对体型大小不同的两种陆生等足类动物进行形态特征和行为特征研究,探讨环境变化对其繁殖特征和种群结构的影响。自2004年5月至2005年4月,在巴西Parque Estadual de Itapua进行野外采样,其中每月采集12个凋落物和土壤样品,实验室手拣法...对体型大小不同的两种陆生等足类动物进行形态特征和行为特征研究,探讨环境变化对其繁殖特征和种群结构的影响。自2004年5月至2005年4月,在巴西Parque Estadual de Itapua进行野外采样,其中每月采集12个凋落物和土壤样品,实验室手拣法收集等足类,共获得2540只,同时进行个体性别鉴定与测量。结果表明,Atlantoscia floridana平均密度为114只Pm2,Balloniscus glaber平均密度为133只Pm2。A.floridana雌性个体全年可育,B.glaber雌性个体只在早春至初夏时段可育,其中春季这两种动物雌性可育个体数量高。2005年夏季干旱,该气候因子对两种动物种群影响存在差异,其中干旱使A.floridana种群减少,而B.glaber种群基本保持稳定,两种动物间形态结构不同是上述差异的主要原因,尤其是B.glaber,特殊的体型和腹肢肺的存在使其更能忍耐干燥。此外,B.glaber可能也依赖行为策略适应环境,例如挖掘活动,在不利气候条件下挖掘活动能够增加年轻个体生存的机会,也可能对成年个体起到保护作用。对于A.floridana来说,它具有连续繁殖、性成熟时间短和高雌性生育比率的特征。展开更多
A new planktonic dinoflagellate, Prorocentrum donghaiense Lu sp. nov., is described in the present paper. The water sample was collected from the Changjiang Estuary, the East China Sea. The species identification is b...A new planktonic dinoflagellate, Prorocentrum donghaiense Lu sp. nov., is described in the present paper. The water sample was collected from the Changjiang Estuary, the East China Sea. The species identification is based on shape, size, surface micro morphology, ornamentation of thecal plates and the architecture of the periflagellar area and the intercalary bands as seen by light and scanning electron microscope. Prorocentrum donghaiense Lu sp. nov. is compared with other prorocentrum species with respect to morphological characteristics and bloom behavior. It is not known whether Prorocentrum donghaiense Lu sp. nov produces phycotoxins like some other Prorocentrum species. Four other red tide species in the family Prorocentraceae (Dinophyceae), namely P. balticum , P. minimum, P. micans, P. triestinum , were examined and identified by light and scanning electron microscope. They have been recorded as bloom forming species. Some aggregates of Prorocentrum are observed at the end of blooms. An event of strong discoloration caused by P. donghaiense could be detected by satellite sensor in the East China Sea in the late spring of 1995.展开更多
A new species of free-living nematode, Pseudolella major sp. nov. is described from the intertidal mudflats of Ximen Island in the East China Sea. Pseudolella major sp. nov. is characterized as follows： body length -...A new species of free-living nematode, Pseudolella major sp. nov. is described from the intertidal mudflats of Ximen Island in the East China Sea. Pseudolella major sp. nov. is characterized as follows： body length -1 300 μm; short cephalic setae, 2-3μm long; amphidial fovea loop-shaped with elongated ventral branch; ventral branch 50-60 μm long and extending past the base of buccal cavity; buccal cavity cylindrical with arching or spherical base; three heavy outwardly-curving odontia with blunt tips located at anterior of buccal cavity; pharynx short with posterior bulb; ventral gland cell elongate oval-shaped, located posterior to pharyngo-intestinal junction; excretory pore situated at the level of the middle of buccal cavity; tail conical to cylindrical; spicules arched, with double-cephalate proximal end; gubemaculum with a strong dorsal caudal apophysis.展开更多
A new species of free-living marine nematode is described from intertidal sediment of the East China Sea.The new species belongs to the Oncholaimidae family.Oncholaimus zhangi sp.nov.is characterized by males having a...A new species of free-living marine nematode is described from intertidal sediment of the East China Sea.The new species belongs to the Oncholaimidae family.Oncholaimus zhangi sp.nov.is characterized by males having a large ventral swelling situated just posterior to the middle of the tail,no precloacal papilla,and a row of 6–7 ventral genital setae.The tails of both males and females are similar,being conico-cylindrical in shape.The new species is distinguished from other closely related species by the presence of a prominent ventral swelling at the tail of males and a similar tail shape in both sexes.About 110valid species in this genus have been recorded to date.展开更多
Statistically significant differences （when p 〈 0.05 using the permutation t-test） among Live Foraminiferal Densities （LFDs） recovered in August, November, March and May were detected at tropical Caroni swamp, Cl...Statistically significant differences （when p 〈 0.05 using the permutation t-test） among Live Foraminiferal Densities （LFDs） recovered in August, November, March and May were detected at tropical Caroni swamp, Claxton bay （Trinidad）, temperate Cowpen marsh and Brancaster marsh （U.K.）. The monthly mean LFDs of the foraminiferal metacommunities （all stations）, assemblages （groups of stations defined by cluster analysis）, and the agglutinated and calcareous specimens within each were compared separately. The LFDs of the Caroni swamp metacommunity did not fluctuate significantly among months, but significantly higher abundances of agglutinated specimens occurred in the upper assemblage in March; and calcareous specimens in the lower assemblage in November. At Claxton bay, monthly LFDs of the metacommunities and assemblages did not vary significantly, but calcareous and agglutinated species within each favoured dry （March and May） and wet （August and November） months respectively At the temperate marshes, significantly higher LFDs of the metacommunities and assemblages were recorded in warmer months. August blooms of the Cowpen marsh metacommunity was attributed to agglutinated specimens in the upper assemblage, and calcareous specimens in the lower assemblage. May blooms of the Brancaster marsh upper assemblage were attributed to calcareous specimens, but there were no seasonal blooms of the lower assemblage.展开更多
基金This research wasfunded bythe grantsfromCNPqto PB Araujo (Proc .473862/2004-2) fromFAPERGS-PROAPPto PB Araujo (Proc .0409925) +2 种基金fromCAPESto AF Quadros SEMA-RSsupportedthe development of field work (Project No.176) Thisis contribution number 497 of the Departamentode Zoologia , UFRGS.
