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Full-Text Articles in Life Sciences

Trophic Transfer Of Fatty Acids, Sterols, And A Triterpenoid Alcohol Between Bacteria, A Ciliate, And The Copepod Acartia Tonsa, Melissa C. Ederington, George B. Mcmanus, H. Rodger Harvey Jul 1995

Trophic Transfer Of Fatty Acids, Sterols, And A Triterpenoid Alcohol Between Bacteria, A Ciliate, And The Copepod Acartia Tonsa, Melissa C. Ederington, George B. Mcmanus, H. Rodger Harvey

OES Faculty Publications

The incorporation of lipids into the copepod Acartia tonsa and its eggs was measured when it was fed either a bacterivorous ciliate (Pleuronema sp.) or a diatom (Thalassiosira weissflogii). Egg production was 10-fold higher on the diatom diet, whereas hatch success of eggs was the same for algal and ciliate diets. Adult copepods fed diatoms contained more total fatty acid and sterols than copepods fed the ciliate diet, and individual lipids reflected the dietary source. Eggs from diatom-fed copepods had fewer fatty acids but more sterols than eggs from copepods on a ciliate diet. Ciliate-fed copepods and …


Phylogenetic Diversity Of The Bacterial Community From A Microbial Mat At An Active, Hydrothermal Vent System, Loihi Seamount, Hawaii, Craig L. Moyer, Fred C. Dobbs, David M. Karl Apr 1995

Phylogenetic Diversity Of The Bacterial Community From A Microbial Mat At An Active, Hydrothermal Vent System, Loihi Seamount, Hawaii, Craig L. Moyer, Fred C. Dobbs, David M. Karl

OES Faculty Publications

The phylogenetic diversity of small-subunit rRNA genes associated,vith the domain Bacteria was examined (by using previously defined operational taxonomic units [C. L. Moyer, F. C. Dobbs, and D. M. Karl, Appl. Environ. Microbiol. 60:871-879, 1994]; those for Pele's Vents Bacteria are hereafter abbreviated PVB OTUs) with samples from a microbial mat at an active, deep-sea hydrothermal vent system. A cluster of phylogenetically related PVB OTUs (OTUs 2, 3, 6, and 8) was closely affiliated with Thiovulum sp. contained within the epsilon subclass of the class Proteobacteria and accounted for 60.5% of the small-subunit rRNA bacterial clone library from Pele's Vents. …


Influence Of Zooplankton Grazing On Free Dissolved Enzymes In The Sea, Alexander B. Bochdansky, Staša Puškarić, Gerhard J. Herndl Jan 1995

Influence Of Zooplankton Grazing On Free Dissolved Enzymes In The Sea, Alexander B. Bochdansky, Staša Puškarić, Gerhard J. Herndl

OES Faculty Publications

In the Northern Adriatic Sea, extracellular enzymatic activity was measured during a Lagrangian study following a drifting buoy for 40 h. Dissolved free enzymatic activity represented 20 to 70% of total activity depending on the type of enzyme. alpha- and beta-glucosidases exhibited a significantly higher free activity than proteolytic enzymes. In subsequent laboratory experiments we investigated the effect of zooplankton on the free enzyme pool. The 4-step approach included: (1) determination of the enzymatic activities in copepods (mainly Acartia clausi); (2) enzymatic activity in fecal pellets; (3) short- and long-term grazing experiments; and (4) degradability of free glucosidase in seawater. …


Elimination Of Dissolved Sulfide Interference In The Flow-Injection Determination Of Sigma-Co2 By Addition Of Molybdate, Rigel L. Lustwerk, David J. Burdige Jan 1995

Elimination Of Dissolved Sulfide Interference In The Flow-Injection Determination Of Sigma-Co2 By Addition Of Molybdate, Rigel L. Lustwerk, David J. Burdige

OES Faculty Publications

A previously described flow injection method for the analysis of ΣCO2 included the addition of ZnCl2 to some samples before analysis in order to precipitate dissolved sulfide (which interferes with the method) as ZnS. However, the use of Zn2+ in samples with high concentrations of dissolved sulfide causes the coprecipitation of ZnCO3, and in our experience with this technique, ZnCO3 also precipitates even in the absence of dissolved sulfide. The addition of molybdate effectively complexes dissolved sulfide without interfering with the determination of ΣCO2 by this technique.


Time To Metamorphosis Of Blue Crab Callinectes Sapidus Megalopae: Effects Of Benthic Macroalgae, Robert D. Brumbaugh, John R. Mcconaugha Jan 1995

Time To Metamorphosis Of Blue Crab Callinectes Sapidus Megalopae: Effects Of Benthic Macroalgae, Robert D. Brumbaugh, John R. Mcconaugha

OES Faculty Publications

There is growing evidence that postlarvae (megalopae) of the blue crab Callinectes sapidus can slow the progression through the molt cycle while in offshore nursery grounds, and delay metamorphosis until reinvasion of coastal habitat occurs. However, the cues that trigger metamorphosis of megalopae are not well known. This study tested the hypothesis that the time to metamorphosis (TTM) from the postlarval megalops stage to the first crab stage is shortened in the presence of 2 potential macroalgal settlement substrates, Ulva lactuca (Chlorophyta), and Gracilaria spp. (Rhodophyta). Megalopae and test water were collected from 3 locations (offshore, at a coastal inlet, …