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1999年  第20卷  第2期

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研究论文
333 bp mitochondrial cytochrome b gene fragment were sequenced from 9 sisorid species of formalin fixed tissues which represent 8 genera of family Sisoridae.Aligned under the software MUST,there are 101 various sites and 39 informative sites.Sequence pairwise distance between species ranges from 8 to 48.The mean interspecies distance ranges from 2.4% to 14.4%.Parsimony analysis generated one maximum parsimonious trees of 162 steps (CI=0.735,RI=0.494).The MP tree indicates that Bagarius is the most primitive genus,and forms a sister group with all other researched groups.The other 8 individuals form a monophyly and they can be divided into 2 sister groups.In the molecular cladogram,the glyptosternoid fishes is not monophyly although it is defined by 13 osteological apomorphies.The uncongruence of cladograms between molecular and morphological sets may be caused by less informative of 333 bp DNA sequences,or unsuitability of cytochrome b gene for phylogeny of Sisoridae.Because no fresh fish material was usd,the DNA sequences only obtained from formalin fixed tissue have to be further tested,and verified.
In this study,15 restriction enzymes were employed to investigate the mitochondrial DNA polymorphism among 93 individuals from 4 Guizhou goat breeds.Mitochondrial DNA polymorphism was detected by 3 enzymes (BamHⅠ,HindⅢ and SalⅠ).18 restriction morphs,which could be sorted into 3 mtDNA haplotypes,were found.Haplotype Ⅰ and Ⅱ are distributed in every breed with relatively high frequency,I.e.77.42% and 21.50%.The frequency of haplotype Ⅲ is lower (1.08%).The relationship between white goat and black goat is the closest,and they are related to ma goat.Our results suggest that haplotype Ⅰ and Ⅱ of Guizhou goats mtDNA might represent two maternal origin,which might separate about 190 thousand years ago.
Chinese sturgeon (Acipenser sinensis) is an endangered species under first rank protection in China.The abundance has been depleting due to overfishing,pollution and dam construction etc.Gezhouba dam already cut off the migratory route and a few broods have been forced to spawn below Gezhouba dam.The Three Gorges Dam will further change hydrological regime of the Yangtze River and has adverse effect on the fishs spawning grounds.In order to make sound conservation program and monitor the resources population,genetics studies on Chinese sturgeon were carried out.In this paper we report results from protein electrophoresis.Total 15 proteins were studied and only 11 proteins are activity detectable.Conservatively,among 11 proteins 26 loci were screened.Among 26 loci screened only 1 locus (MDH-1) was polymorphic and the others were monomorphism.The percentage of polymorphic loci (P) and heterozygosity (H) was 0.039 and 0.004 respectively.The genetic variation at protein level is poor compared with those of the other bony fishes.The present result reflects basic picture of genetic diversity before construction of Gezhouba dam and basic data for monitoring resources in future.
In the present study,water samples of 7 localities in round water areas of Fuxian Lake were used for comparison with different areas water quality and mutagenicity.The qualitative and quantitative determinations of inorganic pollutants in water samples were made by ICP-AES spectrometry.We used the micronucleus test of tadpole (Bufo bufo andrewsi) erythrocytes to investigate the potential mutagenicity of water samples from Fuxian Lake.The results obtained showed that,among 7 localities in round water areas of Fuxian Lake,2 localities of Luchong and Mingxing had mutagenic active substances as manifested by an increase in the frequency of the micronucleated erythrocytes.
At the present paper,adult populations of the psocid,Liposcelis bostrychophila,were exposed respectively for 30 generations to two atmospheres containing 0.5% and 1% O[2](N[2] in mixture as balance),in order to select strains resistant to low O[2] content (LOC) atmosphere.Selection pressure was maintained at around 70% mortality.At the 30th generation,comparison of sensitivity between the selected strains (LOC1 and LOC2) and the original susceptible strain (CA-S) indicated a tolerance factor (TF) at the 50% mortality level (LT[50]) of 4.7- and 3.9-fold,respectively.Throughout the selection process,log-time against probit-mortality lines remained roughly parallel and the slopes remained lower than that of CA-S strain until the last generation.The implication is that at high level of selection,multiple genetic factors continued act together even at the 30th generation to select for adaptation to survival at depleted O[2] concentration.Up to 30th generation,two selected strains still possessed the genetic potential to develop resistance to LOC.Removal of selection pressure for 5 generations from 2 sub-populations of two selected strains from 25th generation caused significant reduction in resistance.In the absence of CA exposure,the two selected strains all possessed the reproductive disadvantages or fitness defect.LOC1 and LOC2 were calculated by R[0] to have a fitness value of 0.56 and 0.75 relative to unselected strain,respectively.
