{"title":"Sexual Reproduction of Hemidinium nasutum Alias Gloeodinium montanum","authors":"L. Pfiester, Joe F. Highfill","doi":"10.2307/3226783","DOIUrl":"https://doi.org/10.2307/3226783","url":null,"abstract":"","PeriodicalId":23957,"journal":{"name":"Transactions of the American Microscopical Society","volume":"109 1","pages":"69-74"},"PeriodicalIF":0.0,"publicationDate":"1993-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84766032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Endoparasites of some malagasy colubrids (Reptilia: Serpentes), with descriptions of two new species of Raillietiella (Pentastomida: Cephalobaenida)","authors":"C. T. McAllister, J. Riley, P. Freed, D. Freed","doi":"10.2307/3226780","DOIUrl":"https://doi.org/10.2307/3226780","url":null,"abstract":"","PeriodicalId":23957,"journal":{"name":"Transactions of the American Microscopical Society","volume":"49 1","pages":"35-42"},"PeriodicalIF":0.0,"publicationDate":"1993-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78577702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The effectiveness of vital staining for assessing lethal and sublethal responses of juvenile mussels was examined. Neutral red was used to quantify survival of juvenile Villosa iris and Anodonta grandis after exposures to aqueous copper in 24-hour static bioassays. Live juveniles readily incorporated the stain, but dead individuals did not. Variation in stain intensity was associated with behavioral responses, permitting diagnosis of alive, dead, and sublethal responses of juvenile V. iris. The amber coloration of juvenile A. grandis prevented detection of variations in stain intensity, thus allowing only livingversus-dead determinations to be made. Responding to precipitous declines in populations of freshwater mussels (Unionidae), several workers recently conducted laboratory tests to measure sensitivity of juvenile stages to various pollutants (Johnson et al., 1990; Keller & Zam, 1991; Lasee, 1991). Both Johnson et al. (1990) and Keller & Zam (1991) determined post-exposure mortality from observations of internal anatomy, but did not detail any sublethal effects of the exposures. By contrast, Lasee (1991) assessed both post-exposure mortality and sublethal responses by individual inspection of the juvenile mussels. Juveniles were recorded as alive (active and moving), stressed (no foot movement but cilia beating), or dead (no foot or cilia movement). Toxicity tests depend on an accurate assessment of post-exposure condition and are complicated by the small size (<1 mm) of juvenile mussels. Healthy juveniles are typically active, extruding the foot and gaping (opening) their valves. If immobile or ungaped, their condition is not as apparent. Because juveniles of many species possess transparent valves, with visible internal structure, the reduction or absence of movement by the foot or cilia may be used to assess responses. This requires close, individual inspections, and the effort is time-intensive. A more rapid and equally precise means of assessing postexposure condition of juvenile mussels thus was desirable. Vital staining has been used successfully to distinguish living from dead We thank Mr. Lou Rifici and Ms. Lisa Wolcott for assistance in the laboratory with rearing juvenile mussels and vital staining procedures. This research was supported by a grant from the American Electric Power Company through the American Electric Power Service Corporation, Columbus, Ohio 43216, U.S.A. 2 Address: Department of Biological Sciences, Arkansas State University, State University, Arkansas 72467, U.S.A. 3 Address: U.S. Fish and Wildlife Service, Virginia Cooperative Fish and Wildlife Research Unit, Department of Fisheries and Wildlife Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, U.S.A. TRANS. AM. MICROSC. SOC., 112(1): 78-80. 1993. ? Copyright, 1993, by the American Microscopical Society, Inc. This content downloaded from 157.55.39.220 on Fri, 02 Sep 2016 04:36:20 UTC All use subject to http://about.jstor
