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2005年  第26卷  第6期

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研究论文
Since the distribution patterns of amphibians are largely determined by the existence of water, we divided the Yangtze River Basin into 18 sub-basins according to the main tributaries. Based on the sub-basins, we synthesized information on amphibian biodiversity in the Yangtze River Basin. We documented 145 species that had been recorded and described from the basin. There are 2 orders, 10 families and 30 genera. Of these, 49 and 69 species are endemic and threatened, respectively. Except two sub-basins at the highest elevation in the basin, the headwater, and the upper and middle of Jinshajiang sub-basin, the other 16 sub-basins show a decreasing tendency in species richness and threatened species richness from the headwater to the estuary. Moreover, the proportion of endemic species decreased gradually from the headwater to the estuary of the basin with a gradient of the elevation. By calculating the G-F diversity index of the 18 sub-basins, the G index was found to reflect the species richness, and F index and G-F index showed similar values among the sub-basins except for three sub-basins of the headwater, Hanjiang and Ganjiang. Based on the species distribution (Jaccard similarity), cluster analysis was used to analyze the similarity of amphibians in 18 sub-basins. The sub-basins were clustered into six groups: (1) the headwater, (2) Hengduanshan Ranges, (3) Yun-Gui Plateau, (4) Eastern West Sichuan Plateau, Sichuan Basin, and Qinling-Dabashan Mountains, (5) Dongting Lake and its tributaries, Poyang Lake and lower reaches of the basin, and (6) Ganjiang sub-basin. The grouping result reflects to the environmental characteristics of the total basin and three large topographic platforms of the Chinese mainland.
The selection of feeding habitats of blue sheep (Pseudois nayaur) was studied by the direct observation method in Helan Mountain during winter (from November to December) and spring (from April to June) from 2003 to 2004. We established 25 line transects to collect information on feeding habitats used by blue sheep. Blue sheep in the study area preferred montane savanna forests, habitat dominated by Ulmus glaucescens, medium tree density (<4 individuals/100 m2), moderate tree height (4-6 m), higher shrub density (>5 individuals/100 m2), taller shrub (>1.3 m), higher food abundance (>50 g), moderate distance to human disturbance (<500 m), short distance to bare rock (<2 m). Such characteristic habitats with 12 ecological factors were preferred as feeding areas by blue sheep during winter. Similarly, blue sheep showed a preference for montane savanna, trees dominated by Ulmus glaucescens, and medium tree density (<4 individuals/100 m2) during spring. Nevertheless, blue sheep preferred medium tree height (<6 m), moderate tree density (5-10 individuals/100 m2), medium shrub height (1.3-1.7 m), higher food abundance (>100 g), moderate altitude (<2 000 m), moderate distance to water resource (<500 m), medium hiding cover (50-75%) during spring. Selection of feeding habitat by sheep showed a significant difference in vegetation type, landform feature, dominant tree, tree height, shrub density, distance to the nearest shrub, food abundance, slope direction, slope angle, distance to water resource, and hiding cover between winter and spring. Results of principal components analysis indicated that the first principal component accounted for 24.493% of the total variance among feeding habitat variance during winter, with higher loadings for vegetation type, dominant tree, tree height, distance to the nearest to tree, shrub density, shrub height, altitude, distance to water resource, and distance to human disturbance. In spring, the first principal components explained 28.777% of the variance, with higher loadings for vegetation type, distance to nearest tree, shrub height, distance to the nearest shrub, food abundance, altitude, and distance to human disturbance. In the northern temperate region, the quantity and quality of forage species have experienced great changes between winter and spring; hence the strategy of feeding habitats used by blue sheep varied with the season. Compared with the sheep of other distribution area, different selection of feeding habitat by sheep resulted from special geographical location and unique habitat of Helan Mountain.
