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901.
902.
Mizuho Sakai Sei-Ichi Okumura Kanami Onuma Hiroaki Senbokuya Kunio Yamamori 《Fisheries Science》2007,73(1):77-80
The telomere sequence type (TTAGGG)n is known to be distributed in various phyla in the Animalia and in Mastigophora (Protista). However, the telomere type of
Porifera (sponges), a phylum comprising the lowest multicellular animals, has not been reported. In this study, we examined
the three sponge species Leucetta chagosensis, Halichondria japonica, and Halichondria panicea for the presence of the telomere type (TTAGGG)n by fluorescence in situ hybridization (FISH). The oligonucleotide probe (TTAGGG)7 clearly displayed signals on the interphase nuclei of all three sponges. In contrast, the (TTAGG)7 probe, which has one base fewer than (TTAGGG)7, did not display the signals. These results suggest that the telomeres of the three sponges consist of (TTAGGG)n, which is identical to the sequence type found in many higher multicellular animals and in Mastigophora. Additionally, this
is the first study to reveal a telomere sequence type for Porifera. Moreover, these results suggest that Porifera are phylogenetically
related to Mastigophora, and supports the general theory that Porifera evolved from Mastigophora. Further, this study strongly
suggests that the origin of the (TTAGGG)n telomere sequence is to be found in a common ancestor of either the Bilateria and Porifera, or the Protista. 相似文献
903.
This study was carried out to investigate the influences of feeding frequency of extruded pellet and moist pellet on growth
and body composition of juvenile flounder (initial mean weight 6.3 g) in sub optimal water temperatures. A 2 (diets: extruded
pellet and moist pellet)×2 (feeding frequencies: two and three times daily)×2 (water temperatures: 12 and 17°C) factorial
design with three replications was used. After 60 days of feeding, the feeding frequency did not significantly affect growth
performance of fish. Weight gain, daily feed intake, feed efficiency and protein efficiency ratio were significantly (P<0.05) higher for fish reared at the higher water temperature. At the same water temperature, weight gain, feed efficiency,
and protein efficiency ratio were significantly (P<0.05) higher for fish fed the extruded pellet than moist pellet. The results of this study indicate that feeding frequency
of two times daily is sufficient for optimal growth of juvenile flounder when reared in suboptimal water temperatures, and
an increase in water temperature from 12 to 17°C improved growth and feed efficiency. 相似文献
904.
ABSTRACT: High- and multi-frequency acoustic measurement systems and the multi-frequency inversion (MFI) method have been used to measure spatial distributions and abundances of zooplankton by size. In this study, the calibration method for high- and multi-frequency systems was developed and the validation of MFI method was carried out by scatterer measurement. The standard sphere calibration method that has not been applied to such high- and multi-frequencies was applied to calibrate our high- and multi-frequency system, TAPS-6 (Tracor Acoustic Profiling System, BAE Systems). An optimum size of standard sphere of tungsten carbide of 1 mm radius was derived to have a small target strength variation for the six frequencies of TAPS-6, and the practicability and precision of the standard sphere calibration method was confirmed for those frequencies. A school or cluster of dummy scatterers of zooplankton with small tungsten carbide spheres were designed to validate the MFI method, and volume back-scattering strength values were measured by the multi-frequency system. By comparing the result of the inversion with their real composition, the features of the MFI method could be validated and examined. 相似文献
905.
Toshihiro Onitsuka Tomohiko Kawamura Satoshi Ohashi Toyomitsu Horii Yoshiro Watanabe 《Fisheries Science》2007,73(2):295-302
ABSTRACT: The feeding behavior and growth of post-larval Haliotis diversicolor with initial shell lengths (SL) of approximately 500 μm (Exp. 1-1 and 1-2), 800 μm (Exp. 2), and 1200 μm (Exp. 3) were studied in a laboratory setting while they fed on four species of benthic diatom Achnanthes longipes , Cocconeis sublittoralis , Cylindrotheca closterium , and Navicula ramosissima . Exp. 1-1 and 1-2 revealed no marked differences in post-larval growth rates (mean 24–39 μm SL/day) among the diatom species. However, marked differences in growth rates among the species were revealed in Exp. 2 and 3. Three species, A. longipes , Co. sublittoralis, and Cy. closterium , produced faster growth (Exp. 2 mean 29–51 μm/day, Exp. 3 mean 36–44 μm/day) than N. ramosissima (Exp. 2 mean 18 μm/day, Exp. 3 mean 23 μm/day). Post-larvae fed N. ramosissima had lower digestion efficiency (42.8%) than those fed other diatom species (90.7–100%). Diatom extracellular substances appeared to be principally used from post-settlement to 800 μm SL, and diatom cell contents were required to produce rapid growth of larger post-larvae (>800 μm SL). It is likely that the availability of each diatom for post-larvae was affected by diatom morphology, attachment strength, frustule strength, and post-larval size. 相似文献
906.