{"title":"Use of neutral red to assess survival of juvenile freshwater mussels (Bivalvia: Unionidae) in bioassays","authors":"P. Jacobson, J. Farris, R. Neves, D. Cherry","doi":"10.2307/3226786","DOIUrl":"https://doi.org/10.2307/3226786","url":null,"abstract":"The effectiveness of vital staining for assessing lethal and sublethal responses of juvenile mussels was examined. Neutral red was used to quantify survival of juvenile Villosa iris and Anodonta grandis after exposures to aqueous copper in 24-hour static bioassays. Live juveniles readily incorporated the stain, but dead individuals did not. Variation in stain intensity was associated with behavioral responses, permitting diagnosis of alive, dead, and sublethal responses of juvenile V. iris. The amber coloration of juvenile A. grandis prevented detection of variations in stain intensity, thus allowing only livingversus-dead determinations to be made. Responding to precipitous declines in populations of freshwater mussels (Unionidae), several workers recently conducted laboratory tests to measure sensitivity of juvenile stages to various pollutants (Johnson et al., 1990; Keller & Zam, 1991; Lasee, 1991). Both Johnson et al. (1990) and Keller & Zam (1991) determined post-exposure mortality from observations of internal anatomy, but did not detail any sublethal effects of the exposures. By contrast, Lasee (1991) assessed both post-exposure mortality and sublethal responses by individual inspection of the juvenile mussels. Juveniles were recorded as alive (active and moving), stressed (no foot movement but cilia beating), or dead (no foot or cilia movement). Toxicity tests depend on an accurate assessment of post-exposure condition and are complicated by the small size (<1 mm) of juvenile mussels. Healthy juveniles are typically active, extruding the foot and gaping (opening) their valves. If immobile or ungaped, their condition is not as apparent. Because juveniles of many species possess transparent valves, with visible internal structure, the reduction or absence of movement by the foot or cilia may be used to assess responses. This requires close, individual inspections, and the effort is time-intensive. A more rapid and equally precise means of assessing postexposure condition of juvenile mussels thus was desirable. Vital staining has been used successfully to distinguish living from dead We thank Mr. Lou Rifici and Ms. Lisa Wolcott for assistance in the laboratory with rearing juvenile mussels and vital staining procedures. This research was supported by a grant from the American Electric Power Company through the American Electric Power Service Corporation, Columbus, Ohio 43216, U.S.A. 2 Address: Department of Biological Sciences, Arkansas State University, State University, Arkansas 72467, U.S.A. 3 Address: U.S. Fish and Wildlife Service, Virginia Cooperative Fish and Wildlife Research Unit, Department of Fisheries and Wildlife Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, U.S.A. TRANS. AM. MICROSC. SOC., 112(1): 78-80. 1993. ? Copyright, 1993, by the American Microscopical Society, Inc. This content downloaded from 157.55.39.220 on Fri, 02 Sep 2016 04:36:20 UTC All use subject to http://about.jstor","PeriodicalId":23957,"journal":{"name":"Transactions of the American Microscopical Society","volume":"26 1","pages":"78-80"},"PeriodicalIF":0.0,"publicationDate":"1993-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82220080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A comparative review of the flatworm gut with emphasis on the Rhabdocoela and Neodermata","authors":"B. J. Bogitsh","doi":"10.2307/3226777","DOIUrl":"https://doi.org/10.2307/3226777","url":null,"abstract":"","PeriodicalId":23957,"journal":{"name":"Transactions of the American Microscopical Society","volume":"69 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"1993-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90584776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lagenophrys crutchfieldi n. sp., a loricate peritrich, is an ectocommensal on two species of the marine amphipod genus Parhyale and becomes one of the few species in its genus known to occur on marine hosts. Differences in the distribution of L. crutchfieldi on the bodies of its two hosts may be linked to a difference in the force of their respiratory currents, which carry food particles to the ciliates. L. crutchfieldi is one of a small group of species in its genus hosted by talitroid amphipods, but there is no indication that members of this group have a close phylogenetic relationship. The 54 species in the peritrich genus Lagenophrys live as ectocommensals on crustaceans in many types of habitats throughout the world (Clamp, 1991); however, only five of them occur on marine or estuarine