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2000年  第21卷  第4期

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研究论文
The survival rate and oviposition number of Tetrastichus kodaikanalensis Saraswat are influenced by temperature noticeably.The generation survival rate is 1.84%,31.83%,80.39%,72.75%,48.08% and 22.81% at 18,21,24,27,30 and 33 ℃ respectively.They have the most oviposition number with the highest oviposition percentage at 30 ℃ (mean 13.21 ova with 84.84%),and the shortest oviposition days at 33 ℃ (mean 5.43 days).There are three peaks for the adults of T.kodaikanalensis in male white wax insect:the last ten days of June,the first-second ten days of August,and the second-last ten days of September.There are also three peaks in female white wax insect:the first-second ten days of August,the second-last ten days of September,and the last ten days of October-the first ten days of November.They have the most population number and the highest hyperparasitization on M.ericeri at the third peak.It is 47.78% and 54.66% respectively to the third and fourth generation hyperparasitization of T.kodaikanalensis on M.ericeri which is parasitized in female white wax insect,and 56.66% and 64.71% respectively in male white wax insect.It is 76.00% to the hyperparasitization of the fifth generation.The hyperparasitization of T.kodaikanalensis on M.ericeri is the fourth instar larvae>the fifth instar larvae>pupae.By putting pupae in the field,T.kodaikanalensis can control the population density of M.ericeri and increase the production of white wax and ovisac remarkably.Putting 30 pupae per host tree,the production of white wax is the control (36.4 g),once (111.3 g),twice (137.6 g);the production of ovisac is the control (82.1 g),once (149.8 g),twice (219.7 g).
"Paramecium bursaria-Chlorella sp." system,a kind of ideal symbiotic system,was selected to research host-symbiont interaction.In order to discover the difference of genomic DNA of host and symbiont,genetic variation of the chlorellae-bearing and chlorellae-free Paramecium bursaria was detected by randomly amplified polymorphic DNA (RAPD) markers.Genetic variation from 12 polymorphic fragments amplified with primers S174,S750,S769,S755,S103 in both strains of Paramecium bursaria exited,though they shared the same fragments amplified with primers S401,S147,S786,S759,S086,S763,S155.It is implied that some changes in genomic DNA of P.bursaria have occurred owing to symbiotic functions.Also,it is shown that there are the similarity between the amplified product of P.bursaria and symbiotic chlorellae.
The specialized schizothoracine fishes belong to subfamily Schizothoracinae (Cyprinidae).Compared to other fishes in the same subfamily,the specialized schizothoracine fishes have the following characters:1)only 1 pair of barbels,2)2 rows of pharyngeal teeth,3)scales degenerated,and even degenerated entirely in genus Gymnodiptychus (Cao et al.,1981).There are 9 species and subspecies belonging to 3 genera [Diptychus (Steindachner,1866),Ptychobarbus (Steindachner,1866) and Gymnodiptychus (Herzenstein,1892)] in this group.In this paper,random amplified polymorphic DNAs (RAPDs) were used to investigate genetic relationships among 22 individuals of the fishes,which represent 6 species and 4 genera,Schizothorax,Diptychus,Ptychobarbus and Gymnodiptychus respectively.234 RAPD markers were observed by using 37 arbitrary primers (10 bp).The molecular phylogenetic tree constructed by NJ (Neighbor-joining) method indicated that these 22 individuals could be divided into 6 clusters (each cluster represents one species).Upon the relationships among the 3 genera,Diptychus,Ptychobarbus and Gymnodiptychus,the conclusion was the same as that concluded from the phylogenetic analysis by using morphological characters.The result showed that RAPD could be used to study the phylogenetic relationships of closely related genera.
Histological observations revealed that ovoviviparous teleost,Sebastiscus marmoratus ovaries consisted of ovarian wall,villi ovariales and ovarian cavity.The muscular layer of the ovarian wall was rather thick.The intraovarian epithelium had secretory function.Villi ovariales were in the ovarian cavity with the shape of tree crown.There were follicles in the villi ovariales.A follicle was made of an oocyte and follicular envelope,which consists of an inner layer,granulosa layer and an outer layer,thecal layer.The thecal layer was rich in capillaries.At each side of the follicle there was a stalk of follicle.The two stalks enabled the follicle to be hanged over the villi ovariales.Ovarian development could be divided into 7 stages.Mature eggs were discharged into the ovarian cavity and were fertilized there.Embryos would develop in the ovarian juice.The ovarian development,the coefficient of maturation in the ovary and the thickness of ovarian wall all showed annual changes.
