2006 Vol. 27, No. 3
Leptodactylus labrosus is a terrestrial sit-and-wait predator; its diet includes ground-level, fossorial, and flying insects, and ants numerically predominate. Bothrops asper is recorded as a predator of L. labrosus. L. labrosus lives mainly in deciduous and semi-deciduous forests, where it is restricted to wet microhabitats, and occasionally in evergreen forests. L. labrosus inhabits northern, central, and southern regions of western coastal Ecuador and northern and central western coastal Peru up to 700 m, and into the dry interandean valleys of southern Ecuador and northern Peru up to 1 300 m. Its distribution encompasses moistly seasonally dry forest in coastal Ecuador and Peru. It also occupies moister areas towards the slopes of the Andes where it is sympatric with three other congeneric species, but at sites of sympatry the species show habitat segregation. The distribution pattern of L. labrosus is shared by several other range-restricted amphibians corresponding to the Tumbesian region, which should be recognized as an endemic Amphibian area. The zone between the Choco and Tumbesian regions, where L. labrosus gets in sympatry with other Leptodactylus species, possess ecological and climatic characteristics that have shaped a unique fauna, including several endemic taxa; and it should be recognized as the west Ecuadorian endemic region.
From June to September, 2005, we compared echolocation calls, the summer diet and morphologic features of three bats species (Myotis siligorensis, Rhinolophus pusillus and Taphozous melanopogon) captured in two caves around Guilin city, Guangxi province, China. We got the following results: (1) Echolocation calls of T. melanopogon are lower modulated frequency (FM), with dominant frequency (32.84±1.17)kHz, and multi-harmonics (usually with four harmonics). This species has the largest body size, highest ratio of wing length to wing width and highest wing loading. This species is adapted to fly fast and forage for larger insects in open area such as those in treetops and above farmland. (2) The echolocation calls of M. siligorensis are FM. Their dominant frequency (84.44±8.13)kHz is higher than T. melanopogon. They have smaller body size, lower ratio of wing length to wing width and lower wing loading which are adapted to fly slower but are more manoeuvrable and suited to forage for small insects. (3) The echolocation calls of R. pusillus are long FM-CF-FM and their dominant frequency (110.78±1.65)kHz is the highest among these three species. R. pusillus and M. siligorensis have similar morphology with similar flight ability and manoeuvrability therefore they forage in similar habitat. In conclusion, these bats species differ from each other obviously in echolocation calls and diets, which lead to their conspicuously partitioned niches.
During April of 2004, alpine blood pheasants (Ithaginis cruentus) were studied in the southwest Shiqu county of Sichuan province. The results show that the alpine blood pheasants are only distributed in the range of 3 400-3 700 m elevation. Among 36 groups and 381 individuals observed, the average group (±SD) has 10.67 (±5.17) individuals. The largest group had 19 individuals and the common group had 8-16 individuals. The main factors affecting the habitat requirements of alpine blood pheasants in the initial mating period, according to the priority sequence, are slope position, distance to water resource, distance to highway, overstory cover, vegetation height, and slope orientation. Alpine blood pheasants prefer lower slope position, farther away from water resource (＞100 m), sparse shrub (15%-30%), low shrub (1.50-2.50 m) and a half-gloomy-half-sunny slope, among which the slope position and the distance to water resource are correlated to group size. Group sizes in the alpine area decrease with increasing slope position and increase with the shortening of distance to water resource in the initial mating period. We suggest that the foregoing results are associated with their food resource available in different habitat types.
2006, 27(3): 249-254.
