Genetics of alkaline phosphatase of the small intestine of the house mouse (Mus musculus)

Four inbred strains of mice exhibited either slow (PL/J), intermediate (DBA/2J, LP/J), or fast (SWR/J) rates of migration of duodenal alkaline phosphatase on cellulose acetate electrophoresis. Hybrids of these strains also had intermediate rates of migration regardless of the combination of strains used as parents. Strain differences were present in all regions of the small but not the large intestine. Crosses of the PL/J strain to hybrids between this strain and the other three strains gave a 1:1 segregation of the slow and intermediate patterns. The symbol Akp-3 is proposed for the locus responsible for the slower migration of the enzyme in this strain. Data from the LP/J × PL/J hybrid crossed with the PL/J strain showed linkage with two loci on chromosome 1 as follows: centromere—Idh-1–13.8±3.1 cM—Akp-3–8.9±2.6 cM—Pep-3. The available data do not reveal the genetic basis for the faster migration rate of the enzyme from the SWR/J strain, but a different response to neuraminidase and apparent nonlinkage to the Pep-3 locus suggest that a locus other than Akp-3 is responsible.This work was supported by a grant from the University Research Committee, Indiana State University.     

Water balance of conifer logs in early stages of decomposition

Seasonal and long-term changes in the water balance of conifer logs during the first 8 years of decomposition were studied in an old-growth Pseudotsuga/Tsuga forest in the Oregon Cascade Mountains. Measurements were made of the moisture content of outer bark, inner bark, sapwood, and heartwood and of the flow of water into and out of logs of four species (Abies amabilis, Pseudotsuga menziesii, Thuja plicata, and Tsuga heterophylla). After the logs had decomposed from 1 to 2 years, 38–47% of the canopy throughfall landing upon them ran off the surface, 29–34% leached from the bottom, and 21–30% was absorbed and evaporated. After 8 years of decomposition, water entering and then leaching from logs increased 1.3 times while runoff decreased a similar amount. The proportion of water stored by and evaporated from logs in this study indicates that in old growth forests they may intercept 2–5% of the canopy throughfall to the forest floor and that, even in early stages of decomposition, they may affect the hydrological cycle of Pacific Northwest old-growth forests.This is paper 2945 of the Forest Research Laboratory, Oregon State University, Corvallis     

Yessotoxin detected in mussel (Mytilus californicus) and phytoplankton samples from the U.S. west coast

Yessotoxin (YTX) was detected in an algal sample and two mussel samples (0.07–0.10 μg g⁻¹) collected from Scripps Pier in La Jolla, California during a bloom of Lingulodinium polyedrum. Mussel samples collected from Monterey Bay, California also contained measurable YTX (levels up to 0.06 μg g⁻¹) in samples obtained during a 6-month (weekly) sampling period. Gonyaulax spinifera and L. polyedrum were identified in background concentrations in Monterey Bay during the time of contamination. An algal sample from Washington coastal waters collected during non-bloom conditions also contained YTX, possibly originating from Protoceratium reticulatum.Three strains of L. polyedrum (CCMP1931, CCMP1936, 104A) isolated from southern California coastal waters and one strain of G. spinifera (CCMP409) isolated from Maine were tested for YTX production using two methods, competitive ELISA and liquid chromatography–mass spectrometry (LC–MS). The ELISA method detected YTX in the particulate phase in two of three L. polyedrum strains. The LC–MS method did not detect YTX in the particulate or dissolved phase of any of the strains.To our knowledge, this is the first study to test and confirm YTX in environmental samples from California and Washington coastal waters. It is highly likely that L. polyedrum was responsible for the YTX contamination in the southern California samples. Future research needs to conclusively determine the biological origin(s) of YTX contamination in central California and Washington coastal waters.     

Pollen morphology ofSonchus and related genera,and a general discussion

The pollen morphology of the taxa belonging to the generaAetheorhiza Cass.,Launaea Cass.,Reichardia Roth andSonchus L. in the Iberian Peninsula has been studied with light and electron microscopy. The pollen is 3(-4)-zonocolporate and echinolophate (without polar lacunae, but in general with prelacunae), with equatorial ridges and 15–20 lacunae: 3–4 poral, 6–8 abporal and 6–8 paraporal. Small to medium size, P × E = 19–36 × 23–42 µm; sometimes two different sizes have been found. Exine 3–9 µm thick and ornamentation microreticulate and echinate. The results clearly show the relationships between genera. Moreno-Socías, E., Mejías, J. A., Díez, M. J., 1994: Morfología polínica deLactuceae (Asteraceae) en la Península Ibérica, I.Lactuca y géneros relacionados. — Acta Bot. Malacitana.19: 103–113.     

