Search results for " fIsh"
showing 10 items of 1414 documents
Application of EMI and FDR Sensors to Assess the Fraction of Transpirable Soil Water over an Olive Grove
2018
Accurate soil water status measurements across spatial and temporal scales are still a challenging task, specifically at intermediate spatial (0.1–10 ha) and temporal (minutes to days) scales. Consequently, a gap in knowledge limits our understanding of the reliability of the spatial measurements and its practical applicability in agricultural water management. This paper compares the cumulative EM38 (Geonics Ltd., Mississauga, ON, Canada) response collected by placing the sensor above ground with the corresponding soil water content obtained by integrating the values measured with an FDR (frequency domain reflectometry) sensor. In two field areas, characterized by different soil clay conte…
Artificial Neural Networks for Predicting the Water Retention Curve of Sicilian Agricultural Soils
2018
Modeling soil-water regime and solute transport in the vadose zone is strategic for estimating agricultural productivity and optimizing irrigation water management. Direct measurements of soil hydraulic properties, i.e., the water retention curve and the hydraulic conductivity function, are often expensive and time-consuming, and represent a major obstacle to the application of simulation models. As a result, there is a great interest in developing pedotransfer functions (PTFs) that predict the soil hydraulic properties from more easily measured and/or routinely surveyed soil data, such as particle size distribution, bulk density (&rho
A reappraisal of the purported gastric pellet with Pterosaurian bones from the Upper Triassic of Italy
2015
A small accumulation of bones from the Norian (Upper Triassic) of the Seazza Brook Valley (Carnic Prealps, Northern Italy) was originally (1989) identified as a gastric pellet made of pterosaur skeletal elements. The specimen has been reported in literature as one of the very few cases of gastric ejecta containing pterosaur bones since then. However, the detailed analysis of the bones preserved in the pellet, their study by X-ray microCT, and the comparison with those of basal pterosaurs do not support a referral to the Pterosauria. Comparison with the osteology of a large sample of Middle-Late Triassic reptiles shows some affinity with the protorosaurians, mainly with Langobardisaurus pand…
Dieta del delfín de Risso (Grampus griseus) en el Mediterráneo occidental
2006
DIETA DEL DELFÍN DE RISSO (GRAMPUS GRISEUS) EN EL MEDITERRÁNEO OCCIDENTAL. – Se ha analizado el contenido gastrointestinal de quince ejemplares de Grampus griseus varados en el Mediterráneo occidental entre 40º25’N 00º32’W y 37º35’N 00º45’E durante el período 1987 a 2003. Los resultados indican una dieta teutófaga, basada principalmente en cefalópodos oceánicos destacando los octópodos pelágicos, especialmente Argonauta argo, como la presa más abundante (media = 41,28%; SD±34,32). Algunas especies pertenecientes a las familias mmastrephidae, Histioteuthidae y Onychoteuthidae son también componentes frecuentes de la misma. La distribución batimétrica de los cefalópodos indica que el área de …
Parasitism of dolfinfhishes, Coryphaena hippurus and Coryphaena equiselis, in the western Mediterranean (Balearic Islands) and central-eastern Atlant…
1999
A total of 648 dolphinfishes were examined for internal and external parasites in western Mediterranean (Balearic Islands) and central-eastern Atlantic (Canary Islands) waters in order to make a comparative study between the two areas. The specimens studied from the Mediterranean Sea was Coryphaena hippurus, with 62 large individuals captured from May to September and 497 juveniles captured from August to December. The specimens studied from the central-eastern Atlantic were 39 adult C. hippurus and 49 adult Coryphaena equiselis. Parasites were found in 70% of the fish examined, and represented a total of nine endoparasitic taxa: six digeneans (Class Trematoda, Subclass Digenea; Dinurus tor…
Biodiversity of Antarctic echinoids: a comprehensive and interactive database
2005
Eighty-one echinoid species are present south of the Antarctic Convergence, and they represent an important component of the benthic fauna. “Antarctic echinoids” is an interactive database synthesising the results of more than 100 years of Antarctic expeditions, and comprising information about all echinoid species. It includes illustrated keys for determination of the species, and information about their morphology and ecology (text, illustrations and glossary) and their distribution (maps and histograms of bathymetrical distribution); the sources of the information (bibliography, collections and expeditions) are also provided. All these data (taxonomic, morphologic, geographic, bathymetri…
Do native white-clawed crayfish impact macroinvertebrate assemblages in Mediterranean limestone headwaters?
2019
Crayfish are among the largest aquatic macroinvertebrates in rivers and streams. Their trophic ecology is important for the understanding of the functioning of benthic communities. This is relevant in key areas, such as headwaters, as they partly condition the processes occurring downstream. To shed light on the effects of native white-clawed crayfish,Austropotamobius pallipes, on local macroinvertebrate assemblages from running headwaters, a three-month mesocosm-based field study was designed. Collection and subsequent analysis of benthic samples under different crayfish density levels yielded a set of metrics indicative of short-term impacts at general and taxonomic scales. Neither signif…
Distribution and depletion of sulfadiazine after a multiple per os dosing in gilthead sea bream (Sparus aurata) fed two different diets
2013
The distribution and depletion profile of sulfadiazine (SDZ) were investigated in gilthead sea bream (Sparus aurata) fed on fish oil (FO) or plant oil-based (PO) diets. Fish averaging 230 g were given medicated feed containing 25 mg SDZ kg-1 fish for 5 days at 24-26°C. Blood and muscle plus skin were sampled on days 1, 3, 5, 6, 8 and 9. Differences in plasma and fillet SDZ levels between the two groups were statistically insignificant. The maximum drug concentrations in plasma were 3.2 ± 1.9 μg mL-1 and 2.9 ± 1.2 μg mL-1 in the PO and FO groups, respectively. In post-medicated samples depletion rapidly reached concentrations close to the level of quantification at 72 h post medication. With…
Evidence of lipofuscin accumulation in the deep-water red shrimp Aristaeomorpha foliacea (Risso, 1827)
2008
Lipofuscin, a non-degradable, degenerative fluorescent pigment which accumulates in post-mitotic cells, represents a promising method for ageing marine crustaceans. The presence and accumulation of lipofuscin has been studied in the deep-water red shrimp Aristaeomorpha foliacea (Risso, 1827) to assess its use as a tool for ageing larger (i.e., older) specimens and thus improve knowledge of the growth and longevity of this species. Specimens, gathered during experimental trawl surveys carried out in the Strait of Sicily (Mediterranean Sea), were stored directly on-board in 10% buffered formaldehyde solution; their brain was thereafter removed, prepared with various current histological techn…
Traditional and experimental floating fish aggregating devices in the Gulf of Castellammare (NW Sicily): Results from catches and visual observations
1999
Floating fish aggregating devices (FADs) have long been used to attract fish in NW Sicily since antiquity. Recently, a number of changes have been made to the type of material employed to construct FADs, with the aim of increasing their effectiveness. In this paper we compare the catches made at eight experimental floating FADs (polypropylene ropes frayed at the ends) with those obtained at eight traditional FADs in the Gulf of Castellammare. A total of 672 samples were collected during summer and autumn in 1995 and 1996 at the 16 FADs using a surrounding net. Visual observations of fishes associated with the FADs were also conducted to obtain qualitative information about the spatial distr…