Genetic structure of asexually reproducing Enteromorpha linza (Ulvales: Chlorophyta) in Long Island Sound

Heterotrophic bacterial uptake and turnover of glycolate were measured in the water column of the New York Bight apex during four seasonal cruises over almost a one-year period between May 1977 and March 1978. Glycolate turnover was most rapid in May and July, when primary productivity and estuarine runoff were high. Extremely rapid glycolate turnover times (<1 h) were detected at some stations during these months. Increased bacterial glycolate tunover did not accompany increased primary productivity in March, when water temperatures were lowest. Glycolate flux calculations indicate that the measured rates of glycolate consumption by bacteria always exceeded estimated glycolate production by phytoplankton, except in March. This excess may reflect an underestimation of phytoplankton production or the input of glycolate from other sources, such as estuarine runoff. Glycolate utilization appears to be seasonally important to bacteria in the New York Bight apex, coinciding with fluctuations in phytoplankton primary productivity.     

Photosynthesis,photorespiration, and dark respiration in eight species of algae

The rates of photosynthesis and dark respiration for 7 marine algae and 1 fresh-water alga were measured and compared. The dinoflagellates Glenodinium sp. and zooxanthellae have high dark respiration rates relative to photosynthetic rates, which may decrease their net growth rates. Photorespiration in the 8 algal species was studied by examining the effects of the concentration of oxygen on the rates of photosynthesis, on the incorporation of ¹⁴CO₂ into the photorespiratory pathway intermediates glycine and serine, and on the postillumination burst of carbon dioxide production and oxygen consumption. A combination of these results indicates that all the algae tested can photorespire, but that Glenodinium sp., Thalassiosira pseudonana, and zooxanthellae either have a photorespiratory pathway different from that proposed for freshwater algae (Tolbert, 1974), or an additional pathway for glycolate metabolism.     

Differences of two polychaete species reflected in enzyme activities

Polychaetes constitute most of the benthic macroinvertebrates in estuarine and coastal environments. We investigated the utilization of organic matter in two polychaete species, Capitella sp. I and Perinereis nuntia brevicirris, living in different coastal habitats. The protease activity of Capitella sp. I (89.7 μg mg⁻¹) was about 10 times that of P. nuntia brevicirris (8.0 μg mg⁻¹). High cellulase (endo-β-1,4-glucanase) activity was detected in P. nuntia brevicirris (3.2 μg mg⁻¹), whereas scarcely any was detected in Capitella sp. I. We isolated cDNA clones of protease mRNA from Capitella sp. I and of cellulase mRNA from P. nuntia brevicirris. The high protease activity of Capitella sp. I enabled it to survive in the sediment under a fish farm, where it degrades organic matter. In contrast, the high cellulase activity of the estuary-dwelling P. nuntia brevicirris allowed it to degrade organic matter originating from terrestrial areas.     

Biodegradation of paclobutrazol by a microbial consortium isolated from industrially contaminated sediment

Biodegradability of the plant growth retardant paclobutrazol by a microbial consortium in which Pseudomonas was the predominant strain was investigated in batch culture. The consortium which had been isolated from an industrially contaminated sediment was proven to be useful for the treatment of effluents containing paclobutrazol. Paclobutrazol was degraded by the pure isolated strain of Pseudomonas sp. as well as the microbial consortium. Paclobutrazol was utilized as the sole source of carbon and energy. Sixty percent of the paclobutrazol was degraded by the microbial consortium from an initial concentration of 54 mg L^?1 within 48 h and more than 98% of an initial concentration of 3.4 mg L^?1 was degraded within 36 h. The optimum temperature and pH were determined to be 30°C and 7.0, respectively. A pure strain of a bacterium, isolated from the enrichment culture was identified as Pseudomonas sp. The microbial consortium was tolerant of high pH and could degrade paclobutrazol faster than the pure strain. The degradation rate of this plant growth regulator in an aerobic environment was greater than that under anaerobic conditions.     