Recent domoic acid closures of shellfish harvest areas in Washington State inland waterways

Several species of the toxigenic diatom Pseudo-nitzschia, together with low concentrations of domoic acid (DA) in shellfish have been observed in Puget Sound, Washington State, since 1991. However, for the first time in September 2003, high-density blooms of Pseudo-nitzschia forced the closure of recreational, commercial, and tribal subsistence shellfish harvesting in Puget Sound. Here we report on the environmental conditions associated with shellfish closures in two inland waterways of Washington State during the Fall 2005. In Sequim Bay, shellfish harvest losses occurred on September 12 following the measurement of elevated macronutrient levels on September 2, and a bloom of P. pseudodelicatissima (up to 13 million cells/L) on September 9. Ambient NH₄ concentrations >12 μM (measured on September 2) were likely due to anthropogenic sources, ostensibly from sewage inputs to Sequim Bay. The closure of a Penn Cove commercial shellfish farm on October 16 was caused by a bloom of P. australis that followed a period of sustained precipitation, elevated Skagit River flow, and persistent southeasterly winds. The relative importance of a number of environmental factors, including temperature, stratification caused by rivers, and nutrient inputs, whether natural or anthropogenic, must be carefully studied in order to better understand the recent appearance of massive blooms of toxigenic Pseudo-nitzschia in the inland waterways of Washington State.     

Ocean color observations of a surface water transport event: Implications for Pseudo-nitzschia on the Washington coast

A persistent patch of high biomass water, associated with the Juan de Fuca Eddy, is often observed in surface chlorophyll a images off the southwest coast of Vancouver Island, Canada. Outbreaks of toxic Pseudo-nitzschia spp. along the Washington, USA, coast are believed to correlate with the transport of waters from Juan de Fuca Eddy southward to Washington beaches. A time series of Sea-viewing Wide Field-of-view Sensor (SeaWiFS) satellite ocean color images from late May 1999 of coastal waters off Washington and Vancouver Island, processed for surface chlorophyll a concentration and spectral remote sensing reflectance, captured a transport event where water from the Juan de Fuca Eddy was transported onto the Washington shelf. Strong upwelling-favorable winds appeared to deform the patch over an 8-day period and move it southward into Washington coastal waters with surface velocities of approximately 8–16 km d⁻¹. SeaWiFS and sea surface temperature imagery showed the local phytoplankton response to wind-driven coastal upwelling restricted to a narrow (10–15 km) region along the Washington coast. Although we did not observe transport of high biomass water originating in the Juan de Fuca Eddy to Washington beaches in May 1999, transport of Pseudo-nitzschia cells could occur following a rapid shift to downwelling-favorable conditions. Tracking the trajectory of surface waters from the Juan de Fuca Eddy by remote sensing could be used to trigger conditional sampling for domoic acid along the Washington coast.     

The dynamics of old-growth Pseudotsuga forests in the western Cascade Range,Oregon, USA

Size and age structure, spatial analysis, and disturbance history were used to analyse the population structures and regeneration patterns of 8 conifer stands in the central western Cascade Range, Oregon, USA. Variation in forest structure reflected the effects of frequent (20–50 yr) low-intensity fires and treefalls, infrequent (100–200 yr) localised, intense fires, and extensive fires that resulted in stand replacement (every ca 400 yr?).The amount of canopy removed and the size of openings formed by fires and treefalls were important determinants of subsequent forest establishment. Single or several species stands of Pseudotsuga and/or Abies procera, or mixed species stands of Pseudotsuga, Abies procera, Tsuga heterophylla and Abies amabilis established in openings where intense fires had removed most of the canopy trees over several ha. Multi-tiered and multi-aged stands, often containing 400–500 yr-old Pseudotsuga and variously-sized more or less even-aged patches of younger shade tolerant Tsuga heterophylla and/or Abies amabilis, occurred where lower-intensity fires did not kill all overstorey trees or where treefalls occurred after the initial fire.Current regeneration processes are influenced by overstorey composition, the availability and size of canopy openings, and the availability of substrates suitable for regeneration. Tsuga heterophylla and Abies amabilis established under Pseudotsuga menziesii and Abies procera canopies and in small canopy openings (<400 m²) created by windfalls, but rarely under Tsuga. Down logs and stumps were favoured establishment sites for Tsuga.The disturbance regime of fires of low-to moderate-intensity, windfalls, and occasional fires that result in extensive stand replacement contrasts with the pattern of infrequent, catastrophic disturbances proposed for other areas of the Pacific Northwest. Although fires at stand establishment commonly determine much of the composition, structure, and subsequent stand development, canopy replacement by shade tolerant species occurs as the different life histories of the species are expressed in response to various disturbances differing in intensity and frequency. Such a non-equilibrium view of vegetation change is consistent with many other fire-dominated forests of the western United States.     