hosts. Lagenophrys eupagurus Kellicott, 1893 and the closely related L. callinectes Couch, 1967 are found on marine and estuarine decapods (Clamp, 1989; Couch, 1967), but the former species also is widespread on freshwater decapods (Clamp, 1989). Both L. cochinensis Santhakumari, 1976 and L. limnoria Clamp, 1988 are symbionts of wood-boring isopods (Clamp, 1988a; Santhakumari, 1976; Santhakumari & Gopalan, 1980; Santhakumari & Nair, 1985). Lagenophrys tattersalli Willis, 1942 occurs on the gills of marine amphipods in Great Britain (Willis, 1942) and France (Clamp, unpublished observations). Also, Fenchel (1965) reported an undescribed species of Lagenophrys from marine amphipods collected in the coastal waters of Denmark. I have discovered and describe herein an additional marine species of Lagenophrys on two members of the amphipod genus Parhyale Stebbing, 1897, whose species are widely distributed in tropical and subtropical environments (Barnard, 1979; Shoemaker, 1956). MATERIALS AND METHODS Specimens of Parhyale hawaiensis (Dana, 1853) were collected with a dip net. They were fixed in Bouin's fluid for 24 h and transferred to 70% ethyl alcohol for preservation. Samples of L. crutchfieldi also were obtained from specimens of P. hawaiensis and P. penicillata Shoemaker, 1956 in the crustacean collection of the National Museum of Natural History, Smithsonian Institution (herein referred to as NMNH-CC). Permanent preparations were made by staining with Heidenhain's iron hematoxylin and protargol. Copper was omitted from the protargol solution. Some I I thank Dr. Austin B. Williams for arranging my visit to the crustacean collection of the National Museum of Natural History and Dave Penrose, who helped me collect amphipods on a memorable trip to Florida. Publication costs, in part, are being met by a grant from the Spencer-Tolles Fund of the American Microscopical Society. TRANS. AM. MICROSC. Soc., 112(1): 62-68. 1993. ? Copyright, 1993, by the American Microscopical Society, Inc. This content downloaded from 207.46.13.124 on Wed, 22 Jun 2016 05:21:34 UTC All use subject to http://about.jstor.org/terms VOL. 112, NO. 1, JANUARY 1993 ciliates were examined alive
{"title":"A new species of Lagenophrys (Ciliophora: Peritrichia) symbiotic on marine amphipods","authors":"J. Clamp","doi":"10.2307/3226782","DOIUrl":"https://doi.org/10.2307/3226782","url":null,"abstract":"Lagenophrys crutchfieldi n. sp., a loricate peritrich, is an ectocommensal on two species of the marine amphipod genus Parhyale and becomes one of the few species in its genus known to occur on marine hosts. Differences in the distribution of L. crutchfieldi on the bodies of its two hosts may be linked to a difference in the force of their respiratory currents, which carry food particles to the ciliates. L. crutchfieldi is one of a small group of species in its genus hosted by talitroid amphipods, but there is no indication that members of this group have a close phylogenetic relationship. The 54 species in the peritrich genus Lagenophrys live as ectocommensals on crustaceans in many types of habitats throughout the world (Clamp, 1991); however, only five of them occur on marine or estuarine hosts. Lagenophrys eupagurus Kellicott, 1893 and the closely related L. callinectes Couch, 1967 are found on marine and estuarine decapods (Clamp, 1989; Couch, 1967), but the former species also is widespread on freshwater decapods (Clamp, 1989). Both L. cochinensis Santhakumari, 1976 and L. limnoria Clamp, 1988 are symbionts of wood-boring isopods (Clamp, 1988a; Santhakumari, 1976; Santhakumari & Gopalan, 1980; Santhakumari & Nair, 1985). Lagenophrys tattersalli Willis, 1942 occurs on the gills of marine amphipods in Great Britain (Willis, 1942) and France (Clamp, unpublished observations). Also, Fenchel (1965) reported an undescribed species of Lagenophrys from marine amphipods collected in the coastal waters of Denmark. I have discovered and describe herein an additional marine species of Lagenophrys on two members of the amphipod genus Parhyale Stebbing, 1897, whose species are widely distributed in tropical and subtropical environments (Barnard, 1979; Shoemaker, 1956). MATERIALS AND METHODS Specimens of Parhyale hawaiensis (Dana, 1853) were collected with a dip net. They were fixed in Bouin's fluid for 24 h and transferred to 70% ethyl alcohol for preservation. Samples of L. crutchfieldi also were