Sydney Rock Oyster Saccostrea Commercialis Research Articles

Molecular detection of Marteilia sydneyi, pathogen of Sydney rock oysters.

The life cycle of Marteilia sydneyi, the aetiological agent of QX disease in the Sydney rock oyster Saccostrea commercialis, is not known. We have developed and optimised 2 diagnostic assays, the polymerase chain reaction (PCR) and in situ hybridisation, for use in investigating the role of possible alternative hosts in the life cycle of this pathogen. PCR primers, designed within the ITS1 rDNA of M. sydneyi, amplified a 195 bp fragment. Sensitivity of the PCR assay was assessed using DNA extracted from known numbers of sporonts purified from infected oyster digestive gland. DNA equivalent to 0.01 sporonts was detectable following agarose gel electrophoresis. The potential inhibitory effect of the presence of host DNA on the PCR assay was tested by the addition of oyster genomic DNA during amplification. Concentrations of host DNA in excess of 50 ng per 20 microliters reaction reduced the sensitivity of the test. Environmental validation of the PCR assay was demonstrated by the amplification of M. sydneyi DNA from 50 ng of genomic DNA extracted from QX-infected oysters. A DNA probe was constructed using the M. sydneyi unique primers and was able to detect 10 pg of M. sydneyi PCR amplified DNA in dot-blot hybridisations. The probe hybridised with presporulating and sporulating M. sydneyi stages in paraffin sections of oyster digestive gland. No non-specific binding was observed. Hybridisation consistency and signal intensity decreased as sporonts matured. While the high sensitivity and specificity of the PCR test will allow rapid screening of large numbers of potential alternative hosts for the presence of parasite DNA, it does not actually identify infective stages. In situ hybridisation conducted on paraffin sections will determine the location of the parasite within the host for morphological characterisation.

Third generation evaluation of Sydney rock oyster Saccostrea commercialis (Iredale and Roughley) breeding lines

The progeny of four breeding lines of Sydney rock oysters, Saccostrea commercialis, selected for faster growth over two generations, were compared with controls in an 18-month farming experiment. Mean whole weights of oysters from all four selection lines did not differ significantly from each other but, were significantly greater ( P<0.05) than mean whole weight of controls (spat produced from two groups of non-selected oyster populations). The mean increase in weight for the selection lines over the controls of 18% (range 14–23%) after two generations of selection (third generation) compares extremely favourably with the 4% reported previously after one generation of selection.

Growth characteristics of Sydney rock oysters Saccostrea commercialis in relation to size and temperature

Sydney rock oyster Saccostrea commercialis spat obtained from a single spawning of four females and two males were allocated to six size classes six months after spawning. The spat from each size class were distributed among twelve treatments, which differed in length of time the spat spent in poor growing conditions, followed by good conditions, or conversely, in good growing conditions followed by poor conditions. A two-phase von Bertalanffy model and a regression model relating relative growth rate to size and water temperature gave similar fits to the results. The monthly growth rate of spat kept in good conditions depended on water temperature (reflected in the phases of the two-phase growth model) and size at the start of the month. It is concluded that because of the nature of oyster growth, comparison of growth rates of oysters of different sizes may be misleading.

The first incidence of clionid sponges (Porifera) from the Sydney rock oyster Saccostrea commercialis (Iredale and Roughley, 1933)

Two species of clionid sponge (Porifera, Demospongiae, Hadromerida, Clionidae) were discovered inhabiting the shells of both living and dead Sydney rock oysters, Saccostrea commercialis. A total of 447 oyster shells were collected from the Pimpama River, south-east Queensland with 28 shells from living oysters and 195 shells from dead oysters showing signs of infection. This is the first recorded incidence of a burrowing sponge from the Sydney rock oyster. The sponges ( Cliona vastifica Hancock, 1849 and Cliona celata Grant, 1826) represent new records for Australia and are redescribed. Radiographs were used to illustrate burrowing patterns in infected shells. The presence of Marteilia sydneyi, a highly pathogenic parasite, in all oysters carrying the sponge infections obscured the pathological effects of the burrowing sponge on the oyster. Burrowing sponges from the family Clionidae are known to have adverse effects on mollusc culture. Excavations by the sponge in living shells compromise structural support which reduces shell strength and affects adductor muscle attachment. The sponge infection correlates with prolonged immersion periods during culture, a practice that may become more common as culture methods are optimised. Oyster stocks cultured either in trays or on sticks that are set at mid-intertidal levels appear free from infection.