A substrate cycling model for nitrate uptake byPisum sativum seedlings: A key to sensitivity of response of net flux to substrate and effectors?

Summary Net nitrate uptake (J) intoPisum sativum L. seedlings has been investigated. J was high initially, but declined with time as NO ₃ ^– efflux (E) approached that of NO ₃ ^– influx (I). Both I and E were higher in plants which had been grown without N. J could be reversibly and immediately inhibited by 5 mmol m^–3 NH ₄ ⁺ , although plants grown in the presence of nitrate were less sensitive. A theoretical model which involves substrate cycling across the plasmalemma is shown to increase the sensitivity to substrate and effectors. It predicts that during growth of Pisum in N free media the cycling rate (E/I) is increased and the sensitivity of net flux of inhibition by NH ₄ ⁺ is highest. The model also provides a means for control of cytoplasmic nitrate pool size [NO ₃ ^– ] c.     

Aspects of the biochemistry and ultrastructure of a cytoplasmically inherited plastid defect (Dp1) of tobacco

Dpl, a cytoplasmically inherited plastid defect of Nicotiana tabacum L., has been further characterized by pigment and ribulose diphosphate carboxylase (RuDPCase) assays and electron microscopy. RuDPCase activity was reduced in defective plastids to 20–67% of that in normal chloroplasts. The chlorophyll content was reduced to 5% or less of that in normal chloroplasts. Leaf areas with only defective plastids were very light green for several days after the leaf began to expand but eventually turned white. This loss of chlorophyll was correlated with a reduction in internal plastid lamellae, but there was much less reduction in RuDPCase activity. The presence of cells with both mutant and normal plastids indicate that the plastid and not some other cytoplasmic factor was the site of the controlling unit.Scientific Paper No. 3812, College of Agriculture, Washington State University, Pullman, Projects 1916 and 1920. Supported in part by funds provided for medical and biological research by Washington State Initiative Measure 171.     

Association of ectomycorrhizal mats with Pacific yew and other understory trees in coniferous forests

This study was designed to determine whether ectomycorrhizal mats (ECM) are more likely to be present in soils at the base of common understory trees than in soils distant from trees and to determine whether occurrence of ECM is related to tree size. Three understory trees were studied: Pacific yew (Taxus brevifolia Nutt.), western hemlock (Tsuga heterophylla (Raf.)Sarg), and vine maple (Acer circinatum Pursh). The 12 sites studied represent a range of climatic conditions and management histories. More than 2,900 plots were surveyed over 18 months. The incidence of ECM was higher at the base of all three species than in control plots. Incidence of mats was also positively correlated with tree size. Saplings consistently had a lower incidence of ECM than did larger trees.Paper 3028 of the Forest Research Laboratory, Oregon State University, Corvallis     

Introduction and establishment of parasitoids for the biological control of the apple ermine moth, Yponomeuta malinellus (Lepidoptera: Yponomeutidae), in the Pacific Northwest

Four parasitoids were imported from five countries in Eurasia and released in northwestern Washington, US, to control the apple ermine moth (AEM), Yponomeuta malinellus Zeller, which colonized the Northwest around 1981. From 1988 to 1991, 95,474 individuals of Ageniaspis fuscicollis (Dalman) from France, China, Korea, and Russia were released in Washington. Parasitism of AEM increased 4- to 5-fold over that produced by preexisting natural enemies between 1989 and 1994 at 22 monitored sites. Subsequently, the wasp dispersed up to 20 km from release sites. A. fuscicollis also parasitized the cherry ermine moth, Yponomeuta padellus (L.), which was discovered in the Pacific Northwest in 1993. A total of 1813 individuals of Herpestomus brunnicornis (Gravenhorst) from France, Korea, and Japan were released in 1989–1991, and 26 wasps were recovered in 1994–1995. From 1989 to 1991, 2647 Diadegma armillata (Gravenhorst) individuals from France were released. D. armillata was recovered at one site in 1991 two months following release, but no other recoveries have been made. A total of 8274 Eurystheae scutellaris(Robineau-Desvoidy) individuals were released in 1989 to 1991. However, this tachinid has not been recovered. A consistent decline of AEM populations occurred in 1989–1995, including at sites where A. fuscicollis was not recovered, suggesting other factors also contributed to this pest’s decline. Now well established in western Washington, A. fuscicollis may help suppress future outbreaks of Y. malinellus and its congener, Y. padellus.     

