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Ppt Salinity (ppt + salinity)
Selected AbstractsLaboratory-based reproduction success of ruffe, Gymnocephalus cernuus (L.), in brackish water is determined by maternal propertiesECOLOGY OF FRESHWATER FISH, Issue 2 2006A. Albert Abstract,, Body length, age, egg size, embryo salinity tolerance and length at hatching of the freshwater (salinity <0.1 ppt, Lake Peipsi) and brackish-water (salinity 2,6 ppt, Pärnu and Matsalu Bay) ruffe, Gymnocephalus cernuus (L.), were examined to reveal their reproductive success in moderate salinity. Eggs of females originating from brackish water were significantly larger than eggs of freshwater females. No correlation between egg size and female size and age was found in brackish-water populations. In the freshwater population there was a small negative correlation between egg size and female size, but no correlation with female age. Fertilisation by sperm of males of different origin (brackish water or freshwater) produced no significant differences at any critical developmental stage (fertilisation, gastrulation, hatching) in the development of eggs from brackish-water or freshwater females at 3.3, 5.5, 7.7 and 9.9 ppt salinity. Survival rates in different salinity depended only on female origin; embryonic salinity tolerance was higher in ruffe inhabiting brackish water. Obviously, embryo salinity tolerance in ruffe is determined by egg qualities. [source] NITZSCHIA OVALIS (BACILLARIOPHYCEAE) MONO LAKE STRAIN ACCUMULATES 1,4/2,5 CYCLOHEXANETETROL IN RESPONSE TO INCREASED SALINITY,JOURNAL OF PHYCOLOGY, Issue 2 2009Fernando Garza-Sánchez The growth of microalgae in hypersaline conditions requires that cells accumulate osmoprotectants. In many instances, these are polyols. We isolated the diatom Nitzschia ovalis H. J. Arn. from the saline and alkaline water body Mono Lake (CA, USA). This isolate can grow in salinities ranging from 5 to 120 parts per thousand (ppt) of salt but normally at 90 ppt salinity. In this report, we identified the major polyol osmoprotectant as 1,4/2,5 cyclohexanetetrol by electron ionization-mass spectrometry (EI,MS), 1H, 13C nuclear magnetic resonance spectroscopy (NMR), and infrared (IR) and showed an increase in cellular concentration in response to rising salinity. This increase in the cyclitol concentration was evaluated by gas chromatography of the derived tetraacetylated cyclohexanetetrol obtaining an average of 0.7 fmol ˇ cell,1 at 5 ppt and rising to 22.5 fmol ˇ cell,1 at 120 ppt. The 1,4/2,5 cyclohexanetetrol was also detected in the red alga Porphyridium purpureum. Analysis of the free amino acid content in N. ovalis cultures exposed to changes in salinity showed that proline and lysine also accumulate with increased salinity, but the cellular concentration of these amino acids is about 10-fold lower than the concentration of 1,4/2,5 cyclohexanetetrol. The comparison of amino acid concentration per cell with cyclitol suggests that this polyol is important in compensating the cellular osmotic pressure due to increased salinity, but other physiological functions could also be considered. [source] Sedimentation of Soils from Three Physiographic Regions of Alabama at Different SalinitiesJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2009Gulnihal Ozbay This study evaluated the rate of sedimentation from water under various salinities, over a time period of 72 h. The particles come from soils that are commonly found in shrimp growing areas of Alabama: Black Belt Prairie, Piedmont Plateau, and Upper Coastal Plain. Different salinity treatments and settling times resulted in significant differences (P, 0.05) in the reduction of turbidity and TSS for each soil type. Solutions containing 2 ppt salinity had a similar rate of turbidity reduction as the solutions with 5, 10, or greater ppt treatments. Concentrations of turbidity and TSS decreased rapidly between 1 and 12 h of sedimentation; very little decline was observed during the time intervals 12,72 h. Higher salinity treatments yielded settling patterns similar to the 2 ppt salinity treatment. After 1 h, turbidity was removed by 65% in the control compared with 85% salinity treated samples. Variations in turbidity and TSS among the three sediments suggest that finer particles, the Piedmont Plateau soils, settled at a slower rate than larger particles. This difference occurs because the percentage of turbidity and TSS removed was significantly higher in mineralized waters compared to freshwater. Therefore, a small amount of salt, 2 ppt, can be used in pond aquaculture treatments to reduce the turbidity and TSS concentrations in shrimp ponds. [source] The Effects of Temperature and Salinity on Early Life Stages of Black Sea Bass Centropristis striataJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 3 2004David L. Berlinsky Along the Atlantic coast black sea bass occur from the Gulf of Maine to Florida and support important commercial and recreational fisheries. Interest in commercial production of black sea bass has increased in recent years due to high demand and limited seasonable availability. Efforts towards large-scale production have been hampered by a high incidence of early larval mortality. Two of the most important environmental variables affecting hatchery production of marine finfish larvae are