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2003年  第24卷  第4期

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研究论文
Fragments of mitochondrial 12S and 16S rRNA genes of 17 individuals were sequenced,including 8 species (subspecies) of 2 genera Megophrys and Brachytarsophrys of Megophrinae,and 3 species used as outgroup including the genera Bombia,Oreolalax and Scutiger.Results pairwised by Clustal W show that there are 949 bp in length with 320 variable sites including 206 parsimony sites.The average contents of T,C,A,and G are 25.6%,24.0%,29.8%,and 20.6%,respectively,and the ratio of transition to transvertion is 1.3.The phylogenetic relationships of these taxa were analyzed using programs of Neighbor-Joining and Maximum Parsimony.The results show that the ingroup are clustered together as one clade,of which 3 individuals of M.glandulosa were clustered together (BSP=100%) and firstly diverged from the other taxa (BSP=100%),3 individuals of B.carinensis were clustered together (BSP=100%) as sister group of M.shapingensis,the rest 5 taxa formed together and included two groups,one consisting of two populations of M.minor brachykolos from Longsheng of Guangxi and Hong Kong,the other containing M.omeimontis,M.minor minor,M.caudoprocta and M.sp from Wulong of Chongqing,the later two species are closely related.These results support M.brachykolos as a valid species rather than a subspecies of M.minor,and suggest that M.glandulosa,M.shapingensis and B.carinensis may belong to three different subgenera or genera.
Body mass (BM),body length (BL),wing length,tarsus length,and body temperature (T[b]) of 13 nestlings of Platalea leucorodia at Zhalong Natural Reserve (47°29′N,124°02′E) were measured every two days in a period from April to June in 1994 and 1995.The growth of the nestlings was in keeping with the logistic equation,and the highest relative growth rate appeared in the period of 4-8 days.T[b] steadily increased with age in days and not fluctuated with ambient temperature (T[a]),and the extent of reduction in T[b] after cold exposure of 25 min to T[a] progressively decreased.Nestlings within first 28 days,BM was positively corrected with T[b] in nests and after cold exposure,and BM and BL were also positively related to the index of homeothermy.This means that body growth is in synchronization with thermogenic ability,reflecting the character of altricial nestlings.
The burrows of Chinese alligator (Alligator sinensis) were surveyed in Anhui National Natural Chinese Alligator Reserve in four periods within Jul.-Oct.from 1999 to 2002.Of the found burrows,24 were in use,and 16 were deserted.Five environmental variables regarding the positions of the burrow entrances were measured.A large percent (87.5%) of entrances were located about the water surface (0-0.5 m and <0 m);85.0% were within 5 m from the water body;32.5% were towards north;72.5% were vegetation-covered less than 70%;and 42.5% were within 100 m from villages.Factors such as the height above water surface,distance to water body,entrance direction,and degree of shelter contributed for 76.6% of the variance in total,and they were in descending order in the contribution.The convenience entering water body is the main factor for Chinese alligators to select the entrances.
Data on birds and their nests were collected in 24 street tree strips in Hangzhou,China,in the breeding season from March to July 2002,and the relationship between the nest-number (NN) and some eigenvalues of the strips was shown by multiple stepwise regression.Thirteen species and their 460 nests in total were observed.Of the nests,83.9% were built by Pycnonotus sinensis and some colonial breeding species including Nycticorax nycticorax,Ardeola bacchus and Bubulcus ibis.Five species including Turdus poliocephalus,N.nycticorax,etc.tended to build nests at tall trees,and the nests for the whole bird community increased with the mean tree height.More positive relations appeared between:1) the foliage height diversity and NN of Lonchura striata and Streptopelia chinensis,2) canopy cover and NN of Pycnonotus sinensis,3) tree species numbers and NN of S.chinensis,4) tree hole numbers and NN of Passer montanusand,5) the distance to large woodland and NN of Lonchura striata,6) the distance to nearest main water resource and NN of N.nycticorax,7) tree strip width and NN of S.chinensis.On the other hand,most bird species avoided the tree strip easily approached by pedestrian,and P.sinensis and S.chinensis were the most sensitive.There are some differences between species in the nest-distributions in the tree strips,reflecting their different way of adaptation.