Food value of live yeasts and dry yeast-based diets fed to Sydney rock oyster Saccostrea commercialis spat

Six yeast species, cultured on both glucose and acetate as carbon sources, and three dry yeast-based diets (Microfeast ®) were compared as potential algae substitutes for feeding Sydney rock oyster spat. At the 80% substitution level, two of the dry yeast-based diets containing 7.6 and 21.5% total lipid gave 72 and 76%, respectively, of the dry spat weight gain obtained with the algae-fed control. Weight gains of 58–67% of that of the algae-fed control were also obtained with the following live yeast diets: Dipodascus capitatus and Candida utilis cultured on either glucose or acetate, and Saccharomyces cerevisiae cultured on glucose. There was a negative correlation between the increase in spat dry weight and nitrogen free extract ( r = −0.58; y = 30.34 − 0.26 x; P < 0.01) and a smaller positive correlation with the protein ( r = 0.51; y = 6.10 + 0.31 x; P < 0.01) content of the diets.

The detection of pollutant impact in marine environments: condition index, oxidative DNA damage, and their associations with metal bioaccumulation in the Sydney rock oyster Saccostrea commercialis.

Specimens of the Sydney rock oyster Saccostrea commercialis were deployed for a 3-month period at control and sewage disturbed marine locations in the Hunter Region, New South Wales, Australia. The DNA damage product,8-hydroxyguanine, was measured by GC/MS-SIM from chromatin extracts of the gill tissues of oysters to assess oxidative damage. The levels ranged from 11.5 to 18.8 modified bases per 10(7) guanine bases. Although the condition indices were significantly different between the Redhead control site (178.3+/-3. 6) and the Burwood sewage disturbed location (140.4+/-4.4), no significant differences in 8-hydroxyguanine concentrations were detected between the sites, and the concentration of 8-hydroxyguanine was not correlated to condition index. However, levels of the DNA base modification were correlated with the concentrations of bioaccumulated lead (r=0.84, P=0.036). This association provides in vivo evidence that the bioaccumulation of lead results in oxidative damage to DNA. An additional control and sewage disturbed site were included to investigate the relationship between heavy metal bioaccumulation and the condition index of deployed oysters. After the 3-month deployment period, the condition index was negatively correlated to concentrations of bioaccumulated mercury (r=-0.80, P<0.001), cobalt (r=-0.65, P<0.01), and nickel (r=-0.69, P<0.01), suggesting a strong negative influence of these metals at relatively low concentrations on the physiological condition of the oysters.

Reducing the impact of environmental variation in a growth rate improvement program for the Sydney rock oyster Saccostrea commercialis

A culture method (‘slats’) being used to compare Sydney rock oysters ( Saccostrea commercialis) for growth rate selection was further evaluated. In this method, oysters are affixed to plastic slats in a matrix pattern. The presence of non-random positional effects associated with an oyster's location within the tray compartment and the impact of their removal was investigated in terms of row and column effects and band effects. Within each tray compartment, oysters were assigned to different ‘bands’ according to their distance from the side of the compartment. The effect of the presence or absence of outliers in the estimation of row, column and band effects was also investigated. The growth rate of oysters was found to be sensitive to apparently small environmental differences. There were substantial and statistically significant row, column and band effects for two of the three growing sites. These non-random positional effects were effectively removed by adjusting individual oyster weights on the basis of row and column means, irrespective as to whether these means had been estimated in the presence or absence of outliers. Data adjusted on the basis of band means tended to retain some substantial row and/or column effects. There was little, if any, additional advantage in adjusting the row and column adjusted data for band effects.

The Detection of Pollutant Impact in Marine Environments: Condition Index, Oxidative DNA Damage, and Their Associations with Metal Bioaccumulation in the Sydney Rock Oyster Saccostrea commercialis

The Detection of Pollutant Impact in Marine Environments: Condition Index, Oxidative DNA Damage, and Their Associations with Metal Bioaccumulation in the Sydney Rock Oyster Saccostrea commercialis

Evaluation of growing methods for use in a Sydney rock oyster Saccostrea commercialis (Iredale and Roughley) selective breeding program

Four growing methods for Sydney rock oysters, Saccostrea commercialis, were evaluated for use in a breeding program to select for greater weight increase and improved disease resistance. These methods were: (1) oysters attached and grown on PVC slats (“slats”), (2) oysters attached and grown on tray mesh (“mesh”), (3) culchless (single and loose) oysters grown individually in chambers (“rings”), and (4) culchless oysters grown together in tray compartments (“loose”). The oysters in all growing methods were contained in tarred wooden framed trays covered with polyethylene mesh and supported intertidally on wooden rails. Oysters were individually measured for whole weight (the primary selection criterion), as well as for shell height, length and width. Both “mesh” and “rings” methods were found to be unsuitable for the breeding program because the oysters in these gained little weight. In addition, the shells of the oysters on “mesh” grew through the mesh, and those in the “rings” often grew onto the chamber wall. Oysters grown on slats were significantly ( P < 0.05) heavier, had higher and longer shells and a significantly ( P < 0.05) lower coefficient of variation for whole weight and shell height than “loose” oysters.