This paper deals with the biodiversity study of freshwater fishes.There are 82 endemic species belonging to 15 families,60 genera in three representative branches (Nanxi River,Luzhi River and Lixiang River) of Yuanjiang River system.Each branch can be treated as a sample.Index number of β diversity are studied among three branches of Yuanjiang River.The results of β diversity analysis indicate that the difference of fish diversity between Luzhi River and Lixian River are not significant,and that is very obvious when these two rivers are compared with Nanxi River.It is less common shared number of species and genera between Luzhi River and Lixian River and this means that there is a bigger isolation in species and genera between these two rivers.It is more common shared number of species and genera between Nanxi River and Luzhi River and this means that there is a more closed relationship in species and genera between these two branches.The reasons that cause the difference of fish diversity among three branches may be probably included that degree of investigation for every branch of Yuanjiang River system,elements of environment and habitat of fish,human activities etc.However,fish diversity among three branches is not related to the length and area of river.Finally,a suggestion for fish conservation is presented.
Xishuangbanna District is one of the three areas where have tropical rain forests in China.In this paper,endemic species,predominant species,species diversity index,evenness index,predominant index,and similarity coefficient of ants in 16 subtypes of vegetation in Xishuangbanna District are studied.220 species belonging to 8 subfamilies and 66 genera were collected.The maximum of species diversity index is observed in the seasonal rain forest in rainy season,that is 2.908;while the minimum of species diversity index is found in the tea garden in dry season,that is 0.114.For the composition of ant species,mountain rain forest and monsoon evergreen broad-leaf forest have the greatest similarity coefficient,that is 0.356;while warm deciduous broad-leaf forest and tea garden have the smallest similarity coefficient,that is 0.017.Each subtype of vegetation has its endemic species.Among them,semi-evergreen monsoon forest is richest in endemic species,reaching to 13 endemic species.In contrast,hill land shrub is poorest in endemic species,with only 1 endemic species.Seasonal rain forest and semi-evergreen monsoon forest are richest in rare species,so these two subtypes of vegetation are most valuable for conservation.Karst monsoon forest,monsoon evergreen broad-leaf forest,mossy evergreen broad-leaf forest,warm deciduous broad-leaf forest,and warm pine forest also have their own rare species,these subtypes of vegetation also have important value for conservation.Predominant species and their percentage in the 16 subtypes of vegetation in dry and rainy seasons are different from one to another.The most common predominant species in dry season is Pseudolasius silvestrii Wheeler.While in rainy season,P.silvestrii Wheeler and Pheidologeton diversus (Jerdon) are the most common predominant ones.
Fig trees are a keystone species in the ecosystem of tropical rainforest in Xishuangbanna.For the species of their flowers,fig trees (Ficus spp.) are dependent upon Hymenoptera of the family Agaonidae (fig wasps).For the propagation and growing of their kind,the fig wasps are dependent upon the gall (ovaries) of the figs,in which their larvae develop.Thus,the complicated symbioses relationship between fig wasps and fig trees have developed.In this paper,the effects of fragmenting of tropical rainforest on the population structure of fig wasps and fig trees,and the population of Agaonidae and Ficus have been described and reported for the first time.As a foundationnal part of the project of biodiversity conservation on fragments of the tropical rainforest in Xishuangbanna,the survey of fig trees and fig wasps on fragments of the tropical rainforest in Menglun has been done in details.As the result:The total number of fig wasps (Agaonidae) collected was 18000 which consisted of 3 genera and 17 species.The species of Agaonidae and Ficus and their populations which had ever lived in the fragmentary tropical rainforest were directly effected,because that the size of fragmented forest is closely interrelated with the number of species which live in it.There are reciprocal and specific relations between figs and fig wasps.
A study on home range,habitat selection and diet of Temmincks Tragopan (Tragopan temminckii) with telemetry was performed from November 1993 to October 1994.The distribution of radio-locations and droppings were relatively concentrated.The distribution of its food items indicated that the habitat selection of T.temminckii was closely relevant to its diet.The preferred habitat situated in the part of the higher elevations and within 100 m along the path in the valley with rich bushes and herbs.In spring and winter,T.temminckii fed mainly on herb and ferns and its home range size was larger.In rainy and foggy weather,T.temminckii.occurred often on the path of valley.In summer and autumn,its food was the mature fruits and its home range was smaller and more regular than that in spring and winter.
