Results 191 to 200 of about 5,195 (227)

Variation in, and Causes of, Toxicity of Cigarette Butts to a Cladoceran and Microtox

Archives of Environmental Contamination and Toxicology, 2005
Cigarette butts are the most numerically frequent form of litter in the world. In Australia alone, 24-32 billion cigarette butts are littered annually. Despite this littering, few studies have been undertaken to explore the toxicity of cigarette butts in aquatic ecosystems. The acute toxicity of 19 filtered cigarette types to Ceriodaphnia cf. dubia (48-
Micevska, T., Warne, M. St J., Pablo, F., Patra, R.   +3 more
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Distribution of marine cladocerans in the Indian Ocean

Marine Biology, 1972
Cladocera of the Indian Ocean have been studied, on the basis of samples collected during the International Indian Ocean Expedition (IIOE). Out of a total of 1927 samples, 552 contained Cladocera. Although the distribution of this group is mainly coastal, one species, Evadne tergestina, has been found in oceanic waters also, where it may establish ...
N. Della Croce, P. Venugopal
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Miniature genomes and endopolyploidy in cladoceran crustaceans

Genome, 1989
The haploid genome sizes (0.37 and 0.47 pg) of two members of the cladoceran crustacean genus Daphnia rank among the smallest known for Crustacea. An examination of cladoceran somatic tissues by scanning microdensitometry revealed abundant endopolyploidy in both species.
Margaret J. Beaton, Paul D. N. Hebert
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Balancing Predation and Competition in Cladocerans

Ecology, 1974
A graphic model is proposed relating the balance between predation and competition to size strategies and species richness in zooplankton communities. As decreasing survivorship, due to predation, and increasing food—collecting ability are arranged along the single dimension of body size, both may be specified clearly.
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Reproductive Biology of Marine Cladocerans

1997
Publisher Summary The chapter discusses the reproductive biology of marine cladocerans. Marine cladocerans are seasonally abundant and widely distributed in continental shelf waters, estuaries, the open ocean, the Baltic, the Mediterranean, and inland seas.
David A. Egloff, Paul W. Fofonoff, Takashi Onbé   +2 more
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Browsing and grazing by cladoceran filter feeders

Canadian Journal of Zoology, 1979
If different Cladocera have similar minimum requirements for suspended food, the capacity to utilize sedimented material would shift the competitive advantage to facultative bottom foragers in ponds, shallow lakes, and laboratory cultures with fluctuating levels of planktonic food. In laboratory cultures, Daphnia pulex browses or forages on the bottom
P. A. Horton, M. Rowan, K. E. Webster, R. H. Peters   +3 more
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Lateral compression and visibility in cladocerans

Limnology and Oceanography, 1981
A simple mathematical model suggests that lateral compression affects a cladoceran’s visibility to fish. The results of a simple test using the lengths and widths of cladocerans suggest that handling by copepods probably does not exert any significant selection on lateral compression in cladocerans, but fish gill rakers and visibility to fish might ...
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CARDIAC PHARMACOLOGY OF THE CLADOCERAN, DAPHNIA

The Biological Bulletin, 1942
1. Acetylcholine was found to have a depressing effect on the heart rate and strength of beat of the heart of Daphnia magna with the threshold at 10-9 and a depression of 25 per cent at 10-5 The effect is reversible.2. Atropine has a depressing effect on the heart rate with the threshold at 10-7 and an inhibition of 15 per cent at 10-4 The effect is ...
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Cladoceran Diversity, Distribution and Ecological Significance

2016
Cladocerans invariably constitute a dominant component of limnological and zooplankton systems. Cladocerans have a key role in aquatic food chain and contribute to secondary production in aquatic ecosystems. Substantially cladocerans represent a very old group of Palaeozoic origin and currently 620 species are reported globally.
M. Karuthapandi, D. V. Rao
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Observations on the ephippia of certain macrothricid cladocerans

Zoological Journal of the Linnean Society, 1972
Ephippia of four maerothricid cladocerans are described, that of Opbryoxus gracilis (perhaps the most primitive anomopod ephippium) for the first time. All are attached to substrata, but each in a different way, in a manner that must inhibit rather than encourage dispersal. Notwithstanding the drought-resistant properties of the eggs of at least two of
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