A Field study of the impact on oysters of tributyltin introduction and removal in a pristine lake

In a pristine lake, the impacts on the Sydney Rock oysterSaccostrea commercialis of the introduction and removal one month later of two boats antifouled with a TBT-based paint, have been examined. A three-factor analysis of variance showed that the presence of shell curls in oysters was significant in the area closest to the boats and the contaminant source was restricted from migration to leases on the other side of a channel. A good correlation between shell deformities and TBT accumulation was obtained. Significant TBT accumulation occurred within the brief exposure of young oysters; however, an analysis of the distribution of butyltins before and after removal of the boats suggested that the oysters were responding to degradation products in the water rather than promotingin vivo degradation.

Accumulation of Tributyltin by the Sydney Rock Oyster, Saccostrea commercialis

Tributyltin (TBT) concentrations have been measured in the tissue of the Sydney rock oyster Saccostrea commercialis sampled from estuaries in New South Wales, Australia. Background TBT levels of below 2 ng Sn g-1 contrasted with values between 80 and 130 ng Sn g-1 in oysters exposed to high boat densities or poor tidal flushing. Shell deformities and reduced tissue weights were associated with all samples displaying elevated TBT levels. Specimens of the Pacific oyster, Crassostrea gigas, growing on the same racks displayed 2-3 times the TBT concentrations of S. commercialis.

Effects of temperature, nutritional factors and salinity on the uptake of L-methionine by the Sydney rock oyster Saccostrea commercialis

The effects of physiological and nutritional factors and of temperature on the uptake of L-methionine by Saccostrea commercialis were investigated on cultured rock oysters from Port Stephens, New South Wales, Australia, in 1983. Optimum conditions for L-methionine accumulation were 30°C, 18 h exposure and concentrations of other amino acids less than that of L-methionine. The uptake of L-glycine was inhibited by L-methionine in a reciprocal manner. There was no effect of salinity on the accumulation of L-methionine by acclimated oysters. During the latter investigations the range of osmoconformity was found to be 15 to 45‰ S. Oysters take 2 d to conform to new media osmolarities after salinity changes of 15‰. Amino acid supplements in oyster diets should be kept within the same order of magnitude to reduce inhibition of uptake.

Uptake of some dissolved organic nutrients by the Sydney rock oyster Saccostrea commercialis

The uptake of D-glucose, L-methionine, L-lysine·HCl, myo-inositol and choline chloride in estuarine water by oysters was studied. All nutrients were absorbed, but only the uptake of L-methionine, L-lysine·HCl and choline chloride was likely to have been nutritionally significant. At low estuarine water nutrient concentrations, active absorption was observed for all nutrients, but in the case of high D-glucose and myo-inositol concentrations, uptakes resembled passive diffusion. The efficiency of absorption as measured by the nutrient accumulation factor in oyster tissues was dependent on the nutrient concentrations in estuarine water. Various tissues concentrated dissolved D-glucose and L-methionine and the highest concentrations of these nutrients after a 4-h filtration time were found in the gill.

Laboratory study of the accumulation and distribution of cadmium in the Sydney Rock oyster Saccostrea commercialis (I &amp;amp; R)

The Sydney rock oyster (S. commercialis) was exposed to a control and four concentrations of cadmium (nominally 0, 10,25,50 and 150�g I-1) in a flowing seawater system in the laboratory. Oysters from the 10 and 50 �g 1-1 groups were briefly exposed to 109Cd, then frozen in liquid CO2 and sectioned. The thin sections of whole oyster were apposed to X-ray film. The resulting images showed that 109Cd accumulated mainly in the gut, kidney and gill, with little in the gonad and glycogen storage areas of the visceral mass. Oysters from all water concentrations of cadmium were removed after 1,4,8 and 16 weeks of treatment with cadmium. The visceral mass, gill, mantle, muscle and heart-kidney were analysed for total cadmium. All groups of oysters rapidly accumulated cadmium. The heart-kidney attained the highest concentration and the muscle invariably displayed the lowest concentration. The visceral mass contained the greatest amount of cadmium in all oysters. The gill changed its position in the ranking of the organ concentrations of cadmium, increasing with increasing water concentrations of cadmium. The results suggest that the gill may be the critical organ during a challenge with cadmium-at both lethal and sublethal concentrations. The long-term nature of this experiment reveals that the accumulation of cadmium in S. commercialis is non-linear at some water concentrations of cadmium.

