2000 Vol. 21, No. 2

Display Method:
The relationships between 17α,20β-dihydroxy-4-pregnene-3-one (17α,20β-DP) and plasma IgM and total protein levels were investigated in rainbow trout,Oncorhynchus mykiss.IgM and total protein levels decreased in both sexes of mature rainbow trout when 17α,20β-DP levels increased during the spawning season,while the elevated 17α,20β-DP suppressed IgM levels and reversibly enhanced total protein concentrations in immature trout.This represents the first report of the effect of 17α,20β-DP on fish immunity.These data suggest that the increase of 17α,20β-DP in spawning season may be related to infectious skin diseases.
Using the sandwich enzyme-linked immunosorbent assay (ELISA) for grass carp (Ctenopharyngodon idellas) growth hormone and different administrations of rcGH,we investigated the possibility of rcGH absorption by gastrointestinal tract of walking catfish (Clarias batrachus),northern sheatfish (Silurus soldatovi) and crucian carp (Carassius auratus gibelio).The specific ELISA can recognize endogenous GH in grass carp,jian carp and crucian carp blood and exogenous rcGH in northern sheatfish and walking catfish blood,but not endogenous GH in northern sheatfish and walking catfish blood.Rectal administration of rcGH to walking catfish (1 μg/g b.w.) and northern sheatfish (5 μg/g b.w.) resulted in rapid and marked increase in serum GH levels,suggesting that rcGH be absorbed by the intestine into the blood.In contrast,exogenous rcGH in serum was undeteted over a period of 48 h after an intragastic administration of rcGH (25 μg/g b.w.) to walking catfish.After an anterior intestine administration of rcGH (5 μg/g) to crucian carp,serum GH levels were significantly higher than the controls (P<0.001 or P<0.05) over a period of 33 h post administration.
The effects of Nile tilapia (Orecohromis niloticus) on the plankton communities were estimated in the enclosures with different treatments in salinealkaline ponds.After tilapia were stocked in the enclosures,abundance,the concentration of chlorophyll-a and primary productivity of phytoplankton increased.The biomasses of phytoplankton were composed mainly by smaller species,in which dominant species were small diatom and green algae,and sub-dominant species was Euglenophyta.The biomasses of zooplankton increased too,predominant by copepods,the size of cladocerans tended to small,the density of protozoa increased.Fertilization,especially apply organic fertilizer,could significantly increase the biomass of phytoplankton and decrease transparency depth,but the impacts of apply inorganic fertilizer to primary production and biomass of zooplankton were insignificant.The density and diversity index of plankton and the biomass of zooplankton in enclosure with apply organic fertilizer were higher than those of enclosures with fish,and the growth of tilapia was the fastest in experimental enclosures.The impacts of tilapia filter feeding and apply fertilizer to the community structures of plankton were discussed,and comparison of these results to that of silver carp were carried out.
The feeding activity of 20 captive Derbys parakeets in four groups was observed by instantaneous method and scan sampling method from March 1994 to February 1995And 254 completed feeding activities were observed by all-occurrences recording method from March 1996 to September 1998.The daily feeding frequency of Derbys parakeets were 32.12±14.28,and the daily time spent on feeding was 153.23±73.11 min,which accounted for 14.51% of the total observing time.The feeding frequency and feeding time in different individuals were different (frequency F=1.747,time F=1.791;P<0.05).The daily feeding frequency and total feeding time were correlated.The daily feeding activity had two main peaks.Generally the first appeared from 7:00 to 10:00 a.m.,the second was from 15:00 to 19:00.However,the time when the peak occurred was different in different season.The feeding activities began earlier and stopped later in summer and vice versa in winter.The daily feeding frequency of young was not significantly different from that of adult,but the duration of each feeding activity lasted longer in young than in adult,e.g.young spent longer time for feeding than adult daily.The daily time spent on feeding by male and female was not significantly different from that by female,while the feeding frequency of female was less than that of male,and the duration of each activity lasted longer in female than in male.The results by using all-occurrences recording method showed that:The feeding activity consisted of a series of behaviors,including picking-up with bill,grabing with foot,chewing,carrying food (in bill or foot),body caring,looking,threatening,and courtship feeding.The picking-up with bill,grabing with foot and chewing were over 90%.The feeding activity began with picking-up (100%),then chewing (96.56%),carrying food (2.87%) or threatening (0.57%);and then picking-up (85.06%),carrying food (7.47%),chewing (1.15%),body caring (1.15%),grabing with foot (3.45%),courtship feeding (0.57%) or looking (1.15%),and etc.The stepwise regression showed that the feeding activity of males and female were affected by all behaviors.Temperature,relative humidity and illumination were not the factors significantly affecting feeding activities.The feeding activities of young birds were affected by resting,fed by parents,bite,locomotion and temperature.The regression equation is as follow:Y=1578.74-1.95X[3]-1.76 X[4]-0.85 X[5]-1.44 X[6]-0.74 X[7] Y stood for daily feeding time,X[3],X[4],X[5],X[6] and X[7] respectively stood for temperature,resting,locomotion,feeding by parents and bite.