In this paper we analyze the calls of four penguin species (Aptenodytes patagonica, Eudyptes chrysolophus, Pygoscelis papua, P. antarctica) recorded in the Antarctic. We analyze the sonogram and power spectrum of the calls and make a comparison among different species in call duration, maximum frequency, minimum frequency and peak frequency. When comparing the temporal and spectral characteristics of their calls we found out that these four species have obvious interspecific variation in the call structure, making it possible for different species to distinguish each other by vocalization. Our results also indicate that the structure of the calls of Aptenodytes patagonica — a non-nesting species, is more complex than that of the other three nesting species.
Using microsatellite markers we determined polymorphism of genomic DNA and classification in four important cultivation species: Common carp (Cyprinus carpio haematopterus Temminck et Schlegel), Scatter scaled mirror carp (C. carpio), Frigid-resistant strain of Purse red carp (C. carpio var. wuyuanensis) and Songpu carp (C. carpio Songpu carp). Amplifications with 24 pairs of primers gave a total of 3 882 fragments ranging from 126 bp to 489 bp in the 4 populations, which included 12 pairs of microsatellites designed according to zebrafish function gene sequences and 12 pairs of microsatellites isolated from common carp. 1-5 alleles per locus in 4 species were amplified, and there were 59 alleles in all populations except common carp which had only 21 loci and 55 alleles. The average number of alleles was 2.46. Additionally, a clustering analysis was made based on the results of the PHYLIP software package (version 3.6) and phylogenetic trees were constructed by MEGA3. The bootstrap values were evaluated for each crunode of the dendrogram by means of 1 000 reiterations of the bootstrap test using the Maximum Likelihood method, the Neighbor-Joining method and the UPGMA method. With these methods we made three observations. (1) the level of genetic variability is relatively high in all populations. Observing value of mean heterozygosity varies from 36.43% to 43.79% and expected value of mean heterozygosity varies from 49.49% to 53.29%. All populations show significant heterozygote deficiencies. (2) The genetic similarity indexes are all above 0.84, indicating closeness of their genetic relationship. The genetic distances are small, ranging from 0.067-0.170. The phylogenetic tree shows that Songpu carp and Scatter scaled mirror carp are the nearest in relationship and Frigid-resistant strain of Purse red carp is better correlated with them than the Common carp. (3) There is no aim fragment amplified in 3 loci of zebrafish function gene microsatellites in the population of common carp, which may mean that the flanking sequence of the microsatellites have changed while the PCR primers were designed according to them or the genomes of common carp have lost these function genes or loci. More research is needed to explore the physiological mechanism and biochemical process. In conclusion, these 24 microsatellite markers can be used for the evaluation of genetic diversity in carps. Three microsatellite markers reveal polymorphism between the common carp and the other three carps, and can be used to distinguish them.
The effects of powders from dry flower buds of Eugenia aromatica Baill., seeds of Piper guineense Schum and Thonn and fruits of Capsicum frutescens L. on adult behaviour, mortality and reproductive fitness of the cowpea seed beetle, Callosobruchus maculatus (Fab.) were investigated under ambient laboratory conditions. All experiments were carried out in glass Petri plates. All powders elicited aversion in adult beetles. The contact toxicity symptoms included restlessness, loss of coordination, knock down and eventual death of adult beetles. These behaviours were more pronounced with E. aromatica in which adult beetles died within 16 hours. P. guineense and C. frutescens powders did not cause 100% mortality of adult beetles, even after 24 hours. Each of the three powders significantly (P<0.05) reduced the mating competition of adult males after sub-lethal exposure for one, two, and three hours, respectively. E. aromatica powder caused more reduction in male mating competition for females than any of the other two powders after each period of exposure. Receptiveness of treated females to courting males was also decreased by exposure to any of the three powders. Similarly, E. aromatica powder caused greater decreases in female receptiveness to males than any of the other two powders after each period of exposure. Exposure of either adult male or female C. maculatus to the powders for sub-lethal times of three, six and nine hours significantly reduced the fecundity of the beetles. E. aromatica powder caused the most reduction of eggs laid and also significantly reduced fertility of the eggs.