Effects of Salinity and Selected Petroleum Hydrocarbons on the Osmotic and Chloride Regulation of the American Oyster, Crassostrea virginica

Previous articleNext article No AccessEffects of Salinity and Selected Petroleum Hydrocarbons on the Osmotic and Chloride Regulation of the American Oyster, Crassostrea virginicaRoger D. Anderson, and Jack W. AndersonRoger D. Anderson Search for more articles by this author , and Jack W. Anderson Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Volume 48, Number 4Oct., 1975 Article DOIhttps://doi.org/10.1086/physzool.48.4.30155667 Views: 4Total views on this site Citations: 13Citations are reported from Crossref Journal History This article was published in Physiological Zoology (1928-1998), which is continued by Physiological and Biochemical Zoology (1999-present). PDF download Crossref reports the following articles citing this article:Edward Olmedo, Michael Smith Development of an IoT Water Quality Monitoring System for Data-Based Aquaculture Siting, (Mar 2021): 1–8.https://doi.org/10.1109/SoutheastCon45413.2021.9401906Olaf Heilmayer, Julian Digialleonardo, Lianfen Qian, Guritno Roesijadi Stress tolerance of a subtropical Crassostrea virginica population to the combined effects of temperature and salinity, Estuarine, Coastal and Shelf Science 79, no.11 (Aug 2008): 179–185.https://doi.org/10.1016/j.ecss.2008.03.022C.T Tirard, R.M Grossfeld, J.F Levine, S Kennedy-Stoskopf Effect of Osmotic Shock on Protein Synthesis of Oyster Hemocytes In Vitro, Comparative Biochemistry and Physiology Part A: Physiology 116, no.11 (Jan 1997): 43–49.https://doi.org/10.1016/S0300-9629(96)00115-6Elizabeth Bokman, Roy B. Laughlin A study of steady state and kinetic regulation of chloride ion and osmotic pressure in hemolymph of oysters,Crassostrea virginica, exposed to tri-n-butyltin, Archives of Environmental Contamination and Toxicology 18, no.66 (Nov 1989): 832–838.https://doi.org/10.1007/BF01160297J. A. Nell, P. R. Dunkley Effects of temperature, nutritional factors and salinity on the uptake of L-methionine by the Sydney rock oyster Saccostrea commercialis, Marine Biology 80, no.33 (Jan 1984): 335–339.https://doi.org/10.1007/BF00392829R.C. Dean, A.A. Paparo Effects of changes of salinity and calcium concentration on ctenidial ciliary activity in the oyster Crassostrea virginica (Gmelin), Comparative Biochemistry and Physiology Part A: Physiology 74, no.33 (Jan 1983): 587–594.https://doi.org/10.1016/0300-9629(83)90552-2Bruce M. S. Mahoney, George S. Noyes Effects of petroleum on feeding and mortality of the American oyster, Archives of Environmental Contamination and Toxicology 11, no.55 (Sep 1982): 527–531.https://doi.org/10.1007/BF01056358Bruce M. Mahoney, Harold H. Haskin The effects of petroleum hydrocarbons on the growth of phytoplankton recognised as food forms for the eastern oyster, Crassostrea virginica gmelin, Environmental Pollution Series A, Ecological and Biological 22, no.22 (Jun 1980): 123–132.https://doi.org/10.1016/0143-1471(80)90188-9Lynn M. Amende, Sidney K. Pierce Cellular volume regulation in salinity stressed molluscs: The response ofNoetia ponderosa (Arcidae) red blood cells to osmotic variation, Journal of Comparative Physiology ? B 138, no.44 (Jan 1980): 283–289.https://doi.org/10.1007/BF00691562Susan R. Zell, Mark H. Bamford, Herbert Hidu Cryopreservation of spermatozoa of the American oyster, Crassostrea virginica Gmelin, Cryobiology 16, no.55 (Oct 1979): 448–460.https://doi.org/10.1016/0011-2240(79)90059-2J.W. Anderson AN ASSESSMENT OF KNOWLEDGE CONCERNING THE FATE AND EFFECTS OF PETROLEUM HYDROCARBONS IN THE MARINE ENVIRONMENT, (Jan 1979): 3–21.https://doi.org/10.1016/B978-0-12-718260-5.50005-0J.W. Anderson RESPONSES TO SUBLETHAL LEVELS OF PETROLEUM HYDROCARBONS: ARE THEY SENSITIVE INDICATORS AND DO THEY CORRELATE WITH TISSUE CONTAMINATION?, (Jan 1977): 95–114.https://doi.org/10.1016/B978-0-08-021613-3.50014-0FREDERICK G. JOHNSON SUBLETHAL BIOLOGICAL EFFECTS OF PETROLEUM HYDROCARBON EXPOSURES: BACTERIA, ALGAE, AND INVERTEBRATES, (Jan 1977): 271–318.https://doi.org/10.1016/B978-0-12-466902-4.50011-4