The big-footed bat (Myotis ricketti) is morphologically similar to piscivorous M.vivesi and Noctilio leporinus,but its piscivorous habit leaves a question open.Eighteen of the returning bats were captured with netting at the entrance of their living cave in Fangshan County,Beijing at night.Of 18 stomachs examined,the remains of seven were exclusively fishes (Zacco platypus,Carassius auratus and Phoxinus lagowskii),those of 10 were mainly fish fragments and only one was consisted of insects.In experimental observation,the rate of success in catching fish was 12.5% of 256.The findings indicate that M.ricketti is piscivorous.Echolocation sounds of the bat were frequency-modulated downward from 67.40 to 23.63 kHz with main energy at 38.21±1.18 kHz and short pulse duration of 2.58±0.34 ms.The echolocation sounds are somewhat species-specific.
Species and amount of birds were surveyed with line transects made in summer 1999 at habitats of desert,wetland,fixing sand forest,and village and farmland in Shapotou Nature Reserve,Ningxia,and then compared with those in 1986 (Liu & Chang,1990).There were 67 species in the reserve in 1999.In comparison with the record of 1986,36 were new,but 10 disappeared.Of the changes,the amount of birds in desert decreased <50%;amount and species number in wetland doubled;species number in fixing sand forest increased from 8 to 34 (mainly insect-eating birds and desert-living birds),H increased 67% and dominance index (D) decreased 63%;species number in village and farmland decreased 42%,and D decreased 22%.The status of bird community in wetland becomes much better because fish-pounds increase;that in fixing sand forest seems better,but the habitat itself is changing to desert due to increased population of insect pests;that in village and farmland is getting worse because of disappearance of traditional houses.
Carps (Cyprinus carpio) were treated with 1)rearing in calcium-enriched freshwater (CEF,supplemented with 0.5% CaCl[2]),2)injecting VD[3] (5000 U per 100 g body weight) or carps corpuscle of Stannius (CS) homogenate (0.5 mg per 100 g body weight) into abdominal cavity after 8 days rearing in CEF,and 3)transferring to natural freshwater after 28 days rearing in CEF.The hypercalcemia of carps was induced by the CEF;and the plasma calcium level (PCL) further increased and decreased by injection VD[3] and CS homogenate,respectively.While PCL increased,CS follicles shrunk,and CS secretory cells changed as follows:the nucleus enlarged,the rough endoplasmic reticulum dilated,and the secretory granules depleted.The shrinking and changes indicate that calcium can stimulate synthesis and releasing of CS secretory cells,but hyperactivity of these cells results in exhaustion and rupture.While PCL decreased,or returned back to the natural freshwater,above symptoms lightened,and the secretory granules in CS secretory cells accumulated.The state of carps CS is influenced by the calcium level out of cell and body,and the influences are reversible.
The gonad index[GI,(gonad weight/body weight)×10[2]],the corpuscle of Stannius (CS) index[CSI,(CS weight/ body weight)×10[6]],and the ultrastructure of CS were observed in a reproductive cycle of carps Cyprinus carpio.CSI was positively correlated with the GI;according to the ultrastructure of follicles and secretory cells,the growth phase,secretory phase and atrophy phase of CS were in succession in an annual cycle.Such a change is in accordance with those observed with light microscope,and likely related to the reproductive cycle of carps.