Impacts of simulated atmospheric nitrogen (N) deposition on soil fauna biomass were studied in a 16 month period from May 2003 to August 2004. Plots were built in pine forest (PF), pine and broad-leaf mixed forest (MF) and monsoon evergreen broad-leaf forest (MEBF) in Dinghushan of subtropical China. Dissolved NH4NO3 equivalent to the control (No addition), low [50 kg/(hm2·a)], and medium [100 kg/(hm2·a)] was sprayed during the testing period. The biomass of soil fauna group was decided by an experimental standard based on research performed a long time in this area. When the data was averaged throughout the period and across the forests, there were no significant effects of N treatment on soil fauna biomass. However, effects could be observed in the interactions between N and forest type, and the interactions between N and sampling date. There were obviously positive effects of N treatment on soil fauna biomass in PF, but negative effects under abundant N deposition in MEBF. After one year the distribution of soil fauna biomass in different forests was changed significantly, with MEBF>MF>PF before the treatments and PF>MEBF>MF after the treatments. Low N treatment was positive to soil fauna biomass to a certain extent, which increased soil fauna biomass by 44.33% in MEBF, 9.19% in MF and 60.66% in PF; but soil fauna biomass declined generally under the medium treatment, 32.55% in MEBF and 2.81% in MF. The results indicated that there might be a threshold in the effects of N deposition on soil fauna biomass.
Previously, we have purified Jerdonitin from Trimeresurus jerdonii venom. Compared with other P-Ⅱ class snake venom metalloproteinases (SVMPs), Jerdonitin has a primary structure comprising metalloproteinase and disintegrin domains. However, no hemorrhagic and fibrinogenolytic activities were detected for Jerdonitin. We thought that organic buffer of high performance liquid charamatography (HPLC) might affect its enzymatic activity. In this study, we purified Jerdonitin by another procedure excluding the HPLC. It was homogenous as judged by SDS-PAGE and had an apparent molecular weight of 36 kDa under non-reducing conditions and 38 kDa under reducing conditions, respectively. Like other typical metalloproteinases, Jerdonitin preferentially degraded alpha-chain of human fibrinogen and this fibrinogenolytic activity was completely inhibited by EDTA, but not by PMSF. It was interesting that Jerdonitin did not induce hemorrhage after intradermal injection in mice.
Frog albumin (XpA-serum) was purified from serum of Xenopus laevis by a combination of gel filtration and ion exchange chromatography steps. Like Bombina maxima albumin, XpA-serum exhibited trypsin inhibitory activity, which was lower than that of B. maxima albumin. XpA-serum at the concentration of 180 nM inhibited 84% activity of trypsin (30 nM). The equilibrium dissociation constants (KD) is 1.44×10-6 M as determined by Surface Plasmon Resonance. Western blot analysis revealed that XpA-serum was also distributed in the skin. It is deduced that serum albumin of amphibian possessing trypsin inhibitory activity can function directly or indirectly as a defensive substance against predators.
Embryo transfer has potential to increase rates of genetic improvement in domestic farm animals. However, numerous factors may contribute to the efficiency of embryo transfer. We applied 6.5-7.5 d embryos to study factors that may affect the pregnancy rates and development of the Dorper sheep. In the present study, totally 236 embryos were transferred to different recipients in spring and fall. The results showed that the pregnancy rates transferred in fall were significantly higher than that in spring, the birth weights of the kids were not different between spring and fall, but 30 d and 60 d weights from spring were heavier than fall. As far as the recipients, there was no significant difference among the three breeds, in which the pregnancy rates of Zhaotong sheep were the highest, and Hu sheep were better than the small-fat-tailed sheep. The birth and 30 d weights of the kids from big recipients (≥40 kg) were heavier than that from small ones (<40 kg), but there was no significant difference from 60 d kids weights. This indicated that the birth weight of the kids related to the recipients weight, but there was no difference between the developments of the kids. Dorper sheep born in the early autumn, which were transferred in spring, developed much better (P<0.05) than those born in the early spring, which were transferred in fall.