A study on roost-site selection of Mrs Hume's Pheasant (Syrmaticus humiae) was conducted in Jinzhongshan Bird Natural Nature Reserve, Guangxi Zhuang Autonomous Region with transect and plot sampling approaches in Dec. 2003, May and Dec. 2004, and Apr. 2005. During the study, 12 roost-sites were found and we recorded 5 parameters about the roost-tree, including: tree species and diameter at breast height, roost size, height and upper cover; and 11 parameters about the habitat, including: vegetation type, elevation, slope orientation, slope degree, tree density, coverage of canopy, shrub and herb, distance to water source, forest edge and road. Also we randomly sampled 10 non-roost sites as the control measuring. The results showed: 1) The pheasant preferred broadleaf forest with good canopy as its roost-site; 2) The size of the roosts is 2.5-4 cm in diameter and the roosting places are usually 2-5 m above the ground; 3) Most of the pheasants roosted in a tree alone with few occasions in which 2 or 3 individuals were sleeping in one tree. The variance analysis showed that the roost-sites are significantly associated with slope, coverage of canopy, shrub and herb, distance of forest edge and tree density but not the distance of water source. The pheasants are likely to roost in places with steep slope, open ground and dense forest deep in the forest. With principal component analysis it was found that the pheasant's roost-site selection is sequentially associated with location, shrub/herb coverage, roost size and weather. We believed that safety, comfort and foraging convenience are the three key considerations for the pheasant's roost-site selection. Therefore protecting broadleaf forest would greatly benefit the pheasant species.
We measured body size and reproductive traits of blue-tailed skinks (Eumeces elegans) from two localities at different latitudes in Eastern China to reveal their inter-population differences in reproductive life-history strategies sp. Females from Ningde, the locality at a lower latitude, produced their eggs from 27th May to 22nd June; whereas females from Hangzhou, the locality at a higher latitude, produced eggs from 4th June to 12th July. Snout-vent lengths of the minimum reproductive female and adult skinks in Ningde population were smaller than that in Hangzhou population. Females from the two populations did not show significant difference in relative clutch mass. After the effect of maternal snout-vent length was statistically removed, clutch size and clutch mass did not differ between the two populations, but mean egg mass still showed considerable inter-population difference, with larger eggs in Hangzhou skinks. This study revealed negative correlation between clutch size and egg mass, and inter-population difference in trade-offs between clutch size and egg size. For a given clutch size, females from Hangzhou laid larger eggs than did those from Ningde. Therefore, in E. elegans, reproductive life histories differ significantly between the two populations, and maternal body size accounts for a large quantity of such inter-population differences. These results suggest that the reproductive strategies for this species change from a high-latitudinal population to a low-latitudinal population.
2006, 27(3): 261-268.
In order to investigate piglet welfare and the effect of transport on piglets, a transport experiment was designed on the road from Beijing to Handan. The piglets' behaviour and performance was measured and the transport temperature, transport space allowance and transport duration were considered in this experiment. Data processing showed: (1) Significant negative correlation between transport temperature and the percent of pigs' lying behaviour in this experiment (Pearson Correlation Test, R＝-0.324，P<0.01); (2) No significant difference between two transport space allowances on the piglets' standing (Mann-Whitney U Test,P>0.05) and active (Chi-square Test，P>0.05) behaviours, but a significant difference between transport space allowances on the piglets' lying behaviour (Mann-Whitney U Test,P<0.05); (3) A significant effect of transport duration on piglets' standing, lying (Friedman Test，P<0.001) and active (Chi-square Test,P<0.01) behaviour; (4) No significant difference between two transport space allowances on pig skin damage (Mann-Whitney U Test,P>0.05) or weight change (t Test,P>0.05). The results indicate that under certain transport conditions the piglets' behavior may be affected by transport duration, but not by transport space allowance in this experiment. It is possible that pigs' sternum area is not the lowest limit of transport space allowance.
The food intake, duration of stay and frequency of visitation of the steppe polecat (Mustela eversmanni) staying in places with different species' odors were investigated through the two-choice test in the laboratory, and the effects of different species' odors on the feeding behaviors of the polecats were determined. The results showed that the food intake, duration of stay and frequency of visitation of the polecat were the same when there were no odors in either of the two patches. The odors of two prey species, the zokor (Myospalax baileyi) and the pika (Ochotona curzoniae) had no significant influence on the polecat behaviour compared with the controls. The variables were all much higher in the control site than in the site of the red fox's odor, The polecat significantly increased total food intake, decreased the living time in nest boxes and spent more time in the control place when the odor of the red fox (Vulpes vulpes) existed in the other patch, as indirect predation risk existed. The polecat had the ability to decrease the predation risk through the strategy of increasing the food intake and decreasing the time of staying in the high predation risk patch.
