共查询到20条相似文献，搜索用时 32 毫秒
1.
The pharyngeal dental formula ofMylopharyngodon piceus is 4–5 as a rule, and the dentition is asymmetrical. It is difficult to identify each tooth in the larval dentition. In this
paper the appearance pattern of tooth germ with development process in this fish is described in detail. The formation pattern
of the left dentition is contrasted with that of the right one. In the developmental process, the left pharyngeal dentition
lacks teeth at position An3. Thus the left dentition is D-type as designated by Nakajima (1984), while the right one is A-type.
This project was funded by the International Cooperation of Japan-China and the National Natural Science Foundation of China. 相似文献
2.
乐佩琦 《中国海洋湖沼学报》1995,(3)
Adult pharyngeal teeth in Mylopharyngodon piceus are molariform. Based on SEM observations ofthe developing teeth, this paper describes the morphological diversification of pharyngeal teeth in M.piceus. The larval and juvenile teeth are changed from conical to adult molariform teeth through sevenstages. Comparisons are made between each stage and corresponding types in some species of differentsubfamilies in Cyprinidae. It is considered that the ontogenetic resemblances of the pharyngeal teehbear relationship to the phylogeny of cyprinids. 相似文献
3.
Sodium thiosulphate and neutron activation determination of iodine content in samples of 18Sargassum species collected in Guangdong and Guangxi Province in April 1996 showed large differences (0.47×10−3 inSargassum hemiphyllum, 0.56×10−3 inSargassum assimile, and 4.5×10−3 inSargassum vachellianum). Traditional titration analysis and neutron activation analysis for determination of total iodine yielded similar results
showing that certainSargassum species had high capacity to accumulate iodine.
Contribution No. 3162 from the Institute of Oceanology, Chinese Academy of Sciences.
The project was supported by the National Ninth Five-Year Plan of China (No. 96-916-04-01). 相似文献
4.
Analysis of cold tolerance on mangroveKandelia candel leaf growing in different soil salinity along Jiulong River Estuary in South China showed that the cold tolerance decreased
as the increase of soil salinity. The lethal temperatures ofK. candel leaf were −10.4, −9.9 and −8.6 °C in Liaodong, Baijiao and Aotou, respectively. Under 1–2°C cold stress treatment on detached
leaves ofK. candel, their caloric value gradually decreased, while electrolyte leakage gradually increased. The leaf's caloric value and electrolyte
leakage in Aotou with higher soil salinity varied more largely than those in Liaodong with lower soil salinity. InK. candel leaf, total water content lowered a little, bound water content rose significantly and free water content dropped significantly
with duration of cold stress. At the same time, reduction sugar, soluble sugar and starch content gradually decreased and
sucrose content gradually increased. Bound water, free water and sucrose content inK. candel leaf from Aotou with higher soil salinity changed more slowly than those from Liaodong with lower soil salinity, but reduction
sugar, soluble sugar and starch content inK. candel leaf from Aotou had faster variations than those from Liaodong. These data indicated that soil salinity can reduce cold tolerance
ofK. candel leaf by increasing negative effect of salt ions in cell membrane, inhibiting variations of water content, and aggravating
consumption of material and energy.
Supported by the Found for Outstanding Young Teacher, the Ministry of Education, China. 相似文献
5.
The meiotic process in Noctiluca scintillans were observed under light microscope.Some abnormal cell divisions, incompletely separated “zoospores” and the changes of the zoospores are described in this paper. Together with the fmdings of field samplings and the previous results by other researchers, the process of meiosis in N. scintillans was supposed to be a pathway to reduce the extra high density of NH3-N within the cell in order to ensure normal population growth. 相似文献
6.
Histological characteristics of gametogenesis of two kinds of scallops, gonochoric Chinese scallop, Chlamys farreri and hermaphroditic bay scallop, Argopecten irradians were investigated in this study. Spermatogenesis in C. farreri has different developmental stages: spermatogonia, primary spermatocyte, second spermatocyte, spermatid and spermatozoon. A large number of same developmental stage spermatic cells converge at a definite area of the testis. Premeiotic, previtellogenic and vitellogenic oocytes can be found during oogenesis in C. farreri, where oocyte distribution is obviously irregular. The A. irradians gonad consists of two different parts in one individual: one part functions as testis, the other as ovary. Between these two parts is a special appearance area, where a large number of spermatic cells are bound with two layers of acellular substance with many oocytes in it. 相似文献
7.
