Description: Seven strains of five species of the genus Ectothiorhodospira were characterized by oligonucleotide cataloguing of their 16S rRNA in order to determine the phylogenetic relationship to one another and to other phototrophic purple bacteria. All representatives of Ectothiorhodospira are members of that line of descent defined by phototrophic purple sulfur bacteria and relatives, showing a moderate relationship to those phototrophic organisms forming globules of elemental sulfur inside the cell (Chromatium and relatives). The 5 Ectothiorhodospira species fall into two subgroups. E.halophila, E. halochloris and E. abdelmalekii form one, E. mobilis, E. shaposhnikovii and the unnamed strain BN 9906 form the second subgroup. Within the two subgroups the strains are closely related, while the degree of relatedness found between members of the two subgroups is more distant.

Description: Rhodopseudomonas globiformis is able to grow on sulfate as sole source of sulfur, but only at concentrations below 1 mM. Good growth was observed with thiosulfate, cysteine or methionine as sulfur sources. Tetrathionate supported slow growth. Sulfide and sulfite were growth inhibitory. Growth inhibition by higher sulfate concentrations was overcome by the addition of O-acetylserine, which is known as derepressor of sulfate-assimilating enzymes, and by reduced glutathione. All enzymes of the sulfate assimilation pathway. ATP-sulfurylase, adenylylphosphate-sulfotransferase, thiosulfonate reductase and O-acetylserine sulfhydrylase are present in R. globiformis. Sulfate was taken up by the cells and the sulfur incorporated into the amino acids cysteine, methionine and homocysteine. It is concluded, that the failure of R. globiformis to grow on higher concentrations of sulfate is caused by disregulation of the sulfate assimilation pathway. Some preliminary evidence for this view is given in comparing the activities of some of the involved enzymes after growth on different sulfur sources and by examining the effect of O-acetylserine on these activities.

Description: In SCUBA-diving monitored field experiments (Flensburg Fjord, 15 m, 1981) and parallel aquarium tests,the behavior of Metridium senile under anoxic conditions and its oxygen-deficiency resistance were studied. When oxygen is lacking the fluffy sea anemone diminishes body surface, and then, successively, shuts off most energy consuming activities. By means of this strategy, 50% of the tested individuals survived 3 weeks of total anoxia

Description: A suite of marble specimens from the Sierra Alhamilla (Spain), deformed to large strains under natural conditions at about 300° C shows distinct variations in microstructure and fabrics. It can be demonstrated that the development of crystallographic preferred orientations and grain shape fabrics are strongly dependent on recrystallized grain size. This is interpreted to reflect the relative importance of various deformational mechanisms. Superplasticity seems to have a sharp upper grain size limit at 10–15 /smm. Within the power law creep regime, deformation in fine grained aggregates is probably dominated by diffusional, in coarser ones by dislocation mechanisms. The transition is a gradual one, and may span a grain size range of 30 /sm.

Description: The response of the benthos to the break up of anoxia in the Kiel Bight (Western Baltic Sea), and to three succeeding events of “external” food supply, consisting of a settled autumn plankton bloom, resuspended matter and macrophyte input during winter, and of a sedimented spring phytoplankton bloom, is described on a community level. The first input of oxygen broke up anoxic conditions and made stored food resources available to decomposition. This “internal” food supply, mainly consisting of protein (folin positive matter), was followed by a drastic increase in heat production and ATP-biomass and caused a period of low redox potential, which lasted for several weeks. During this phase, a plankton bloom (dinoflagellates and diatoms) settled to the sea floor. Although there was an immediate response of benthic activity, this food input was not completely consumed by the strongly disturbed benthic community. During winter resuspended matter and the input of macrophyte debris caused another maximum in benthic activity and biomass despite the low temperature. The response to sedimentation of cells from a diatom bloom during mid March was also without any time lag and was consumed within 5–6 wk. A comparison of the amount of particles collected in a sediment trap with the increase of organic matter in the sediment demonstrated that the sediment collected four times (autumn) and seven to eight times (spring) more than measured by the sediment trap. Strong indications of food limitation of benthic activity were found. During autumn and winter these indications were caused more by physical than by biological processes. The three events of “external” food supply caused a temporary shift in the type of metabolism towards fermentation processes and reduced the redox potential. In spring the development of the benthic community was still being strongly influenced by the events of the preceding summer and autumn.

