Dog Fish Research Articles

Possible Food Sources of Listeriosis for Aborted Women in Menoufia Province

The study was carried out during the period extended from September 2018 to February 2019 at El-Menoufia Governorate to investigate the presence of Listeria species in some food sources as well as aborted women. A total of 250 different samples were collected including; milk (100), kariesh cheese (25), beef meat (25), hot dog (25) and Bolti fish (25). Moreover, 50 vaginal swabs were collected from 50 aborted women from El-Menoufia University Hospital and Shibin El-Kom Teaching Hospital. The obtained results in the current work showed that the highest rate of isolation of Listeria spp. was recorded in the examined samples of Bolti fish (40%), followed by beef meat (28%) then raw milk (25%), Hot dog (24%) and finally kariesh cheese (20%) with statistically significant association between these rates of isolation. In addition, distribution of Listeria spp. isolated from raw milk samples clarified the identification of L. monocytogenes (2%), L. ivanovii (7%), L. innocua (5%), L. seeligeri (6%) and L. murrayi (5%), distribution of Listeria spp. isolated from kariesh cheese samples clarified the identification of L. monocytogenes (4%), L. ivanovii (8%), L. innocua (4%), and L. seeligeri (4%), distribution of Listeria spp. isolated from beef meat samples clarified the identification of L. monocytogenes (8%), L. ivanovii (4%), L. innocua (4%), L. seeligeri (4%) and L. welshimeri (8%), distribution of Listeria spp. isolated from Hot dog samples clarified the identification of L. monocytogenes (4%), L. ivanovii (8%) and L. welshimeri (12%) and finally, distribution of Listeria spp. isolated from Bolti fish samples clarified the identification of L. monocytogenes (4%), L. ivanovii (12%), L. innocua (4%), L. seeligeri (4%) and L. welshimeri (16%). On the other side, the rate of isolation from vaginal swabs of aborted women was 16% and distribution of Listeria spp. clarified the presence of L. monocytogenes (4%), L. ivanovii (4%), L. seeligeri (2%), L. grayi (2%), L. welshimeri (2%) and L. innocua (2%). Finally, PCR was applied successfully to detect LM1 gene in identification of isolates of L. monocytogenes. The recorded results in the current study throw the light upon the zoonotic potential of L. monocytogenes in El Menoufia Province where investigated samples were found to be positive for presence of Listeria with different rates that could ring the hazard bell about the significant role of different food products in transmitting these organisms to pregnant women. Moreover, PCR is a useful diagnostic tool for detection of L. monocytogenes because it sensitive and specific so this technique should be adopted as a complementary tool to conventional tests.

Critical Thinking and Constructivism: Mambo Dog Fish to the Banana Patch

Constructivist pedagogies cannot achieve their critical thinking ambitions. Constructivism, and constructivist epistemological presuppositions, actively thwarts the critical thinking process. Using Wittgenstein's private language argument, this paper argues that corrective mechanisms—the ability to correct a student's propositions and cognitions against the background of a shared, knowable world—are indispensible to critical thinking. This paper provides concrete examples of actual constructivist practice and shows how a particular constructivist classroom exercise can be modified to incorporate critical thinking elements as detailed by the American Philosophical Association. Finally, the paper states the significance of these arguments, particularly as they extend from the educational arena into the public and governmental domains.