Intensive male-infant caretaking (IMC) in the Barbary macaque (Macaca sylvanus),which is promiscuous and highly uncertain in the paternity of infants,has theoretically embarrassed primatologists since 1980s because it is beyond the sphere of action of kin selection and sexual selection,two powerful tools for interpreting social behavior at this time.Fortunately the same kind of behavior has recently been observed in the Tibetan macaque (M.thibetana),in which male mating opportunity is rank- and age dependent,and the paternity is higher than that in Barbary macaques.But both species have similar habitats at high latitude and altitude,and in short of fruits.The comparison of etho-ecological data suggests a logical connection of the IMC with the habitat.For wild Tibetan macaques,except supplied with fruits and bamboo shoots,which are suitable for macaques,in autumn,they have to feed mainly on leaves and grass in other seasons.Interestingly,the onset of weaning (bottleneck for infant survival) and the mating are concentrated on the best season,autumn,but remaining half of births in harsh winter.The contradiction between very low nutrient-intake and increased energy demand on maintaining body temperature for both sexes and on pregnancy and lactation for females in winter is solved by way of storing energy as fat before winter,and consuming intrinsic body material in late winter.This is suggested by the fluctuation of body weight in a year period:peaked in late autumn and dropped to valley point in late winter.Taking the mean of the two extremes,18.3 kg for males and 14.1 for females,as the baseline,the margin of the fluctuation is ±19% for females and ±7% for males.Of the margin,the weight loss of females is over that of males for 2.7 times,giving an approximate measurement of the difference of parental investment to offspring.The difference demonstrates the necessity and possibility of IMC,males timely help to exhaust females,which would benefit the reproductive success of the group.Thus so far,the poor habitat shaping the IMC is proven with both logical and physiological evidences.In fact,the rule seems held right for the Old World primates regardless of their mating system because the only monogynous form,Hylobates syndactylus showing the IMC also lives in habitat lacking of fruit.In addition,the male-infant-male interaction in Barbary and Tibetan macaques is also recognized as a byproduct of IMC.Accordingly,our work has offered a firm foothold for a more general hypothesis of energy-related habitat factors shaping social behavior.Obviously,the IMC possesses the nature of"cooperation for existence".The cooperation then is integrated with Darwins "struggle for existence"—predator defense and competition for food,forming a concept of "ecological selection".Furthermore,the ecological selection is integrated with sexual selection and kin selection in a way of parallel and not contrary to each other,constructing a unifying framework of"general natural selection".Within the framework,a series of conceptual confusions,which are produced by the absence of ecological selection in the evolutionary theory of social behaviors,can be effectively eliminated.That is,most of the behaviors can be related to ones own shaping force(s).For this,what we need to do is to find the problem,or the need for survival and/or reproduction,behaviorally addressed to by the animal,and then to match the problem with specific one or more selective pressure.At the end,the operatedness of"ecological selection"and its potential value of applying to the management of human societies are also discussed.
This paper reviewed the recent researches on the stanniocalcin (STC) produced by the corpuscles of Stannius in teleost.STCs are homodimeric glycoprotein hormones with apparent molecular weight ranging from 46 kDa(chum salmon)to 56 kDa (rainbow trout) in native form and 23-28 kDa in the reduced condition.The amino acid sequence analyses of STCs and cDNAs have revealed that reduced STCs (monomer) consist of 179 (chum salmon),223 (coho salmon) and 231 (Australian eel) amino acid residues,respectively.Other studies show that secretion of STC is regulated by calcium concentrations and that the cholinergic nerves are involved in the release of STC.
S (somatostatin) is widely distributed in the bodies of different animals from the low invertabrates (such as protozoa) to vertabrates.The distribution of SS in the brain varies in species.In mammalian brain,except cortex,hypothalamus co ntains the highest SS level (Zhou,1989).Evidences for SS innervation in the mam malian and human hypothalamus have been obtained by a number of investigators.Ho wever,the reports are very few in birds.The present paper disclosed the distrib ution of SS-like immunoreactivity in the chicken hypothalamus by using immunocy tochemical (ABC) technique to provide phylogenetical evidence for a better understanding of SS function.