Description: Seasonal variations in bacterial populations (total number, biomass, biomass-spectrum, number of dividing cells) as well as in concentrations and decomposition rates of particulate organic material were followed in a sandy mud sediment of the Western Kiel Bight (Baltic Sea; FRG). The strong seasonal variations observed could be traced back to the effect of certain ecological situations and events in the sediment from which the input of the phytoplankton blooms in autumn and spring, respectively, the accumulation of organic material during winter, and the spring development of the benthic fauna turned out to be the most important. Bacterial carbon net production following the breakdown of the phytoplankton blooms ranged between 9 μg (autumn) and 16 μg (spring) per g of dry weight sediment per day. The consequences of shifts in the size composition of the bacterial populations as well as the importance of the measurement of enzymatic decomposition rates of particulate organic material in sediments are demonstrated and discussed in relation to the events mentioned above

Description: Ceratium hirundinella cells in Lake Constance divided during the second half of the night. Growth rates are calculated from the fraction of cells undergoing cell division. Potential growth rates are compared with observed changes in population density. The discrepancy between both is discussed as a possible function of fungal parasitism.

Description: Radiative transfer modelling for a coupled ocean-atmosphere system near 685 nm indicates a sufficiently high fluorescence signal of the chlorophyll a transmitted to the top of the atmosphere. However, only the shortwave half is seen at the top of the atmosphere, the longwave half is fully masked by atmospheric oxygen and water vapour absorption. The impact of atmospheric aerosol extinction on the signal transmission is almost negligible. The Hα line of the sun, atmospheric water vapour absorption, and chlorophyll absorption near 670 nm influence radiative transfer in the shortwave tail of the fluorescence line making the search for a baseline in order to eliminate the background radiation a difficult task.

Description: In two closely spaced moorings in the Kiel Bight, four different current meterstwo rotor current meters (Aanderaa and Vector averaging), an acoustic current meter (designed by Gytre), and a pendulum current meter (designed by Niskin) were moored for 22 days. The Vector averaging current meter (VACM) was used as reference instrument on one mooring with the floatation at 7 m depth. The floatation of the second mooring was at 5 m depth in the first 17 days of the experiment, but in 2.7 m depth in the last 5 days to make their mooring more effected by surface waves. The Niskin wing current meter was most effected by wave-induced mooring motion. The Gytre instrument showed the smallest surface-wave effects. The vector variances of this instrument in 7.4 m depth on the surface-wave effected mooring and those of the VACM in 10 m depth on the reference mooring were about equal.

Description: Statoliths of the short-finned squid Illex illecebrosus were chemically analyzed to define their chemical composition and surveyed by scanning electron microscope to differentiate internal structural patterns. X-ray diffraction data demonstrated that L Illecebrosus statoliths were composed principally of CaCQ in the aragonite crystal form. The crystals occurred in a protein matrix to form incremental patterns which radiated from the nucleus to the edge of the statoliths. The protein matrix comprised approximately 5% of the statolith by weight. The protein was principally composed of acidic amino acids. A high abundance of aspartic acid in the protein matrix indicated that the matrix would function as a template in the initiation and acceleration of the crystal growth of CaCO. The rhythmic microstructural patterns, constructed of aragonite crystals in the protein matrix, wer e suggested to be daily in formation and subsequent growth estimations were in agreement with known life history information. The stable isotopic composition of the carbonate of L illecebrosus statoliths suggested that oxygen may be deposited in isotopic equilibrium with the surrounding environment while carbon appeared to be related to biological processes. The information recorded in the statotiths as incremental growth and stable isotopic composition could provide valuable insights into the ecological history of squid.