907.
908.
Vishwanath Patil Torsten Källqvist Elisabeth Olsen Gjermund Vogt Hans R. Gislerød 《Aquaculture International》2007,15(1):1-9
Twelve algal strains representing the classes Cyanophyceae, Prymnesiophyceae, Bacillariophyceae, Rhodophyceae, Cryptophyceae,
Chlorophyceae, Xantophyceae and Eustigmatophyceae were selected mainly from the culture collection of the Norwegian Institute
for Water Research (NIVA). The algae were grown as continuous cultures in a 1.8 l. reactor, internally illuminated with an
11 W fluorescent tube. The retention time was adjusted in the range 2–4 days to fit the growth rate of the algae. The growth
responses and fatty acid composition were analysed. The maximum production rate was obtained with Pseudokirchneriella subcapitata (0.63 g 1−1 day−1) and the lowest with Porphyridium cruentum 0.13 g 1−1 day−1. Arachidonic acid (AA) and eicosapentaenoic acid (EPA) were the dominating polyunsaturated fatty acids (PUFAs) in P. cruentum, while only EPA accumulated in Phaeodactylum tricornutum. Docosahexaenoic acid (DHA) was the major PUFA in Isochrysis galbana, while Pavlova sp. had both EPA and DHA. This is the first report on the fatty acid profiles of Nannochloropsis oceanica, Chroococcus sp., Synechococcus sp. and Tribonema sp. 相似文献
909.
Classifications of fish production methods, wild or farm-raised salmon, by elemental profiles or C and N stable isotope ratios combined with various modeling approaches were determined. Elemental analysis (As, Ba, Be, Ca, Co, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, Sr, Ti, and Zn) of wild and farm-raised salmon samples was performed using an inductively coupled plasma atomic emission spectroscopy. Isotopic and compositional analyses of carbon and nitrogen were performed using mass spectrometry as an alternative fingerprinting technique. Each salmon (king salmon, Oncorhynchus tshawytscha ; coho salmon, Oncorhynchus kisutch ; Atlantic salmon, Salmo salar ) was analyzed from two food production practices, wild and farm raised. Principal component analysis (PCA) and canonical discriminant analysis (CDA) were used for data exploration and visualization. Five classification modeling approaches were investigated: linear discriminate function, quadratic discriminant function, neural network, probabilistic neural network, and neural network bagging. Methods for evaluating model reliability included four strategies: resubstitution, cross-validation, and two very different test set scenarios. Generally speaking, the models performed well, with the percentage of samples classified correctly depending on the particular choice of model and evaluation method used. 相似文献
910.
Kim HJ Suh HJ Kim JH Park S Joo YC Kim JS 《Journal of agricultural and food chemistry》2010,58(22):11633-11638
The extract of soybean exposed to biotic elicitors such as food-grade fungus is known to have antioxidant activity. Glyceollins were major bioactive compounds present in soybean elicited by fungi and shown to have antifungal and anticancer activities. The purpose of present study was to evaluate the antioxidant activities of glyceollins by measuring ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, singlet oxygen quenching, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, hydroxyl radical scavenging activity, and lipid peroxidation inhibition. In addition, the antioxidant potential of glyceollins were measured by a fluorescent probe, 2',7'-dichlorofluorescin diacetate (DCFDA), and dihydroethidium (DHE) in mouse hepatoma hepa1c1c7 cells in which they were insulted with H2O2 to generate reactive oxygen species (ROS). Glyceollins showed a strong reducing power and inhibited lipid peroxidation, with significant scavenging activities of radicals including singlet oxygen, superoxide anion, ABTS, and DPPH. We also found that glyceollins significantly suppressed H2O2-induced ROS production in hepa1c1c7 cells. Therefore, glyceollins deserve further study as natural antioxidants and nutraceuticals. 相似文献