This paper describes the breeding biology of Little Egret and Night Heron in Yuantouzhu of Taihu Lake.In the research area,the dominant vegetations are Pinus massoniana and Cinnamomum hupehanum,which are suitable for herons to make their nests.The results showed that there were totally ten thousand nests,the nest density was about 0.36 m[-2] and the number of nests per tree in average was 1.06.The average clutch size was 3.55 for Night Heron and 4.89 for Little Egret.The average brood size was 2.68 for Night Heron and 3.96 for Little Egret.Incubating time for Little Egret ranged from 19 to 21 days and for Night Heron was from 22 to 23 days.Hatching success was 84.25% for Little Egret and 75.46% for Night Heron.Nestlings of Little Egret fed mainly on small fish and shrimps,nestlings of Night Heron fed mainly on fish and amphibians.
The distribution and abundance of waterbirds on 6 kinds of wetlands in Hangzhou were surveyed between December in 1997 and November in 1998.Eleven habitat characteristics were selected to determine the factors influencing wetland waterbird communities,and urbanization synthetical index so as to explore the impacts of urbanization on the waterbird communities.Other than food,water pollution and water depth,the habitat characteristics of landscape level (wetland shape,percent of surrounding building,wetland connectivity,distance to city center) and disturbance (noise and human disturbance) also showed strong relationships with species distributions,densities or diversities.Diversity of food and human disturbance played the significant roles in determining the variety of waterbird species diversity all year round.Species density and diversity decreased with increasing urbanization.Although some species showed a little adaptation to urbanization,there was no real adapted species.
In 1996,a field survey was conducted to investigate the giant panda population in Huanglongsi Nature Reserve and cluster analysis method was used to analyse its age structure.The results showed that there were 23 pandas in the reserve and the ecological density in bamboo forests was 0.439 giant pandas/km[2].The population could be divided into four age groups with the Sum of Square Method.The cub group accounted for 13.33%,the juvenile group for 6.67%,the adult group for 60%,and the senile group for 20%.This determination was almost in accordance with the principle proposed by Hu (1987),and at the same time it indicated that this population had a stable tendency.However,it was such a small population that a little interrupt could lead it to extinct.Thus,at present it is urgent to protect the habitat and the corridors and ban the mining in the area.
Two new genera of the ant subfamilies Dorylinae and Ponerinae are collected and described from the tropical rain forest of Xishuangbanna Nature Reserve,Yunnan Province,China.Yunodorylus gen.nov.belongs to the subfamily Dorylinae,which is monotypic and terrestrial with 2 colonies of the species Ysexspinus sp.nov.collected from the soil sample of seasonal rain forest and deciduous monsoon forest.Bannapone gen.nov.belongs to the tribe Amblyoponini of Ponerinae,which is also monotypic and known only from a dealate female of the species B.mulanae sp.nov.collected from a soil sample in semi-evergreen monsoon forest.
The present paper describes five new species of the genus Helina from Yunnan Province,China,namely H.baoshanensis sp.nov.,H.gongshanensis sp.nov.,H.larginigra sp.nov.,H.maae sp.nov.and H.pardiabdominis sp.nov..All materials are deposited in the Institute of Entomology,Shenyang Normal College.
In order to analyze skull variation in the genus Macaca,seventy-seven craniodental variables were taken from eleven species.They were first defined seven functional units comprising three anatomical regions.Twenty-seven variables were finally selected to carry out the morphology of the whole skull.The data,organized in these ways,were examined to discover variations between and within the various species.The methods used were Principal Components Analysis (PCA) and Discriminant Function Analysis (DFA).PCAs of the functional units anatomical regions,and the whole skull provided similar,though not identical,separations of species clusters in both sexes separately.These differences in structure could be related to size,sexual dimorphism,diet,ecology,classification and phylogeny.The question of size should have been easy to settle.Unfortunately,this is not the case.In this study where the raw data are measurements of the specimens,the main differences should be size.However,the size differences seem to occur in both the first and second (independent) multivariate axes.In some analyses the size differences between the species are biggest and appear in the first axis.In other analyses it is the separation between the sexes (and these too are largely size) that are the biggest and appear in the first axis.Yet in other analyses,both of these size separations,though still orthogonal to one another,present in the combination of the first two axes.This certainly implies that a single axis of body size is not present and that shape differences have not been isolated form size differences.It also implies that sexual dimorphism is a complex matter.As a result,the question of the relationships between the species is therefore also complex.One cluster of species that includes M.fascicularis,M.sinica and M.radiata was significantly isolated from all others regardless of level of analysis.This relationship is quite different from that proposed on the anatomy of the reproductive organs (Delson,1980;Fooden,1976,1980).
Penaeid shrimp Penaeus japonicus,commonly named as Flowery Shrimp or Banded Shrimp,is one of the most commercially important species of marine crustacean fishery in China.Being of the warm-water species conducting short distance migr ation,the animal is mainly distributed in the coastal waters of south China,I.e.the southern part of the East China Sea and the South China Sea (Liu et al.,1986).