phytoplankton Primary Productivity and Population Efficiency Studies in a Prairie‐Parkland Lake Near Edmonton, Alberta, Canada
Authors: Hickman Michael , Jenkerson C. G.
Published: February 2007

The standing crop and primary productivity of a small eutrophic, prairie‐parkland lake were measured. In general, both standing crops and primary productivity were large, 29.4 and 73.09 mg chlorophyll a m−3 and m−2 and 78.71 and 196.77 mg C hr −1m−3 and m−2 respectively. Productivity decreased with increasing depth, therefore, decreasing light intensity. Relations between productivity and chlorophyll a content, productivity and light intensity, phytoplankton productivity efficiency and light intensity, productivity and water temperature were investigated, as was the photosynthetic index. Experiments designed to determine the photosynthetic capacity of the phytoplankton distinguished between actively growing and senescent populations. The latter were present during the winter ice cover.
Effects of Artificial Rise of Temperature on Stagnant Waters and Their Biocenoses
Authors: Biesiadka Eugeniusz , Kaspbzak Krzysztof , Kolasa Jerzy
Published: February 2007

A change of the thermal regime results in a variety of reactions of both abiotic and biotic components of the environment. The aim of this paper is to present new data (on Turbellaria, Oligochaeta, Hirudinea, Coleoptera and Hydracarina) on biological responses to the thermal factor discussed in a broad context of literature and, to evaluate their impact on the subsequent ecosystem development. A theoretical interpretation of all phenomena related to this factor is proposed within a widely‐conceived theory of adaptation.
Phytoplankton Production at Two Stations in Lindåspollene, a Norwegian Land‐locked Fjord, and Limiting Nutrients Studied by Two Kinds of Bio‐assays
Authors: Lännergren Christer
Published: February 2007

At two stations in a Norwegian land‐locked fjord, one more and one less influenced by freshwater run‐off, studies were made of the primary production, chlorophyll a concentrations, and the quantity and composition of phytoplankton. Samples were taken for analyses of phosphate, nitrate, and silicate, and temperature and salinity were measured. Two kinds of bio‐assays were performed: combinations of phosphate, nitrate, and silicate were added to I, natural water incubated in situ, and II, natural water incubated in the laboratory. Lower salinities and higher concentrations of all nutrients were found at the station most influenced by fresh‐water. Although the bio‐assays indicated that nitrogen was the main limiting nutrient, the biological parameters showed no consistent differences between the two stations. The similarity is tentatively explained by the growth of nanoplankton algae, partly depending on nutrients other than those analysed.
Population Dynamics and Production of a Planktonic Marine Copepod,. Acartia clausii, in a Small Temperate Lagoon on San Juan Island, Washington
Authors: Landry Michael R.
Published: February 2007

The population dynamics and production of Acartia clausii, a planktonic marine copepod, were studied during 1973 and 1974 in a small temperate lagoon. An approach which integrated laboratory and in situ experiments with time‐series sampling of the field population was used to analyze seasonal changes in the parameters of population growth (development, growth, fecundity, and mortality) and to elucidate the processes which affect these changes. The objective of the study was to understand the factors which control the seasonal cycle of abundance.

The cycles of abundance were similar in the two years of study and were not affected by differences in the cycles of tidal inflow, temperature, and food availability even though the latter two factors appreciably affected growth, development, and fecundity rates. The abundance cycle is controlled by an annually consistent pattern of copepodid and adult mortality believed to be due to predation by the three‐spined stickleback, the dominant fish species in the lagoon. Cannibalism and periodic tidal stimulation of hatching of accumulated eggs in the sediment help to regulate population abundance within seasonal limits.

Production by the lagoon population was 229 kg C for the entire study period; 84—88% of the annual production occurred from April through July. In the area of the lagoon greater than 3‐m deep the mean daily productions during the peak months of each year were 70 and 55 mg C m−2 for 1973 and 1974, respectively.
The Saline Lakes of Saskatchewan II. Locale, Hydrography and other Physical Aspects
Authors: Hammer U. Theodore , Haynes Robert C.
Published: February 2007

The geology and physiography, climate, soils and vegetation of the saline lakes region of southern Saskatchewan are briefly reviewed. The location and morphometry of 60 saline lakes was determined. Some of them are large (307 km2) but mean depths do not exceed 10 m and many are very shallow. Light penetration varied considerably from very turbid shallow lakes to Redberry Lake where the 1% light level was below 16.5 m. Light extinction coefficients for the entire water column of deeper lakes (7) varied from 0.256 to 2.558.

Shallow lakes failed to stratify thermally but a dozen deeper lakes stratified for at least several months. Higher salinity tends to prolong stratification. Thermal stratification augmented chemical stratification in two meromictic lakes. Maximum temperature up to 30 °C in very saline shallow waters was recorded while temperatures as low as‐3 °C occurred under the ice. Freezing was delayed and thawing accelerated in more saline lakes. Annual heat budgets varied from 3350 to 13,900 g cal cm‐2 in seven lakes.