The effects of interspecific competition on the population dynamics of four insect grain Insecp pests (Sitophilus zeamais,Rhizopertha dominica,Tribolium castaneum and Cryptolestes ferrugineus) was studied at 30 ℃, 75% relative humidity. A regression analysis of the population dynamics was conducted. The results showed that population growth of S. zeamais,R. dominica, T. castaneum and C. ferrugineus was restrained under mixed rearing. Population growth of T. castaneum and C. ferrugineus was remarkably accelerated when they coexisted with S. zeamais or R. dominica, while that of S. zeamais and R. dominica was restrained to some extent. Regression analysis results showed that the population growth potential of S. zeamais was the largest and that of C. ferrugineus was the smallest, and the changing trends of population growth rates were not distinct.
Locust plagues are one of the most severe plague problems in human history. Among the many factors influencing locust plagues, soil moisture content plays an important role. Three locations in Huanghua county of Hebei province were used as the study area, a region that has been severely affected by locust plague. Soil moisture content was extracted using MODIS remote sensing images from the time that fall locusts are at oviposition (September-October) to the time that summer locust is at hatching (March-April). The study was conducted in 2002, when the region had been severely suffered by locust plague, and from the same time in 2004, when locust plague was less severe. The study shows that soil moisture content in 2002, a year of locust plague, was lower than that in 2004. The effect was greater in September to October, when fall locusts are at ovipositon and in March to April. when summer locusts are hatching.
The effects of multiple mating on quantitative depletion of spermatozoa, fecundity and hatchability in Monochamus alternatus Hope were investigated by dissecting spermatheca and observing the biological characteristics in the laboratory. The reproductive systems of the female, spermatozoon morphology and dynamic distribution of spermatozoa in female reproductive system were also described in this paper. The results showed that about 120 thousand spermatozoa were always retained in the spermatotheca of multiple mating females, but the amount of spermatozoa declined according to the time extension after copulation in the spermatotheca of single mating females, and the amount of spermatozoa declined to 50 thousand after 16 d. The fecundity (167.087 0) and hatchability (94.38%) of multiple mating females were significantly higher than the fecundity (113.521 7) and hatchability (83.79%) of single mating females. However, the period of reproduction and longevity were not significantly different between multiple and single mating females.
Ultrastructure and morphology of the spermatozoa in Vibrissaphora boringii was studied by light microscopy, transmission and scanning electron microscopy. The structural features of spermatozoa in V. boringii and its taxonomical sense in Vibrissaphora and Megophryidae were discussed. The results show that the sperm of V. boringii present basic morphological and structural characters of Megophryidae by having a spiral head, forniciform tail, conical acrosome vesicle, perforatorium composed of fibers, parallel centrioles, two axonemes and mitochondrion lying in the tail, and lacking distinct nuclear fossa, axial fibers and an undulating membrane. Additionally, comparative analyses of the sperm structure among Megophryidae and other families of tailless Amphibians (Anura) indicates that: 1) The ultrastructural and morphological characters of spermatozoa in Megophryidae, including spiral nucleus, parallel centrioles and two axonemes in the tail, obviously differs from those of the other families of Anura; 2) The distinct differences in size of sperm, the amount and the distribution of mitochondrion, and the range of axonemes also exist among the species and genera of Megophryidae; 3) The ultrastructure and morphology of spermatozoa of Leptobrachium aff. hasselti and Vibrissaphora boringii notably differs from each other.
Bovine mammary epithelial cells were isolated and purified by using collagenase digestion of the mammary gland tissue for the primary cell culture, and subsequently using trypsin-selected digestion of the cultured cells for cell purification. Morphological observation revealed that the cultured cells possessed the typical character of epithelial cells. Karyotyping analysis showed the normal chromosome number in cultured cells. The tissue-specific expression of cytokeratin 5 and 8 genes in mammary epithelial cells was identified by immunofluorescent cytochemical staining. The transcription of the betacasein gene was detected by RT-PCR, when the purified cells were induced with insulin, hydrocortisone and prolactin in the culture medium without serum. The above results indicate that the purified cells are mammary epithelial cells, which can transcript beta-casein mRNA in the induction condition.