Glyptosternoid fishes are a group of sisorid catfishes living in torrents of rivers mainly originating from the Qinghai-Tibet Plateau. Based on our survey in the Drung River Basin, seven collecting sites were investigated and 271 glyptosternoid fishes caught belong to three species (Pareuchiloglanis kamengensis, Exostoma labiatum and Oreoglanis macropterus). Features of the distribution of the three catfishes were assessed. More individuals of E. labiatum were caught in the lower reaches of the Drung River with fast water velocity and it might be more adapted to a torrent habitat. The relationships between standard length (L) and weight (W) for P. kamengensis, E. labiatum and O. macropterus were also studied, and the parameter b of the L-W relationship (W=aLb) ranged between 2.8201 and 3.0131. From the present study, all the three catfish species grow allometrically and the growth type of E. labiatum is the closest to a symmetrical one.
The nuptial pad microstructures of Rana chensinensis in the Qinling Mountain China were observed by light microscopy during the annual reproductive cycle; meanwhile, testosterone (T) and androgen receptor (AR) localization were examined by immunocytochemistry in the nuptial pad. The results indicated that the formation of nuptial spines was caused by multiplication of germinal cells, granular cells, and volume expansion of granular cells. The regression of nuptial spines was caused by desquamation of granular cell globules, which wrapped by a layer of horny cells and detaching from epidermis surface. The development of nuptial glands synchronized with nuptial spines morphogenesis. Secretory activity of the nuptial glands was active during courtship. The distribution of T and AR in germinal cells, granular cells and nuptial glands showed a good agreement with aspection of microstructures in nuptial pad. These indicated that the formation and regression of nuptial pad were regulated by T. Seasonal variation in the development of nuptial pad were associated with testis somatic index and spermatogenesis progress. It suggested that pad morphological characters reflected indirectly the development condition of testis.
The isolation of Rhinolophus affinis from Guangdong and Hainan near the Qiongzhou Strait, and the differences in climate and landscape between the South of China and Sichuan Province, prompted our study of morphological divergence. We obtained data on 23 external characteristics and 22 skull characteristics, and the data of 12 external characteristics and 22 skull characteristics was analyzed with SPSS12.0. Principal components and discriminant analyses revealed there were distinct differences both in the external morphological measurements and in the skull measurements among Rhinolophus affinis in Sichuan, Guangdong and Hainan Province. These data suggest that there are three subspecies of Rhinolophus affinis, I.e, R. a. himalayanus Anderson, 1905, R. a. macrurus Anderson, 1905 and R. a. hainanus J Allen, 1906.
A library rich in CA/GT microsatellites was constructed from the Paralichthys olivaceus genome by combining biotin capture method and radioactive labeling hybridization. Five hundred and twenty six positive clones were obtained through twice screens. Sequencing confirmed 133 microsatellite loci (number of repeats≥5) in 119 positive clones. Of these microsatellites, two (1.5%) had compound repeat motifs, 63 (47.37%) had perfect motifs and 68 (51.13%) had imperfect motifs. Primer pairs were designed in the flanking regions of 22 microsatelites and subjected to PCR amplification. In 8 artificial gynogenesis families, four pairs failed to amplification, one pair was monomorphic, and the rest were polymorphic with an average of 5.2 alleles per locus. Heterozygosities ranged between 0.375 and 0.846, PIC ranged between 0.305 and 0.823. The results suggested that most of the microsatellites we isolated were qualified to be applied to the population genetic studies of P. olivaceus.