Selection of poly(R)-3-hydroxybutyric acid utilising bacteria by enrichment,optimisation and compatibility testing for consortia development

Bacterial strains with poly-3-hydroxybutyrate (PHB) degradation potential were isolated from waste yard soil samples of selected industrial sites in Uttarakhand, India, and two microbial consortia were developed, i.e. Consortium I comprises Pseudomonas sp. strain Rb10, Pseudomonas sp. strain Rb11 and Bacillus sp. strain Rb18, and Consortium II is composed of Lysinibacillus sp. strain Rb1, Pseudomonas sp. strain Rb13 and Pseudomonas sp. strain Rb19. The current study involved enrichment selection via liquid and semi-solid media, followed by isolation and screening of bacterial strains using PHB pellets and films. Furthermore, the identification and characterisation was done by triphasic approach. The utilisation of PHB by the characterised strains was confirmed by Fourier transform infrared spectroscopy and scanning electron microscopy. Moreover, the minimum inhibitory concentration of solubilised PHB was found to be 2.5?mg/mL, which was detected through ‘clear zone assay’. Further, the selection and biocompatibility testing of potential isolates were performed for the formation of bacterial consortia. Thus, the present work would provide direct and standardised protocol for screening and selection of potential microbiomes for biodegradation of polymers by overcoming the negative effect of organic solvents. Moreover, indigenously developed consortia would be evaluated for their in situ biodegradation potential against various bioplastic films.     

Effects of salinity on soil bacterial and archaeal community in estuarine wetlands and its implications for carbon sequestration: verification in the Yellow River Delta

Soils from two typical tidal salt marshes with varied salinity in the Yellow River Delta wetland were analysed to determine possible effects of salinity on soil carbon sequestration through changes in soil microbiology. The mean soil respiration (SR) of the salt water–fresh water mixing zone (MZ) was 2.89 times higher than that of the coastal zone (CZ) (4.73 and 1.63?μmol?m^?2?s^?1, respectively, p?Pseudomonas sp. and Limnobacter sp. that might have led to its higher dehydrogenase activity and respiratory rates. Additionally, the CZ possessed more Halobacteria and Thaumarchaeota with the ability to fix CO₂ than the MZ. Significantly lower soil salinity in MZ (4.25?g?kg^?1) was suitable for β-Proteobacteria, but detrimental for Halobacteria compared with CZ (7.09?g?kg^?1, p?相似文献   

Stimulation of phytoplankton production in coastal waters by natural rainfall inputs: Nutritional and trophic implications

Recent evaluations of estuarine and coastal nutrient budgets implicate atmospheric deposition as a potentially significant (20 to 30%) source of biologically available nitrogen. We examined the potential growth stimulating impact of atmospheric nitrogen loading (ANL), as local rainfall, in representative shallow, nitrogen limited North Carolina mesohaline estuarine and euhaline coastal Atlantic Ocean habitats. From July 1988 to December 1989, using in situ bioassays, we examined natural phytoplankton growth responses, as¹⁴CO₂ assimilation and chlorophylla production, to rain additions over a range of dilutions mimicking actual input levels. Rainfall at naturally occurring dilutions (0.5 to 5%) stimulated both¹⁴CO₂ assimilation and chlorophylla production, in most cases in a highly significant manner. Parallel nutrient enrichments consistently pointed to nitrogen as the growth stimulating nutrient source. Generally, more acidic rainfall led to greater magnitudes of growth stimulation, especially at lower dilutions. Nutrient analyses of local rainfall from May 1988 to January 1990 indicated an inverse relationship between pH and NO ₃ ^- content. There have been growing concerns regarding increasing coastal and estuarine eutrophication, including ecologically and economically devastating phytoplankton blooms bordering urban and industrial regions of North America, Europe, Japan, and Korea. It appears timely, if not essential, to consider atmospheric nutrient loading in the formulation and implementation of nutrient management strategies aimed at mitigating coastal eutrophication.     

Dibenzofuran: Bakterielle Mineralisierung

The degradation of uniformly¹⁴C-labelled dibenzofuran (DBF) by the strainPseudomonas sp HH 69 and a consortium consisting of the DBF-degrading Pseudomonas strain NRM and an accompanying Nocardia-like strain NRH, was monitored in liquid-batch cultures and in different soil samples. Experiments involving the strain and a consortium in aereated liquid cultures (batch process) showed that DBF was utilized as a source of energy and carbon. Thereby, more than 65% of DBF is rapidly converted to CO₂, about 20% to biomass and only about 10% to slow-degrading intermediate metabolites, respectively. The same microorganisms also exhibited comparable degrees of degradation efficiency in various types of soils contaminated with DBF. For instance, DBF, uniformly distributed in sterile soil samples, in concentrations between 0.2 to 200 ppm, was converted to CO₂, within 10 days, to the extent of about 75% by the strainPseudomonas sp. HH 69.     

