2007 Vol. 28, No. 2
This study analyzed nucleotide sequences from the mitochondrial cytochrome oxidase submit (COI) gene region (450 bp) to investigate the genetic structure of the oriental river prawn (Macrobrachium nipponense) among nine populations from the Yangtze and Lancang Rivers. A total of 79 individuals were collected for this work. Eighty-nine nucleotides were found to be variable, resulting in 46 haplotypes. Among the nine populations,the population from Kunming shows the greatest level of variability (h=1.000,π=0.028), whereas the population from Chongqing exhibits the lowest level of variability (h=0.700,π=0.008). Analysis of molecular variance suggested that of the total genetic diversity,9.66% was attributable to inter-population diversity and the remainder (90.34%) to differences within populations. A molecular phylogenetic tree constructed using the Neighbor-joining (NJ) method showed that the 46 haplotypes were assigned to two clades associated with geographic regions. These results provide basic information for the conservation and sustainable exploitation of this species.
In order to determine the applicability of microsatellite primers developed from common carp (Cyprinuscario) for genomic analysis in mud carp (Cirrhina olitorella), 24 primer pairs from common carp were designed to amplify microsatellite loci in the mud carp containing CA, GA, AT and GGGA sequences. Thirteen primers (54%) successfully amplified specific products in the mud carp and 11 primers (48%) showed high polymorphism in the mud carp population. The results indicated that the average number of alleles per locus in the mud carp stocks was 5.2. Average heterozygosity (Ho), unbiased expected heterozygosity (He) and polymorphism information content (PIC) in the wild population were 0.61±0.2, 0.8±0.09 and 0.72±0.1 respectively. Several Hardy-Weinberg departure value were significantly departed from Hardy-Weinberg equilibrium. The study showed that microsatellite primers from a species of Cyprinidae can be used for mud carp genetic analysis without much cost or time input.
Using microsatellite markers, we analysed genetic polymorphism in four populations of Eriocheir sinensis, sampled from Jiangsu, Anhui, Liaoning and Tianjin. Twenty-four pairs of primers were used to amplify the target fragments ranging from 80 bp to 445 bp, which included 16 pairs designed in our laboratory and eight pairs published internationally. Two to 10 alleles per locus in four populations were amplified, and there were 155 alleles in all populations. The average number of alleles per locus was 6.458. The average number of effective alleles per locus (Ne) was 4.3491 to 4.7234; the average observed heterozygosity (Ho) was 0.5690 to 0.6722; and the average expected heterozygosity (He) was 0.7238 to 0.7546. Hardy-Weinberg equilibrium analysis (χ2 test, P<0.05) revealed that seven loci in the four populations were in equilibrium. The genetic distances between the four populations were calculated and revealed that the Anhui, Jiangsu and Tianjin crabs belong to a Yangtse River population, while the Liaohe crabs form another branch.
Chemical communication plays an important role in survival and reproductive success in mammalian species. In the present study, we examined the ontogenetic pattern of behavioral responses of male giant pandas (Ailuropoda melanoleuca) to urine odors of conspecific individuals. Our data showed that exposure to the urine of adult females induced a significant increase in sniffing and environmental sniffing/licking behaviors, but a decrease in biting behavior, in males. Males of different ages displayed specific behaviors to female urine odors. Adult males spent more time licking than juvenile and sub-adult males. Further, sub-adult and adult males displayed high levels of environmental sniffing/licking, which was absent in the juvenile males. Juvenile males displayed scent rubbing behavior significantly more frequently than sub-adult and adult males, and also spent more time showing biting behavior than sub-adult males. Finally, juvenile and sub-adult males showed no difference in response to female and male urine odors. Together, these data suggest that chemosensory cues from conspecific urines induce age-specific responses in male giant pandas.
2007, 28(2): 141-148.