obtained from specimens of P. hawaiensis and P. penicillata Shoemaker, 1956 in the crustacean collection of the National Museum of Natural History, Smithsonian Institution (herein referred to as NMNH-CC). Permanent preparations were made by staining with Heidenhain's iron hematoxylin and protargol. Copper was omitted from the protargol solution. Some I I thank Dr. Austin B. Williams for arranging my visit to the crustacean collection of the National Museum of Natural History and Dave Penrose, who helped me collect amphipods on a memorable trip to Florida. Publication costs, in part, are being met by a grant from the Spencer-Tolles Fund of the American Microscopical Society. TRANS. AM. MICROSC. Soc., 112(1): 62-68. 1993. ? Copyright, 1993, by the American Microscopical Society, Inc. This content downloaded from 207.46.13.124 on Wed, 22 Jun 2016 05:21:34 UTC All use subject to http://about.jstor.org/terms VOL. 112, NO. 1, JANUARY 1993 ciliates were examined alive","PeriodicalId":23957,"journal":{"name":"Transactions of the American Microscopical Society","volume":"36 1","pages":"62-68"},"PeriodicalIF":0.0,"publicationDate":"1993-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81093565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chemotactic responses of Acanthamoeba castellanii to bacteria, several representative bacterial products, and chemotactic peptides were studied by following migration of amebas under agar. Amebas showed a positive chemotactic response to all bacterial species tested, even to those which were not ingested by amebas because of toxic pigments. Lipopolysaccharide and lipoteichoic acid, components of the outer membrane and cell wall, respectively, of Gram-negative and Gram-positive bacteria, evoked a neutral response from the amebas indicating that they are not attractants. Cyclic adenosine monophosphate, either as a bacterial product or as a pure compound was not an attractant. The chemotactic peptide formyl-methionyl-leucyl-phenylalanine served as an attractant, but the antagonist peptides N-t-boc-norleucyl-leucyl-phenylalanine and N-t-boc-methionylleucyl-phenylalanine did not. Amebas respond to these chemical stimuli, probably by means of membrane receptors. Chemotaxis is an oriented response to a stimulus (Wilkinson, 1982). It may be an important factor in the location of bacteria by soil amebas, as it has been shown to be for mammalian phagocytes locating invading microbes (Hugli, 1989). Amebas such as Acanthamoeba, a free-living protozoon found in soil and water, share a number of similarities with phagocytes in that both types of cells ingest bacteria and probably possess some mechanism that enables them to locate these microbes. A large body of information is available about the chemotactic responses of mammalian phagocytes (Devreotes & Zigmond, 1988; Wilkinson, 1982), but less is known about mechanisms used by amebas in locating bacteria. Studies of Acanthamoeba and Hartmannella (see McIntyre & Jenkin, 1969; Tharavanij, 1965; Urquhart, 1984) have indicated that a chemotactic factor present in, or released from, bacteria serves as the signal in attracting amebas, and that both chemotaxis and chemokinesis are exhibited by Naegleria fowleri toward bacteria and chemotactic peptide (MarcianoCabral & Cline, 1987). Entamoeba histolytica was shown to migrate toward filtrates of Escherichia coli, as well as toward complement component C5a, and lysed human erythrocytes (Urban et al., 1983). This study was undertaken to examine chemotaxis in Acanthamoeba, using migration under agar toward bacteria, bacterial components, and chemotactic peptides as a means of evaluating the ability of soil amebas to locate microbial I The authors thank Dr. Savanat Tharavanij, Mahidol University, Bangkok, Thailand, for making available sections of his doctoral thesis dealing with chemotaxis of amebas. We thank Professor David Raab, Brooklyn College, Psychology Department, for advice on statistical treatment of data. This research was supported in part by a City University of New York research award 669171 and by NIH-NIGMS Grant 5T34 GM08078 (NIH-MARC Program). Portions of this research were presented at meetings of the Society of Protozoologists. TRANS. AM. MICROSC. Soc.,
