Institute, University D-2000 Hamburg Institution. Coastal Research sul - PDF document

January 3 ' Institute, University D-2000 Hamburg Institution. Coastal Research sulphidic environments which exploit with bacteria, experimental ecological results gutless oligochaete lipid which showed biochemical fluxes appears that gutless annelids is strongly obtain their metabolic energy. The storage bacterial reserve butyric acid) worms usually 1988b). Only rarely, i.e. greyish-transparent. Hence, the the steep column should either the between bacterial ts a nutritional their gutless hosts is difficult intricate structural & Langheld 1987). biochemical composition and measurement give indications on (Conway & McDowell Capuzzo 1990a). experimental studies were done in 1989 in Aquarium, Museum Zoo, close to the sample in Flatts seawater sampling site. were taken vertical cores essentially identical methods the same in the sublittoral sediment in Flatts divers to worms in relation to into 2.5 redox in the water was measured in 7.9 to 8.5), water sam- & Wakeham spectrophotometric analysis Cline 1969) could not done in Bermuda, conse- precipitated by alkaline Millipore filters were kept filter jars refrigerator until where the HC1. the amount sulphide in samples may during handling syringe, precipitation acids was pled by a 'pore water lance' 1988a). Manipulation of the redox potential discontinuity experiments were designed vertical distribution a given tubes (diam. 15 cm) filled with sand, and redox-cline up at with nylon (10 to worms into a chosen layer, the small glass contained a sediment layer oxygenated surface. The the tube and aerated seawater around it. a generalized 1988a) in the redox every 3 experimental run (mostly after careful decantation 5 resulting subsamples 16 cm3 the new redox value. A evaluation. Regrettably, time avail- all experiments on sufficient (see 'Results'). palelwhite variations in nutrient supply bacteria was cm3) filled with original sediment or oxic tanks used experiment was h before were retrieved color iments performed incorporated into dried worms, sampled October 1989 Hole (for Conway al. 1989). Due to determination was specimens); thus, the ues obtained are version to fatty Conway & McDowell Capuzzo (1990b). The values given here are averages 3 extractions pooled worms. acid composition was measured after formation phenylcarbamyl derivatives preferred occurrence parallel cores. Equation + 17.455~ - 2.503x2 + 0.12?x3 -2.155 X 10-3~4 clearly significant per subsample these parameters 0.01 for redox variation in rather transpa- replicate boxes sluggishness during this experimental light-refractile (bacterial) reserve substance apparently had decreased data see 198813). In some longer-term experiments with conditions from oxic reduced and back highly sulphidic 2 5 40. Z 30. 20. indicating preferred occur- rence around redox discon- cores. Equation X 10-3x - 3.1210 X lo4x2 Sediment Redox Potential [Eh] + 4.3588 X IO-~X~ . . . . redox worm distribution in the 292 Mar. Ecol. Prog. Ser. 68: 287-299, 1991 E X 'f 0 z 2 d. I" 'Y 20 white worms Fig. 5. Migration experiments with RPD set in centre of the tube and (white) worms inserted at bottom: aggregation in middle layers ind. (n=4 experiments) Setting the position (6 to 7 at the gentle decrease bers towards top 4 runs, middle layers significantly different % positioned close again starting % fractions with sul- phidic horizon close to could not in about above the core, while at the top (Fig. % regularly found near the 5 experimental runs, uppermost layers; p a non-random distribution). sulphidic served that it worms. This by additional runs in the experiment, experiments lasting less than about discernible, but a never developed short time experiments lasting was evident was maintained. F 'Y J Fig. 6. Migration experiments with RPD set 1 under the surface the tube and (white) 20 whlte worms in top I. I I b layers 294 Mar. Ecol. Prog. Ser. 68: 287-299, 1991 Table 1 Inanldnlus sampling area analytical methods) g-' dry wt) '10 of total '10 of total Aspartic Glutamic acid P-Glutaric acid 2.5 Hydroxy-proline 15 0.4 Asparaginea 5 0.1 5.2 serineb 54 1.5 1.6 Glutaminea 0 0 13.2 Glycine 640 17.5 2.3 Histidine 43 1.2 1.1 Taurine/arginine/tyrosine 149 4.1 1.9 Threonineb 136 3.7 Alanine 560 15.3 6.8 13- Alanine 2.0 Proline 4 1 Valine/methionine 475 12.9 2.8 Cystine/cysteine 21 0.6 Isoleucine 290 7.9 0.8 Leucine 396 10.8 0.8 Phenylalanine 186 5.1 1.4 ~ryptophan~ 0 0 Lysine 193 5.3 0 Others 0.9 Total 3670 100 100 a amino acids are largely