Yan Xinghong 《中国海洋湖沼学报》1993,11(3):235-244
Isolated protoplasts from thalli ofPorphyra haitanensis andPorphyra yezoensis were treated with colchicine or irradiated by ultraviolet (UV). Several types of color variants were observed among the protoplast
offspring. After treatment with colchicine: (1) 0.04–0.09% of red type variants inP. haitanensis were obtained; (2) The rate of red type variants and the variegated chimeral thalli composed of red type and wild type of
sectors were 0.31–1.11% inP. yezoensis. After irradiation with UV: (1) 3.5–10.5% of red type variants inP. yezoensis were obtained: (2) 0.5–2.0% of red type variants and the variegated chimeral thalli composed of red type and wild type of
sectors were obtained inP. haitanensis. Colchicine and UV’s mutangenic effects onP. yezoensis protoplasts were stronger than those onP. haitanensis protoplasts. The most efficient concentration of colchicine was 0.05%. The optimal length of UV-radiation was 1/2 min (radiation
distance 5 cm). The red type variants induced by colchicine treatment grew faster than the wild type thalli. The clones of
vegetative propagation from protoplasts of red type variants were still red type thalli. The red type variants will be good
materials for genetic studies and improvement ofPorphyra strains. 相似文献
8.
Porphyra haitanensis andP. yezoensis are two mainPorphyra species cultured in China. Their life histories are slightly different. So far we have not observed thatP. haitanensis naturally produces monospores developing into thalli.P. yezoensis produces monospores which directly germinate into young thalli used in cultivation (Zeng, et al., 1985). Some somatic cells
inP. yezoensis develop in vitro into monospore-like cells which later grow into young thalli (Lu, 1983). Studies on whether or not somatic
cells inP. haitanensis can produce in vitro monospore-like cells that later grow into young thalli is important for understanding its life history
and for culturing new varieties. 相似文献
9.
This study on the cytological changes of the body wall ,aspiratory intestine and crissal bursa in Urechis unicincuts by light microscope(LM) and transmission electron microscope(TEM) showed that the difference between the body wall and the natural environment rich in H2S was not obvious,that the wall color of the aspiratory intestine in H2S rich environment changed from normal semitransparency to dark brown.that its epithelia were disassembled and the electron density of its cytoplasm matrix was lower;and that in H2S rich environment many basoplhilic granules occurred in the epithelia of the crissal bursa.Granules with single membrane and myelinefingure were found with TEM. 相似文献
10.
11.
Zhu Xiaobin Xu Weihai Wang Xinting Huang Xinping Deng Liping Kang Xinglun Jiang Zhigang Ma Xuli 《中国海洋湖沼学报》2005,23(1):39-42
Heavy metals pollution in Jiaozhou Bay was studied inRuditapes. philippinarum, a bioindicator of seawater pollution. Heavy metals in soda industry wastes “white mud” were also studied. Comparison of
microwave digestion method with general digestion method revealed that microwave digestion is superior to general digestion
in precision, recovery, digestion speed and efficiency, etc. Cd concentration in HongdaoR. philippinarum samples exceeded the national standard by 0.046 mg/kg, that of Yinghai sample by 0.02 mg/kg, and that of Hongshiya sample
by 0.22 mg/kg. Sample Pb concentration in Hongshiya was found to exceed the national standard by 0.02 mg/kg. However the heavy
metals concentration inR. philippinarum near the Qingdao Alkaline Factory was complied with the standard. This was proved byPenaeus chinensis culture experiment. Therefore, the possible contamination source may come from other land areas.
This study is supported by Project 973 (NO.2002CB 412402), and key project of the Chinese Academy of Sciences (Grant NO.KJCX315W-215). 相似文献
12.
Jin Hai-zhu Guo Cheng-hua He Jun Wang Qing-hua Jiang Zhu-mao Sun Fu-zhang 《中国海洋湖沼学报》1998,16(4):364-368
The effect of Mg2+, NaCl and citric acid on the accumulation of β-carotene inDunaliella Salina was studied. The experimental results showed that 10.5 mmol/L Mg2+, 5 mol/L NaCl, 3 μmol/L citric acid, and CO2 are favorable forDunaliella Salina cell growth and β-carotene accumulation. After 144 h culture under the above conditions, theDunaliella Salina biomass increased by 7.18 times; β-carotene reached 9.61%.
Project 89023990 supported by the Shandong Natural Science Fund. 相似文献
13.
Isabella A. Abbott 《中国海洋湖沼学报》1995,13(4):343-347
A new species ofLiagora, L. perennis sp. nov. from Hawai’i, is described. Unlike species of this genus in China, it is carpotetrasporangial, and at the place
of expected carposporangia bears cruciately divided tetrasporangia, a detail which differentiates it from the usual species
ofLiagora without tetraspores that have been reported in China. Notes are provided on otherLiagora species that have an impact on the taxonomy of species found in China.
Dedicated to the memory of Zhang Junfu(C. F. Chang) whose studies on marine algae I respect highly, and whose good-humored
friendship I treasure. 相似文献
14.
Ranlnoides longifions new species, off SE coast of Hainan Island, dorsal surface of carapace with an arched granular edge across carapace between the anterolateral teeth, median frontal tooth longest, second frontal teeth subquadrate. 相似文献
15.
Liu Jing-ke 《中国海洋湖沼学报》1998,16(2):173-176
The requirement for dietary n−3 HUFA (highly unsaturated fatty acid) for growth and survival of black seabream (Sparus macrocephalus) larvae was tested usingArtemia with various levels of n−3 HUFA. Four treatments withArtemia differing in their n−3 HUFA were prepared by feeding them various oil emulsions.
