The morphology and ultrastructure of Bullacta exarata spermatozoa observed by light and transmission electron microscopy are presented in this paper. The spermatozoon is composed of head with a simple acrosomal comple...The morphology and ultrastructure of Bullacta exarata spermatozoa observed by light and transmission electron microscopy are presented in this paper. The spermatozoon is composed of head with a simple acrosomal complex and an elongated nucleus, and tail with a midpiece, principal piece and an end piece. The midpiece consists of a mitochondrial ring, and the principal piece is composed of axoneme and lateral fin. The structure of 5. exarata spermatozoa differs significantly from that of other gastropods, especially in the lateral fin and the principal piece, which was described scarcely before. A comparison is made between B. exarata and other gastropods, and its significance on reproductive evolution and physio-ecological adaptation is preliminarily discussed.展开更多
The Qinghai-Tibetan Plateau is the highest biogeographic unit on earth and widely regarded as its ‘third pole＇.The high-altitude,frigid and arid alpine ecosystems that form the Plateau are extremely sensitive to cli...The Qinghai-Tibetan Plateau is the highest biogeographic unit on earth and widely regarded as its ‘third pole＇.The high-altitude,frigid and arid alpine ecosystems that form the Plateau are extremely sensitive to climate change and human disturbance.Unsurprisingly,the Plateau is therefore a global epicenter of ecological and global change research and provides the ideal conditions and context to study the impacts of global change.Ecological research conducted on the Plateau can be partitioned into four developmental and chronological phases,beginning with the gathering of primitive knowledge and progressing towards a description of mechanistic processes.Throughout the course of Plateau research paradigm shifts from standalone surveys of biogeographic patterns to fixed monitoring and mechanism research;from isolated population,community and ecosystem approaches to more integrated,multidisciplinary research;and from pure theoretical research to an emphasis on effective resource utilization and sustainable development.Future ecological research will likely pay increasing attention to quantifying the impacts of climate warming and human activity on ecosystem change,and climate and ecosystem feedback processes.Multidisciplinary and comprehensive research should be strengthened amongst fields such as ecosystem ecology,physical geography,environmental science and remote sensing in order to support climate change adaptation and sustainable development in this fragile and unique region.展开更多
Although background matching is a common form of camouflage across a wide diversity of animals, there has been surprisingly little experimental work testing the fitness consequences of this camouflage strategy, especi...Although background matching is a common form of camouflage across a wide diversity of animals, there has been surprisingly little experimental work testing the fitness consequences of this camouflage strategy, especially in marine ecosystems. In this study, we tested whether color camouflage enhances survival of the intertidal marine isopod Pentidotea （Idotea） wosnesenskii, quantified patterns of camouflage in different algal habitats, and examined how algal diet affected color change and growth using laboratory assays. In the field, isopods collected from two differently colored algal habitats （the brown alga Fucus distichus and the red alga Odonthaliafloccosa） matched the color of their respective algal habitats, and also differed significantly in body size： smaller red isopods were found on red algae, while larger brown isopods were found on brown algae. Predation ex- periments demonstrated these color differences had fitness benefits： brown isopods that matched their brown algae habitats sur- vived at higher rates than red unmatched isopods. Surprisingly, despite the propensity of isopods to match their algal habitats, algal diet had no effect on color change in color change experiments. Instead, isopods in all treatments turned browner, matching the color of the algal habitat that many isopods are found on as adults. In summary, our data supported our hypothesis that back- ground matching serves an adaptive function in reducing predation, with important evolutionary implications for explaining the wide variation in color change mechanisms in idoteid isopods [Current Zoology 61 （4）： 739-748, 2015].展开更多
文摘The morphology and ultrastructure of Bullacta exarata spermatozoa observed by light and transmission electron microscopy are presented in this paper. The spermatozoon is composed of head with a simple acrosomal complex and an elongated nucleus, and tail with a midpiece, principal piece and an end piece. The midpiece consists of a mitochondrial ring, and the principal piece is composed of axoneme and lateral fin. The structure of 5. exarata spermatozoa differs significantly from that of other gastropods, especially in the lateral fin and the principal piece, which was described scarcely before. A comparison is made between B. exarata and other gastropods, and its significance on reproductive evolution and physio-ecological adaptation is preliminarily discussed.
文摘The Qinghai-Tibetan Plateau is the highest biogeographic unit on earth and widely regarded as its ‘third pole＇.The high-altitude,frigid and arid alpine ecosystems that form the Plateau are extremely sensitive to climate change and human disturbance.Unsurprisingly,the Plateau is therefore a global epicenter of ecological and global change research and provides the ideal conditions and context to study the impacts of global change.Ecological research conducted on the Plateau can be partitioned into four developmental and chronological phases,beginning with the gathering of primitive knowledge and progressing towards a description of mechanistic processes.Throughout the course of Plateau research paradigm shifts from standalone surveys of biogeographic patterns to fixed monitoring and mechanism research;from isolated population,community and ecosystem approaches to more integrated,multidisciplinary research;and from pure theoretical research to an emphasis on effective resource utilization and sustainable development.Future ecological research will likely pay increasing attention to quantifying the impacts of climate warming and human activity on ecosystem change,and climate and ecosystem feedback processes.Multidisciplinary and comprehensive research should be strengthened amongst fields such as ecosystem ecology,physical geography,environmental science and remote sensing in order to support climate change adaptation and sustainable development in this fragile and unique region.
文摘Although background matching is a common form of camouflage across a wide diversity of animals, there has been surprisingly little experimental work testing the fitness consequences of this camouflage strategy, especially in marine ecosystems. In this study, we tested whether color camouflage enhances survival of the intertidal marine isopod Pentidotea （Idotea） wosnesenskii, quantified patterns of camouflage in different algal habitats, and examined how algal diet affected color change and growth using laboratory assays. In the field, isopods collected from two differently colored algal habitats （the brown alga Fucus distichus and the red alga Odonthaliafloccosa） matched the color of their respective algal habitats, and also differed significantly in body size： smaller red isopods were found on red algae, while larger brown isopods were found on brown algae. Predation ex- periments demonstrated these color differences had fitness benefits： brown isopods that matched their brown algae habitats sur- vived at higher rates than red unmatched isopods. Surprisingly, despite the propensity of isopods to match their algal habitats, algal diet had no effect on color change in color change experiments. Instead, isopods in all treatments turned browner, matching the color of the algal habitat that many isopods are found on as adults. In summary, our data supported our hypothesis that back- ground matching serves an adaptive function in reducing predation, with important evolutionary implications for explaining the wide variation in color change mechanisms in idoteid isopods [Current Zoology 61 （4）： 739-748, 2015].