To research the retention of parental odours of female root voles (Microtus oeconomus), the behavioural responses to urine from parents were recorded 0, 10, 20, 30, and 40 days after weaning (20, 30, 40, 50, 60 days of age respectively). The results showed that: (1) The frequency of self-grooming in the presence of paternal or a strange male's odour was significantly different when subjects were 20 days of age. The frequency of approach to paternal odour was higher than to a stranger's odour. In addition, the counter-mark frequency for paternal odours was less than for strange odours when subjects were 30 days of age. (2) There was no difference between the behavioural responses to paternal and strange odours when subjects were 40 days of age. (3) There was no difference between the behavioural responses to maternal and strange odours when subjects were 20 days of age. (4) Females showed different behavioural patterns to maternal and strange odours 10-40 d after weaning. In conclusion, the retention of paternal odour can continue until 10-20 d after weaning, and maternal odour can continue until 40 d after weaning.
From June 2000 to February 2001, focal sampling and occurrence recording were used to quantify the behavioural patterns of captive male alpine musk deer (Moschus sifanicus) at Xinglongshan Musk Deer Farm in Gansu Province, northwest China. The behavioural patterns of unsuccessfully mounting males (UM) and successfully mounting males (SM) were compared to identify behavioural differences. The results showed that, in the non-mating season (Aug. to Oct.), SM foraged significantly less than UM, and bedding and tail rubbing behaviour of the former were significantly more frequent than those of the latter. In the mating season (Nov. to Jan.), the bedding behaviour of SM was less than that of UM. However, conflict behavior, tail rubbing and urinating/defecating of SM were all significantly higher than those of UM. This research showed that bedding behavior and tail rubbing behavior were significantly different between SM and UM during the mating and non-mating seasons. These behaviours, especially tail rubbing, could be used as behavioral indicators to differentiate the reproductive performance of captive male musk deer. Using this method, males with high frequency of tail rubbing could be chosen as the mating males, improving the pregnancy rate of female musk deer, and reducing the cost of the musk deer farming.
In order to investigate the relationships between cage floor systems, behaviours and breast blisters in broiler chickens, we observed behavioural patterns and the incidence of breast blisters in chickens housed in three types of cages with different floors from the age of three weeks to six weeks. At three-four weeks, there were no occurrences of breast blisters among the broilers in all types of cages. At five and six weeks, there was a breast blister incidence of 14.75% and 20.68% respectively in broilers housed in wire-floored-cages. In plastic-floored cages, there was a 1.69% incidence of breast blister at both five and six weeks of age and in bamboo-floored cages an incidence of 0.76% at both ages. This presents a significant difference in breast blister incidence between wire floor-caged broilers and plastic/bamboo floor-caged broilers (P<0.05). Although there was no significant difference in lying behaviour of broilers in the three types of cages, lying was the most common behavioral pattern of broilers in all three types of cages at over 70% at the age of six weeks. Meanwhile, broilers in bamboo-floored cages displayed significantly higher frequency of walking and shaking than did broilers in wire/plastic-floored cages (all P<0.05). In wire-floored cages, walking and shaking frequency reduced notably with age, while the duration of lying and the weight on the sternum both increased. This results in the breast frequently touching and rubbing the wire floor accounting for the prevalence of breast blisters. These results suggest that the association of behavioural patterns with the type of cage floor and the prevalence of lying behaviour are key issues influencing the occurrence of breast blisters in battery broilers.
Between March and May 2005, bird communities in four sample plots at Baita Airport were studied using strips methods in Hohhot, Inner Mongolia. A total of 59 species belonging to 10 orders and 26 families were recorded. Based on the principles of avian community ecology, the community parameters were discussed, including the comparative importance value, distribution coefficient, density and probability of interactive encounter. By analyzing these indices, combined with their flight behaviors at the airport and its neighbourhood, we identified bird species that have the potential to threaten flight security at Baita Airport; The results showed that the 23 bird species including magpie and red falcon are the most hazard to flight security and the eight bird species including sparrow Hawk and Greenfinch are the hazard. Furthermore, we assessed the bird species' different hazard grades to flight security.