Methodology for Hg determination in honey using cloud point extraction and cold vapour-inductively coupled plasma optical emission spectrometry

This paper describes the development of a method for the determination of mercury in honey. Analyte pre-concentration/matrix separation is carried out by cloud point extraction (CPE), while cold vapour-optical emission spectrometry (CV-ICP OES) is used to detect the analyte. A careful analytical work was carried out in order to evaluate precision and accuracy of the method. Mercury was complexed with ammonium diethyldithiophosphate (DDTP) and Triton X-114 was used as surfactant. Parameters such as type and concentration of acid (HCl or HNO3 + KCl), concentrations of complexant, surfactant and reductant (NaBH4), dilution of the surfactant-rich phase and the mass of honey were evaluated. Two procedures of sample preparation were investigated: sonication in presence of L-cysteine and acid decomposition in closed vessel. Sonication was very effective for extraction of inorganic mercury (Hg2+), but it was observed the sample should be decomposed to ensure the quantification of total mercury. Certified dog fish liver, analyte recovery and comparison with an independent technique (cold vapour-inductively coupled plasma mass spectrometry) were used to evaluate the method. Analyte recovery close to 100% was observed when up to 2.0 g of honey were subjected to sonication or up to 1.0 g of honey was decomposed with acid. The enrichment factor (EF) obtained was 13 and the limit of detection (LOD) was 2.2 ng g−1. The Hg concentration in the analyzed samples was lower than the LOD.

Optimization of Ultrasonic-Assisted Acid Extraction of Mercury in Muscle Tissues of Fishes Using Multivariate Strategy

A simple and rapid ultrasound-assisted extraction procedure was developed for the determination of total mercury (Hg) in muscle tissues of freshwater fish species. A Plackett-Burman experimental design was used as a multivariate strategy for the evaluation of the effects of variables, such as presonication time (without ultrasonic stirring), sonication time, ultrasonic bath temperature, nitric acid concentration, hydrochloric acid concentration, and sample mass of muscle tissues. Some variables showed a significant effect on recovery, and they were further optimized by a 2(3) + star central composite design that involved 16 experiments. The validation was carried out by analysis of certified reference material DORM-2 (dog fish muscles); for comparative purposes, an acid digestion induced by microwave energy was used. Cold vapor atomic absorption spectrometry was used for the determination of total Hg. No significant differences were established between the analytical results and the certified values (paired t-test at P > 0.05). The LOD and LOQ of Hg were 0.133 and 0.445 microg/kg, respectively, which demonstrated the high sensitivity of the proposed procedure for the determination of Hg at trace levels. The Hg concentrations in the muscle tissues of 10 freshwater fish species were found in the range of 35.3-67.8 microg/kg on a dried basis, which were within the permissible limit of the World Health Organization.

Numerical modeling of groundfish target strength compared to in situ data

Acoustic scattering models of zooplankton and fish are an essential component of the process of converting in situ target strength of marine organisms into meaningful biological parameters such as size and numerical density. This study compared the numerical model of axisymmetrically shaped groundfish target strength (e.g., cod, dog fish, haddock) with measurements obtained in situ. Experimental target strength data were obtained using a bottom-mounted 200-kHz acoustical platform, fitted with four laser beams and an optical recording system to correlate species, length, and incidence angle to the measured target strength. Based on the length of the groundfish obtained from the data in situ, target strength modeling estimates were computed using the FMM (Fourier matching method), assuming an axisymmetrically shaped swim bladder with soft boundary conditions. The scattering coefficients for the truncated modal series solutions were predicted in quad precision, which added stability to the results. Data-model comparisons of target strength at 200 kHz are presented as a function of incidence angle for a number of groundfish of different lengths and species. [Work supported by NOAA.]