converted aspartic and glutamic reduced during sulphur bacteria the area where micro- sulphidic conditions overlap is Movement towards this factorial combinations these types sulphur bacteria changing gradients (Jerrgensen & pers. comm.). Here, even redox conditions in pers. comm.). Thus, about the in different ways preferred conditions Less mobile like bivalves pogonophorans may the range coelomic fluid al. 1986, Reid & 1986, Powell & 1989). Small meiobenthic thiobiota, however, can the steep much changing 1982, 1984, Powell & Powell 1987, et al. various meiobenthic experimentally fluctuating water changes & Novak (1989), with thiobiotic found a corresponding redox experimental studies provide direct the depth animals. Fluctuations in oxic/anoxic sediment than per se. population is regularly found completely anoxic horizons. This specific not only hydrogen sulphide (Giere al. 1982, Giere 1988b), explains observations experiments: pale worms, inoculated high concentrations sul- Prog. Ser. 287-299, 1991 average values of -30 O/O to -42 (-47 %o) for sulphur- given by al. (1987) al. (1989). According to our the annelid tissue in then have 613c -23 to %o. than the isotope ratios carbon sour- ces in animals, which %o, inorganic carbon %o; a dominant nutritive role the chemosynthetic bacterial 613c -23.4 to in some symbiotic pogonopho- a supply % fixation by their endosymbionts. ratios cover a wide N-ratio is altered during 15~ by 3 %o (Minagawa & 1984, Paull Peterson & Fry 1987). The ratio recorded in Inanidrilus leukodermatus (-1.4 %o) is clearly lower than that +20; et al. 1985), in most 21°N (Rau 1985, Fisher 1988). This indicates that organic matter worms is not a phytoplankton-based chain, but N sources. the absence geothermal vents these suggest that in the biosis may orginate bacterial nitrogen other bacterial N-metabolic processes that the nitrate. Indeed, pm01 g-l dry wt annelid tissue were measured. the sam- in the pm01 dm-3 with maxima � 700 pm01 dm-3 showed the presence substantial nitrate The interesting in these the presence these gutless worms, with total. Many chemoautotrophic e.g. Thiomicrospira crunogena, can produce all the essential amino acids (Conway 1990). Also, Trytek & Allen (1980) acids by shipworm and the derives its these substances frac- tionation, demonstrated good indication prokaryotic origin many amino acids. that the take up their supply amino acids the high amino acids in the ambient pore Compared to seawater sediment surface, was about dissolved amino yM 1-l measured (analyses in 1981 by analytical methods amino acids pore water 3 sediment cores complete set amino acids pore water by glutamic amino acids only 15 % total. Particularly leucine were much lower relative 1 % each) than in the annelid homogenate containing teria (Table Thus, the many amino by selective the annelids endosymbiotic prokaryonts. 3 extractions pooled worm lipids is probably representative, could not analyzed immediately fatty acids indicates that lipid (cis-vaccenic acid) metabolic role in the symbiosis with is often a bacterial with 16 w 7 produced a secondary (Goldfine 1972, Fulco 1983). This could leukodermatus in not only take up Solemya velum, lipid composition is lipid much lower (Conway & McDowell Capuzzo 1990a, remarkably high comparison with other marine lipid reflects utilization Ecol. Prog. 287-299, 1991 study. In: Barnes, Gibson, Trophic relation- ships in marine environment. 24th Eur. Mar. Conway, N., McDowell Capuzzo, J. (1990b). (in press) Conway, N., McDowell stable isotope P. R., R. L. pro- karyotes symbiotic with Felbeck, H., G., Dawson, CO2 in tissues marine oligochaetes (PhallodriIus leukodermatus and P, planus) (1988). Energetics. In: P,, Smithsonian Institution Press, (1988). Microhabitat variation hydrothermal vent mussel, ther- Garden vent E. N. CO2 acoel turbellarians. meiofauna aerobic? Biochem. Physiol. Fulco, A. Lipid Res. 22: hydrologic factors on the intertidal marsh sediments. South- Geol. 15: Wolaver, T. in the sulfur chemistry marsh sediments Inlet, South Carolina, Res. 46: lecture: meiofauna hosts with their symbiotic Wash. 102: Giere, O., (1988a). In: Higgins, the study Smithsonian Institution D.C., gutless oligochaete Hvdrobioloaia 115: - C. (1987). Structural organization, trans- oligochaetes.-~ar. Biol. 93: 641-650 gutless oligochaete Phallo- leukodermatus. Mar. O., Schmidt, C., (1988b). thiosulfide on symbiotic (Anne- lida). Mar. 413419 Comparative aspects Microb. Physiol. 8: 1-58 Howes, B. 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