Cytoplasmic reorganization accompanies the deposition of a bipolar cell wall in the large-celled red alga Anotrichium tenue

The filamentous red alga Anotrichium tenue C. Aghard (Naegeli) (formerly Griffithsia tenuis C. Aghard; Baldock, 1976, Aust. T. Bot. 24, 509–593) has large (1–2 mm long), cylindrical, multinucleate cells that exhibit a daily, cyclic redistribution of chloroplasts. Chloroplasts accumulate in the mid-region of each growing cell during the day; consequently, filaments appear banded with a light apical end-band, a dark mid-band and a light basal end-band in each growing cell. Chloroplasts disperse at night so that the bands are no longer visible and the cells appear evenly pigmented. Anotrichium tenue also has a type of cell elongation, known as bipolar band growth, in which new material is added to the microfibrillar part of the wall in bands located at the apical and basal poles of elongating cells. This site of wall growth corresponds to the position of the light-colored end-bands present during the day. Here we examine the structural relationship between the cytoplasmic bands and the wall-growth bands. Our results show that, in addition to the previously described bipolar wall bands, there is a non-microfibrillar wall band in the mid-region of the cell. This wall component apparently branches from near the top of the microfibrillar outer wall and terminates near but not at the bottom of the cell. It contains nodules of sulphated polysaccharide material secreted from a band of vesicles, which co-localize with the chloroplasts in the mid-band. The outer wall appears to enclose the entire cell. Nuclei do not redistribute with the chloroplasts or wall vesicles into the mid-band but remain evenly distributed throughout the cytoplasm. Each wall component grows by a different mechanism. We show that two types of wall growth, diffuse and the bipolar-type of tip growth, occur in the same cell and we propose that the observed segregation of the cytoplasm supports localized growth of the unique inner wall component. Additionally, we show that A. tenue is an excellent model for study of the role and mechanism of cytoplasmic compartmentalization and cell polarity during plant cell growth.We wish to thank Dr. Richard Cloney (University of Washington and Dr. Tom Schroeder (Friday Harbor Laboratories, Friday Harbor, Wash.) for helpful discussions and critical review of this work. We also thank Dr. Susan Waaland (University of Washington) for sharing her original observations on the chloroplast banding phenomenon in Anotrichium tenue. We are grateful to the Friday Harbor Laboratories for the use of their space and facilities. This research was supported by funds from the Washington Sea Grant Program (awarded to J.R.W.) and by the Developmental Biology Training Grant, predoctoral fellowship, National Institutes of Health, No. HD07183 to A.W.S.     

Pseudo-nitzschia pungens (Bacillariophyceae): A cosmopolitan diatom species?

Genetic, reproductive and morphological variation were studied in 193 global strains of the marine diatom species Pseudo-nitzschia pungens (Grunow ex Cleve) Hasle to assess potential intraspecific variation and biogeographic distribution patterns. Genetic differentiation between allo- and sympatric strains was investigated using the ITS1–5.8S–ITS2 rDNA region. Three ITS clades were found. Clones of opposite mating type were sexually compatible within clades I or II, and viable F1 hybrid offspring were produced in crosses between them. The molecular differences between these clades were correlated with slight but consistent morphological differences. At present, nothing can be said about morphology and mating behavior for clade III clones because only ITS data were available. The three ITS clades showed different geographic distributions. Clade II was restricted to the NE Pacific, whereas clones belonging to clade III originated from geographically widely separated areas (Vietnam, China and Mexico). ITS clade I was recovered in all locations studied: the North Sea (Belgium, The Netherlands, France), the eastern and western N Atlantic (Spain, Canada), the NW and S Pacific (Japan, New Zealand) and the NE Pacific (Washington State). Clade I thus appears to be globally distributed in temperate coastal areas and provides the first strong evidence to date for the global distribution of a biologically, genetically and morphologically defined diatom species.     

Essay review: The history of ecology

Joel B. Hagen,An Entangled Bank: The Origins of ecosystem Ecology (New Brunswick, N.J.: Rutgers University Press, 1992); Gregg Mitman,The State of Nature: Ecology, Community, and American Social Thought, 1900–1950 (Chicago and London: University of Chicago Press, 1992).     