Relationship effects in psychological explanations of nonhuman behavior

Research suggests that close relationships with animals encourage psychological explanations of their behavior. To determine the causal effect of ownership on psychological explanations, we conducted experiments in which we manipulated participants' ownership of a target imagined dog (experiment 1), animated object (experiment 2), and real pet fish (experiment 3). Adapting scales used in previous research, we obtained ratings of how intentional the target's behavior was, the target's reasons (rather than causes), and references to complex human-like emotions, motives or characteristics. In experiment 1, 26 volunteers and staff at an animal shelter imagined scenarios involving their dog, a neighbor's dog, their friend, or a visitor. Participants' intentionality ratings and the target's reasons were similar for a friend, a visitor, and their dog. In experiment 2, 36 participants watched a film of three moving objects. Half of the participants were told the small triangle was theirs. In the ownership condition, participants vilified the “aggressive” big triangle more, gave more causal history for reasons, and gave more social, humanlike narratives. In experiment 3, 82 university students and staff were given a Betta fish either to own or to care for temporarily, and they were to report daily or weekly on the fish's behavior. Ownership and reporting frequency did not directly influence outcomes. Rather, ownership predicted commitment to, and affection for, the fish. Affection, in turn, significantly predicted participants' psychological explanations including how smart the fish was, how much the fish liked the participant, how similar the fish was to the participant, and psychological explanations of social behavior such as turning toward a visitor. Automated analyses of participants' language showed that affection also predicted their use of social psychological and emotion words to describe the fish. We discuss alternative processes whereby social relationships give rise to psychological explanations of behavior.

Determination of volatile elements in biological materials by isotopic dilution ETV-ICP-MS after dissolution with tetramethylammonium hydroxide or acid digestion

Isotopic dilution for the determination of Ag, Cd, Hg, Pb and Tl in biological materials by ETV-ICP-MS is proposed. The sample was simply dissolved with tetramethylammonium hydroxide (TMAH) or acid digested in a microwave furnace, with an on line matrix separation. When the dissolution was employed, Ir was used as a chemical modifier for Hg and Pb and Pd was used for Cd and Tl. No modifier was used for Ag. The pyrolysis temperatures were taken from pyrolysis temperature curves. The on line preconcentration was performed in a flow injection system with solenoid valves and was based on the analyte complexation with ammonium diethyldithiophosphate and sorption of the complexes on C 18 bonded to silica gel in a minicolumn. For the digested sample submitted to the analyte preconcentration procedure, a modifier, Ir, was only used for Hg. For the other analytes, since a low pyrolysis temperature, 300°C, was employed, no modifier was added. The isotopic dilution calibration was applied to two certified materials, bovine liver and dog fish muscle, dissolved with TMAH or acid digested, and to another two certified materials, corn bran and rice flour, acid digested and submitted to analyte preconcentration. The obtained concentration values agree with the certified ones, showing that this calibration procedure leads to accurate results in the determination of low concentrations of volatile elements. Due to simplicity, the dissolution with TMAH is very attractive.

Dogfish (Squalus acanthias) and dogfish silage as feed-stuffs in growing-furring diets for mink (Mustela vison)

A production trial was carried out with 120 mink (Mustela vison) of standard genotype to demonstrate the effects of dogfish (DF) and dogfish silage (DFS) on growth and fur development from weaning until pelting. The experimental treatments were 1) Control, 2) DF15%, 3) DF30%, 4) DF45%, 5) DFS15%, and 6) DFS30%. The test ingredients were used to replace the haddock-herring (35%:10%) mixture in the Control diet at percentage levels indicated by the diet group designation. The rest of the diet was compounded of 10% beef tripe and lungs, 8% poultry offal, 10% cereal, 5% corn gluten meal, 0–2% vegetable oil, 0.4% vitamin-mineral premix and water. All diets guaranteed the females normal body weight gain during the trial. The males receiving the dogfish test diets had significantly poorer growth compared with the males in the Control group. Two males of the DF30% group also developed rickets. The incidence of cotton fur syndrome in the experimental groups was: Control, 0/20; DF15%, 6/20; DF30%, 7/17; DF45%, 0/19; DFS15%, 2/18; and DFS30%, 3/17 pelts produced. Acid ensiling of dogfish was shown to reduce the incidence of cotton fur in the mink but also produced an increased trend in the occurrence of enteritis in the females. Based on the haematology results and tissue iron store analysis, impaired iron metabolism was demonstrated in the DF15-30% and DFS15-30% groups. It can be concluded that the anti-nutritional factor, trimethylamine oxide (TMAO), present in dogfish reduced iron absorption in most of the experimental groups and resulted in disturbances in the fur development of the mink. The absence of cotton fur in the DF45% group is likely due to greater ammonia formation in the feed thus preventing TMAO degradation by triamine oxidase. The improved iron store status in the mink fed the DF45% diet compared with the Control and other dogfish test groups may be explained by the chelating effect of polyamines on iron consequently enhancing its absorption. Key words: Anaemia, cotton fur, trimethylamine oxide, TMAO, nutrition

