scholarly journals Laboratory experiments on the effects of a gastropod (Hydrobia totteni) on survival of an infaunal deposit-feeding polychaete (Capitella capitata)

1984 ◽  
Vol 18 ◽  
pp. 263-268 ◽  
Author(s):  
PS Petraitis
Keyword(s):  
Laboratory Experiments ◽  
Capitella Capitata ◽  
Deposit Feeding

Association between the ghost shrimp Trypaea australiensis Dana 1852 (Crustacea : Decapoda) and a small deposit-feeding bivalve Mysella vitrea Laserson 1956 (Mollusca : Leptonidae)

1998 ◽  
Vol 49 (8) ◽  
pp. 801 ◽  
Author(s):  
Geoff Kerr ◽  
Jamie Corfield
Keyword(s):  
Laboratory Experiments ◽  
New South ◽  
Sediment Surface ◽  
Energetic Cost ◽  
Carbon Distribution ◽  
Intertidal Sediments ◽  
Feeding Mode ◽  
South Wales ◽  
Reducing Conditions ◽  
Deposit Feeding

The deep-burrowing species Trypaea australiensis and Mysella vitrea inhabit intertidal sediments of the Richmond River, northern New South Wales. Laboratory experiments indicated that a facultative commensal association may exist between the two organisms, because although the bivalves survived independently, their vertical distribution in sediment was significantly different in the presence of T. australiensis. Field observations indicated that redox potential and bivalve abundance in sediment are weakly correlated. However, the absence of strongly reducing conditions in the first metre of the sediment, due to T. australiensis burrow irrigation, may increase potential niche size for M. vitrea. Tank observations revealed no aggregation of M vitrea around the burrows. Feeding observations suggested that M. vitrea can feed either by collecting particles off the sediment surface or by interstitial pedal feeding; the latter feeding mode would allow use of shrimp burrows for feeding. T. australiensis alters organic carbon distribution in the sediment profile, concentrations being significantly higher in the lowermost regions where T. australiensis was present than in controls. Thus, enrichment resulting from the activities of T. australiensis may provide some reward for the energetic cost to M. vitrea of burrowing deeply.

Interactions of Globobulimina Auriculata with Nematodes: Predator Or Prey?

2019 ◽  
Vol 49 (1) ◽  
pp. 66-75
Author(s):  
Nicolaas Glock ◽  
Julia Wukovits ◽  
Alexandra-Sophie Roy
Keyword(s):  
Soft Tissue ◽  
Laboratory Experiments ◽  
Alternative Interpretation ◽  
Feeding Strategies ◽  
Soft Sediment ◽  
Controlled Experiments ◽  
Benthic Foraminifers ◽  
Foraminiferal Species ◽  
Video Observations ◽  
Deposit Feeding

Abstract Studies of carnivorous behaviour of benthic foraminifers are rare and mostly focused on laboratory experiments. Controlled experiments have shown that some agglutinated and intertidal species prey on meio- to macrofaunal metazoans. Here we present observations of the behaviour of specimens of the infaunal benthic foraminiferal species, Globobulimina auriculata and G. turgida, made within several hours of collection from ∼117 m depth in the Alsbäck Deep of the Gullmar Fjord, Sweden. We observed live nematodes within the tests of G. auriculata. Video observations recorded over a 17-hour period showed a G. auriculata specimen with a living nematode whose tail appeared to be entangled within the foraminifer's reticulopodial network. The nematode eventually coiled around the foraminifer's aperture and became much less active, though ingestion into the foraminifer's test was not documented. If these observations indicate feeding by G. auriculata, they differ from previous observations of predation by Ammonia tepida, which utilised external reticulopodial activity to extract the soft tissue of its prey. An alternative interpretation of the video observations, consistent with the observations of the live nematodes inside G. auriculata, was that the nematode was attempting to prey upon the foraminifer. The G. turgida specimens, in contrast, relatively quickly surrounded themselves in soft sediment spheres commonly seen in deposit-feeding foraminifers, and were never observed with nematodes within their tests. We speculate that these contrasting feeding strategies might reduce competition and facilitate the coexistence of these two globobuliminid species.