Characterization of electrophoretically cryptic variation in the alpine butterfly Colias meadii

Enzyme polymorphism was characterized among the proteins of 14 loci of Coliae meadii by replicate electrophoresis in polyacrylamide gels of differing pore size. The results reveal a large number of variants, with a very skewed frequency distribution. A large fraction of the variants cannot be differentiated by electrophoresis in 5–7% acrylamide gels. This gel sieving approach permits an estimate of the relative contributions of charge and of conformation to electrophoretic mobility. Many of the variant proteins do not differ in charge. Most variants exhibit different degrees of interaction with the gel and presumably differ in conformation.This work was supported by grants from Washington University, the American Philosophical Society, the National Institutes of Health, and the National Science Foundation. Analysis was developed and carried out while the author was a Carnegie Institution of Washington Fellow.Carnegie Institution of Washington Department of Plant Biology Publication No. 569.     

Heterologous gene expression in <Emphasis Type="Italic">Thermus thermophilus</Emphasis>: β-galactosidase,dibenzothiophene monooxygenase,PNB carboxy esterase, 2-aminobiphenyl-2,3-diol dioxygenase,and chloramphenicol acetyl transferase

Enzymes from thermophiles are preferred for industrial applications because they generally show improved tolerance to temperature, pressure, solvents, and pH as compared with enzymes from mesophiles. However, nearly all thermostable enzymes used in industrial applications or available commercially are produced as recombinant enzymes in mesophiles, typically Escherichia coli. The development of high-temperature bioprocesses, particularly those involving cofactor-requiring enzymes and/or multi-step enzymatic pathways, requires a thermophilic host. The extreme thermophile most amenable to genetic manipulation is Thermus thermophilus, but the study of expression of heterologous genes in T. thermophilus is in its infancy. While several heterologous genes have previously been expressed in T. thermophilus (Fridjonsson et al. in J Bacteriol 184:3385–3391, 2002, Koyama et al. in Appl Environ Microbiol 56:2251–225, 1990, Lasa et al. in J Bacteriol 174:6424–6431, 1992, Mathew et al. in Appl Environ Microbiol 58:421–425, 1992, Takagi et al. in J Ind Microbiol Biotechnol 23:214–217, 1999, Tamakoshi et al. in Extremophiles 5:17–22 2001), the data reported here include the first examples of the functional expression of a gene from an archaeal hyperthermophile (bglA from Pyrococcus woesei), a cofactor-requiring enzyme (dszC from Rhodococcus erythropolis IGTS8), and a two-component enzyme (carBa and carBb from Sphingomonas sp. GTIN11). A thermostable derivative of pnbA from Bacillus subtilis was also expressed, further expanding the list of genes from heterologous hosts that have been expressed in T. thermophilus.     

A common allergenic epitope of Bermuda grass pollen shared by other grass pollens

The present study disclosed the cross-reactivity between Bermuda grass pollen (BGP) and other grass pollens using monoclonal antibodies (MAbs) and polyclonal antiserum. MAb 9–13, directed against a group of minor allergens of BGP (Cyn d Bd68K, 48K, 38K) was found to cross-react with extracts of ten other grass pollens. Immunoblotting assays illustrated that MAb 9–13 cross-reacted with multiple components of most of these pollens, and the major cross-reactive components had molecular weights of 29–36 kD. The cross-reactivity between BGP andLol pI, the group I allergen of rye grass pollen, was further evaluated;Lol pI was recognized by MAb 9–13, but not by our MAbs/polyclonal antiserum againstCyn dI, the major allergen of BGP. These results suggest that the epitope recognized by MAb 9–13 is a common (C) epitope shared byLol pI andCyn d Bd68K, 48K, 38K, andCyn dI does not share significant antigenicity withLol pI. In a modified radio-allergosorbent test, IgE antibodies in the serum of BGP-allergic patients reacted mildly with C-epitope-bearing components of both BGP and rye grass pollens, and this binding could be blocked specifically by MAb 9–13. This suggests that in addition to an antigenic cross-reaction, the C epitope can also lead to an allergenic cross-reaction.     