The ultrastructure of follicular cells in the Exopalaemon modestus ovary,and their connection with oocytes at the different developmental stages were observed with a transmission electron microscopy.Developed with the oocytes,follicular cells experienced a process from development to deterioration.At the stage of yolk mass-occurrences,oocytes were surrounded by several layers of follicular cells,and sinuses extended between the layers.Endoplasmic reticulum,Golgi bodies,mitochondria,ribosomes and pro-yolk granules were abundant in follicular cells.At the autumn of eggs,follicular cells started to retrogress sequentially from the inner layer to the outer layer,sinuses atrophied.These morphological changes are in keeping with the observation that follicular cells function in absorbing nutrients from blood,synthesizing and transferring pro-yolk substance to oocytes.The function is somewhat different from those documented for Scylla serrata,Penaeus penicillatus and Eriocheir sinensis.
Total mRNA was extracted from the venom glands of snakes Trimeresurus jerdonii.The cDNAs encoding lectin were amplified by RT-PCR and cloned into PMD18-T vector.The positive clones encoding lectin were selected and sequenced,and was named TJL.The deduced amino acid sequence contains 135 residues,preceded by a signal peptide of 23 residues,including a galactose-binding site and a Ca2+ binding site.This C-type lectin shows great similarity to ones from Viperidae venoms and less similarity to one from Elapidae venom.
Pengze crucian carp eggs and sea carp sperm,which were artificially produced by the injection of LRH-A2 and HCG for females and pituitary for males,were mixed in fry production.Three types of offspring were observed:Ⅰ,females,phonotypically the same as the mother,developed by eggs activated by sperm of see carps;Ⅱ,males,also as the mother,but developed in a unknown way;Ⅲ,similar to the mother but with a few paternal characters,indicating some occurrence of the mixis.Type I only appeared most often in the offspring;type Ⅱ only or mostly occurred sometimes;type Ⅲ occasionally presented,and if seen it was <1% of the fries.
Fourteen adult crossbred geese (Chuan white×Tai lake) fitted with chronic wing vein cannulas were used to evaluate the effect of cysteamine (CS) on the metabolisms of surgar and protein,which were checked with radioimmunoassay,spetrophotometery and other methods.This experiment began with collecting blood samples from the cannulas as control,and then the geese were fed on food with CS (100 mg/kg·bw).Their blood samples were collected after 1,3,5 and 7 days after the treatment.In the four days,the urea acid in plasma decreased,and the activity of the glutamicpyruvic transaminase increased.The blood sugar decreased on day 5 and day 7.On day 5,the insulin increased while the glucagon decreased and the ratio of insulin to glucagon reached a peak.These results imply that CS can enhance the assimilation in geese.
Song is one of important secondary sexual characters of birds.The song of male birds is often rich in connotations about species,territory quality,and genetic and physiological states.Thus,according to the song,females can judge the quality of their potential mates,and females preference for complicated songs,in turnover,shapes the song of males,I.e.,the evolution of songs is induced by female choice.The gene of the choice is proposed to be in the W chromosome determining sex in birds.
The primary goal of all semen analyses is to accurately determine the fertilizing potential of semen samples rapidly.Since a spermatozoon must possess many attributes in order to fertilize an oocyte,the only way that we can more precisely predict the fertility is to develop unbiased assays that measure several sperm traits simultaneously.Conventional laboratory assays of spermatozoa,using subjective method,many are time consuming,and are necessarily conducted on samples of relatively small size,fall short of predicting the sperm function.Flow cytometry (FCM) permits us to objectively measure thousands of sperm for multiple characteristics in a short time with minimum preparation.The applications of FCM to evaluation of semen quality including sperm plasma membrane integrity,acrosome status,chromatin structure,mitochondrial activity as well as apoptosis etc,provide us valuable information regarding sperm function.FCM offers powerful tools and exciting opportunities for improving our ability to accurately evaluate semen quality with new fluorescent probes and techniques continuously being developed.
Gonads were observed in the section of the second egg-zoea stage of swimming crabs,Portunus trituberculatus with a microscope.The gonads appearance is saclike,inside has a cavity,and cells arrange like a strand that opens to the surface of the embryo.One embryo has two gonads linking with a tube structure.