在95% (v/v)的乙醇中浸泡，然后用火焰燃烧掉酒精，对用于打井的软木钻进行灭菌。琼脂糖(Litex, HSA型;在1和1.5% w/v下的几个实验中，使用Accurate Chemical & Scientific Corp. (Westbury, New York)代替琼脂。在琼脂中排成一行打了三个孔(Nelson & Herron, 1988)。其中一口井位于板块中心，另外两口井沿中心井轴线(一口井位于1200小时，另一口井位于1800小时)，使用网格模式进行定向。井与井之间的中心间距为20毫米(或10平方)。在中心井中加入变形虫;将琼脂中的试验物质(细菌、细菌产物等)加入第二孔(1200小时孔)。第三孔(1800小时孔)作为对照孔，接受用于准备试验材料的盐水或溶剂添加到琼脂中。每口井可容纳50升液体。图1是实验设计示意图，如图所示为平板表面，用点画表示阿米巴在中心孔周围的分布。试验物质的制备。以活菌为试验物质，分别在营养肉汤和脑心灌注培养基中培养，温度为37℃。每天在几天内转移培养物。实验中，收获摇培养的过夜培养物，使用Sorvall RC-2离心机(12,000 x g)用稀盐水洗涤三次，并在盐水中悬浮至44。本内容下载自2016年9月10日星期六207.46.13.57 05:40:07 UTC。一九九三年一月一日
{"title":"Chemotactic responses of Acanthamoeba castellanii to bacteria, bacterial components, and chemotactic peptides","authors":"F. Schuster, M. Rahman, S. Griffith","doi":"10.2307/3226781","DOIUrl":"https://doi.org/10.2307/3226781","url":null,"abstract":"Chemotactic responses of Acanthamoeba castellanii to bacteria, several representative bacterial products, and chemotactic peptides were studied by following migration of amebas under agar. Amebas showed a positive chemotactic response to all bacterial species tested, even to those which were not ingested by amebas because of toxic pigments. Lipopolysaccharide and lipoteichoic acid, components of the outer membrane and cell wall, respectively, of Gram-negative and Gram-positive bacteria, evoked a neutral response from the amebas indicating that they are not attractants. Cyclic adenosine monophosphate, either as a bacterial product or as a pure compound was not an attractant. The chemotactic peptide formyl-methionyl-leucyl-phenylalanine served as an attractant, but the antagonist peptides N-t-boc-norleucyl-leucyl-phenylalanine and N-t-boc-methionylleucyl-phenylalanine did not. Amebas respond to these chemical stimuli, probably by means of membrane receptors. Chemotaxis is an oriented response to a stimulus (Wilkinson, 1982). It may be an important factor in the location of bacteria by soil amebas, as it has been shown to be for mammalian phagocytes locating invading microbes (Hugli, 1989). Amebas such as Acanthamoeba, a free-living protozoon found in soil and water, share a number of similarities with phagocytes in that both types of cells ingest bacteria and probably possess some mechanism that enables them to locate these microbes. A large body of information is available about the chemotactic responses of mammalian phagocytes (Devreotes & Zigmond, 1988; Wilkinson, 1982), but less is known about mechanisms used by amebas in locating bacteria. Studies of Acanthamoeba and Hartmannella (see McIntyre & Jenkin, 1969; Tharavanij, 1965; Urquhart, 1984) have indicated that a chemotactic factor present in, or released from, bacteria serves as the signal in attracting amebas, and that both chemotaxis and chemokinesis are exhibited by Naegleria fowleri toward bacteria and chemotactic peptide (MarcianoCabral & Cline, 1987). Entamoeba histolytica was shown to migrate toward filtrates of Escherichia coli, as well as toward complement component C5a, and lysed human erythrocytes (Urban et al., 1983). This study was undertaken to examine chemotaxis in Acanthamoeba, using migration under agar toward bacteria, bacterial components, and chemotactic peptides as a means of evaluating the ability of soil amebas to locate microbial I The authors thank Dr. Savanat Tharavanij, Mahidol University, Bangkok, Thailand, for making available sections of his doctoral thesis dealing with chemotaxis of amebas. We thank Professor David Raab, Brooklyn College, Psychology Department, for advice on statistical treatment of data. This research was supported in part by a City University of New York research award 669171 and by NIH-NIGMS Grant 5T34 GM08078 (NIH-MARC Program). Portions of this research were presented at meetings of the Society of Protozoologists. TRANS. AM. MICROSC. Soc.,","PeriodicalId":23957,"journal":{"name":"Transactions of the American Microscopical Society","volume":"5 1","pages":"43-61"},"PeriodicalIF":0.0,"publicationDate":"1993-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78693642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Formation of Egg Capsules by Flatworms (Phylum Platyhelminthes)","authors":"G. L. Shinn","doi":"10.2307/3226779","DOIUrl":"https://doi.org/10.2307/3226779","url":null,"abstract":"","PeriodicalId":23957,"journal":{"name":"Transactions of the American Microscopical Society","volume":"18 1","pages":"18-34"},"PeriodicalIF":0.0,"publicationDate":"1993-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74092162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A two-component silicone rubber kit makes possible the fabrication of custom embedding molds for use with epoxy resins. The kit contains a base material and a curing agent, which are combined by weight, degassed under vacuum (if necessary), and poured into the reservoir of a cast. The silicone rubber mixture cures within 24 hours at room temperature, producing a strong mold that is both flexible and tear-resistant. A three-piece aluminum cast, especially designed for mold-making, consists of a frame surrounding the template that rests on the wings of a platform and forms a reservoir to hold the silicone