Methods of extraction composition and stability of vitamin A and other components in dogfish ( Squalus acanthias) liver oil

Oil was extracted from dog fish ( Squalus acanthias) livers by the Bligh and Dyer, Soxhlet and steaming extraction methods. Oil yields using the steaming method (22% w w ) were lower than from the solvent extraction methods (68% w w ). The vitamin A content of the oil produced by steaming was 54 mg retinol/100 g oil, and slightly higher (62–68 mg/100 g) contents were recorded in the solvent extracted oils. The Bligh and Dyer extraction produced an oil containing 12% phospholipid, much higher than the 4% via the Soxhlet and 1 % in the steaming extractions. The level of squalene (40 mg/100 g) in the oil produced by steaming was higher than in the other oils (28 and 32 mg). Concentrations of vitamin E and cholesterol were similar in all three oils at approximately 25 mg tocopherol/100 g and 1.1 g cholesterol/100 g, respectively. Oils were stored under air at room temperature in half filled dark coloured bottles. Although highest PVs were observed in the stored Bligh and Dyer-extracted oils, the highest apparent loss of vitamin A (30% in 3 weeks) occurred in the oil extracted by steaming.

The adult dogfish (Scyliorhinus canicula L.) testis: a model to study stage-dependent changes in steroid levels during spermatogenesis

The unit structure of the testis of Scyliorhinus canicula L. is the seminiferous lobule arranged in topographically distinct zones and comprised of cysts formed by steroid-producing Sertoli cells associated with germ cells at an identical stage of spermatogenesis. In this experiment, testicular tissues from different dogfish corresponding to the zones of lobules with spermatogonia (A), spermatocytes (B), early spermatids (C) and late spermatids (D) were dissected out and pooled. They were either used for steroid radioimmunoassay or incubated to measure steroid production in response to dogfish pituitary extract or to dibutyryl cyclic AMP (dbcAMP). Our results indicate that testosterone is the main testicular androgen in this species. Furthermore, marked changes in the distribution of steroids were observed according to the zone of spermatogenesis, testosterone concentrations being highest in zones A and D. The relative contents of this hormone (steroid levels normalized to an equivalent number of Sertoli cells) as well as of delta 4-androstenedione and of progesterone increased from A to D. The concentrations of delta 4-androstenedione and progesterone were highest in zone D. Relative contents of 5 alpha-androstane-3 alpha,17 beta-diol, dihydrotestosterone and 11-ketotestosterone were very low in A when compared with the other zones. Finally, whereas no significant stage-related variation in the concentration of oestradiol-17 beta and 17 alpha-hydroxy, 20 beta-dihydroprogesterone was observed, the relative content of these steroids was lowest in zone A. Incubation experiments revealed that dogfish pituitary extract and dbcAMP can stimulate androgen synthesis (about twofold) and that a stage-related change of steroid responsiveness to dbcAMP exists (only zones A and D were responsive). Overall, the results of this study indicate that germ cells most probably influence Sertoli cell steroidogenesis and responsiveness in the adult dog fish testis.

