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971.
972.
Sedimentary Pigments and Organic Matter in Relation to Benthic Fauna in the Tan-Shui Estuary, Taiwan
The benthic ecological structure of the Tan-Shui estuary, Taiwan is changed due to long term effects of dumping of urban wastewater and of engineering actions. to monitor these changes, we sampled and analyzed benthos and sediment from 12 stations on the estuary.
The composition of the dominant species of benthos varied seasonally, with molluscan and crustacean species having greater numbers and higher frequencies of occurrence than other species. the dominant taxa during winter were Nassarius sp. and Maldanidae at two stations. Analysis using Simpson's index and Shannon's index showed the benthic community varied more in coastal areas than in offshore areas.
Physicochemical analysis showed that most of the Tan-Shui estuary consisted of sandy sediment. the variations in concentrations of organic carbon and total nitrogen at each station were small. Although the concentrations of chlorophyll-a and carotenoid at all stations were generally low, the two stations had the highest concentrations, and we concluded that the concentration of pigments in these sediments was related to the abundance of benthos. the community structure of the benthos reflected the characteristics of the sediments, and benthic species exhibited selection of and adaptation to specific sedimentary environments. 相似文献
The composition of the dominant species of benthos varied seasonally, with molluscan and crustacean species having greater numbers and higher frequencies of occurrence than other species. the dominant taxa during winter were Nassarius sp. and Maldanidae at two stations. Analysis using Simpson's index and Shannon's index showed the benthic community varied more in coastal areas than in offshore areas.
Physicochemical analysis showed that most of the Tan-Shui estuary consisted of sandy sediment. the variations in concentrations of organic carbon and total nitrogen at each station were small. Although the concentrations of chlorophyll-a and carotenoid at all stations were generally low, the two stations had the highest concentrations, and we concluded that the concentration of pigments in these sediments was related to the abundance of benthos. the community structure of the benthos reflected the characteristics of the sediments, and benthic species exhibited selection of and adaptation to specific sedimentary environments. 相似文献
973.
We investigated mycosporine amino acid (MAA) involvement as protective sunscreens in spawn of the sea hare Aplysia dactylomela to determine if adult diet and ultraviolet (UV) exposure affected the UV sensitivity of developing embryos. Adults were fed
a red alga rich in MAAs (Acanthophora spicifera) or a green alga poor in MAAs (Ulva lactuca). Adults on each diet were exposed for 2 wk to ambient solar irradiance with two types of acrylic filters; one allowed exposure
to wavelengths >275 nm (designated UV) and one to wavelengths only >410 nm (designated NOUV). Spawn from each adult group
was likewise treated with UV or NOUV and monitored during development for differences in mortality and metabolic rate (measured
as oxygen consumption: V˙
O2). Also recorded were number of eggs or embryos per capsule, times to hatching, hatching success, size at hatching, and V˙
O2 of adults. Spawn from adults eating red algae was almost twice as rich in MAAs as spawn from adults eating green algae, suggesting
that MAA content is diet-related. Although overall quantities of MAAs in the spawn reflected MAA contents of the adult diet,
specific MAAs were differentially sequestered in the spawn. Thus, porphyra-334, found in high concentration in Aplysia dactylomela's preferred red algal food, was present in only low concentration in the spawn. Conversely, mycosporine-glycine, in low concentration
in red algal food, was the most abundant MAA in the spawn. UV treatment of adults had no effect on quantities of MAAs in the
spawn. Adults exposed to UV had significantly higher V˙
O2s and spawned twice as often. The UV-treated adults produced spawn with significantly higher V˙
O2s and their embryos developed to hatching sooner. The only significant effect of UV exposure of the spawn was to reduce the
percentage of veligers hatching from 71 to 50%. There was no significant effect on hatching time or size of the veligers at
hatching, nor on number of eggs per capsule.
Received: 13 May 1997 / Accepted: 27 June 1997 相似文献
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Workplace entitlement is a pressing concern for modern organizations and managers. Organizational scholars, however, have largely overlooked this phenomenon in their research. In this Incubator, we summarize the untapped opportunities that entitlement research offers for impacting both scholarly thinking and practitioner knowledge on the subject. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献