{"title":"Custom Silicone Rubber Molds for Epoxy Resin Embedding","authors":"M. J. Cavey, G. K. Wong","doi":"10.5072/PRISM/30234","DOIUrl":"https://doi.org/10.5072/PRISM/30234","url":null,"abstract":"A two-component silicone rubber kit makes possible the fabrication of custom embedding molds for use with epoxy resins. The kit contains a base material and a curing agent, which are combined by weight, degassed under vacuum (if necessary), and poured into the reservoir of a cast. The silicone rubber mixture cures within 24 hours at room temperature, producing a strong mold that is both flexible and tear-resistant. A three-piece aluminum cast, especially designed for mold-making, consists of a frame surrounding the template that rests on the wings of a platform and forms a reservoir to hold the silicone","PeriodicalId":23957,"journal":{"name":"Transactions of the American Microscopical Society","volume":"30 1","pages":"81-84"},"PeriodicalIF":0.0,"publicationDate":"1993-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89172357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The presence of the pathogenic protozoan Haplosporidium nelsoni is documented for the first time in the American oyster, Crassostrea virginica, from South Carolina, U.S.A. Initially incriminated in 1957 as the causative agent of mass mortalities in the American oyster, Crassostrea virginica, in Delaware Bay, Haplosporidium nelsoni was given the acronym MSX (multinucleated sphere X) because its systematic relationship to other organisms was unknown. Subsequently, it was designated as Minchinia nelsoni by Haskin et al. (1966). Still later, Sprague (1979) transferred the species to the genus Haplosporidium (Balanosporida: Haplosporidiidae). The devastating effects of H. nelsoni on C. virginica are well known (see reviews by Lauckner, 1983; Sindermann, 1990; Sparks, 1985). It, along with Perkinsus marinus, another protistan parasite, are undoubtedly the major causes of the decline of the oyster industry in both the Delaware and Chesapeake Bays. Although H. nelsoni has been known by a few investigators to parasitize C. virginica in South Carolina, its occurrence in this state has never been recorded (Burrell, 1986). MATERIALS AND METHODS During November and December 1991 and January 1992, we examined 35 young oysters, 5-6 cm long, collected intertidally in Charleston Harbor (salinity 15-17%oo at Fort Johnson. The soft tissues of these bivalves appeared watery, with recessed mantles, and in each one of the six clusters studied, at least one or two were dead. These were native, wild oysters, the ancestors of which had inhabited Charleston Harbor for at least 100 years. No drought had occurred for at least three years prior to the time of collection. Moreover, no mass mortalities of oysters had been reported at the time. 1 This research was supported by a grant (NA16FL0408-01) from the National Marine Fisheries Service, U.S. Department of Commerce. TRANS. AM. MICROSC. Soc., 112(1): 75-77. 1993. ? Copyright, 1993, by the American Microscopical Society, Inc. This content downloaded from 157.55.39.224 on Wed, 14 Dec 2016 05:02:50 UTC All use subject to http://about.jstor.org/terms TRANS. AM. MICROSC. SOC. All of the living oysters were removed from their shells and processed for histopathologic examination. All were fixed in 10% seawater formalin, embedded in paraffin, sectioned at 7 ,im, and stained with hematoxylin and eosin for light microscopy. RESULTS AND DISCUSSION Intercellular plasmodia of Haplosporidium nelsoni were found in each oyster. All of the observed plasmodia were in relatively early stages of karyokinesis in that none was observed to include more than 10 nuclei. A few dividing nuclei, with conspicuous spindle fibers, also were observed (Farley, 1967). The plasmodia observed measured 6-10 ,um in greatest diameter. Although the majority of the plasmodia occurred between Leydig cells (i.e., vesicular connective tissue cells) situated between acini of the digestive diverticula and in the matrices of gill filaments, some also were found in vari