The Pioneers of Dog Fish Bay

by Rangvald Kvelstad 6 The Pioneers of Dog Fish Bay Only Canada FOUR and years the United after the States boundary was set between at the Canada and the United States was set at the 49th Parallel, the first Norwegian arrived in the Pacific Northwest. It was 1849, the year of the great gold rush to California, and his name was Zachariah Martin Toftezen . Exact details of his trek are wanting, but it is known that at age twenty-eight he had shipped out as a sailor and landed in New Orleans. Thomas Ostenson Stine in his book Scandinavians on the Pacific (1900) says of him: "He was a pioneer of heart and courage - chivalrous Martin Toftezen. He had drifted around the Horn on a ship, and was tossed into the mouth of Puget Sound, where the breath of the deep calmed to a gentle zephyr, and the wings of speed flapped in disconsolation ." In a less flowery vein, Alice Essex in her Stanwood Story (1975) says of his landing on Whidbey Island: "Enroute, he met Col. Ulrich Freud of Switzerland, who was also seeking a land of promise .... they were joined by C. W. Sumner, a Yankee from New England with the same yearning. The three teamed up, hired a sloop, and via Indian canoe and guide found themselves 196 PIONEERS OF DOG FISH BAY in Crescent Harbor, where they landed at a spot called 'Big Springs' in December, 1849. After climbing to the top of a high hill, Toftezen pronounced the view 'the most glorious on earth' and shouted to his companions, 'Our search is over - we have at last found our earthly paradise.'" The "paradise" Toftezen saw was from a hill now overlooking the town of Oak Harbor. Alice Essex continues her story: "Stirred with a tinge of wanderlust, Toftezen left his Paradise three times, but always returned to the island he loved, where he died in 1901 at the age of 80. He was buried in an old cemetery in Oak Harbor, the place that was his first love in the West." The remains of the first Norwegian settler in what is now the state of Washington were consigned to a forgotten grave in an abandoned cemetery. Thirty years later compassionate fellow Norwegians on Whidbey Island and in the Stanwood community were instrumental in having the body moved to the Lutheran cemetery in Stanwood. A marker was erected over his grave by the Pioneer Historical Society of the Stillaquamish Valley and the Sons of Norway. Suitably, the monument was dedicated by the future King Olav V of Norway, on May 27, 1939. The founders of what was to become the city of Seattle followed Toftezen by two years, in 1851. The Arthur Denny party came over the Oregon Trail from Illinois to Portland, and then by ship to the Puget Sound. They landed on what is now known as Alki Point. In the party was Mary Denny's newborn baby boy. Eighty years later he was still alive and well. Rolland Denny had spanned the years from the Indian cayuse to the automobile , from the canoe to the airplane. He saw Seattle grow from one roofless cabin in the wilderness to a city of towering buildings. When the Norwegians moved into the Pacific North197 Rangvald Kvelstad west they found a land very similar in climate and scenery to their homeland. The surprising difference was the huge stands of big trees. The forests provided them with a livelihood until they could clear a piece of land and begin to grow their food. Dozens of sawmills sprang up, some the largest in the world, and the timber products found a worldwide market. Amidst this abundance of timber, game, waterfowl, fish, shellfish, wild berries, and fruit lived the children of Nature, the Indians. At first the white man posed no threat to their livelihood and the relationship was amicable. There were here none of the fierce military confrontations that shook the Midwest, though the Indians' lack of a sense of ownership of land was later to create problems. The Indian tribes limited their activities within fairly well defined areas. A tribe would usually number only a few hundred souls...

The component acids of lipids from marine and freshwater species with special reference to furan‐containing acids

AbstractThe component acids of lipids extracted from the liver of roach, powan, brown trout, perch, pike, sea trout, salmon, ice fish, dog fish and cod, the flesh of capelin, haddock, herring and mackerel, and the digland of octopus have been examined. Differences between lipids from freshwater and marine sources and between those obtained from male and female species are noted. Particular attention is directed to a group of furan‐containing acids present at low levels (up to 5%) in most of the samples. These unusual acids tend to concentrate in the cholesterol esters. In two starved cod the proportion of furanoid acids rose dramatically to 34 and 48% respectively.

