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Previous experiments indicated nutritional deficiencies in the artificial diet of Rana catesbeiana larvae were responsible for up to 95% severe skeletal deformities in laboratory reared larvae. Radiographs showed the skeletal deformities occur in the calcified and cartilagenous skeletal structure. In this study three aspects of the larval diet and its preparation were modified and tested in feeding experiments at pH 6.5 to 6.9 and 7.5 to 8.3. Diets containing from 2% to 8% vitamin C were associated with a reduced incidence of scoliosis at both pH ranges, with greater reduction occurring at the high pH. Survival and growth were greater at the lower pH for larvae fed vitamin C supplemented diets. Lowering the temperature of the food mix to 40°C before adding vitamins to the diet did not reduce the occurrence of deformities. Oxytetracycline and sulfathiazole were replaced by sodium benzoate as a food preservative. There was no difference in survival, growth, or skeletal deformities in the larvae.

Aeromnas hydrophila, an opportunistic pathogen identified to be the causative agent of disease in many ectothermic animals, was grown in batch culture in a variety of complex and defined media to determine the effects of changes in medium composition on the production of extracellular hemolytic and proteolytic activities. A lag period of 24 hours was seen in cultures in defined media. This lag period was eliminated by adding yeast extract to the medium but was not eliminated by the addition of any of a group of vitamins or major energy and carbon sources. The effects of a group of trace minerals were studied, and it was found that zinc stimulated production of hemolysin, and that iron increased the growth yield and depressed both protease and hemolysin production. Although individual amino acids stimulated or retarded growth, changes in the amino acid composition of the medium did not greatly alter hemolysin production, in the absence of added zinc. In the presence of magnesium and zinc some amino acids stimulated hemolysin production. In view of the effects of the trace metals on toxin production in vitro, it is possible that nutritional immunity involving these metals could be a valuable exploitable defense mechanism in attempts to control Aeromonas-caused disease.

Skeletal deformities previously observed in Rana catesbeiana larvae reared in water containing

We analyzed 40 coal samples and 45 carbonaceous shale samples of varying thermal maturity (vitrinite reflectance 0.59% to 4.28%) from the Upper Carboniferous coal-bearing strata of the Upper Silesian, Lower Silesian, and Lublin basins, Poland, to evaluate their potential for generation and expulsion of gaseous and liquid hydrocarbons. We evaluated source rock potential based on Rock-Eval pyrolysis yield, elemental composition (atomic H/C and O/C), and solvent extraction yields of bitumen. An attempt was made to relate maceral composition to these source rock parameters and to composition of the organic matter and likely biological precursors. A few carbonaceous shale samples contain sufficient generation potential (pyrolysis assay and elemental composition) to be considered potential source rocks, although the extractable hydrocarbon and bitumen yields are lower than those reported in previous studies for effective Type III source rocks. Most samples analysed contain insufficient capacity for generation of hydrocarbons to reach thresholds required for expulsion (primary migration) to occur. In view of these findings, it is improbable that any of the coals or carbonaceous shales at the sites sampled in our study would be capable of expelling commercial amounts of oil. Inasmuch as a few samples contained sufficient generation capacity to be considered potential source rocks, it is possible that some locations or stratigraphic zones within the coals and shales could have favourable potential, but could not be clearly delimited with the number of samples analysed in our study. Because of their high heteroatomic content and high amount of asphaltenes, the bitumens contained in the coals are less capable of generating hydrocarbons even under optimal thermal conditions than their counterpart bitumens in the shales which have a lower heteroatomic content.

