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Tomohiro Takeyama Naoko Namizaki Masanori Kohda 《Behavioral ecology and sociobiology》2013,67(3):421-428
Theoretical models predict that increased mate availability accelerates filial cannibalism by the parental male, but we do not yet fully understand how the various aspects of mate availability contribute to this effect. We examined the effects of two elements of mate availability—female fecundity and sex ratio—on filial cannibalism by the lizard goby, Rhinogobius flumineus, which is a paternal nest brooding fish. We used three types of females (stimulus-females): a single female with slim belly (not ready to spawn), a single gravid female (ready to spawn), and two gravid females. Stimulus-females were housed in a transparent cage and shown to subject males just before and after spawning with a separate female, after which males cared for the brood. A single gravid stimulus-female accelerated filial cannibalism, compared with a control-stimulus consisting of an empty cage, but only during the early care period. In contrast, a single slim-bellied stimulus-female did not accelerate cannibalism. A stimulus of two gravid females accelerated cannibalism to the same degree as a single gravid female stimulus. Our results suggest that in lizard gobies, filial cannibalism by parental males is accelerated by female quality (fecundity) in the early care period, but not by a higher number of available females (sex ratio). 相似文献
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Cadmium, 100 μg/rat/day, was administered orally 100 times (total amount of Cd administered, 10 mg), under conditions of low protein intake. The total amount of Cd in the liver and kidneys was as follows: females fed 20% protein diets > females fed 5% protein diets > males fed 20% protein diets ≒ males fed 5% protein diets. A decreased Zn concentration was found in the liver of males and the pancreas of males and females fed with the 5% protein diet. The Cu concentration in the kidneys was markedly influenced by low protein intake. 相似文献
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Youssouf Boundou Sylla Masao Kuroda Masayuki Yamada Naoko Matsumoto 《Waste management & research》2006,24(5):456-464
Pilot-scale composting was carried out with cow manure to evaluate the performances of two passive aeration systems: a conventional passive aeration system equipped with horizontal pipes and an unusual passive aeration method based on air delivery by means of vertical pipes. The effects of both types of passive aeration apparatus were investigated in order to determine the degree of composting rate by continuously monitoring temperature, moisture content, organic matter, electrical conductivity, pH and C/N ratio in the piles. Temperatures in the range of thermophily (55-65 degrees C) were reached in all runs within 1-2 days then lasting for about 1 week, a span long enough for pathogen abatement. Results suggest that passive aeration carried out by vertical pipes is more effective for air delivery into compost piles than conventional passive aeration of air adduction with horizontal pipes. The variation in the number of vertical pipes was revealed to be an important parameter for the control of composting rate and temperature. Composting rates estimated from the heat balance equation were substantially in agreement with those computed through the conversion ratio of total organic matter decrement. The conversion ratios and composting rates obtained in this study using passive aeration with vertical pipes were well aligned with those found using forced air delivery systems. 相似文献
4.
Web spiders are considered to have expanded their habitats from dim to bright environments during the evolutionary history.
Because they are sedentary predators exposed to the sun, they may have developed a suite of adaptive traits to cope with thermal
stress. We examined the critical thermal maximum, spectral reflectance of solar energy by the body surface, and surface–volume
ratio (SVR) for 11 spider species. Analysis of the four genera having a pair of species inhabiting both bright and dim environments
showed that species in bright environments exhibited higher lethal temperatures, but spectral reflectance and SVR did not
differ. Independent contrasts using the 11 species indicated that critical thermal maximum was positively correlated with
spectral reflectance and spectral reflectance was negatively correlated with SVR. These results suggest that physiological
tolerance to high temperatures and a biophysical mechanism to reduce heat gain evolved jointly during the history of habitat
expansion in araneoid spiders. 相似文献
5.
The objective of this study was to investigate the reproductive success (fertility and fecundity) of medaka (Oryzias latipes) exposed to 4-nonylphenol (4-NP) in water and the viability of their F(1) offspring. In addition, we measured the bioconcentration of 4-NP in eggs. After a 21-d exposure to 100microg/l 4-NP, medaka showed reduced egg production and fertility. Hepatic vitellogenin levels were increased significantly in males treated with 10, 50 and 100microg/l of 4-NP. In the F(1) generations, the hatchability and time to hatching of embryos in the 100microg/l treatment group were adversely affected, and 2-7microg 4-NP/g egg was found in spawned eggs (the bioconcentration factor: 30-100). These results indicate that (1) 4-NP adversely affected the reproduction (fecundity and fertility) of adult medaka, (2) 4-NP accumulated in eggs through maternal transfer and (3) these levels of 4-NP were associated with adverse effects in the F(1) offspring. 相似文献
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Saki Harii Naoko Yasuda Mauricio Rodriguez-Lanetty Takahiro Irie Michio Hidaka 《Marine Biology》2009,156(6):1203-1212
The establishment of symbiosis in early developmental stages is important for reef-building corals because of the need for
photosynthetically derived nutrition. Corals spawn eggs and sperm, or brood planula larvae and shed them into the water. Some
coral eggs or planulae directly inherit symbiotic dinoflagellates (Symbiodinium spp.) from their parents, while others acquire them at each generation. In most species examined to date, the larvae without
dinoflagellates (aposymbiotic larvae) can acquire symbionts during the larval stage, but little is known regarding the timing
and detailed process of the onset of symbiosis. We examined larval uptake of symbiotic dinoflagellates in nine species of
scleractinian corals, the onset of symbiosis through the early larval stages, and the distribution pattern of symbionts within
the larval host, while living and with histology, of two acroporid corals under laboratory conditions. The larvae acquired
symbiotic dinoflagellates during the planktonic phase in all corals examined which included Acropora digitifera, A. florida, A. intermedia, A. tenuis, Isopora
palifera, Favia pallida, F. lizardensis, Pseudosiderastrea tayamai, and Ctenactis echinata. The larvae of A. digitifera and A. tenuis first acquired symbionts 6 and 5 days after fertilization, respectively. In A. digitifera larvae, this coincided with the formation of an oral pore and coelenteron. The number of symbiotic dinoflagellates increased
over the experimental periods in both species. To test the hypothesis that nutrients promotes symbiotic uptake, the number
of incorporated dinoflagellates was compared in the presence and absence of homogenized Artemia sp. A likelihood ratio test assuming a log-linear model indicated that Artemia sp. had a significantly positive effect on symbiont acquisition. These results suggest that the acquisition of symbiotic
dinoflagellates during larval stages is in common with many coral species, and that the development of both a mouth and coelenteron
play important roles in symbiont acquisition. 相似文献
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Seiichi Ishikawa Naoko Ueda Yuji Okumura Yoshikazu Iida Kenzo Baba 《Journal of Material Cycles and Waste Management》2007,9(2):167-172
Spent coagulant in water supply plant sludge was extracted with H2SO4 and the efficiency of the reused coagulant was studied. The optimum pH values for coagulant extraction and clarification
with the reused coagulant were 3.0–4.0 and about 6, respectively. In treating raw influent obtained from a sewage treatment
plant and wastewater from a coastal landfill site, the removal of chemical oxygen demand (COD), total nitrogen, and total
phosphorous with the recovered coagulant was higher than that with commercial aluminum sulfate or polyaluminum chloride. In
addition, the sludge settling properties, the extra sludge mass formation, the supernatant quality, and the cost of reagents
were also studied. The coagulant recovered from water supply plant sludge by H2SO4 extraction could be successfully reused for the clarification of domestic and food industry wastewaters. 相似文献
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