Studies on the glycoprotein component of ( [formula omitted])-ATPase from dog fish salt gland Binding to concanavalin A and removal of sialic acid by neuraminidase

1. 1. The presence of concanavalin A binding sugars in the glycoprotein component of a partially purified (Na + + K +) ATPase preparation from dog fish salt gland was demonstrated by binding of a Triton X-100 extract of the enzyme and isolated glycoprotein to concanavalin A-Sepharose, and by binding of membrane-associated enzyme to free concanavalin A. 2. 2. The binding of concanavalin A to the glycoprotein in both membrane-associated enzyme and a Lubrol extract of the enzyme had no effect on (Na + + K +)-ATPase activity. Binding was completely inhibited by methyl-α-mannoside. Also, enzyme activity was not affected by removal of 50% of glycoprotein sialic acid by neuraminidase. These results suggest that the carbohydrate moiety of the glycoprotein does not play a catalytic role in the (Na + + K +)-ATPase. 3. 3. When a Triton X-100 extract of (Na + + K +)-ATPase was chromatographed on concanavalin A-Sepharose, 37% of total protein was bound to the column and eluted by methyl-α-mannoside. The bound fraction was free of lipid, and contained not only the glycoprotein but also the large protein which is the catalytic subunit of the enzyme, and small amounts of other membrane derived proteins. The ratio of large protein to glycoprotein, as measured by the relative Coomassie blue absorbance of the two proteins separated by gel electrophoresis, was the same in the bound fraction as in the membrane. These results suggest that the glycoprotein and large protein are either associated together in the membrane or become associated during lipid replacement by Triton.

Molecular weight heterogeneity of the α-chain sub-units of collagen

The α-chain sub-units of rat and bovine collagen, previously believed to have the same molecular weights are shown to exhibit different mobilities on SDS-polyacrylamide gel electrophoresis corresponding to a molecular weight difference of about 6,000 Daltons. Comparison with the mobilities of proteins of accurately known molecular weight gave approximate molecular weights for the α 1 and α 2 chains in the expected region of 100,000. Further heterogeneity in the molecular weight of the α components of other species is also apparent using this technique, the α 1 components of cod skin and dog fish skin having a molecular weight intermediate between mammalian α 1 and α 2.

Comparative studies of aortic acid mucopolysaccharides in fifteen species

1. 1. Aortic acid mucopolysaccharides (AMPS) were studied in fifteen different species including: dusky shark, dog fish, frog, turtle, chicken, pheasant, mouse, rat, guinea pig, hamster, rabbit, cat, dog, cow and rhesus monkey. 2. 2. Phylogenetically close species (e.g. cat and dog, rat and mouse chicken and pheasant) had similar concentration of AMPS in aortic tissue. 3. 3. Thoracic aortic segment had a higher concentration of total AMPS and chondroitin sulfate B than abdominal segment. 4. 4. Chondroitin sulfater B was not observed in aortic tissue of dusky shark and dog fish, the most primitive species subjected to this study.

Electron Microscopic Studies of the Ultimobranchial Body of the Elasmobranchs

The ultimobranchial bodies of two species of elasmobranchs-smooth dog fish, Mustelus manazo BLEEKER and sting ray, Dasyatis akajei MULLER and HENLE-were observed with the electron microscope.1. In the ultimobranchial bodies of smooth dog fish many vesicles are scattered in abundant connective tissue, while in those of sting rays vesicles and cell cords are closely packed.2. Two types of cells, barrel cells and finger cells, are found in the vesicles in both species. The barrel cells are more endocrine in nature, and the finger cells are more exocrine or supporting. In sting rays the barrel cells are more prevalent in number than the finger cells and the cell cords are exclusively composed of the barrel cells.3. The barrel cells are round to oval and do not directly limit the vesicle cavity. Many secretory granules are stored in the cytoplasm, and are often in direct contact with the lateral or basal plasma membranes without changing their size and density. The secretory granules appear to be formed in the Golgi zone. Occasionally, filament bundles appear around the nucleus where mitochondria, secretory granules and rough-surfaced endoplasmic reticulums are entangled. The secretory granules are larger and denser in sting rays than in smooth dog fish.4. The finger cells have elongated cell bodies, well developed interdigitations and desmosomes and surround the barrel cells. They limit the vesicle cavity with free apical surfaces from which short microvilli project to the lumen.