Selective pseudosolubilization capability of Pseudomonas sp. DG17 on n-alkanes and uptake mechanisms analysis

Pseudosolubilized ability of Pseudomonas sp. DG17 on n-alkanes, role of biosurfactants in n-octadecane uptake and trans-membrane transport mechanism of n-octadecane were studied by analyzing amount of pseudosolubilized oil components in water phase, and the fraction of radiolabeled ¹⁴C n-octadecane in the broth and cell pellet. GC-MS results showed that pseudosolubilized oil components were mainly C₁₂ to C₂₈ of n-alkanes. In n-octadecane broth, pseudosolubilized n-octadecane could be accumulated as long as pseudosolubilized rate was faster than mineralization rate of substrate, and the maximum concentration of pseudosolubilized n-octadecane achieved to 45.37 mg·L^?1. All of these results showed that Pseudomonas sp. DG17 mainly utilized alkanes by directly contacting with pseudosolubilized small oil droplets in the water phase. Analysis of ¹⁴C amount in cell pellet revealed that an energy-dependent system mainly controlled the trans-membrane transport of n-octadecane.     

The trophic role of glycolic acid in coastal seawater. II. Seasonal changes in concentration and heterotrophic use in Ipswich Bay,Massachusetts, USA

Glycolic acid is a known algal excretory product which is found in marine waters and is readily metabolized by marine bacteria. The following parameters were measured over the course of a year in Ipswich Bay: chlorophyll a, temperature, viable bacteria, heterotrophic uptake of glycolate, and glycolate concentrations. The latter two were combined to give estimates of the flux of glycolate for a station 3 km out in the bay and for an inshore station. Pronounced seasonal changes were found for all parameters. Statistically significant correlations between heterotrophic V _max and glycolic acid concentrations and temperature were found, but not between planktonic chlorophyll a and any of the other parameters. Measurements of glycolic acid flux yielded an annual flux of 2.84 g m^-2 for the bay station, which is about 0.5% of the bay phytoplankton production. Glycolic acid turns over roughly 12 times per year in the bay. It contributes perhaps as much to bacterial metabolism as any other single substrate, but is apparently not of dominating importance.     

Phaeocystis blooms and eutrophication of the continental coastal zones of the North Sea

It is suggested that novel nuisance algal blooms can result from major shifts in N/P or NH₄ ⁺/NO₃ ^- ratios. Inland hydraulic engineering caused a shift from P-limitation (before 1977) towards N-limitation (after 1977) in the Marsdiep area (Dutch coastal waters). Following this shift the colonial flagellate Phaeocystis sp. became more abundant and started to bloom during the nutrient-controlled period (later spring to autumn). Competition experiments showed that the N/P ratio can influence the species composition of marine phytoplankton. In addition, the natural distribution of some species like Rhodomonas sp. and Emiliania huxleyi may be affected by the frequency of nutrient pulses in the system. Phaeocystis was a poor competitor under P-limitation and a good competitor under N-limitation. Colony formation was absent under P- and NH₄ ⁺-limitation. Colonies were formed under NO₃ ^--limitation. These preliminary results suggest that colony-forming Phaeocystic blooms may be restricted (besides light-controlled environments) to those N-controlled environments where nitrate is consumed by Phaeocystis. The distribution of Phaeocystis along the European continental coast is evaluated on the basis of its ability to compete for nutrients and to form colonies when nitrate is the major N-source.     

Biodegradation kinetics of cymoxanil in aquatic system

A potential method to detoxify pesticides in aquatic system is using bioremediation. In this study, four microorganisms (Pseudomonas sp (EB11), Streptomyces sp. (EB12), Aspergillus niger (EB13) and Trichoderma viride (EB14) were isolated from cucumber leaves previously treated with cymoxanil using enrichment technique. These strains were evaluated for their potential to detoxify cymoxanil in aquatic system at the concentration level of 5×10^?4M. The effect of pH and temperature on the growth ability of the tested strains was also investigated by measuring the intracellular protein and mycelia dry weight for bacterial and fungal strains, respectively. Moreover, the remaining toxicity of cymoxanil after 28 days of incubation with tested strains was evaluated to confirm the complete removal of any toxic materials (cymoxanil and its metabolites). The results showed that the optimum pH for the growth of cymoxanil degrading strains (bacteria and fungi) was 7. A temperature of 30°C appears to be the optimum for the growth of either fungal or bacterial strains. Pseudomonas sp. (EB11) was the most effective strain in cymoxanil degradation followed Streptomyces sp (EB12), Trichoderma viride (EB14) and Aspergillus niger (EB13), with half-lives of 4.33, 9.5, 17.3 and 24.7 days, respectively. The degradation of cymoxanil by bacterial strains was much faster than fungal one. There is no remaining toxicity of cymoxanil detected in aqueous media previously treated with Pseudomonas sp. (EB11) for 28 days. The results suggest that bioremediation by Pseudomonas sp. (EB11) are promising for the detoxification of cymoxanil in aqueous media.     