{"title":"Occurrence of the pathogen Haplosporidium nelsoni in oysters, Crassostrea virginica, in South Carolina, USA.","authors":"W. Dougherty, T. Cheng, V. Burrell","doi":"10.2307/3226784","DOIUrl":"https://doi.org/10.2307/3226784","url":null,"abstract":"The presence of the pathogenic protozoan Haplosporidium nelsoni is documented for the first time in the American oyster, Crassostrea virginica, from South Carolina, U.S.A. Initially incriminated in 1957 as the causative agent of mass mortalities in the American oyster, Crassostrea virginica, in Delaware Bay, Haplosporidium nelsoni was given the acronym MSX (multinucleated sphere X) because its systematic relationship to other organisms was unknown. Subsequently, it was designated as Minchinia nelsoni by Haskin et al. (1966). Still later, Sprague (1979) transferred the species to the genus Haplosporidium (Balanosporida: Haplosporidiidae). The devastating effects of H. nelsoni on C. virginica are well known (see reviews by Lauckner, 1983; Sindermann, 1990; Sparks, 1985). It, along with Perkinsus marinus, another protistan parasite, are undoubtedly the major causes of the decline of the oyster industry in both the Delaware and Chesapeake Bays. Although H. nelsoni has been known by a few investigators to parasitize C. virginica in South Carolina, its occurrence in this state has never been recorded (Burrell, 1986). MATERIALS AND METHODS During November and December 1991 and January 1992, we examined 35 young oysters, 5-6 cm long, collected intertidally in Charleston Harbor (salinity 15-17%oo at Fort Johnson. The soft tissues of these bivalves appeared watery, with recessed mantles, and in each one of the six clusters studied, at least one or two were dead. These were native, wild oysters, the ancestors of which had inhabited Charleston Harbor for at least 100 years. No drought had occurred for at least three years prior to the time of collection. Moreover, no mass mortalities of oysters had been reported at the time. 1 This research was supported by a grant (NA16FL0408-01) from the National Marine Fisheries Service, U.S. Department of Commerce. TRANS. AM. MICROSC. Soc., 112(1): 75-77. 1993. ? Copyright, 1993, by the American Microscopical Society, Inc. This content downloaded from 157.55.39.224 on Wed, 14 Dec 2016 05:02:50 UTC All use subject to http://about.jstor.org/terms TRANS. AM. MICROSC. SOC. All of the living oysters were removed from their shells and processed for histopathologic examination. All were fixed in 10% seawater formalin, embedded in paraffin, sectioned at 7 ,im, and stained with hematoxylin and eosin for light microscopy. RESULTS AND DISCUSSION Intercellular plasmodia of Haplosporidium nelsoni were found in each oyster. All of the observed plasmodia were in relatively early stages of karyokinesis in that none was observed to include more than 10 nuclei. A few dividing nuclei, with conspicuous spindle fibers, also were observed (Farley, 1967). The plasmodia observed measured 6-10 ,um in greatest diameter. Although the majority of the plasmodia occurred between Leydig cells (i.e., vesicular connective tissue cells) situated between acini of the digestive diverticula and in the matrices of gill filaments, some also were found in vari","PeriodicalId":23957,"journal":{"name":"Transactions of the American Microscopical Society","volume":"76 1","pages":"75-77"},"PeriodicalIF":0.0,"publicationDate":"1993-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86445308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A revision of Schilbetrema (Monogenoidea : Dactylogyridae), with descriptions of four new species from African Schilbeidae (Siluriformes)","authors":"D. C. Kritsky, S. Kulo","doi":"10.2307/3226704","DOIUrl":"https://doi.org/10.2307/3226704","url":null,"abstract":"","PeriodicalId":23957,"journal":{"name":"Transactions of the American Microscopical Society","volume":"1 1","pages":"278-301"},"PeriodicalIF":0.0,"publicationDate":"1992-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72567579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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