Purification and some properties of α-l-fucosidase from Littorina littorea L.

Author(s):  
Maria Angeles de Pedro ◽  
Angel Reglero ◽  
JoséA. Cabezas
Keyword(s):  

Two medium-scale ecosystems (mesocosms) were built on the Oslofjord: one a hard-bottom intertidal system and the other a subtidal soft-sediment system. The hard-bottom mesocosm consists of four basins, two controls and two which were dosed with diesel-oil (129 μg 1 -1 a high oil (HO) dose and 29 μg 1 -1 a low oil (LO) dose). Both oil doses caused high mortality of Mytilus edulis and growth was reduced in the macroalgae Ascophyllum nodosum and Laminaria digitata . Recruitment of Littorina littorea was also affected by oil so that populations declined over time. Subtidal benthic communities have been established in the mesocosm and show variations in sediment chemistry within the range found in the field. Although recruitment of benthic macrofauna is reduced, dominant species and species structure remain closely similar to that in the field over six months. Bioturbation effects studied in the mesocosm have shown the important influence of large, rare species in structuring benthic communities, a finding which would not be possible in nature by diving or by the use ofsubmersibles. Preliminary results from a community taken from 200 m depth and established in the mesocosm suggest that it is now possible to do detailed manipulation experiments on communities simulating the whole continental shelf.


1995 ◽  
Vol 30 (2) ◽  
pp. 180-194 ◽  
Author(s):  
P. Matthiessen ◽  
R. Waldock ◽  
J.E. Thain ◽  
M.E. Waite ◽  
S. Scropehowe

1971 ◽  
Vol 8 (11) ◽  
pp. 1487-1491 ◽  
Author(s):  
D. A. Walker

Investigations by scanning electron microscopy have revealed that ingestion of Rosalina floridana (Cushman) and Quinqueloculina seminulum (Linné) (Foraminiferida) by the common periwinkle Littorina littorea Linné results in severe etching of the surface veneer in the rotalids studied, and removal of the surface veneer and partial dissolution of the underlying tabular layer of calcite in the miliolids examined. The acidic nature of the digestive juices is suggested as the agent responsible for this phenomenon. Observations of test wall construction is compared to current models of calcite secretion.


Author(s):  
P.E. Gibbs ◽  
J.C. Green ◽  
P.L. Pascoe

In the summer of 1995 a massive kill of the dog-whelk, Nucella lapillus, occurred in Bude Bay on the north Cornish coast. High mortality was detectable along 12 km of shoreline. The only other intertidal species affected appeared to be another neogastropod, Ocenebra erinacea. The cause of the kill is unknown but the evidence suggests that it occurred in early July following an extended period of warm, calm weather in June. Possible causes of this event are discussed: algal toxicity may have been responsible since an algal bloom was detected offshore in July in the area. Laboratory experiments exposing gastropods to different species and concentrations of microalgae, designed to test whether N. lapillus is more sensitive than Monodonta lineata and Littorina littorea, gave inconclusive results. No comparable kill has occurred in the Bude area for at least 20 y, but it is suggested that nutrients from a newly-constructed, offshore sewage outfall may now stimulate local algal bloom development during calm weather periods.


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