Importance of Sediment Working by the Deposit-Feeding Polychaete Arenicola marina on the Weathering Rate of Sediment-Bound Oil

1978 ◽  
Vol 35 (5) ◽  
pp. 591-603 ◽  
Author(s):  
Donald C. Gordon Jr. ◽  
Jacqueline Dale ◽  
Paul D. Keizer
Keyword(s):  
Laboratory Experiments ◽  
Large Population ◽  
American Petroleum Institute ◽  
Arenicola Marina ◽  
Weathering Rate ◽  
Black Duck ◽  
Low Concentrations ◽  
Clean Environment ◽  
Key Words Sediment ◽  
Deposit Feeding

The interactions between the polychaete Arenicola marina, a common deposit feeder in sandy intertidal areas, and sediment contaminated with the fresh API (American Petroleum Institute) reference oils and weathered Bunker C oil remaining from the 1970 Arrow spill were investigated in laboratory experiments. Worms can tolerate low concentrations of sediment-bound oil, although the sediment working rate is reduced depending upon oil type, concentration, and degree of weathering. Hydrocarbon concentrations, measured gravimetrically and by gas chromatography and fluorescence spectroscopy, were substantially lower (17–72%) in worm casts than in initial sediment. This loss can be accounted for by microbial degradation, which is stimulated by the worms' activity, uptake of hydrocarbons into worms, and perhaps dissolution. A large population (10–25/m2) of Arenicola is present at Black Duck Cove, N.S., living in sediment contaminated with weathered Bunker C oil remaining from the Arrow spill. These worms, which have spent their entire lives in oil-polluted sediment, do not have markedly elevated hydrocarbon concentrations and behaved no differently in experiments than worms collected from a clean environment. Calculations suggest that they are capable of removing the oil present in a square metre of sediment in 2–4 yr. After any oil spill, when concentrations reach tolerable levels, activities of deposit-feeding animals such as Arenicola can apparently accelerate the weathering rate of sediment-bound oil. Key words: sediment, Arenicola marina, polychaete, petroleum, weathering rate, pollution, hydrocarbon

Covering of cometary nucleus by refractory crust and its evolution into asteroid-like body

1999 ◽  
Vol 173 ◽  
pp. 365-370
Author(s):  
Kh.I. Ibadinov
Keyword(s):  
Laboratory Experiments ◽  
Cometary Nucleus ◽  
Sublimation Rate ◽  
Cometary Nuclei ◽  
Short Period Comet ◽  
Short Period ◽  
Brightness Decrease ◽  
Crust Thickness ◽  
Ice Sublimation ◽  
Period Comet

AbstractFrom the established dependence of the brightness decrease of a short-period comet dependence on the perihelion distance of its orbit it follows that part of the surface of these cometary nuclei gradually covers by a refractory crust. The results of cometary nucleus simulation show that at constant insolation energy the crust thickness is proportional to the square root of the insolation time and the ice sublimation rate is inversely proportional to the crust thickness. From laboratory experiments resulted the thermal regime, the gas productivity of the nucleus, covering of the nucleus by the crust, and the tempo of evolution of a short-period comet into the asteroid-like body studied.

When Does Voice Have to be More Than Only Listening? Procedural Justice Effects as a Function of Confident Leadership

2010 ◽  
Vol 9 (2) ◽  
pp. 69-78 ◽  
Author(s):  
David De Cremer ◽  
Maarten Wubben
Keyword(s):  
Procedural Justice ◽  
Interaction Effect ◽  
Laboratory Experiments ◽  
Negative Emotions

The present research examined how voice procedures and leader confidence affect participants’ negative emotions and willingness to withdraw. It was predicted that receiving voice would be valued out of instrumental concerns, but only when the enacting leader was high in confidence. Two laboratory experiments indeed showed an interaction between type of voice (pre-decisional vs. post-decisional) and leader’s confidence (low vs. high) on participants’ negative emotions and willingness to withdraw. In particular, post-decision voice only led to more negative responses than did pre-decision voice when the enacting leader was high in confidence. Negative emotions mediated this interaction effect of type of voice on willingness to withdraw. Implications for integrating the leadership and procedural justice literatures are discussed.

Review of Laboratory Experiments in Psychology.

1968 ◽  
Vol 13 (10) ◽  
pp. 536-536
Author(s):  
Peter G. Polson
Keyword(s):  
Laboratory Experiments
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