Chemical synthesis of 1- O-(D)- and 3- O-(L)-glyceryl monoethers, diethers and derivatives: Glycerides, monoester phospholipids and diether phospholipids

1. 1. A convenient route to the synthesis of 1- O-glyceryl ether from 3- O-glyceryl ether is reported. This technique, which is based on the procedure of Lands and Zschocke 35 for conversion of 3- O-benzylglycerol to 1- O-benzylglycerol, utilized either 3- O-hexadecylglycerol or 3- O-octadecylglycerol as the starting material. The ether was converted to its ditosylate and this latter group was displaced with freshly fused potassium acetate in anhydrous ethanol. Alkaline hydrolysis yielded the desired 1- O-alkyl glycerol, with an equal but opposite optical rotation to the starting material, in good yields. 2. 2. 1- O- cis-9'-Octadecenyl-2- O-octadecanoylglycerol (2-stearoyl selachyl al-cohol) was synthesized by borate replacement of 1- O- cis-9'-octadecenyl-2- O-octade-canoyl-3- O-tritylglycerol in triethyl borate and boric acid, followed by column chromatography on neutral silicic acid. Catalytic amounts of HClO 4 isomerizes 2-stearoyl selachyl alcohol completely to its positional isomer 3-stearoyl selachyl alcohol. Acylation of 1- O-cis-9'-octadecenylglycerol in the presence of up to 2 M excess of acyl chloride, was found to occur preferentially at the primary hydroxyl group forming 3-stearoyl selachyl alcohol and the diacyl derivatives (dipalmitoyl, dioleoyl and distearoyl selachyl alcohol) formed in good yield only when a 4–6 M excess of acyl chloride was used. The properties of the synthetic diacyl-glyceryl derivatives correlated closely with the natural diacyl-glyceryl monoether isolated from dog fish liver oil. 3. 3. 1,2-Di- O- cis-9'-octadecenylglycerol which was synthesized by acid hydrolysis of its trityl derivative was converted to the corresponding phosphorylethanolamine and phosphorylcholine derivatives; 2- and 3-stearoyl selachyl alcohol were converted to their phosphoryl ethanolamine and phosphorylcholine derivatives. The physical properties of the monoethers, monoacyl monoethers, diethers and their corresponding phospholipids are tabulated and discussed. Comparable results in properties between the synthetic 1- O- cis-9'-octadecenyl-2- O-octadecanoyl-3-glycerophosphorylethanolamine and the natural monoether monoacyl glycerophosphorylethanolamine isolated from bovine erythrocytes were found.

Some factors contributing to the development of subatmospheric pressure in the heart chambers and pericardial cavity of Mustelus canis (Mitchill)

1. 1. Four experiments were designed to investigate some factors contributing to the development of subatmospheric pressure in the pericardial cavity and heart chambers of the smooth dog fish. 2. 2. Pericardiotomy resulted in a change in atrial and ventricular dynamics and abolished the occurrence of subatmospheric intracardiac pressure. 3. 3. Intrapericardial injections of Elasmobranch-Ringer's solution produced similar results. 4. 4. These results and those from experiments with epinephrine and bradycardia provide evidence to support the hypothesis that subatmospheric pressure within the pericardial cavity depends on a noncompliant parietal pericardium and the diastolic fiber length of heart muscle. 5. 5. Respiratory activity also contributes to the negativity of intrapericardial pressure.