Platform Transmitter Terminals (PTTs) were fitted onto four Black-necked Cranes (Grus nigricollis) at Dashanbao National Nature Reserve in Northeast Yunnan in the spring of 2005. Two of the four birds completed the whole migration, while the other two lost their signals on the half way. Of the two birds that completed their migration, they started to migrate on 4th and 6th of April respectively and arrived at the breeding ground Ruoergai Marsh within 3-4 days, traveling 700-740 km, and stopping at 4 counties in Sichuan Province.
The reproductive ecology of birds is important in the study of life history evolution centers. We briefly review progress in the reproductive ecology of alpine meadow passerines on the Qinghai-Tibetan plateau, to which we add the published results of our recent study. The current studies includes nest architecture, nest-site selection, the evolution of clutch size, nestling growth, parental care, breeding productivity, and breeding strategy etc. Based on these observations, we hypothesised that (1) the length of the breeding season, food resources and predation are critical for the evolution of passerine reproductive patterns in alpine meadows; (2) that alpine meadow passerines used single-investment and accumulative-investment strategies; (3) that the typical clutch size was actually the most efficient for reproductive purposes; (4) and that the transition from neonate to fledgling passerines is a relatively fixed process as compensatory growth does not appear to occur; (5) and that growth period is volatile. In future studies we propose: (1) to study the evolution and stability of parent-offspring communications, and to determine if the parent-offspring communication is the result of evolutionary trade-offs between visual and vocal signals; (2) to establish a life history table under the gradient of nest habitat; (3) to determine the ecological field under the gradient of nest habitat (from open to closed). Finally, we will try to obtain the transformation table of parent-offspring communication under the gradient of nest habitat and test the trade-offs between visual and vocal signals. Those results will provide more information on diversity, adaptive strategies and of life history of alpine meadow avians, and predict reproduction and life history of birds in response to global changes.
Amphioxus, as the closest living animal of the last common ancestor of all vertebrates, occupies an extremely important phylogenetic position in the evolution of vertebrates and has attracted the interest of scientists from various research fields in recent years. However, despite their importance for the life sciences, taxonomic studies of amphioxus are relatively limited. In present review, we summarize current progress in both field investigations and taxonomic research of Chinese amphioxus. Based on the investigation data, we assume that amphioxus is distributed in all habitable sandy beaches along the Chinese coast from south to north. According to the rule of priority and recent taxonomic studies on amphioxus, we also propose that the original subspecies Brnachiostoma belcheri tsingtauense together with the population in most Japanese waters is an independent species and its name should be revised to B. japonicus. Consequently, there are at least two species of genus Brnachiostoma and 1-3 of Epigonichthys and one of Amphioxides in the China Sea. Finally, the application of DNA molecular markers in systematic studies of cephalochordate is evaluated.
Eight genera and twenty-three species of glyptosternoid fish (Sisoridae) have been recorded in China. However, there is some dispute about the taxonomic status and validity of some species distributed in Lancangjiang and Nujiang of Yunnan province, and some species of genera Pareuchiloglanis and Euchiloglanis in southwest area of Sichuan province. Molecular biology and microscopic techniques have been only partically helpful in resolving the dispute of species status and for the study of phylogeny. Even results obtained by the same author using morphology and molecular biology in different years have yielded conflicting results. Therefore, we have reexamined the taxonomic status and validity of certain species of glyptosternoid fish. The distribution pattern of glyptosternoid fish and differentiation of genera and species are closely related to the three uplifts of the Qinghai-Xizang (Tibet) Plateau. The differentiation of glyptosternoid fish occurred in the great water drainages, among the different tributaries, and even the upper and lower reaches of the same drainage. The differentiation course of glyptosternoid fish included two processes. One was due to vicariance caused by natural geographic obstructions and another was a dispersal process caused by ecological adaptation. These two processes intersected, resulting in an unusually complex differentiation and distribution of glyptosternoid fish. Our future objectives are to collect data for all recorded species, to find more taxonomic data, and to combine the techniques of morphology and molecular biology in order to refine the classification, phylogeny and the geography distribution of glyptosternoid fish.