Sequences from a region of the nuclear ribosomal 18S rDNA gene of approximately 1 912 base pairs (bp) were used to generate a molecular phylogeny for the Pentatomomorpha based on 53 species representing 21 putative families. Phylogenetic analyses using the most parsimony method (MP), maximum likelihood method (ML), and neighbor joining method (NJ) showed strong support that the Pentatomomorpha lineage is a monophyly and the superfamily Aradoidea is a sister group to the remainder of the Pentatomomorpha (Trichophora). The Trichophora could be divided into two clades: one clade consisted of the monophyletic superfamilies Pentatomoidea and Pyrrhocoroidea; the other was mainly the polyphyletic superfamilies Lygaeoidea, Coreoidea and Idiostoloidea. The superfamilies Lygaeoidea and Coreoidea were both polyphyletic. Within Lygaeoidea, Piesmatidae was sister to Berytidae. They formed a clade locating at the basal of the Trichophora and distantly related to the other two families Lygaeidae and Rhyparochromidae. This research suggested that 18S rDNA was a proper marker to reconstruct the phylogeny of Pentatomomorpha that was accordant to morphological studies and the research of Li et al (2005). The Pyrrhocoroidea was further divided from the Coreoidea (s.lat). It was suggested that the Piesmatidae might be assigned as a superfamily of Pentatomomorpha rather than a family in Lygaeoidea.
The primary genetic linkage maps of Fenneropenaeus chinensis were constructed by using a "two-way pseudo-testcross" strategy with RAPD and SSR markers. Parents and F1 progeny were used as segregating populations. Sixty-one RAPD primers and 20 pairs of SSR primers were screened from 460 RAPD primers and 44 pairs of SSR primers. These primers were used to analyze the parents and 82 progeny of the mapping family. One hundred and forty-six marker primers (128 RAPDs, 18 microsatellites) were used in the female and 127 primers (109 RAPDs, 18 microsatellites) in the male were used as segregating markers. The female linkage map included eight linkage groups, nine triplets and 14 doublets, spanning 1 173 cM with the average marker density of 11.28 cM. The observed coverage was 59.36%. The male linkage map included 10 linkage groups, 12 triplets and seven doublets, spanning 1 144.6 cM with the average marker density of 12.05 cM. The observed coverage was 62.01%. The construction of the F. chinensis genetic linkage maps here open a new prospect for marker-assisted selection programs, comparative genomics and quantitative trait loci (QTL) gene location and cloning.
2006, 27(3): 325-330.
Total RNA was extracted from the prefrontal cortex (PFC) of rhesus monkeys with TRIzol reagent. mRNA was further purified from total RNA using a purifying kit for mRNA. According to the manual of cDNA Synthesis Kit (200401), ZAP-cDNA Synthesis Kit (200400)，and ZAP-cDNA GigapackⅢ Gold Cloning Kit (200450) from Stratagene, we constructed a cDNA-library of the PFC of rhesus monkeys. Our aim was to identify brain-function (such as cognition and memory) related genes and gene families. The cDNA library has a capacity of 2.0×10 6 clones, and 97.3% of them are recombinant clones. The average size of the inserted cDNA fragments is 1.0 kb with the majority of inserts larger than 0.5 kb, which meets the requirement of a standard cDNA library. The PFC cDNA library constructed will be useful in cloning and sequencing brain-function related genes, and in dissecting the alternative splicing patterns of genes expressed in the brain. Meanwhile, it will also serve as a useful resource in understanding the expression regulations within the brain.
We sampled wild birds for the Avian Influenza Virus (AIV)(H5, H7 and H9) survey in the AI infected regions of Guangdong during its eruptive period in early 2004. Seventy-six samples of blood serum, 125 swab samples and 21 organic samples were collected. The method of agar gel precipitation (AGP) and hemagglutination inhibitory (HI) was adopted in serum detection. The chicken embryo culture was adopted in virus detection. Our results showed: (1) H9 viruses were only found in starlings of Nan'ao, Shantou，in the AI noninfected regions.(2) 31.6% H5 and 23.7% H9 immunoreactive blood serums were detected in Leizhou, Luoding, Haifeng and Shantou. The positive rates of wild birds in inshore area are higher than in other regions. (3) The positive rate of migratory birds is higher than resident birds. Therefore, we concluded that migratory birds would spread AIV in its eruptive period.