Diel activity of Sarpa salpa (Sparidae) by ultrasonic telemetry in a Posidonia oceanica meadow of Corsica (Mediterranean Sea)

in Aquatic Living Resources (2002), 15(6), 343-350

In the Mediterranean Sea, the fish Sarpa salpa (Sparidae) is the only vertebrate grazer of Posidonia oceanica meadows. In order to gain knowledge about the behaviour of S. salpa and a better understanding ... [more ▼]

In the Mediterranean Sea, the fish Sarpa salpa (Sparidae) is the only vertebrate grazer of Posidonia oceanica meadows. In order to gain knowledge about the behaviour of S. salpa and a better understanding of the meadow's primary production recycling, an original study was designed using ultrasonic telemetry to investigate activity patterns and space utilisation in the field. During June-September 2000, we compared diel movements of, six adult S. salpa (249-317 nim FL and 313-633 g) in the Bay of Calvi. These fish were tagged by intraperitoneal insertion of ultrasonic transmitters. Their positions were recorded with a directional hydrophone from a small boat with an accuracy between 10 and 50 m, depending on the local environment. The tracking duration ranged from 3 to 22 days (average 11.8 +/- 7.3). Locations were performed from at least dawn to dusk or early night, and one fish was tracked during the entire 24-h cycle. Fish were more mobile during the twilight periods, but statistical analysis indicated individual differences for the precise period of mobility. Two major behavioural patterns were observed: first, the fish remained in close vicinity of the harbour during the day and moved away to the north or the south at dusk to access nocturnal sites, occupying a home range of about 4.3 ha. The second behavioural pattern involved persistent occupation of the same sites during day and night within a relatively restricted home range (about 0.8 ha). Great variation in mobility was found and the same individual fish could show both kinds of behaviour. (C) 2002 Ifremer/CNRS/Inra/IRD/Cemagref/Editions scientifiques et medicales Elsevier SAS. All rights reserved. [less ▲]

Dielectric Multilayer Films Fabricated by Magnetron Sputtering: How Far Can the Iridescence Be Tuned?

in Plasma Processes and Polymers (2009), 6

Periodic dielectric multilayer structures can generate interferential colours from optically transparent basic materials. Their iridescence property, i.e. the change of colour with the illumination or ... [more ▼]

Periodic dielectric multilayer structures can generate interferential colours from optically transparent basic materials. Their iridescence property, i.e. the change of colour with the illumination or viewing angle, is exploited in the industry to produce structurally coloured coatings and paints. Magnetron sputtering is an efficient technique for producing multilayer films owing to its ability to deposit films on large surfaces with excellent uniformity and reproducibility in both the film thickness and composition. Based on a theoretical model of the optical response, we investigated the iridescence tuning range of the technologically important SiO2/TiO2 material system. Radically different iridescent behaviours were predicted theoretically and demonstrated experimentally by selecting appropriate combinations of period and layer thickness ratio. [less ▲]

Dielectronic structure of 2l-1s Transitions of Multicharged Ions of Argon with nuclear charges Z = 10 - 17

in Physica Scripta (2000), 61

Diem Werner, Ein arabisches Rechtsgutachten zum Eherecht aus dem 11.-12. Jahrhundert aus der Heidelberger Papyrussammlung.

in Bulletin Critique des Annales Islamologiques (2009), 25

Diem Werner, Wurzelrepetition und Wunschsatz. Untersuchungen zur Stilgeschichte des arabischen Dokuments des 7. bis 20. Jahrhunderts. Wiesbaden, Harrassowitz, 2005, XI-863 p. ISBN: 3-447-05267-8.

in Bulletin Critique des Annales Islamologiques (2012), 26 (2010-2011)

Diesel and Gasoline for HCCI Combustion

in Acosta, M. J. (Ed.) Advances in Energy Research (2010)

Diet and foraging ecology of Roseate terns and lesser noddies breeding sympatrically on Aride Island, Seychelles

in Waterbirds (2008), 31(239), 248

Inferences on seabird ecology from stable isotopes ratios (δ13C, δ15N) and mercury concentrations analysis of feathers have been made for temperate and polar species but are far more rare for tropical ... [more ▼]