Arsenic detoxification potential of <Emphasis Type="Italic">aox</Emphasis> genes in arsenite-oxidizing bacteria isolated from natural and constructed wetlands in the Republic of Korea

Arsenic is subject to microbial interactions, which support a wide range of biogeochemical transformations of elements in natural environments such as wetlands. The arsenic detoxification potential of the bacterial strains was investigated with the arsenite oxidation gene, aox genotype, which were isolated from the natural and constructed wetlands. The isolates were able to grow in the presence of 10 mM of sodium arsenite (As(III) as NaAsO₂) and 1 mM of d+glucose. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that these isolated strains resembled members of the genus that have arsenic-resistant systems (Acinetobacter sp., Aeromonas sp., Agrobacterium sp., Comamonas sp., Enterobacter sp., Pantoea sp., and Pseudomonas sp.) with sequence similarities of 81–98%. One bacterial isolate identified as Pseudomonas stutzeri strain GIST-BDan2 (EF429003) showed the activity of arsenite oxidation and existence of aoxB and aoxR gene, which could play an important role in arsenite oxidation to arsenate. This reaction may be considered as arsenic detoxification process. The results of a batch test showed that P. stutzeri GIST-BDan2 (EF429003) completely oxidized in 1 mM of As(III) to As(V) within 25–30 h. In this study, microbial activity was evaluated to provide a better understanding of arsenic biogeochemical cycle in both natural and constructed wetlands, where ecological niches for microorganisms could be different, with a specific focus on arsenic oxidation/reduction and detoxification.     

Suitability of estuarine nursery zones for juvenile weakfish (Cynoscion regalis): effects of temperature and salinity on feeding,growth and survival

Juvenile weakfish, Cynoscion regalis (Bloch and Schneider, 1801), exhibit significant spatial diffrences in growth rate and condition factor among estuarine nursery zones in Delaware Bay. The potential influence of temperature and salinity on the suitability of estuarine nursery areas for juvenile weakfish was investigated in laboratory experiments by measuring ad libitum feeding rate, growth rate and gross growth efficiency of juveniles collected in Delaware Bay in 1990 (40 to 50 mm standard length; 1.4 to 2.1 g) in 12 temperature/salinity treatments (temperatures: 20, 24, 28°C; salinities: 5, 12, 19, 26 ppt) representing conditions encountered in different estuarine zones during spring/summer. Feeding rates (FR) increased significantly with temperature at all salinities, ranging from 10 to 15% body wt d^-1 at 20°C to 33–39% body wt d^-1 at 28°C. Specific growth rates (SGR) ranged from 1.4 to 9.4% body wt d^-1 (0.3 to 1.5 mm d^-1) and gross growth efficiencies (K ₁) varied from 13.6 to 26.4% across temperature/salinity combinations. Based on nonlinear multiple regression models, predicted optimal temperatures for SGR and K ₁ were 29 and 27°C, respectively. Salinity effects on SGR and K ₁ were significant at 24 and 28°C where predicted optimal salinity was 20 ppt. At these warmer temperatures, SGR and K ₁ were significantly lower at 5 than at 19 ppt despite higher FR at 5 ppt. Therefore, maximum growth rate and growth efficiency occurred under conditions characteristic of mesohaline nurseries. This finding is consistent with spatial patterns of growth in Delaware Bay, implying that physicochemical gradients influence the value of particular estuarine zones as nurseries for juvenile weakfish by affecting the energetics of feeding and growth. Laboratory results indicate a seasonal shift in the location of physiologically optimal nurseries within estuaries. During late spring/early summer, warmer temperatures in oligohaline areas permit higher feeding rate and faster growth compared to mesohaline areas. By mid-late summer, spatial temperature gradients diminish and mesohaline areas provide more suitable physicochemical conditions for growth rate and growth efficiency whereas oligohaline areas become energetically stressful. Substantial mortality occurred at 5 ppt and 28°C, providing additional evidence that oligohaline conditions are stressful during late summer. Furthermore, juveniles provided a choice among salinities in laboratory trials preferred those salinities which promoted higher growth rates. The extensive use of oligohaline nurseries by juvenile weakfish despite the potential for reduced growth rate and growth efficiency suggests this estuarine zone may provide a substantial refuge from predation.     

