Aspects of the oyster season in Maryland: Involving labor conflicts detrimental to both seafood and cannery industries, with special reference to the latter

For fully three decades there has been an almost steady decline in Maryland's oyster production... are alarmed for its future. Reasons for decline, data supplied,importance of brood oysters and clutch replenishment. Problems of warm weather and bacterial activity as well as tongs grinding the bottom. Conflicts in canning of early season oysters and late season crops like tomatoes. (PDF contains 16 pages)

Production primaire, secondaire et régéneration des sels nutritifs dans l'upwelling de Mauritanie

Primary and secondary productions and nutrient regeneration in the Mauritanian upwelling area were studied by following a drogue for 9 days, from the point of upwelling till the water mass dives under offshore waters. The lag between phytoplanktonic bloom, zooplanktonic peak and bacterial activity is very short and may be explained by a well-settled biological cycle connected with an undercurrent. Organic production was estimated in two ways: (1) from chlorophyll 'a' values, considering a C/Chla ratio of 25 during the 5.5 day phytoplankton growth period, primary production computed by this method reaches 13.5 g C/m2; (2) from 14C values net primary production calculated for the same period reaches 10.5 g C/m2 and total organic production (net production + organic excretion) reaches 19.5 g C/m2. Organic production computed ratios, delta O/ delta C/ delta N/ delta Si/ delta P are equal to 130/43/11/7.4/1. Secondary production and 'grazing' are estimated from mesozooplankton respiration values and have a huge increase during the bloom. Net secondary production is assessed to be 1.0-4.2 g C/m2 for 6 days. Evidence of nutrient regeneration as ammonia, phosphate and silicate is given and regeneration rates are calculated. Zooplankton excretion plays an important part in nitrogen and phosphorus regeneration. Bacterial activity is induced by zooplankton organic excretion, then increased by phytoplankton decomposition at the end of the bloom.

Extraction, purification and analysis of conotoxin of Conus textile captured from Persian Gulf and the investigation of analgesic effects of conotoxins in an animal model

Identification of venomous species of Persian Gulf cone snails and characterization of venom composition and their features is so important from the point of medical importance. Marine cone snails from the genus Conus are estimated to consist of up to 700 species. The venom of cone snails has yielded a rich source of novel neuroactive peptides or conotoxins. The present study was aimed to study the analgesic effect of Persian Gulf Conus textile and its comparison with morphine in mouse model. The specimens of Conus textile were collected of Larak Island from depth of 7 m. The collected samples were transferred to laboratory alive and were stored at -700 c. he veno s ducts were separated and ho ogenized with deionized water he ixture centrifuged at rp for inutes upernatant was considered as extracted veno and stored at - C after lyophylization. The protein profile of venom determined by using SDS-PAGE and HPLC used to investigate the extracted venom and to evaluate the analgesic activity, formalin test was carried out. SDS-PAGE indicated several bands ranged between 6 and 250 kDa. Chromatogram of the venom demonstrated more than 44 large and small fractions. The amount of 10 ng of Conus crude venom and analgesic peptide showed the best anti-pain activity in formalin test. No death observed up to 100 mg/kg, which is 250,000 times higher than the effective dose.Venom characterization of Persian Gulf Conus textile may be of medical importance and potential for new pharmaceutical drugs as well.

Comparative electrophoretic patterns of lactase dehydrogenase and malate dehydrogenase in five Lake Victoria cichlid species

Biochemical techniques designed to compare species on the basis of protein differences were started by NUTTALL (1904) who used immunological methods to compare the serum of humans with that of other primates. Since then more refined techniques have led to better results at the protein level in taxonomy, The analyses of proteins are considered to be the simplest indirect approach to understanding the structure and function of the genetic material, deoxyribonucleic acid (DNA). Interest in these analyses arises because of the close relationship between protein structure and gene structure. Thus by comparing the properties of homologous proteins from different taxa one is in essence comparins their genes (GORMAN er al., 1971). It is now an established fact that genetic information coded in molecules of DNA is translated through a series of reactions in the structure of proteins which form the principal morphological units of the animal body at the molecular level of organization (SIBLEY, 1952). A convenient method of comparing molecular differences between species is to measure the electrophoretic mobility of proteins in a starch gel medium (ASPINWALL and TSUYUKI, 1968) or acrylamide gel (RAYMOND and WEINTRAUB, 1959; BOUCK and BALL, 1968). Proteins with enzymatic properties can be compared on the basis of catalytic activity in the presence or absence of inhibitors (KAPLAN et al., 1959); BAILEY et al., t 1970). A combination of gel electrophoresis and histochemical enzyme detection techniques (HUNTER and MARKERT, 1957) makes it possible to combine electrophoretic mobility anti catalytic activity comparison, Enzyme patterns exhibited in starch gel or acrylamide gel have been used to classify different species. BOUCK and BALL (1968)working with lactate dehydrogenase in species of Trout found that each Trout species had LDH pattern characterbtic of that species. ASPINIWALL and TSUYUKI (1968) used muscle protein electrophoretic patterns to identify hybrid fishes. TSUYUKI and ROBERTS (1963) and TSUYUKI et al. (1964-65) found that myogen protein patterns in fishes were species specific. The myogen patterns within one family were remarkably parallel with the existing morphometric classification and these patterns constituted a single criterion by which the fishes could be identified. The fish used in these investigations were collected from shallow waters (10 metres) of Lake Victoria in two areas, Jinja and Kisumu, using gillnets and beach-seines. The study included ten specimens of each of the following specIes: (l) Haplochromis michaeli (2) Haploehromis obems (3) Astatoreochromis ulluaudi (4) Tilapia zillii and (5) Tilapia nilotica.