Coalbed gases in the Lower Silesian Coal Basin (LSCB) of Poland are highly variable in both their molecular and stable isotope compositions. Geochemical indices and stable isotope ratios vary within the following ranges: hydrocarbon (CHC) index CHC=CH4/(C2H6+ C3H8) from 1.1 to 5825, wet gas (C2+) index C2+=(C2H6+ C3H8+ C4H10+ C5H12) / (CH4+ C2H6+ C3H8+ C4H10+ C5H12) 100 (%) from 0.0 to 48.3%, CO2–CH4 (CDMI) index CDMI=CO2/(CO2+ CH4) 100 (%) from 0.1 to 99.9%, δ13C(CH4) from −66.1 to −24.6‰, δD(CH4) from −266 to −117‰, δ13C(C2H6) from −27.8 to −22.8‰, and δ13C(CO2) from −26.6 to 16.8‰. Isotopic studies reveal the presence of 3 genetic types of natural gases: thermogenic (CH4, higher gaseous hydrocarbons, and CO2), endogenic CO2, and microbial CH4 and CO2. Thermogenic gases resulted from coalification processes, which were probably completed by Late Carboniferous and Early Permian time. Endogenic CO2 migrated along the deep-seated faults from upper mantle and/or magma chambers. Minor volumes of microbial CH4 and CO2 occur at shallow depths close to the abandoned mine workings. “Late-stage” microbial processes have commenced in the Upper Cretaceous and are probably active at present. However, depth-related isotopic fractionation which has resulted from physical and physicochemical (e.g. diffusion and adsorption/desorption) processes during gas migration cannot be neglected. The strongest rock and gas outbursts occur only in those parts of coal deposits of the LSCB which are dominated by large amounts of endogenic CO2.

This study was conducted to compare the fatty acid composition of muscle, liver, and depot fat of common snapping turtles Chelydra serpentina from the wild with those of captive common snapping turtles fed a diet of known fatty acid composition. Total lipid from each tissue was separated by thin-layer chromotography, methylated, and analyzed by gas chromatography/mass spectrometry. The fatty acid composition of total lipid, polar lipid, and nonpolar lipid in muscle and depot fat of wild and captive turtles exhibited greater variability than liver polar lipid. Cultured turtles contained significantly lower levels of linolenic and arachidonic acids in liver polar lipid than wild turtles. Total n-9 fatty acids were significantly higher in whole-lipid and nonpolar fractions of muscle, liver, and depot fat of cultured turtles indicating de novo synthesis. Total polyunsaturated fatty acids were significantly lower in total lipid of muscle tissue from cultured turtles. Total polyunsaturated fatty acids were significantly lower in both depot fat and liver nonpolar lipid of cultured turtles, but did not differ (P > 0.05) in the polar lipid fractions of cultured and wild turtles.

Although the common snapping turtle Chelydra serpentina is cultured commercially in the United States, little information is available on nutritional and culture requirements. This study was conducted to evaluate the effects of dietary energy: protein ratio and stocking density on survival, growth, feed consumption, feed conversion, liposomatic index, dress-out percentage, and productive protein value of cultured, common snapping turtles. Hatchling turtles were stocked at 29 and 58 animals/m2 and fed one of seven prepared diets. Six diets contained 30, 35, or 40% protein at two digestible energy (DE) levels (7 or 9 kcal DE/g protein); the seventh was a reference diet (66% protein and 5 kcal DE/g protein) formulated to equal or exceed the whole-body essential amino acid composition of wild, common snapping turtles. Turtles stocked at 58/m2 exhibited greater mortality, lower weight gain, higher feed consumption, less-efficient feed conversion, lower liposomatic index, and lower productive protein value than turtles stocked at 29/m2 (P < 0.05). The reference diet produced the greatest weight gain (P < 0.001). The superior performance of turtles fed the reference diet suggests that: 1) the protein (amino acid) content and/or energy: protein ratio of the reference diet was superior to that of the other diets tested; 2) improvements in growth parameters can be made with dietary manipulation; and 3) high levels of plant protein can be used in prepared, snapping turtle diets.

From abstract: This report is about six gas samples that were obtained from the Mississippian Leadville Limestone in the McElmo field, Colorado, and the Lisbon field, Utah. These samples were recorded to contain a high reading of carbon dioxide and the report investigates these results.