Benthic macroinvertebrate communities in Spartina alterniflora zones in the Yangtze Estuary, in China, were investigated seasonally in 2005, and their structure and biodiversity were analyzed. Twenty-one species were identified, across four Classes; 10 species of Crustacea, five species of Polychaeta, five species of Gastropoda, and one species of Lamellibranchia. Dominant species included: Assiminea sp., Notomastus latericeus, Cerithidea largillierl, Glauconome chinensi and Gammaridae sp. Functional groups were comprised of a phytophagous group and a detritivorous group. The average density of all benthic macroinvertebrates was 650.5±719.2 inds/m2 in the survey area. The high value of the standard deviation of the average density was a result of abundant Assiminea sp. at Beihu tidal flats. The average density of macroinvertebrates from Beihu tidal flat, Chongming Dongtan to Jinshanwei tidal flat decreased gradually. There was significant difference between compositions and abundance of macroinvertebrates along the estuary gradient (P<0.05). The density and biodiversity were highest in summer and lowest in winter. The mean biomass of macroinvertebrates was 20.8±6.1 g/m2. Biomass changed seasonally in the same way as density, with the change in biomass being: summer (Aug.) >autumn (Oct.) >spring (Apr.) > winter (Dec.). A BIO-ENV analysis showed that the mean grain size of sediment, height of Spartina and salinity were the major factors which affected the structure of the macroinvertebrate community. Variations in the community structure were probably caused by the population dynamics of S.alterniflora along with the variation in sampling time and location.
The Sichuan Hill Partridge (Arborophila rufipectus) requires successional broadleaf forest and their populations have declined as a result of fragmentation of endemic bird areas in subtropical forest in the mountains of southwestern China. In this paper, habitat utilization of the Sichuan Hill Partridge was studied in replanted broadleaf forests, in Laojunshan Nature Reserve of Sichuan, to determine the importance of habitat features, during the non-breeding period from November to December 2005. The Sichuan Hill Partridge utilized habitats within elevations of 1 000 to 1 600 m and with a south-facing slope of two to 15 degrees, close to road and forest edges. The birds preferred sites with smaller bamboo density, lower bamboo cover and snow cover and shrub cover was greater at used sites than at random sites. Principal components analysis indicated that food on the ground layer, topographic condition, concealment and temperature were the first four components of bird habitat selection, and the load of the first component was 29.407%. The findings indicated that the Sichuan Hill Partridge might face the well-documented trade-off between food resource and predation risk when utilizing habitat. We suggest that the conservation and restoration of successional broadleaf forest habitats will benefit the Sichuan Hill Partridge.
During field surveys of habitat use behaviours of Hoolock gibbons (Hoolock hoolock), 30 used sites and 30 corresponding available sites were established in Nankang, Mt. Gaoligong, from 24th March to 6th May, 2006. Results indicated that Hoolock gibbons tended to inhabit eastern slopes (Ei=0.344) as they were relatively windproof. They also favoured the tree species Querucus acutissima (Ei=0.455) and Eurya pseudocerasifera (Ei=0.068) for their large crown, as they provide more continual movement routes and large spaces for the gibbons, compared with other plant species. Quantitative factors showed that a total of 12 factors (slope; average tree and bamboo height, average circumference of tree at breast height (ACTBH); tree and shrub coverage; tree, bamboo and lianas density; and distance to water, roads and fields of Fructus amom), were significantly different between used and available sites, which revealed high selectivity to the spatial structure of habitats. Stepwise discriminant analysis showed that slope, ACTBH, bamboo density, distance to water and average tree height were the key factors, discriminating used sites from available sites, accounting for 98.3% of correct classifications. Optimal habitats of the arboreal Hoolock gibbon were characterized by having connected crowns of tall trees (14.14±3.19 m) with large basal area (ACTBH: 90.72±26.12 cm), steep slopes and high bamboo density, providing reduced ground disturbance and plentiful food for Hoolock gibbons in spring.
The Black-spotted pond frog (Rana nigromaculata) is one of the most widely distributed species in China. However, to date there are few qualitative descriptions of their breeding ecology and oviposition site selection. Such issues have important implications for establishing more effective conservation and protection management strategies for this species. From 2004 to 2006, we studied R. nigromaculata in Ningbo, China, to quantify their breeding ecology and oviposition site selection. Analyses of breeding ecology showed that: (1) mean frog density in the breeding season was 0.0903±0.0029/m (n=11) (all data are listed as Mean±SE); (2) R. nigromaculata is a sexually dimorphic species, with females significantly larger than males in both body weight and snout-vent length; (3) the clutch size averaged 4643.04±235.96 eggs (range 1 546-7 897, n=50); and (4) the egg size ranged from 1.50 to 1.74 mm in diameter, with an average egg size of 1.6050±0.0046 mm (n=226). Oviposition sites differed significantly from randomly selected sites in percentages of water, bare ground and vegetation cover, water depth (cm), water temperature (℃) and water turbidity. Rana nigromaculata preferred microhabitats with higher percentages of water and vegetation cover, while it avoided microhabitats with deeper water. The results suggest that microhabitats with higher percentages of water and vegetation cover, but not deeper water, should be priorities for protection to conserve the breeding habitats of R. nigromaculata.