About 1 500 wintering nigh-herons were stu died during December 1983-May 1994 and December 1998-May 1999 in Shanghai.The results were as the follows:1) The population of birds was 1.531±273,ratio of juv./adult 1.731∶1±0.035.Most of the adults migrate to the north during the middle of March-end of April and the juveniles migrate in the middle of April-middle of May (Fig.1).2) Luminosity is the main factor for regulating the birds daily time budget,however,the birds tend to leave from roosting area earlier and come back later as the night time becomes longer and day time becomes shorter (Figs.2,3,4).3) The distribution pattern of the night-herons at roosting area are variable in different periods:uniform distribution in middle of winter when the bird number is at its peak,but aggregation at the migrant period when bird number drops (Table 1).The result strongly indicates the possibility that night-herons have fixed roosting sites in winter (Table 2).4) The wind is the most important factor affecting the birdss distribution.Other climate factors have no much influence on it (Tables 3,4;Fig.5).
The population age structure and sexual ratio of wild black bear (Selenarctors thibetanus) were studied,and the static life-span table of black bear population was comfilead,and the innate capacity of increase was analysed.The results showed the mean life span of black bear is 6.366 years,the net reproductive rate (R[0]) is 1.69325,the mean time of per generation (T) is 11.544 years,the innate rate of increase (r[m]) is 0.04552857,and the finite rate increase (x) is 1.0466110.All these results based on the skull specimens of black bear,and combined with the data of age structure and reproduction and death of black bears which have been collected in domesticated population,and with mathematical analysis way.
DNAs of Sarcocystis hominis-like cyst from the nature infected water buffalo (Bubalus bubalis),Sarcocystis hominis from cattle (Bos taurus),and Sarcocystis suihominis from swine (Sus scrofa) were extracted respectively.The 18S rRNA genes PCR productions of each isolate were directly sequenced.The cysts from both cattle and water buffalo sources showed a high homology within the compared 863 bp 18S rRNA gene sequences,which contain 4 main varied regions.According to the analysis,the 4 isolates both from cattle and water buffaloes probably are the same species,Sarcocystis hominis.And water buffalo can also serve as the intermediate host for S.hominis besides cattle in south China.
The present paper deals with stridulation apparatuses,observed by SEM,of 6 species of the genus Agromyza from China (2 species among them are newly recorded to China).Some morphological terms are proposed for the first time,and a key to 6 species of Agromyza applied by the characteristics of stridulatory file is given.We also scheme out a diagram showing relationship between two stridulatory file types.
In the present paper,four new species of Tetrigidae from Guangxi are described.Type specimens are deposited in the Institute of Zoology,Shaanxi Normal University. Tetrix longzhouensis sp.nov.(Figs.1-2) This new species is allied to Tetrex grossifemura Zheng et Jiang 1998,but differs in:1) in profile,upper margin slightly protruding before the shoulder,then nearly straight backward;2) hind process of pronotum not reaching the top of hind femur;3) hind wing only reaching two-thirds of hind femur;4) hind tibia black,with two white rings in middle part. Length of body:♂10 mm,♀11-12 mm. Length of pronotum:♂8 mm,♀9-10 mm. Width of shoulders:♂3 mm,♀4 mm. Length of hind femur:♂ 6 mm,♀6-7 mm. Holotype:♀,Guangxi:Longzhou (Longgang),106°8′E,22°3′N,11-Ⅹ-1998,collected by Jiang Guo-fan;paratypes 1♂,2♀♀,Longzhou (Longhu),106°7′E,22°5′N,9-Ⅹ-1998,collected by Jiang Guo-fan. Formosatettixoides guangxiensis sp.nov.(Figs.3-4) This new species is related to Formosatettixoides hunanensis Zheng et Fu 1992,but differs in;1) width of vertex as wide as an eye;2) hind process of pronotum reaching two-thirds of hind femur;3) elytra absent,hind wing distinct;4) hind femur short and stout,its length two times its width;with fine teeth on the upper and lower keels of hind femur;5) ovipositor stout and short;6) hind tibia brown,with two black bands in the middle and top. Length of body:♀14-15 mm;length of pronotum;♀5.5-6 mm;length of hind femur:♀6-6.5 mm. Holotype ♀,paratype♀,Guangxi:Longzhou (Longhu),300-400 m,106°7′E,22°5′N,9-Ⅹ-1998,collected by Jiang Guo-fan. Euparatettix nigritibis sp.nov.(Figs.5-6) This new species is allied to Euparatettix variabilis (Bolivar 1887),but differs by the hind tibia black,hind wing black,with a series white spots near the anterior margin. Length of body:♂6-6.5 mm;length of pronotum;♂8-9 mm;length of hind femur:♂4-5 mm. Holotype♂,paratypes 3♂♂,Guangxi:Longzhou (Longhu),300-400 m,106°7′E,22°5′N,9-Ⅹ-1998,collected by Jiang Guo-fan. Euparatettixoides longipennis sp.nov.(Figs.7-8) This new species is related to Euparatettixoides guangxiensis Zheng 1994,but differs in;1) width of vertex slightly narrower than an eye;2) pronotum tectiform,median keel high,lobe like;3) without a pair of short longitudinal keels;4) hind wing reaching beyond the hind process of pronotum;5) anterior half of pronotum dark brown,posterior half light brown,with a black broad band behind the shoulder. Length of body:♂6-7 mm;length of pronotum:♂5-6 mm;length of hind femur:♂4-4.3 mm. Holotype ♂,paratype ♂,Guangxi:Jinxiu,1 200-1 300 m,110°2′E,24°75′N,28-Ⅷ-1998,collected by Jiang Guo-fan.
