Search results for "Littoral"

Littoral Dunes on Valencia Coast

2018

The dunes development needs an excess of sediment supply, wind speed able to transport sand to backshore and low atmospheric humidity. Foredunes, dunes fields and Pleistocene fossil dunes are the most characteristics features of the Valencian coast. Fossil dunes are abundant at the southern part. They are the main supply for the Holocene dunes and formed l’Altet field that survived thanks to be just in front of the L’Altet Airport. The foredunes have been mainly destroyed by human action and only few remains still are active. Guardamar and El Saler dune fields had a quite different evolution. Guardamar evolved covering previous fossil dunes and was fixed with pine trees to avoid the sand pr…

On the ecology of littoral Oligochaeta of an oligotrophic Finnish lake

1982

In material sampled from 0.5–6 m on two sampling dates and three subareas the dominant Oligochaeta were Limnodrilus hoffmeisteri Claparede and Peloscolex ferox (Eisen), both composing more than 30% of the abundances of oligochaetes present. The numbers of Oligochaeta were mostly higher in August than in May. Regional differences could be found although the lake seems to be very homogenous. Temporal and vertical variations were detectable in separate subareas. The oligochaete biomass was maximal at 2 m depth. In soft bottom sediments the oligochaetes composed 15.9% of macrobenthos biomass and 12.2% of numbers, but on the stony bottom only 1.9% of numbers. The ratio of Oligochaeta/Chironomida…

Visual conditions and habitat shape the coloration of the Eurasian perch (Perca fluviatilis L.): a trade-off between camouflage and communication?

2009

In theory, selection for effective camouflage (i.e. dull coloration) in fish should be strongest when the conditions for visual predation are most favourable, such as in structurally simple pelagic habitats. By contrast, in more sheltered (e.g. littoral) habitats, selection may favour effective intra-specific communication (i.e. bright coloration) (at the expense of crypsis). Poor transparency, as in highly humic waters, should constrain colour adaptations. We investigated phenotypic variation in body coloration of Eurasian perch (Perca fluviatilis L.) in littoral and pelagic habitats of four humic boreal lakes. Perch from the most transparent lake had the lightest and less coloured belly a…

Effects of paper mill effluents on the fish fauna of stony shores of Lake Päijänne

1992

The fish fauna of the stony littoral in the central parts of L. Paijanne was studied by electric fishing on four occasions during 1988–1989. Ten fish species and 1681 individuals (14.5 kg) were caught in the 15 fishing sites (4096 m2) which gives a mean density of 0.41 ind. m-2 and biomass of 3.5 g m-2. Effluent from two large paper mills causes a clear zonation of the fish fauna in the area. In the most polluted shores, only burbot and perch occurred regularly and the reproduction of other species was inhibited. In the semipolluted area (5–15 km from the Kaipola paper mill), burbot and stone loach occurred regularly, but owing to low numbers of perch and bullhead the total densities were u…

Volatile constituents of Scutellaria rubicunda Hornem subsp. linnaeana (Caruel) Rech. (Lamiaceae) endemic in Sicily

2006

Sesquiterpenes from Onopordum illyricum and their antifeedant activity

2012

Phytochemical investigation of the acetone extract of the aerial parts of Onopordum illyricum L. afforded five known sesquiterpenoids: compounds 3 and 4 already isolated from O. illirycum, and 8α-[4′-hydroxymethacryloyloxy]-sonchucarpolide (1), 8α-[4′-hydroxymethacryloyloxy]-4-epi-sonchucarpolide (2) and 8-(4′-hydroxymethacryloyl)-dehydromelitensin (5), not previously detected in this species. Compounds 4 and 5 showed moderate antifeedant activity against larvae of Spodoptera littoralis.

Investigation of the steps involved in the difference of susceptibility of Ephestia kuehniella and Spodoptera littoralis to the Bacillus thuringiensi…

2011

BUPM95 is a Bacillus thuringiensis subsp. kurstaki strain producing the Vip3Aa16 toxin with an interesting insecticidal activity against the Lepidopteran larvae Ephestia kuehniella. Study of different steps in the mode of action of this Vegetative Insecticidal Protein on the Mediterranean flour moth (E. kuehniella) was carried out in the aim to investigate the origin of the higher susceptibility of this insect to Vip3Aa16 toxin compared to that of the Egyptian cotton leaf worm Spodoptera littoralis. Using E. kuehniella gut juice, protoxin proteolysis generated a major band corresponding to the active toxin and another band of about 22kDa, whereas the activation of Vip3Aa16 by S. littoralis …

Seismic stratigraphy of the north-westernmost area of the Malta Plateau (Sicily Channel): The Middle Pleistocene-Holocene sedimentation in a tidally …

2022

In this study we present the results of a seismic-stratigraphic analysis of sub-bottom profiles in the north-westernmost area of the Malta Plateau in order to define the depositional mechanisms for the upper Quaternary sequences. During this interval the morphology of the Malta Plateau was characterized by a ramp and bathymetries not exceeding 200 m. Two major unconformities, related to MIS 6 and MIS 2 (the latter corresponding to the Last Glacial Maximum, LGM), characterize the upper Quaternary sequences. The geometries of the recognized seismic units indicate as depositional mechanisms were controlled by subsidence and sea-level fluctuations. In detail, deposits related to the last glacia…

Essential oils of three species of scutellaria and their influence on Spodoptera littoralis

2013

DEEP RHODOLITH BEDS IN THE USTICA ISLAND (SICILY, SOUTHERN TYRRHENIAN SEA): A SEDIMENTARY AND PALEOECOLOGICAL APPROACH

2018

The results of a multidisciplinary study conducted on the circali- ttoral soft bottom assemblages at Secchitello (Sicchiteddu) and in the neighbouring areas along the southern coast of Ustica Island (Sicily, Southern Tyrrhenian Sea) are presented. In particular, the study pro- vided useful data for a taxonomic, ecological and paleoecological revi- sion of the Coastal Detritic facies with free-living calcareous algae and for a critical analysis of their relationship with the sedimentary dynamics. During a survey, carried out by the University of Catania (1991) with a R.O.V. (remotely operated vehicle), the presence of the Coastal Detritic (DC) biocoenosis, characterized by a surprisingly hig…