The Piceance basin is a hydrocarbon-rich province that has natural gas production from reservoirs ranging in age from Late Jurassic to Eocene and large undeveloped resources of natural gas in coal beds and tight sandstone reservoirs of Cretaceous age. Gases from all producing intervals are of predominantly thermal origin and become isotopically heavier (delta isotope{13}C[1]: -51.3 to -29.1 o/oo) and chemically drier (C[1]/C[1-5]: 0.26 to 1.00) with increasing thermal maturity of reservoirs (R[o]: 0.45 to 2.40%) over a depth range of 1100 to 11,702 ft (335-3567 m). Scatter in trend is attributed to source rock differences and considerable vertical and lateral migration. Based on chemical and isotopic composition, three major types of gases can be distinguished: those generated from mixed type II and III kerogens, those from dispersed type III kerogen, and those from coal. Gases generated from mixed type II and III kerogens are produced from the Upper Jurassic Morrison Formation, the Lower Cretaceous Cedar Mountain Formation, the Upper Cretaceous Dakota Sandstone, the Upper Cretaceous Mancos "B" producing interval, and marginal marine sandstones of the Upper Cretaceous Iles producing interval. These gases are associated with minor amounts of oil and probably were generated from kerogen in the marine Mancos Shale. Gases generated from dispersed type III kerogen are produced from nonmarine sandstones of the Upper Cretaceous Williams Fork producing inter al and from thermally immature reservoirs in the overlying Paleocene and Eocene Fort Union and Wasatch Formations. These nonassociated gases contain large amounts of CO[2] and probably were generated from carbonaceous shales in the Williams Fork producing interval. Their presence in immature Fort Union and Wasatch reservoirs implies considerable vertical migration. The third type of gas is methane rich, is produced by devolatilization of humic coal, and is generally in coal beds of the Cameo-Fairfield zone of the Williams Fork producing interval. These gases are not the major source for adjacent sandstone reservoirs. A fourth, distinct type of isotopically light thermogenic gas occurs in immature reservoirs of the Eocene Green River Formation. This gas is inferred to have migrated from u identified deeper, more mature source rocks.

Natural gas production in the Anadarko basin comes from three geographically separated areas that can be differentiated by age of reservoir and by inferred nature of organic, thermal origin of the gases. In the central basin, non-associated gases are produced mainly from Upper Mississippian and Pennsylvanian sandstones. Gas samples are from reservoirs as much as 6588 m deep. Gases become isotopically heavier ( δ 13 C 1 -values range from −49.8 to −33.2‰) and chemically drier (C 2+ -values range from 1–33%) with increasing level of thermal maturity. Gases were generated mainly from interbedded shales with type-III kerogen during the mature and post-mature stages of hydrocarbon generation. Deviations from the trend are due to vertical migration and mixing of gases generated at different levels of thermal maturity over the past 250 Myr. In the giant Panhandle-Hugoton field, non-associated gases are generally produced from Permian carbonates at depths of δ 13 C 1 -value is −43.2‰, mean C 2+ -value is 14%). Because organic-rich, mature source rocks are not present in the area, gases probably were generated in the central basin from Pennsylvanian or older source rocks during the mature stage of hydrocarbon generation. This interpretation implies migration over distances as much as several hundred kilometers. In the Sooner Trend, associated gases are produced from Silurian, Devonian and Mississippian carbonates at depths as great as 2950 m and were generated from type-II kerogen during the mature stage of hydrocarbon generation. Associated oil usually correlates with extracts of the Upper Devonian and Lower Mississippian Woodford Shale. Gases are isotopically lighter (mean δ 1 3 C 1 -value is −43.9‰) and chemically wetter (mean C 2+ value is 14%) than those derived from type-III kerogen at an equivalent level of thermal maturity.