Spermiogenesis and spermatozoon ultrastructure in the Nile catfish Chrysichthys auratus are described using transmission electron microscopy. Spermiogenesis involves some unique peculiarities such as: the development of the centriolar complex and the initial segment of the flagellum in a position directly perpendicular to the basal pole of the nucleus, as a result of absence of nuclear rotation; lack of a cytoplasmic canal during differentiation of the spermatids into spermatozoa; the base of the basal body is not traversed by the basal plate; a basal foot anchors the basal body to the nucleus; and the presence of numerous vesicles around the midpiece and base of the flagellum. In addition, spermiogenesis includes some common features such as: chromatin compaction; formation of a medial shallow nuclear fossa; and elimination of excess cytoplasm. The mature spermatozoon has an elongate conical-shaped head with no acrosome or acrosomal vesicle, a long midpiece with numerous vesicles that continue backwards around the base of the flagellum and a long tail or flagellum, which has no lateral fins or a membranous compartment. The mitochondria lie close to the nucleus basal pole and surround the initial segment of the axoneme and are separated from the flagellum by the inner mitochondrial envelope due to disappearance of the cytoplasmic canal. The flagellum has the classical axoneme structure of a 9+2 microtubular pattern. On the basis of the peculiar features mentioned above, it is concluded that spermiogenesis in this Nile catfish is a synapomorphic type derived from types I and II spermiogenesis, which are common among teleosts. Accordingly, this type could be considered as a novel type of spermiogenesis and could be termed as “type III”.
One hundred and fifty specimens of Pelteobagrus intermedius from 12 drainage systems were collected to measure 21 morphometric characters using traditional taxonomic methods. Data on the morphometric characters were analyzed using principal component analysis in order to discuss the morphological variation and geographical differentiation of the characters. The populations of the 12 drainage systems are divided into three clusters by the first three principal components, which express 58.918% of the cumulative variance. The populations of P.intermedius from the coastal area of western South China were more closelyrelated to the populations of Hainan Island than to the populations of the Xijiang River. In addition, distinct differences were shown in the populations from the three small drainage systems of Fangchenggang. The main morphological differences between populations were related to the snout, eyes and tail.
To establish an in vitro system for isolating and culturing the mesenchymal stem cells (MSC) of Rhesus monkeys, and to provide research data for its further application, the bone marrow of Rhesus monkeys was collected and separated by gradient centrifugation to discard most of the blood cells. The MSC contained in the monocyte centrifuging layer was obtained and cultured in Dulbecco's modified media (low glucose, L-DMEM) supplemented with 10% Fetal bovine serum (FBS) and 1 ng/ml basic fibroblast growth factor (bFGF). The non-MSC was screened out by continuously renewing the medium. A passage culture was undertaken while the MSC monolayer formed. The spindle-shaped MSC formed a monolayer after 18 days of primary culturing, and the cells appeared in an oriented array with a swirling and irradiating growth trend. In the anaphase of passage culture, the cell proliferation rate was decreased and the morphology changed into triangular, polygon and flat appearance. These results suggested that mesenchymal stem cells (MSC) of the Rhesus monkey can be passaged in vitro with the established optimized culture system.
2007, 28(2): 217-224.
Trichodinids (Ciliophora: Peritrichida) are one of the most common parasitic ciliates, which can cause serious diseases in aquaculture animals of both marine and freshwater environments. Therefore the study of these ciliates is necessary in order to prevent and control such diseases. Here we review the history of the taxonomy and phylogeny of the trichodinids. Under taxonomy, we introduce the parasitic positions and geographic distribution of trichodinids. Furthermore, we summarize a three-stage pylogenetic process based on morphological and molecular characters. Finally, we make some suggestions on the future study of the taxonomy and phylogeny of trichodinids.