Oxygen concentration was reduced below thermoclines and was virtually absent below the ice in very shallow lakes and, at times, in a very productive lake.
Zur Autökologie von Opistomum pallidum O. Schmidt, 1848, einer Turbellarienart astatischer Kleingewässer. Autecology of Opistomum pallidum O. SCHMIDT, 1848, a Turbellarian Species of Astatic Freshwater Biota
Authors: Heitkamp Ulrich
Published: February 2007

In the freshwater turbellarian, Opistomum pallidum, facultative self‐fertilization occurs. The duration of development follows the van't Hoff/Arrhenius temperature rule. An acceleration of development is caused by a crowding effect at low temperatures. In the natural habitat, one generation requires 6‐7 months, lasting from November to May, or 2‐3 months from March to May.
Wirkungen von Silberkarpfen (Hypophthalmichthys molitrix) auf das Plankton in Flachgewässern nach Untersuchungen in Karpfenteichen. Influence of Silver Carp (Hypophthalmichthys molitrix) on Plankton of Shallow Waters According to Investigations in Carp Ponds
Authors: Barthelmes Detlev
Published: February 2007

No severe changes take place in the plankton of highly eutrophic non‐stratified water bodies up to a stocking rate of 1,000 Si3/ha. This rate gives additional yield of 200‐300 kg/ha. Stocking rates of 10,000 Si3/ha allow selective overexploitation of microphytoplankton incl. bluegreens and of nearly all zooplankton. Yield reaches in this case 1 t/ha in 1 m deep waters.
Effect of Thermal Effluents and Retention Time on Lake Functioning and Ecological Efficiencies in Plankton Communities
Authors: Hillbricht‐Ilkowska Anna , Zdanowski Bogusław
Published: February 2007

The following changes were observed in three lakes as a result of their heating and decrease of retention time (data for summer periods): increase of mixing rate, active bottom area, and nutrients (Pinorg., Ninorg.) concentrations; significant changes in gross primary production, phytoplankton biomass and production of filtering cladocerans. These changes seem to indicate the higher efficiency of utilization of autochthonous trophic resources and energy transfer in plankton.
Spatial Distribution of the Phytoplankton in a Tropical Lake (Lake Lanao, Philippines)
Authors: Lewis William M.
Published: February 2007

The distribution of phytoplankton was studied in Lake Lanao, Philippines. In calm weather, the species segregate vertically with motile species and buoyancy‐regulating species above other species in the water column. On a distance scale of 12.5 km, horizontal variability yields a coefficient of variation of 23.6% for total biomass, 30.2% for net primary production, and an average of 30.3% for individual species biomass after removal of error variances. Variabilities on a scale of 1 km are about half as large. Horizontal patchiness of individual species is not related to their abundance, surface to volume ratio, morphotype, or taxon, but is negatively related to their size.
Setting of Estuarine Invertebrates in Delaware Bay, New Jersey, Related to Intertidal‐Subtidal Gradients
Authors: Hidu Herbert
Published: February 2007

Attachment of eight groups of estuarine benthic species was recorded on a 4000 ft. intertidal‐subtidal transect on Delaware Bay, Cape May, New Jersey. Asbestos‐board panels were spaced at 3‐foot vertical intervals and harvested at weekly intervals for two seasons. Intraspecies attachment patterns were very regular both spatially, and temporally indicating specific setting behavior interacting with a relatively stable environmental influence.

Intertidal, on‐bottom patterns were associated with Crepidula sp. and Balanus sp. whereas Sabellaria vulgaris preferred subtidal, on‐bottom panels. Subtidal, off‐bottom panels were colonized by Tubularia crocea, Conopeum tenuissimum, Caprellidae and Gammaridae. Crassostrea virginica showed a variable pattern, predominantly on‐bottom and subtidal, but occasionally on‐bottom intertidal, inshore. Factors producing concentration of larvae and release of the setting response are important in the inshore recruitment of oysters. All information indicates that the mechanism of selective settlement is a dominant factor in producing benthic assemblages.
Résultats de la mission Hydratlante I du N. O. Jean Charcot (au large des côtes atlantiques françaises) I. Dénombrement des population microplanctoniques. Results of Hydratlante I cruise of R. V. Jean Charcot (off the Atlantic French coast). I. Microplankton enumeration
Authors: Travers Marc
Published: February 2007

Among numerous physical, chemical and biological parameters, the enumeration and identification of microplankton cells have been carried on at all stations and depths, by means of UTERMÖHL'S method (on board and on land). After dealing with space and time distribution of the data, they are compared with some features of environment and particulate organic matter. Abundance and composition of the populations depend on the supply of nutrients, which on its turn depends on the thermal stratification. More or less clear or sure other correlations are discussed: with density, light, bacterioplankton, varied seston parameters, etc….
Limnological Studies on the River Tigris, Iraq. I. Environmental Characteristics
Authors: Saad Massoud A. H. , Antoine Samir E.
Published: February 2007

Regional and seasonal variations of some environmental characteristics in the 630 km stretch of the lower Tigris were studied and discussed. The lowest air and average water temperatures were recorded in January. The highest average pH values, generally found in October and July, are due mainly to the abundance of phytoplankton. The remarkably low average chlorosity values found in the periods of high water were correlated with the high discharge. The highest average values for dissolved oxygen concentration were generally recorded in January and April, and the lowest ones were observed in October and July.
A Small‐volume Filtration Method for Field Use
Authors: Blakar Inggard Arne
Published: February 2007

A robust and easily portable filtration unit constructed of disposable plastic syringes and other inexpensive and readily available material, is described. The unit is simple and easy to operate, and is particularly useful in connection with primary production analyses (14C‐technique in situ).