Coal beds are considered to be a major source of nonassociated gas in the Rocky Mountain basins of the United States. In the San Juan basin of northwestern New Mexico and southwestern Colorado, significant quantities of natural gas are being produced from coal beds of the Upper Cretaceous Fruitland Formation and from adjacent sandstone reservoirs. Analysis of gas samples from the various gas-producing intervals provided a means of determining their origin and of evaluating coal beds as source rocks. The rank of coal beds in the Fruitland Formation in the central part of the San Juan basin, where major gas production occurs, increases to the northeast and ranges from high-volatile B bituminous coal to medium-volatile bituminous coal (Rm values range from 0.70 to 1.45%). On the basis of chemical, isotopic and coal-rank data, the gases are interpreted to be thermogenic. Gases from the coal beds show little isotopic variation (δ13C1 values range −43.6 to −40.5 ppt), are chemically dry (C1/C1–5 values are > 0.99), and contain significant amounts of CO2 (as much as 6%). These gases are interpreted to have resulted from devolatilization of the humic-type bituminous coal that is composed mainly of vitrinite. The primary products of this process are CH4, CO2 and H2O. The coal-generated, methane-rich gas is usually contained in the coal beds of the Fruitland Formation, and has not been expelled and has not migrated into the adjacent sandstone reservoirs. In addition, the coal-bed reservoirs produce a distinctive bicarbonate-type connate water and have higher reservoir pressures than adjacent sandstones. The combination of these factors indicates that coal beds are a closed reservoir system created by the gases, waters, and associated pressures in the micropore coal structure. In contrast, gases produced from overlying sandstones in the Fruitland Formation and underlying Pictured Cliffs Sandstone have a wider range of isotopic values (δ13C1 values range from −43.5 to −38.5 ppt), are chemically wetter (C1/C1–5 values range from 0.85 to 0.95), and contain less CO2 (< 2%). These gases are interpreted to have been derived from type III kerogen dispersed in marine shales of the underlying Lewis Shale and nonmarine shales of the Fruitland Formation. In the underlying Upper Cretaceous Dakota Sandstone and Tocito Sandstone Lentil of the Mancos Shale, another gas type is produced. This gas is associated with oil at intermediate stages of thermal maturity and is isotopically lighter and chemically wetter at the intermediate stage of thermal maturity as compared with gases derived from dispersed type III kerogen and coal; this gas type is interpreted to have been generated from type II kerogen. Organic matter contained in coal beds and carbonaceous shales of the Fruitland Formation has hydrogen indexes from Rock-Eval pyrolysis between 100 and 350, and atomic H:C ratios between 0.8 and 1.2. Oxygen indexes and atomic O:C values are less than 24 and 0.3, respectively. Extractable hydrocarbon yields are as high as 7,000 ppm. These values indicate that the coal beds and carbonaceous shales have good potential for the generation of liquid hydrocarbons. Voids in the coal filled with a fluorescent material that is probably bitumen is evidence that liquid hydrocarbon generation has taken place. Preliminary oil-source rock correlations based on gas chromatography and stable carbon isotope ratios of C15+ hydrocarbons indicate that the coals and (or) carbonaceous shales in the Fruitland Formation may be the source of minor amounts of condensate produced from the coal beds at relatively low levelsof thermal maturity (Rm=0.7).

Duckweed, Spirodela punctata (G.F.W. Mey) Thompson, was grown on cattle manure dilutions in small outdoor tanks, under different environmental conditions, during the autumn of 1979 and the spring of 1980. Daily growth rates and solar energy conversion (photosynthetic) efficiencies of duckweed were similar for plants grown on manure dilutions of 2.5, 5.0 and 10.0 gl −1 . There were no significant differences in the daily growth rate or efficiency of photosynthesis for growth periods of 1–4 days. The maximum mean growth rate and solar energy conversion efficiency observed were 12.7 g m −2 day −1 and 4.2% of the photosynthetically active radiation (PAR). The highest values obtained for a single sample were 19 g m −2 day −1 and 4.9%. In terms of dry organic matter production, duckweed was observed to grow as much, or more, during the night as during the day. The source of energy for night growth was not determined. Percent moisture of the duckweed was less at high air temperatures than at low temperatures. Insolation was not significantly related to percent moisture. Percent ash remained relatively constant for all levels of temperature and insolation.