DISTRIBUTION OF A RADIOMERCURY-LABELLED DIURETIC (CHLORMERODRIN) IN TISSUES OF MARINE FISH

1. Chlormerodrin labelled with radiomercury has been injected into marine fish with different types of nephrons. The kidneys of flounder (Paralycthys dentatus), with glomerulus and proximal tubular segment, of dog fish (Mustelus canis), with proximal, distal segment, and glomerulus, and toadfish (Opsanus tau), with proximal segment only, all concentrate mercury to a high degree.2. High mercury U/P ratios in the toadfish indicate mercury excretion by a secretory mechanism. Excised flounder tubules will not concentrate phenol red if the animal has previously been injected with a toxic amount of chlormerodrin. Accumulation of mercury is also noted under certain conditions in the bile, especially in the dogfish, but is not seen in either stomach or gills.3. Evidence is reviewed that in many animal species mercury accumulation is greatest in the proximal tubular segment.

FISHERY ON THE COAST OF THE SEA OF OKHOTSK

The region that is contiguous to the Sea of Okhotsk in Hokkaido is a tract of land covering Cape Notsuke, by way of Cape Shiretoko to Cape Soya. In this thesis, however, Wakkanai is also included. There lie three cities, nine towns, and three villages in this region, and about 5, 000 families of fishermen are living depending upon the Sea. 1. STATIONARY FISHING: Salmon and trout fisheries are done in this method, which excel in Shari and in Shibetsu. Especially the fishermen of Utoro in Shari depend upon this stationary fishing, and in the fishing season they move, to Shiretoko Peninsula, to the north of Utoro, to fish. 2. CO-OPERATION FISHING: This is cheifly practised in gathered tangle and catching hairy-crab. The tangle is called Rishiri tangle, and is grown on the rocky shore of Wakkanai and Rausu. As the fishing season approches, in Rausu they move to the northern part of Shiretoko Peninsula hairy-crab pot fishery is practised on a huge continental shelf lying in front of the coast from Tokoro to Hamatombetsu. Omu, Esashi, and Mombetsu excel in their catch because of their convenient location. 3. PERMISSION FISHERY: In this, scallop dredge fishery, saury stick-held dip net fishery, one-boat medium trawl fishery, dog fish drift line fishery are chiefly included. The fishing-places of scllops are the continental shelf off the coast of Kitami and C. Notsuke and its cheif producting districts are Yubetsu, Tokoro, Abashiri, and Esashi. The cheif fishing place of saury stick-held dip net fishery is the offing Mombetsu, and the fishermen sail out fishing from Abashiri and Mombetsu as thier bases. Fishing season being late, the fleets of vessels belonging to the Pacific Ocean also take part in it. One-boat medium trawl fishery is done to catch pollacks, cod, lockingtons, sharks on the huge continental shelf covering off the coast of Tokoro to Sakhalin, and their bases are Abashiri, Mombetsu, Esashi, and Wakkanai. Abashiri and Tokoro excel in dog fish drift line fishery and its fishing-places are near the isobathyic line of 200 metres. But in late autumn sharks being near thes hore and living on the bottom of the sea, they fish with one boat medium trawl fishery. 4. SECTIONAL FISHERY: This is done in gathering oysters in Lake Saroma in under-water method, and gathering immatured scallops. Fishermen depending upon Lake Saroma amount to 320 families. 5. Regional figures of sea products are as follow: one is the large producting district having many kinds of fish and the other is a small producing district having a few kinds of fish. To the former belong Rausu, where maltiple manegement is practised, Abashiri, Mombetsu, Esashi, and Wakkanai, where off-shore fisheries chiefly practised: and to the latter the other regions. 6. The distribution of fishing boats is as follows; (a) region which has a large number of fishingboats, (b) region which has a small number of fishing boats. The former is the region where ships are improved to be large and modernized, and the latter is not. And these agree to each region mentioned in the last section. In short, the fisheries of the coast of the Sea of Okhotsk are, in the eastern parts, coastal fishing based on the base of continental shelf as its fishing place.