Meiosis and fertility of interspecific hybrids betweenPhaseolus vulgaris L. andP. acutifolius A. Gray

Summary Meiosis and fertility of interspecific hybrids obtained from reciprocal crosses between Phaseolus vulgaris and P. acutifolius were examined. Bivalents as well as univalents were found at Metaphase I. The majority of the microsporocytes had four or more univalents and the average was 6.3 univalents per cell. The average number of lagging chromosomes at Anaphase I was 2.3 per cell and the most frequent chromosome distribution at late Anaphase I was 10–12. The lower than expected number of lagging chromosomes as compared with the number of univalents at Metaphase I suggests the possible occurrence of precocious separation of bivalents. The male fertility as measured by pollen stainability was 17%, however, the frequency of pollen germination in selfing was 3.5%. Upon selfing of the interspecific hybrids, no dividing embryos were found even though 7 and 26% of the ovules were fertilized at 12 hours and four days after pollination. In backcrosses to P. vulgaris (male), 6 and 20% of the ovules were fertilized and 0 and 4% of the ovules contained dividing embryos at the same sampling times. When P. acutifolius was the male parent, respective values were 8 and 31% for fertilization and 0 and 13% for ovules with dividing embryos. The frequencies of backcross embryos recovered at 14–26 days were in agreement with the frequencies of dividing embryos at four days. The ability to obtain backcross plantlets demonstrates the feasibility to further utilize interspecific hybrids for the improvement of P. vulgaris Technical paper No. 5311 of the Oregon Agricultural Experiment Station. Research was supported by the Oregon Agricultural Experiment Station, the Science and Education Administration of the U.S. Department of Agriculture under Grant 5901-0410-8-0028-0 from the Competitive Research Grants Office, the Research Council of Oregon State University (NIH Biomedical Research Support Grant RR 07079) and the Processor Research Council of Oregon, A.R. and C T.S. are respectively supported by an African Graduate Fellowship from the African-American Institute and a fellowship from the National Science Council of the Republic of China     

中国橐吾属(菊科-千里光族)的分类学研究(五):君范橐吾、长毛槖吾和南川橐吾原白中一些排印错误的改正

对我国菊科橐吾属(Ligularia Cass.) 3种植物原白中模式标本引证的排印错误进行了改正。君范橐吾(L. lingiana S.W. Liu)原白中错误地将主模式标本引证为赵清盛82946,实际应为赵清盛、牟克平和杨亚斌8294。长毛槖吾(L. changiana S.W. Liu ex Y. L. Chen & Z. Yu Li)(=L. heterophylla C. C. Chang,为L. heterophylla Rupr.的晚出同名)主模式为蔡希陶59771,但L. heterophylla C. C. Chang 的原白中错误地将主模式标本引证为蔡希陶59711;该号标本属于唇形科的灯笼草[Clinopodium polycephalum (Vaniot) C. Y. Wu & Hsuan]。南川橐吾(L. nanchuanica S. W. Liu)原白中引证的副模式标本熊济华和周子林93871实际应为李国凤63871,前者属于桤叶树科的城口桤叶树(Clethra fargesii Franch.)。     

Halotolerance of the oyster predator, Imogine mcgrathi, a stylochid flatworm from Port Stephens, New South Wales, Australia

The stylochid flatworm, Imogine mcgrathi was confirmed as a predator of the pteriid oyster Pinctada imbricata. Occurring at an average of 3.2 per oyster spat collector bag, the flatworms were found to consume oysters at a rate of 0.035–0.057 d^–1 in laboratory trials. Predation was affected by flatworm size with larger worms capable of consuming larger oysters and of consuming greater dry weights of oyster flesh. Irrespective of flatworm size, predation was generally confined to oysters less than 40 mm in shell height. Although all predation occurred at night, shading flatworms during the day did not significantly increase the rate of predation, but there were significant increases in the dry weight of oyster meat consumed. As a means of controlling flatworm infestations, salt, brine baths (250 g kg^–1) and freshwater baths were effective in killing I. mcgrathi. The ease of use of hyper- or hyposaline baths then encouraged assessments of I. mcgrathi halotolerance. The flatworms were exposed to solutions ranging in salinity from 0 to 250 g kg^–1for periods of from 5 min to 3 h. Despite showing both behavioural and physiological signs of stress, I. mcgrathi survived the maximum exposure time of 3 h at salinities in the range 7.5–60 g kg^–1, inclusive. Beyond this range, the duration of exposure tolerated by flatworms decreased until 0 and 250 g kg^–1, at which the flatworms no longer survived the minimum tested exposure of 5 min. Thus, despite the significant impact of other stylochids on commercial bivalves, at their current prevalence, I. mcgrathi can be controlled by exposing them to hyper- and hyposaline baths for the culture of P. imbricata in Port Stephens, NSW, Australia.