储粮昆虫物种组成初次级仓虫跟随关系及寄生关系研究

分析了害虫和天敌种群的动态趋势,表明寄生蜂复合种群数量消长与谷蠹和赤拟谷盗相近;分析了小麦散装粮堆储粮昆虫群落结构及演替特点,表明该群落由鞘翅目的玉米象、谷蠹、锯谷盗、赤拟谷盗、扁谷盗,膜翅目的米象小蜂、谷象小峰、谷虫小蜂,啮虫目的书虱,蜱螨目,鳞翅目的麦蛾组成。该群落在4-7月份昆虫种类和数量逐渐增加,7-9月份昆虫种类和数量达到最大,10-12月份昆虫种类和数量逐渐减少;2006年5、6间群落系数为0.6441,9、10月间群落系数为0.5910,2006年冬季和2007年春季群落系数为0.4516,月份、季节之间物种组成和数量相近。

Embryonic and larval development in barfin flounder Verasper moseri (Jordan and Gilbert)

Broodstock of Verasper moseri （Jordan and Gilbert） aged 3-4 years old were selected, and reinforced cultivation was conducted to promote maturation under controlled water temperature and photoperiod conditions. Fertilized eggs were obtained by artificial fertilization, and the development of embryos, larvae and juveniles was observed continuously. The results showed that the fertilized eggs of V. moseri were spherical, with transparent yolk and homogeneous bioplasm, and had no oil globule inside. The average diameter of the eggs was 1.77＋0.02 mm. The eggs of V. moseri were buoyant in water with salinity above 35. The cleavage type was typical discoidal. Young pigment cells appeared when olfactory plates began to form. Hatching occurred at 187 h after fertilization at a water temperature of 8.5℃. The newly hatched larvae, floating on the water surface, were transparent with an average total length of 4.69±0.15 mm. During the cultivation period, when the water temperature was raised from 9 to 14.5℃, 4-day old larvae showed more melanophores on the body surface, making the larvae gray in color. The pectoral fins began to develop, which enabled the larvae to swim horizontally and in a lively manner. On days 7-8, the digestive duct formed. The yolk sac was small and black. The yolk sac was absorbed on day 11. Larvae took food actively, and body length and body height clearly increased. The rudiments of dorsal and anal fin pterygiophores were discernible and caudal fin ray elements formed on day 19. On day 24, the larval notochord flexed upwards, and the rays of unpaired fins began to differentiate. Pigment cells converged on the dorsal and anal fin rays, and the mastoid teeth on the mandible appeared. On day 29, the left eyes of juveniles began to move upwards. Depigmentation began in some juveniles and they became sandy brown in color on day 37. Most juveniles began to settle on the bottom of the tank. The left eyes of juveniles migrated completely to the right side on day 50, when the average body length attained 2.5±0.18 cm, and juveniles accomplished metamorphosis to young. The embryonic and larval characters of several flounder species are compared.

Effect of human milk and colostrum on Entamoeba histolytica

AIM:Many defense factors of the mother's colostrum or milk protect infants from intestinal, respiratory and systemic infections. In the present study, we investigated the effect of colostrum and mature human milk on E. histolytica parasites in vitro.METHODS:Samples of human milk were collected from 5 healthy lactating mothers.The medium with human milk at concentrations of 2%, 5% and 10% was obtained.RESULTS:The lethal effect of E. histolytica on the medium supplemented with different concentrations of both colostrum and mature human milk was significant during the first 30min. We also detected that the results of colostrum and mature human milk were similar. No statistically significant differences were found between same concentrations of colostrum and mature human milk at the same times.CONCLUSION:Colostrum and mature human milk have significant lethal effect on E. histolytica and protect against its infection in breast fed children.