The infrared absorption spectra of fused B2O3 and of a series of soda borate glasses are presented. These spectra were obtained using vacuum-pressed briquettes of the powdered glass and powdered KBr. The spectrum of fused B2O3 shows quite definitely that this glass does not consist of a completely continuous triangularly coordinative network. It is shown that hydrogen bonds play an important part in the atomic arrangement of the glasses of zero or low soda content. The B2O3 glass apparently consists of complexes of an approximate unit (B9O14)- held together by hydrogen bonds. One in nine borons is tetrahedrally coordinated. The glasses of low soda content are similar. The spectra for soda concentrations greater than 15% did not permit the determination of the atomic arrangement with exactitude, but it is shown to be quite different from that found in glasses with 10% Na2O or less.

Biogenic gas is generated at low temperatures by decomposition of organic matter by anaerobic microorganisms. More than 20% of the world's discovered gas reserves are of biogenic origin. A higher percentage of gases of predominantly biogenic origin will be discovered in the future. Biogenic gas is an important target for exploration because it occurs in geologically predictable circumstances and in areally widespread, large quantities at shallow depths. In rapidly accumulating marine sediments, a succession of microbial ecosystems leads to the generation of biogenic gas. After oxygen is consumed by aerobic respiration, sulfate reduction becomes the dominant form of respiration. Methane generation and accumulation become dominant only after sulfate in sediment pore water is depleted. The most important mechanism of methane generation in marine sediments is the reduction of CO2 by hydrogen (electrons) produced by the anaerobic oxidation of organic matter. CO2 is the product of either metabolic decarboxylation or chemical decarboxylation at slightly higher temperatures. The factors that control the level of methane production after sediment burial are anoxic environment, sulfate-deficient environment, low temperatu e, availability of organic matter, and sufficient space. The timing of these factors is such that most biogenic gas is generated prior to burial depths of 1,000 m. In marine sediments, most of the biogenic gas formed can be retained in solution in the interstitial (pore) waters because of higher methane solubility at the higher hydrostatic pressures due to the weight of the overlying water column. Under certain conditions of high pressures and (or) low temperatures, biogenic methane combines with water to form gas hydrates. Biogenic gas usually can be distinguished from thermogenic gas by chemical and isotopic analyses. The hydrocarbon fraction of biogenic gas consists predominantly of methane. The presence of as much as 2% of heavier hydrocarbons can be attributed to admixture of minor thermogenic gas due to low-temperature degradation of organic matter. The amounts of hydrocarbon components other than methane generally are proportional to temperature, age, and organic-matter content of the sediments. Biogenic methane is enriched in the light isotope 12C (^dgr13C1 lighter than -55 ppt) owing to kinetic isotope fractionation by methanogens. The variations in isotopic composition of biogenic methane are controlled primarily by ^dgr13C of the original CO2 substrate, which reflects the net isotopic effect of both addition and removal of CO2. The methane isotopic composition also can be affected by mixing of isotopically heavier thermogenic gas. The possible complicating factors require that geologic, chemical, and isotopic evidence be considered in attempts to interpret the origin of gas accumulations. Accumulations of biogenic gas have been discovered in Canada, Germany, Italy, Japan, Trinidad, the United States, and USSR in Cretaceous and younger rocks, at less than 3,350 m of burial, and in marine and nonmarine rocks. Other gas accumulations of biogenic origin have undoubtedly been discovered; however, data that permit their recognition are not available.

