为研究胶州湾小型底栖动物时空分布格局及其环境影响因素,本研究团队于2021年1月和4月分别在胶州湾内、外海域各进行了1个航次的野外观测和采样,对小型底栖动物的类群组成、丰度、生物量、群落结构、水平和垂直分布及其与环境因子的关...为研究胶州湾小型底栖动物时空分布格局及其环境影响因素,本研究团队于2021年1月和4月分别在胶州湾内、外海域各进行了1个航次的野外观测和采样,对小型底栖动物的类群组成、丰度、生物量、群落结构、水平和垂直分布及其与环境因子的关系进行了研究。研究结果显示:调查海域共鉴定出小型底栖动物12个类群;冬季和春季小型底栖动物的平均丰度分别为(769.6±184.8)和(683.3±173.3)ind./10 cm^(2),平均生物量分别为(587.0±78.0)和(426.7±67.4)μg/10 cm^(2);自由生活海洋线虫为最优势类群,在冬、春两季分别占小型底栖动物总丰度的87.60%和92.36%;此外,底栖桡足类、轮虫和无节幼体等也是较重要的类群;在季节分布上,小型底栖动物群落结构存在显著差异,生物-环境因子匹配(Biological and environmental data matching,BioEnv)分析表明,解释其群落结构变异的最佳环境因子组合为水深、底温、沉积物含水量和中值粒径;在水平分布上,两个季节小型底栖动物群落结构在胶州湾口内、外均无显著差异,但每个季度的丰度最低值均出现在湾口站位,这可能与沉积物中值粒径以及底层水温有关;本海域小型底栖动物的平均丰度比其他海域要低,这与近海的人类活动密不可分;海洋线虫与桡足类之比(N/C)偏高,表明胶州湾沉积环境存在一定程度的有机污染,这可能是由于研究海域存在双壳类底播养殖活动,造成沉积环境中有机物富集。展开更多
Pelagic appendicularians,known for their rapid bloom capability,are important secondary producers and play essential roles in marine ecosystems.To assess the environmental adaptation of the most common appendicularian...Pelagic appendicularians,known for their rapid bloom capability,are important secondary producers and play essential roles in marine ecosystems.To assess the environmental adaptation of the most common appendicularian species Oikopleura dioica in Jiaozhou Bay,Shandong,China,its annual variations in abundance and body size were investigated monthly at 12 stations in 2011,and the relationship between somatic growth and gonadal development was compared with previously published laboratory data.Oikopleura dioica exhibited distinct seasonal abundance patterns,peaking in summer and autumn,particularly in the inner bay,reflecting its adaptation to the eutrophic conditions and high food availability.Compared to laboratory results,O.dioica in Jiaozhou Bay exhibited shorter body lengths,smaller gonad volumes,and earlier maturation at reduced body sizes,despite high natural chlorophyll-a concentration,suggesting that factors beyond food availability,such as resource competition and environmental stressors,may limit its growth in natural settings.Correlation analysis indicated that the somatic growth of natural O.dioica was primarily influenced by temperature,while gonadal development was related to chlorophyll-a concentration,and its population abundance was linked to food availability and the abundance of other zooplankton,such as copepods and jellyfish.It was suggested that the growth and recruitment of O.dioica were constrained by resource limitations in natural environments,further exacerbated by interactions with other zooplankton,including predation and competition.This study provides valuable data on the mechanisms underlying bio-environmental interactions and their spatiotemporal variations,offering critical insights into the ecological roles of appendicularians in marine ecosystems.展开更多
Nereididae is a prolific annelid family widely distributed in the world oceans,especially in the Indo-Pacific Convergence Zone(IPCZ).However,its biogeographic pattern remains unexplored in IPCZ.To contribute to the un...Nereididae is a prolific annelid family widely distributed in the world oceans,especially in the Indo-Pacific Convergence Zone(IPCZ).However,its biogeographic pattern remains unexplored in IPCZ.To contribute to the understanding of biodiversity and biogeography of Nereididae in the IPCZ,we integrated historical data of species distributions with those of model-predicted ones to determine the biogeographic patterns of nereid species,from which we projected to its future distribution patterns for 2090-2100 under different climate scenarios(SSP1-1.9 and SSP5-8.5).Functional diversity within IPCZ was assessed using functional richness,functional evenness,and functional disparity.Divergence times within Nereididae were estimated using three DNA marker genes(COI,16S,and 18S rRNA),and a time tree was constructed based on a strict molecular clock model.The IPCZ was established as a key Nereididae biodiversity hotspot through distribution modelling of 256 species(44 genera),and temperature emerging as the predominant climatic driver of species distribution patterns.The distribution of species and functional diversity is notable for its non-centralized pattern.We projected that by the end of the century,areas of medium-to-high species richness will expand significantly under the low-emission SSP1-1.9 climate scenario.However,under the high-emission SSP5-8.5 scenario,the suitability of these regions significantly declines,posing an increasingly severe threat to biodiversity.In addition,by molecular clock analysis,we revealed that the evolutionary divergence of extant nereidid species occurred mainly in the Cretaceous and Jurassic,suggesting that paleogeographical and environmental events,such as oceanic anoxic events,might have played a pivotal role in shaping the evolutionary trajectory and ecological adaptations of marine annelids.These findings highlight the importance of considering both current biodiversity patterns and historical contexts in conservation planning,and provided insights into the potential factors on the biogeographic distribution and evolutionary processes of Nereididae.展开更多