Distribution and Elimination of Norfloxacin in Fenneropenaeus chinensis Larvae

This study examined the distribution and elimination of Norfloxacin （NFLX） in Fenneropenaeus chinensis ovary and egg and newly hatched larvae. Mature parental shrimp were exposed to 4 or 10mgL-1 NFLX for 2 or 5d. Ovary and eggs of the shrimp were sampled after spawning in order to detect NFLX residue using high-performance liquid chromatography （HPLC）. Re- suits showed that NFLX residue accumulated in F. chinensis eggs after the parental exposure, with the highest residue detected in ovary. To examine the fate of NFLX residue in larvae, we further determined the concentration of NFLX residue in F. chinensis eggs and larvae at 4 different developmental stages after 24-h exposure. From the newly metamorphosed larvae （Oh post-metamorphosis, h.p.m）, samples were taken at different time intervals to 72 h,p.m. HPLC assay showed that the concentrations of NFLX residue in zoea exposed to 4 and 10mgL-1 NFLX were the highest at 1.5h, i.e., 0.332 and 0.454μgg-1, respectively. At the two NFLX expo- sure levels, the elimination time of half NFLX （half life） in nauplius was 45.36 and 49.85h, respectively, followed by that in zoea （31.68 and 33.13 h）, mysis larvae （42.24 and 47.28 h） and postlarvae （24.48 and 30.96 h）. Both NFLX exposure levels had a germi- cidal effect. The distribution and elimination of NFLX residue in F. chinensis tissue, eggs and larvae correlated well with the drug exposure level. The disappearance of NFLX residue coincided with the larval growth, and the half-life of NFLX decreased with the larval development.

唇口目苔藓虫群体早期发育的演化意义——Ⅰ.软壁亚目膜孔苔虫科和琥珀苔虫科的群体早期发育特点及一新属、六新种

苔藓动物的群体是由生理上互相连系、以无性繁殖方法复制的称之为个虫的成员组成。幼虫变态后,绝大多数苔藓虫形成构成群体基础的单一个虫,称为初虫,这些单一的初虫通常为一摄食个虫,有时则为形态多样的无摄食功能的空个虫;另一些幼虫变态后则形成2个、3个或5个个虫,称之为初虫群,初虫群的每一个体均为摄食个虫。绝大多数苔藓虫群体都由单一的初虫或初虫群以无性出芽而成,只有极少数苔藓虫群体由休眠芽产生或由裂殖方式产生。按照苔藓动物学关于群体性质的一般概念。

Distribution of living radiolarians in spring in the South China Sea and its responses to environmental factors

Using a planktonic net(62-?m mesh) and a Rose-Bengal staining method, we studied the spatial distribution of living radiolarians in spring along two sections of the South China Sea(SCS) in spring and discussed the responses of living radiolarian distribution to tropical environmental factors. Generally, the highest abundance of living radiolarians occurred at the depth range of 25–75 m, where the chlorophyll-a maximum and the highest primary productivity were. In contrast, the maximum living abundance occurred in the top 25 m in cold eddies in the open seas and the abundance decreased with depth. We found that the inhibition effect of changing salinity(due to runoffs) on living radiolarians was much stronger than the promotion effect of mesoscale cold eddies. We observed that large variation of temperature was unfavorable for living radiolarians. The dominant species composition consisted of tropical-subtropical warm species. We identified some indicator species for tropical environments. Living Didymocyrtis tetrathalamus tetrathalamus could be an indicator for tropical surface water or mixed-layer water, and even for tropical oligotrophic water. Living Tetrapyle octacantha could be used to indicate tropical thermocline and eutrophic environment. Living Acanthodesmia vinculata could indicate tropical surface and subsurface waters. T. octacantha and A. vinculata should only be used as indicators for upwelling in the open seas, i.e., far away from river mouths. Living Siphonosphaera polysiphonia preferred to form colonies, which might be related to the effect of warm eddies. Living Cyrtopera laguncula and living Cornutella profunda occurred in the tropical upper layer, even in the surface layer, which suggests that they should not be used as indicators for intermediate and deep waters.