The results indicated that dietary n−3 HUFA significantly influences fish n−3 HUFA levels and are necessary for good growth
and survival of black seabream larvae. The proper value of n−3 HUFA level and DHA, EPA level inArtemia should be 4.273% and 0.873% (wet weight) for good growth and survival in black seabream larvae respectively.
Contribution No. 3044 from the Institute of Oceanology, Chinese Academy of Sciences. Project 39470562 supported by NSFC. 相似文献
16.
Progress of limnology in China 总被引：1，自引：0，他引：1
The following six aspects in the utilization of lake resources and progress of limnological research in China are described:
1. Expeditions for comprehensive investigation of lakes; 2. Physical limnology; 3. lacustrine sedimentology and paleolimnology;
4. Hydrobiology and ecology; 5. Hydrochemistry and environmental protection; 6. Development and utilization of lake resources.
This paper was published in Chinese inScientia Limnologica Sinica
1 (1): 1–11, 1989. 相似文献
17.
Zhang Cheng Han Xiaotian Zou Jingzhong Yu Zhiming Song Xiuxian Christian Schuett 《中国海洋湖沼学报》2005,23(3):317-322
A fragment of a large sub-unit ribosomal DNA (LrDNA) of 12 strains ofProrocentrum species was amplified by polymerase chain reaction (PCR). The PCR products were digested by 3 restriction endonucleases (Cfo
I, Hae III, and RSA I) and then resolved in agarose gels. Results show that different species had different RFLP patterns,
except forP. arcuatum (ME 131), which had the same pattern toP. micans (ME160 and 04). The same fragment of 19 strains of the genus was also amplified and subjected to denaturing gradient gel
electrophoresis (DGGE). 11 different patterns were resolved. Different cultures of a same species had the same pattern. The
results of RFLP and DGGE analyses showed that eight newly isolated epibenthicProrocentrum species were different from each other, and also from other cultured ones examined in this study.P arcuatum (ME132) could not be differentiated fromP. micans (ME160 and 04), it was probably mis-identified, since they are quite different morphologically.P. redfieldii (ME138) could also not be distinguished formP. triestinium (ME132), it should be regarded as a synonym ofP. triestinium. Unexpectedly, a restriction site was found inP. micans, compared with previous sequence data.
Project supported by National Basic Research Priorities Program (2001CB409701, 2001CB409710) and supported by NSFC (40376040,
40025614) 相似文献
18.
Kojima Hiroyuki Song Qin Ajith Kumar Thankappan Kawata Yoshikazu Yano Shin-ichi 《中国海洋湖沼学报》1998,16(1):30-39
Transposable elements in cyanobacteria are briefly reviewed. Evidence is presented to show that transposable elements inSpirulina platensis is actually reflected on the phenotype change, i e., helical to straight filaments. Transposition intermediates of DNA were isolated from the extrachromosome and the transposition was related to helical variations inSpirulina. Uses of transposable elements for microalgal recombination are discussed based on the transposition mechanism.
相似文献19.
The morphology of larval and 1st postlarval stages ofPenaeus penicillatus are described. Results from comparative studies on larval development ofP. penicillatus, P. merguiensis andP. chinensis are as follows:
These three species could not be identified during their naupliar stages.
In the 1st protozoea, the antennule L1/L2 value is 1.7–2.0 inP. merguiensis, but less than 1.7 inP. chinensis andP. penicillatus; in the 2nd protozoea, the supra-orbital spine inP. chinensis is not bifurcated, while those ofP. merguiensis andP. penicillatus are bifurcated; in the 3rd protozoea, there is a minute (or no) dorso-median spine on the posterior margin of the 1st and
2nd abdominal somite inP. chinensis, but they are prominent inP. merguiensis andP. penicillatus. In the mysis and 1st postlarval stages,P. chinensis differs fromP. merguiensis andP. penicillatus in having 9 (8 in the other 2 species) long setae on the exopod of pereopods 1–3; additionally, one dorsal tooth appears
on the rostrum ofP. chinensis in the 2nd mysis and that of the other 2 species in the 3rd mysis;P. chinensis has 2 (mostly) or 1 dorsal tooth on the rostrum in the 3rd mysis and 2–3 in the 1st postlarva, whileP. penicillatus andP. merguiensis have only 1 in the 3rd mysis and 1st postlarva. Comparative studies on larval development showedP. penicillatus has closer affinity withP. merguiensis than withP. chinensis.
Contribution No. 2218 from the Institute of Oceanology, Chinese Academy of Sciences 相似文献
20.
Two new species of the genus Tinocladia Kylin, T. gracilis sp. nov. and T. microsporangii sp. nov,, are described. T. gracilis is characterized by its slender frond, variable size, infrequently branched medullary filaments, and short assimilating filaments with 2 - 7 cells. T. microsporangii is characterized by its medullary cells which are slightly larger than sub-cortical ones; narrow sub-cortical layer, usually consisting of 4- 6 cells and very small unilocular sporangia. The holotypes are deposited at the Herbarium of the Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China. 相似文献