文摘对体型大小不同的两种陆生等足类动物进行形态特征和行为特征研究,探讨环境变化对其繁殖特征和种群结构的影响。自2004年5月至2005年4月,在巴西Parque Estadual de Itapua进行野外采样,其中每月采集12个凋落物和土壤样品,实验室手拣法收集等足类,共获得2540只,同时进行个体性别鉴定与测量。结果表明,Atlantoscia floridana平均密度为114只Pm2,Balloniscus glaber平均密度为133只Pm2。A.floridana雌性个体全年可育,B.glaber雌性个体只在早春至初夏时段可育,其中春季这两种动物雌性可育个体数量高。2005年夏季干旱,该气候因子对两种动物种群影响存在差异,其中干旱使A.floridana种群减少,而B.glaber种群基本保持稳定,两种动物间形态结构不同是上述差异的主要原因,尤其是B.glaber,特殊的体型和腹肢肺的存在使其更能忍耐干燥。此外,B.glaber可能也依赖行为策略适应环境,例如挖掘活动,在不利气候条件下挖掘活动能够增加年轻个体生存的机会,也可能对成年个体起到保护作用。对于A.floridana来说,它具有连续繁殖、性成熟时间短和高雌性生育比率的特征。
文摘A new planktonic dinoflagellate, Prorocentrum donghaiense Lu sp. nov., is described in the present paper. The water sample was collected from the Changjiang Estuary, the East China Sea. The species identification is based on shape, size, surface micro morphology, ornamentation of thecal plates and the architecture of the periflagellar area and the intercalary bands as seen by light and scanning electron microscope. Prorocentrum donghaiense Lu sp. nov. is compared with other prorocentrum species with respect to morphological characteristics and bloom behavior. It is not known whether Prorocentrum donghaiense Lu sp. nov produces phycotoxins like some other Prorocentrum species. Four other red tide species in the family Prorocentraceae (Dinophyceae), namely P. balticum , P. minimum, P. micans, P. triestinum , were examined and identified by light and scanning electron microscope. They have been recorded as bloom forming species. Some aggregates of Prorocentrum are observed at the end of blooms. An event of strong discoloration caused by P. donghaiense could be detected by satellite sensor in the East China Sea in the late spring of 1995.
基金Supported by the National Natural Science Foundation of China(No.41176107)
文摘A new species of free-living nematode, Pseudolella major sp. nov. is described from the intertidal mudflats of Ximen Island in the East China Sea. Pseudolella major sp. nov. is characterized as follows： body length -1 300 μm; short cephalic setae, 2-3μm long; amphidial fovea loop-shaped with elongated ventral branch; ventral branch 50-60 μm long and extending past the base of buccal cavity; buccal cavity cylindrical with arching or spherical base; three heavy outwardly-curving odontia with blunt tips located at anterior of buccal cavity; pharynx short with posterior bulb; ventral gland cell elongate oval-shaped, located posterior to pharyngo-intestinal junction; excretory pore situated at the level of the middle of buccal cavity; tail conical to cylindrical; spicules arched, with double-cephalate proximal end; gubemaculum with a strong dorsal caudal apophysis.
基金Supported by the National Natural Science Foundation of China(No.41176107)
文摘A new species of free-living marine nematode is described from intertidal sediment of the East China Sea.The new species belongs to the Oncholaimidae family.Oncholaimus zhangi sp.nov.is characterized by males having a large ventral swelling situated just posterior to the middle of the tail,no precloacal papilla,and a row of 6–7 ventral genital setae.The tails of both males and females are similar,being conico-cylindrical in shape.The new species is distinguished from other closely related species by the presence of a prominent ventral swelling at the tail of males and a similar tail shape in both sexes.About 110valid species in this genus have been recorded to date.
文摘Statistically significant differences （when p 〈 0.05 using the permutation t-test） among Live Foraminiferal Densities （LFDs） recovered in August, November, March and May were detected at tropical Caroni swamp, Claxton bay （Trinidad）, temperate Cowpen marsh and Brancaster marsh （U.K.）. The monthly mean LFDs of the foraminiferal metacommunities （all stations）, assemblages （groups of stations defined by cluster analysis）, and the agglutinated and calcareous specimens within each were compared separately. The LFDs of the Caroni swamp metacommunity did not fluctuate significantly among months, but significantly higher abundances of agglutinated specimens occurred in the upper assemblage in March; and calcareous specimens in the lower assemblage in November. At Claxton bay, monthly LFDs of the metacommunities and assemblages did not vary significantly, but calcareous and agglutinated species within each favoured dry （March and May） and wet （August and November） months respectively At the temperate marshes, significantly higher LFDs of the metacommunities and assemblages were recorded in warmer months. August blooms of the Cowpen marsh metacommunity was attributed to agglutinated specimens in the upper assemblage, and calcareous specimens in the lower assemblage. May blooms of the Brancaster marsh upper assemblage were attributed to calcareous specimens, but there were no seasonal blooms of the lower assemblage.