文摘为研究胶州湾小型底栖动物时空分布格局及其环境影响因素,本研究团队于2021年1月和4月分别在胶州湾内、外海域各进行了1个航次的野外观测和采样,对小型底栖动物的类群组成、丰度、生物量、群落结构、水平和垂直分布及其与环境因子的关系进行了研究。研究结果显示:调查海域共鉴定出小型底栖动物12个类群;冬季和春季小型底栖动物的平均丰度分别为(769.6±184.8)和(683.3±173.3)ind./10 cm^(2),平均生物量分别为(587.0±78.0)和(426.7±67.4)μg/10 cm^(2);自由生活海洋线虫为最优势类群,在冬、春两季分别占小型底栖动物总丰度的87.60%和92.36%;此外,底栖桡足类、轮虫和无节幼体等也是较重要的类群;在季节分布上,小型底栖动物群落结构存在显著差异,生物-环境因子匹配(Biological and environmental data matching,BioEnv)分析表明,解释其群落结构变异的最佳环境因子组合为水深、底温、沉积物含水量和中值粒径;在水平分布上,两个季节小型底栖动物群落结构在胶州湾口内、外均无显著差异,但每个季度的丰度最低值均出现在湾口站位,这可能与沉积物中值粒径以及底层水温有关;本海域小型底栖动物的平均丰度比其他海域要低,这与近海的人类活动密不可分;海洋线虫与桡足类之比(N/C)偏高,表明胶州湾沉积环境存在一定程度的有机污染,这可能是由于研究海域存在双壳类底播养殖活动,造成沉积环境中有机物富集。
基金Supported by the National Key Research and Development Program of China(Nos.2023YFC3108205,2023YFC3108201)the National Natural Science Foundation of China(No.42306153)。
文摘Pelagic appendicularians,known for their rapid bloom capability,are important secondary producers and play essential roles in marine ecosystems.To assess the environmental adaptation of the most common appendicularian species Oikopleura dioica in Jiaozhou Bay,Shandong,China,its annual variations in abundance and body size were investigated monthly at 12 stations in 2011,and the relationship between somatic growth and gonadal development was compared with previously published laboratory data.Oikopleura dioica exhibited distinct seasonal abundance patterns,peaking in summer and autumn,particularly in the inner bay,reflecting its adaptation to the eutrophic conditions and high food availability.Compared to laboratory results,O.dioica in Jiaozhou Bay exhibited shorter body lengths,smaller gonad volumes,and earlier maturation at reduced body sizes,despite high natural chlorophyll-a concentration,suggesting that factors beyond food availability,such as resource competition and environmental stressors,may limit its growth in natural settings.Correlation analysis indicated that the somatic growth of natural O.dioica was primarily influenced by temperature,while gonadal development was related to chlorophyll-a concentration,and its population abundance was linked to food availability and the abundance of other zooplankton,such as copepods and jellyfish.It was suggested that the growth and recruitment of O.dioica were constrained by resource limitations in natural environments,further exacerbated by interactions with other zooplankton,including predation and competition.This study provides valuable data on the mechanisms underlying bio-environmental interactions and their spatiotemporal variations,offering critical insights into the ecological roles of appendicularians in marine ecosystems.
基金Supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB42000000)the National Natural Science Foundation of China(No.42376092)the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(No.2022QNLM030004)。
文摘Nereididae is a prolific annelid family widely distributed in the world oceans,especially in the Indo-Pacific Convergence Zone(IPCZ).However,its biogeographic pattern remains unexplored in IPCZ.To contribute to the understanding of biodiversity and biogeography of Nereididae in the IPCZ,we integrated historical data of species distributions with those of model-predicted ones to determine the biogeographic patterns of nereid species,from which we projected to its future distribution patterns for 2090-2100 under different climate scenarios(SSP1-1.9 and SSP5-8.5).Functional diversity within IPCZ was assessed using functional richness,functional evenness,and functional disparity.Divergence times within Nereididae were estimated using three DNA marker genes(COI,16S,and 18S rRNA),and a time tree was constructed based on a strict molecular clock model.The IPCZ was established as a key Nereididae biodiversity hotspot through distribution modelling of 256 species(44 genera),and temperature emerging as the predominant climatic driver of species distribution patterns.The distribution of species and functional diversity is notable for its non-centralized pattern.We projected that by the end of the century,areas of medium-to-high species richness will expand significantly under the low-emission SSP1-1.9 climate scenario.However,under the high-emission SSP5-8.5 scenario,the suitability of these regions significantly declines,posing an increasingly severe threat to biodiversity.In addition,by molecular clock analysis,we revealed that the evolutionary divergence of extant nereidid species occurred mainly in the Cretaceous and Jurassic,suggesting that paleogeographical and environmental events,such as oceanic anoxic events,might have played a pivotal role in shaping the evolutionary trajectory and ecological adaptations of marine annelids.These findings highlight the importance of considering both current biodiversity patterns and historical contexts in conservation planning,and provided insights into the potential factors on the biogeographic distribution and evolutionary processes of Nereididae.