temperature and salinity. In the wild, larval black sea bass are found in waters with temperatures of 12,24 C and salinity levels of 30,35 ppt. Studies were conducted to define the temperature and salinity ranges that support growth and development of black sea bass during early life stages. Three developmental phases were investigated: 1) fertilization to hatch: 2) hatch through yolk sac absorption: and 3) during the initial exogenous feeding stage (5,14 days post hatch: DPH). Fertilized eggs were obtained by manual spawning of fish following administration of LHRHa. Fertilized eggs were transferred to 300-mL glass Petri dishes or 500-mL beakers to assess the effects of salinity and temperature through hatch and yolk sac absorption, respectively. To determine environmental effects on growth and survival during initial exogenous feeding 400 actively feeding larvae were cultured in green water and fed enriched rotifers for a 9-d period. For investigation of the effect of salinity, sea water (35 ppt) was diluted gradually to 15, 20, 25, and 30 ppt and maintained at 21 C. For examination of the effect of temperature, seawater was adjusted from 21 C to 12, 15, 21, 27, or 30 C at a rate of 3 C/h. No eggs hatched at 12 C or when salinity was maintained at 0 or 5 ppt. Hatching was uniformly high (, 85%) at temperatures between 15 and 27 C and at salinities , 15 ppt. Survival through yolk sac absorption was greatest at temperatures between 18 and 27 C and at salinities , 20 ppt. Survival through first feeding stage was highest at temperatures , 18 C and 30 ppt salinity. Larval growth through first feeding was not significantly affected by salinity level but did increase with rearing temperature. The results indicate that survival and development of black sea bass during early life stages are most favorable at temperatures >18 C with salinity levels approaching full strength seawater. [source] Control of the Trematode Bolbophorus confusus in Channel Catfish Ictalurus punctatus Ponds Using Salinity Manipulation and Polyculture with Black Carp Mylopharyngodon piceusJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2000Darrel L. Venable This study evaluated the use of black carp Mylopharyngodon piceus and salinity manipulation for controlling the infection of channel catfish Ictalurus puncratus by a digenetic trematode (tentatively identified as Bolbophorus confusus). Control methods focussed mainly on the eradication of the intermediate snail host, the marsh rams-horn Phanorbella trivolvis (previously referred to as Helisoma trivolvis), and were evaluated in laboratory tests and field experiments at a commercial catfish culture facility in southern Louisiana that was seriously impacted by the trematode. Introduction of fingerling black carp into catfish ponds at a density of 62 carpha resulted in an almost total elimination of P. trivolvis. The farm is now successfully using a facility-wide stocking rate of 40 carp/ha. Laboratory experiments were conducted to investigate the effect of salinity manipulation using NaCl on free-swimming trematode cercariae, the snail P. trivolvis, and catfish fingerlings infected with the cercariae. A salinity of 2.5 ppt had a detrimental effect on snail survival, growth, and reproduction. Salinity did not have a negative effect on the other two aspects of the trematode life cycle tested (in fact, survival of both cercariae and infected catfish fingerlings showed a positive dependence on NaCl over the 0,2.5 ppt range). A field-experiment was then conducted in catfish ponds maintained at three salinities (2.5, 1.25, and 0.25 ppt) with rock salt, NaCl. Snail densities in ponds at 2.5 ppt salinity were consistently lower than in the other treatments and no trematode infection was noted among snails or catfish in the 2.5 ppt salinity ponds. Both the use of 2.5 ppt NaCl and black carp appear valuable management tools for controlling the digenetic trematode in caffish ponds. [source] Decimal reduction times of Pyrodinium bahamense var. compressum and Escherichia coli in chlorine- and ultraviolet-treated seawaterLETTERS IN APPLIED MICROBIOLOGY, Issue 5 2001M.P.V. Azanza Aims:,Decimal reduction times (D -values) of the vegetative cells of Pyrodinium bahamense var. compressum and Escherichia coli in ultraviolet- and chlorine-treated seawater were established. Methods and Results:,The cells of the test organisms were exposed to ultraviolet- and chlorine-treated seawater and maintained at 20,35 ppt salinity and 20 to 35°C. The dinoflagellate cells which cause Paralytic Shellfish Poisoning (PSP) were found to be more resilient than the bacterial cells. Ultraviolet treatment was found to be more effective than chlorine to both test organisms. Irreversible morphological changes in the treated dinoflagellate cells were noted, including protoplast discoloration, cellular membrane leakage and damage to the thecal armour. Conclusions:,The vegetative cells of both test organisms in seawater were more sensitive to ultraviolet treatment than to chlorine exposure. Generally, the dinoflagellate cells were less susceptible than bacterial cells to both disinfection treatments. Significance and Impact of the Study:,Results of this study may have significant implications in depuration procedures for molluscs and cleaning protocols for ballast waters of ships. [source] | ||||||||||