Four new species of Eosentomon are described in this paper,collected in 1996 from Yunnan,China.They are E.rehaiense,E.tengchongense,E.megastigma and E.guyongense.These four species are all with 6/9 pattern of chaetotaxy on abdominal sternites Ⅳ-Ⅶ.All the specimens are presserved in Shanghai Institute of Entomology,Academia Sinica.
This paper describes a new species of the genus Sinocyclocheilus Fang 1936,collected from the cave Shadong in Lingyun County,Guangxi,China. Holotype No.990418004,total length 137 mm,standard length 110 mm,collected on April 18,1999 from Shadong of Lingyun County (24°20′N,106°32′E,altitude 470 m) in Guangxi Province.Paratype 12 specimens No.990418002-03,990418005-08,990420001-02,990422001-04.Total length 84-174 mm,standard length 64-137 mm,collected with the holotype. Description:D.iii,7;P.I,11-13;V.I,7-8;A.iii 5;Branched caudal fin rays 16.Lateral lin scales 71-78.Gill-rakers 2+7-8.Pharyngeal teeth 3 rows 2.3.5/5.3.2.Body depth in standard length 2.97-3.55(3.18),head length 3.44-4.03(3.73),length of caudal peduncle 4.06-5.33(4.85),depth of caudal peduncle 6.60-8.00(7.25).Snout in head 2.42-3.00(2.74),eye 6.00-11.33(8.46),interorbital 2.42-3.00(2.80).Depth of caudal peduncle 1.30-1.60(1.46) in its length. Diagnosis:The new species is similar to S.jii Zhang et Dai 1992,but differs from the latter in:1)lateral line scales 71/14-17/8-11-Ⅴ/78;Vs 48/22-24/17-19-Ⅴ/50:2)harnen and serrated of last unbranched drosal ray;Vs smooth,slender and soft:3)barbel long and sturdy.4)eye in head 6.00-11.33(8.46);Vs 6.6. All type specimens are kept in Heilongtan Reservoir of Shilin County,Yunnan Province,and the Department of Biology of Yunnan University.
Fish diversity has been paid more and more attentions because of bio-diversity crisis.That how fish diversity is so rich is gradually getting a hotspot in research fields."Chance favors the prepared genome."Present studies suggest that plastic genomes be genetic basis for speciation,form evolution,adaptation etc.In this paper,we tried to give evidences at both chromosomal and molecular levels on why and how fishes evolve in such diverse species.It suggests that fishes have plastic genomes by existences of the variable ranges of chromosome numbers,polyploidy,supernumerary (or B) chromosomes.In addition,gene clusters relevant to diverse forms and other clusters by polyploidy at molecular level have been gradually found.Therefore,chromosomal and molecular characteristics suggest plastic genomes in fishes.Due to plastic genomes,polyploidy and genetic introgression,especially polyploidy,may contribute to species diversity and population genetic polymorphism.Yet unfortunately,plastic genome may be the genetic defect of loss of fish diversity.
The ecology of urban avian community is an important but not much recognized field.Urbanization and the characteristics of urban habitat have drawn some ecologists attention on urban avian community,and the study contents and methodology.The effects of the generalization of urbanization on wildlife and the instrinsic value of the researches of urban avian community should be recognized.In this paper,its research progress and status were reviewed,the existing research highlights and the development in the future were discussed,and the applications of some new theories and methods to the research were also introduced.We hope the research of the ecology of urban avian community in China will develop rapidly in near future.