Prior to 1970, shallow gas production was established in "sweet spots" where the reservoirs are best developed in the northern Great Plains. Recent advances in completion technology coupled with higher gas prices have led to the expansion of these areas through the development of submarginal, low-permeability reservoirs. The development is concentrated in two main areas which cover more than 22,000 sq km. The gas occurs at depths less than 600 m, and recoverable reserves average 2 Bcf of gas per section. The reservoirs are of Late Cretaceous age and generally consist of siltstone and sandstone laminae, a few millimeters or less in thickness, enclosed in organic-rich silty shale that serves as a seal and was the source for the biogenic gas. The laminae are discontinuous because of depositional processes and/or biologic activity. Coarsening-upward sandstone cycles are locally developed. Although these cycles display the best reservoir properties, they are volumetrically minor. Porosity is confined to small passageways within the laminae, among randomly oriented allogenic clay platelets, and to well-sorted sandstone near the top of coarsening-upward cycles. Diagenesis has reduced permeability and resulted in the formation of fluid-sensitive clays and carbonate cement. However, dissolutio has enhanced porosity and permeability in well-sorted lithologies. The reservoirs are stimulated with sand proppant, carbon dioxide, and water to provide economic flow rates. Typical wells have initial potentials of 300 Mcf of gas per day. Production declines rapidly the first year, but levels off to about 100 Mcf of gas per day. Wells are difficult to evaluate because conventional logs cannot distinguish pay zones in sequences of thin, discontinuous, low-permeability reservoirs. End_of_Article - Last_Page 773

Hydrocarbons are being produced at depths ranging from 4,000 to 8,500 ft along the axis of the Denver basin. On the basis of chemical and isotopic composition, gases from the three main reservoirs of Cretaceous age are interpreted to be of thermogenic origin. Gases from the Terry and Hygiene Sandstone Members of the Pierre Shale, the youngest reservoir, are the isotopically lightest (^dgr13C1 values range from -55.7 to -49.2 ^pmil) and chemically wettest (C1/C1-5 values range from 0.67 to 0.83), and are associated. Gases from the Codell Sandstone Member of the Carlile Shale generally become isotopically heavier (^dgr13C1 values range from -47.8 to -43.9^pmil) as they become chemically drier (C1/C SUB>1-5 values range from 0.76 to 0.8). During the main part of mature stage, oil and associated gas (isotopically lightest and chemically wettest) were generated from type II kerogen. During the hotter, later part of the stage, wet gas (isotopically heaviest and chemically driest) and condensate were generated from residual kerogen and from heavier hydrocarbons previously generated. Variations in character of the gases from the "J" sandstone, the oldest reservoir, are similar to those of the Codell; they become isotopically heavier (^dgr13C1 values range from -47.9 to -43.1^pmil) as they become chemically drier (C1/C1-5 values range from 0.84 to 0.87). Gases from "J" are interpreted to have been generated at similar levels of maturity as those of the Codell, but from type III kerogen. These gases are nonassociated and are isotopically heavier and chemically drier at similar levels of maturity than are those generated from type II kerogen. End_of_Article - Last_Page 301

Natural gas is produced at shallow depths from chalk beds of the Upper Cretaceous Niobrara Formation in northeastern Colorado and northwestern Kansas. The depth of gas-productive trend increases to the northwest from 250 to 850 m (820-2,790 ft). The chalks are fine-grained limestone, consisting mainly of calcareous nannofossils and other microfossils, that are characterized by high porosity (30-45%) and low permeability (about 1 md). Core samples from the productive area average 30% acid-insoluble residue. Most of the insoluble residue, which consists of clay minerals and organic matter, is concentrated in alternating laminations. The gases are methane-rich (C1/C1-5 > 0.98), are enriched in the light isotope 12C (13C1 values range from -65 to -55 ppt), and become isotopically heavier with increasing depth across the trend. The shallow gas in the Niobrara is interpreted to be of biogenic rather than thermogenic origin because of its chemical and isotopic composition and of source-rock studies indicating that Upper Cretaceous rocks in this region are immature with respect to thermogenic hydrocarbon generation. To the northwest, however, these rocks are mature and were capable of generating oil at the time of maximum burial and/or heat flow. The biogenic gas was generated early in the burial history of the chalks by microbial degradation of organic matter in an anaerobic, presumably sulfate-free environment. In-situ gas generation is indicated, because low permeability inhibited long-range migration and because organic-rich laminae provided an adequate source for the gas. Organic-carbon values average 3.2%, and the organic matter consists primarily of hydrogen-rich sapropelic kerogen (type II), typical of an open-marine environment. The chalks are overlain by a thick section of shale containing many bentonite beds in the lower part that served as a seal for gas after the reservoirs were naturally fractured later in the burial history.