Root respiration and oxygen flux in salt marsh grasses from different elevational zones

Plants growing in waterlogged environments are subjected to low oxygen levels around submerged tissues. While internal oxygen transport has been postulated as an important factor governing flooding tolerance, respiration rates and abilities to take up oxygen under hypoxic conditions have been largely ignored in plant studies. In this study, physiological characteristics related to internal oxygen transport, respiration, and oxygen affinity were studied in low intertidal marsh species (Spartina alterniflora and S. anglica) and middle to high intertidal species (S. densiflora, S. patens, S. foliosa, a S. alterniflora × S. foliosa hybrid, S. spartinae, and Distichlis spicata). These marsh plants were compared to the inland species S. pectinata and the crop species rice (Oryza sativa), corn (Zea mays), and oat (Avena sativa). Plants were grown in a greenhouse under simulated estuarine conditions. The low marsh species S. anglica was found to transport oxygen internally at rates up to 2.2 μmol O₂ g fresh root weight⁻¹ h⁻¹. In contrast, marsh species from higher zones and crop species were found to transport significantly less oxygen internally, although rice plants were able to transport 1.4 μmol g⁻¹ h⁻¹. Under hypoxic conditions, low marsh species were better able to remove dissolved oxygen from the medium compared to higher marsh species and crops. The oxygen concentration at which respiration rates declined due to limited oxygen (P _crit) was significantly lower in low marsh species compared to inland and crop species; P _crit ranged from <4 μM O₂ in the low marsh species S. anglica up to 20 μM in the inland species corn. Flooding-sensitive crop species had significantly higher aerobic respiration rates compared to flooding-tolerant species in this study. Crop species took up 3.6–6.7 μmol O₂ g⁻¹ h⁻¹ while all but one marsh species took up <3.5 μmol O₂ g⁻¹ h⁻¹. We conclude that oxygen transport, aerobic demand, and oxygen affinity all play important and interrelated roles in flood tolerance and salt marsh zonation.     

High levels of genetic subdivision of marine and estuarine populations of the estuarine catfishCnidoglanis macrocephalus (Plotosidae) in southwestern Australia

The cobblerCnidoglanis macrocephalus (Valenciennes) is an endemic marine and estuarine catfish from southern Australia. Conflicting views on the degree of isolation of the estuarine populations underscore general questions about genetic divergence in coastal species. Although estuaries are widely recognized as ecologically important, little work has been done on their role in favouring genetic divergence. In order to estimate the extent of genetic subdivision among nearshore marine and estuarine populations, electrophoretic variation of enzymes was examined in seven marine and six estuarine populations of cobbler from sites spanning 1500 km along the southwest Australian coastline. Among all populations, the mean standardized variance in allelic frequencies (F _ST) for six polymorphic loci was 0.277, a high value comparable to those of other shallow-water teleosts whose life-history characteristics and habitat preferences restrict their dispersal capability. The pattern of genetic identities between populations showed divergence between west and south coast sites. Within these regional groups, however, there was substantial heterogeneity, much of which was associated with estuaries. Among all six estuarine sites, the averageF _ST was 0.333, 40% higher than the value of 0.237 for the marine sites. Low estimates of the genetically effective number of migrants suggest population subdivision between marine and estuarine environments and between similar habitat types. This study indicates the importance of habitat in affecting the connectedness of populations, even in apparently open marine systems.     

Swimming ability of eels (<Emphasis Type="Italic">Anguilla rostrata,Conger oceanicus</Emphasis>) at estuarine ingress: contrasting patterns of cross-shelf transport?