Inferences on seabird ecology from stable isotopes ratios (δ13C, δ15N) and mercury concentrations analysis of feathers have been made for temperate and polar species but are far more rare for tropical species. In this paper, we used this approach combined with analysis of regurgitations and feeding observations at colonies to examine diet segregation between Roseate Terns (Sterna dougallii) and Lesser Noddies (Anous tenuirostris) breeding sympatrically on Aride Island (Seychelles), western Indian Ocean. Our results indicated extensive overlap between the two species in trophic level and foraging area during the breeding season. Goatfish predominated (93-97%) in all diet samples of adults and chicks collected in the colonies, except in prey fed to mates by Roseate Terns, of which scad and tuna comprised 20%. The isotopic analyses of feathers replaced by adults during molt (primary and body feathers) suggested, however, that the two species differ in foraging ecology during the nonbreeding period. Roseate Tern adults had consistently lower δ15N values than Lesser Noddies which, in turn, had δ15N values comparable to those of chick feathers grown on Aride. Moreover, low but similar mercury levels were found in body feathers of Lesser Noddy adults and Roseate Tern chicks, whereas Roseate Tern adults were significantly more contaminated. Overall, these results support the hypothesis that the Lesser Noddy is largely sedentary, being associated with the same food web in the vicinity of the colonies year-round. In contrast, Roseate Terns rely on distinct prey during the molting (nonbreeding) season which may be also consistent with a change in food web (i.e., a migratory regime) although the assignment of potential wintering areas remain difficult without isotopic basemaps currently available for the Indian Ocean. [less ▲]

Diet of Damselfishes (Pomacentridae): a multidisciplinary approach

Poster (2006, October)

Coral reefs are the marine ecosystem showing the greatest fish diversity. Damselfishes (Pomacentridae) represent, with more than 340 species, one of the most important families in the coral reef ... [more ▼]

Coral reefs are the marine ecosystem showing the greatest fish diversity. Damselfishes (Pomacentridae) represent, with more than 340 species, one of the most important families in the coral reef environment. Currently their diet is understudied. This work has 2 aims: (i) to characterize the diet of 13 pomacentrid species of the reef of Toliara (Madagascar) and (ii) to investigate if the specific diversity of this family would result from a strong trophic segregation. A multidisciplinary approach including morphological data (teeth, lower jaw-lever mechanics and intestine length), stomach contents and stable isotope analysis were used. The morphological approach and the stomach contents show that each studied species is able to capture small planktonic preys (e.g. copepods). However, the 13 species can be divided into two trophic guilds: alguivores and planktivores (respectively species where the filamentous algae and the planktonic preys count for more than 60% of their diet). Within these two principal classes, the analysis of the stomach contents and stable isotopes permit to define sub-groups : (1) the species having a food behaviour exclusively alguivore or planktivore (> 90% of their diet) (2) species showing a more varied diet by also eating other types of preys such as vagiles and/or sessiles invertebrates. The diet would contribute but could not explain all diversity in Pomacentridae. Some species show a very similar diet. Consequently other ecological factors should be responsible for the reduction of interspecific competitions and for the existence of such diversity. [less ▲]

The diet of the European mink (Mustela lutreola) in south west France. First results.

in Reig, S. (Ed.) Abstracts of the Euro American mammal congress (1998, July)

Diet overlap between the newly introduced Lamprichthys tanganicanus and the Tanganyika sardine in Lake Kivu, Eastern Africa

in Hydrobiologia (2011), 675(1), 75-86

This study evaluates the possible competition for food between Lamprichthys tanganicanus, recently introduced in Lake Kivu, and Limnothrissa miodon, which has been the basis of the pelagic fishery in this ... [more ▼]

This study evaluates the possible competition for food between Lamprichthys tanganicanus, recently introduced in Lake Kivu, and Limnothrissa miodon, which has been the basis of the pelagic fishery in this lake for several decades. Since 2006, L. tanganicanus has expanded in the lake and its numbers have increased in the captures, raising concern for the sardine fishery. We carried out a 2-year monthly survey, based on experimental captures in littoral and pelagic stations, which demonstrated the invasive dispersal of L. tanganicanus in littoral and pelagic waters. The diet of both species was determined on the basis of gut content analyses, taking into account the influence of site and season, and a diet overlap index was calculated. In the pelagic zone, where almost all size classes of both species were present and essentially fed upon mesozooplankton, the diet overlap was high. This situation stems from the fact that L. tanganicanus has colonized the pelagic zone in Lake Kivu, likely in search for more abundant mesozooplankton. Inshore, the diet overlap between the two species was lower, as L. tanganicanus consumed a broad range of food, whereas L. miodon strongly selected insects and, chiefly for the largest specimens, fishes. These results suggest a likelihood of interspecific competition, particularly offshore, where mesozooplankton is the main available food type, and call for further monitoring of the sardine fishery, to assess a possible impact of the invader. © 2011 Springer Science+Business Media B.V. [less ▲]