The transport of eel early life stages may be critical to their population dynamics. This transport from ocean spawning to freshwater, estuarine and coastal nursery areas is a combination of physical and biological processes (including swimming behavior). In New Jersey, USA, the American eel (Anguilla rostrata) enters estuaries as glass eels (48.7–68.1 mm TL) in contrast to the Conger eel (Conger oceanicus) that enters as larger (metamorphosing) leptocephali (68.3–117.8 mm TL). To begin to understand the mechanisms of cross-shelf transport for these species, we measured the potential swimming capability (critical swimming speed, U _crit) under ambient conditions throughout the ingress season. A. rostrata glass eels were collected over many months (January–June) at a range of temperatures (4–21°C), with relative condition declining over the course of the ingress period as temperatures warmed. C. oceanicus occurred later in the season (April–June) and at warmer temperatures (14–24.5°C). Mean U _crit values for A. rostrata (11.7–13.3 cm s⁻¹) and C. oceanicus (14.7–18.6 cm s⁻¹) were comparable, but variable, with portions of the variability explained by water temperature, relative condition, ontogenetic stage, and fish length. Travel times to Little Egg Inlet, New Jersey, estimated using 50% U _crit values, indicate it would take A. rostrata ~30 and ~60 days to swim from the shelf edge and Gulf Stream, respectively. Travel times for C. oceanicus were shorter, ~20 days from the shelf edge, and ~45 days from the Gulf Stream. Despite differences in life stage, our results indicate both species are competent swimmers, and suggest they are capable of swimming from the Gulf Stream and/or edge of the continental shelf to estuarine inlets.     

Isolation and characterisation of a carbofuran degrading Burkholderia sp. PCL3 from carbofuran-phytoremediated rhizosphere soil

A bacterial strain capable of degrading carbofuran as the sole carbon source was isolated from carbofuran-phytoremediated rhizosphere soil of rice. A 16S rRNA study identified the strain as Burkholderia sp. (isolate PCL3). Free cells of isolate PCL3 possessed inhibitory-type degradation kinetics with a q _max of 0.087 day^?1 and S _m of 248.76 mg·L^?1. Immobilised PCL3 on corncob and sugarcane bagasse possessed Monod-type degradation kinetics with a q _max of 0.124 and 0.098 day^?1, respectively. The optimal pH and temperature with the highest degradation rate coefficient of carbofuran were pH 7.5 and 35 °C, respectively.     

Anaerobic heat production of bivalves (Polymesoda caroliniana andModiolus demissus) in relation to temperature,body size,and duration of anoxia

Anaerobic heat-production rates of two co-occurring species of estuarine bivalves (a clam and a mussel) were measured with double-twin heat-flow calorimeters, one at 20°C, the other at 30°C. There is no significant difference between the two species in metabolic rates. There is evidence of initial aerobic metabolism in some individuals, as shown by high initial rates exponentially decreasing with time, while others had fluctuating but stable average metabolic activity from the beginning. During aerobic as well as anaerobic metabolism, the bivalves showed rhythmic periods of activity and quiescence. The two species differed in their rhythmic pattern of active and resting metabolism. In the case ofPolymesoda caroliniana, periods of resting metabolism tend to be longer and periods of active metabolism shorter at 30°C than at 20°C. There is a similarity between thermograms ofModiolus demissus at 20° and 30°C. Following acute temperature changes from 5° to 20° and 30°C, the bivalves showed stable metabolic rates in a matter of hours. The stabilized average rates [pooled averages for both species of 1.34×10^-4 (standard error of the mean=0.17×10^-4) W g^-1 dry weight of tissue at 20°C and 2.10×10^-4 (SE=0.20×10^-4) W g^-1 at 30°C] signify a temperature coefficient (Q₁₀) of 1.56 between 20° and 30°C, or partial temperature acclimation. Subtracting heat production as a result of physical activity, i.e., considering only resting metabolism, the corresponding means and standard errors of the means are 1.24×10^-4 and 0.14×10^-4 W g^-1 at 20°C and 1.91×10^-4 and 0.077×10^-4 W g^-1 at 30°C. Anaerobic heat production rate at 20°C is proportional to body size (r=0.84, 9 degrees of freedom, DF). ForM. demissus, measured anaerobic heat production is on the order of 7.5% of the level of aerobic respiration reported in the literature.     

Significance of active and passive depuration in the clearance of naphthalene from the tissues of Hemigrapsus nudus (Crustacea: Decapoda)

Photosynthate incorporation into lipids, low molecular weight compounds, polysaccharides and proteins by individual phytoplankton species isolated from natural populations is described. This sensitive method uses serial solvent extraction and liquid scintillation counting and gives results indentical to those obtained from filtering large numbers of cells from suspension. The time course of incorporation of ¹⁴C into these polymers for algae isolated from estuarine and coastal populations shows (i) considerable differences in the carbon metabolism among species, (ii) the pattern of incorporation by any individual species may not reflect that of the phytoplankton community and (iii) significant reallocation of cell carbon among carbon pools and net protein synthesis at night. This technique permits the in-situ carbon metabolism of individual species to be examined.