190 research outputs found
MS-222 toxicity in juvenile seabream correlates with diurnal activity, as measured by a novel video-tracking method
©2010. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
This document is the Accepted version of a Published Work that appeared in final form in Aquaculture. To access the final edited and published work see
https://doi.org/10.1016/j.aquaculture.2010.06.028Fish are frequently exposed to anaesthetics since their use is necessary in several
aquaculture procedures. The aim of this study was to investigate the existence of day night differences in toxicity and effectiveness of a common fish anaesthetic (MS-222)
in juvenile gilthead seabream (Sparus aurata), determining the induction time of
anaesthesia and subsequent recovery by a novel video-recording system. Our results
showed that MS-222 toxicity was significantly higher at ML (mid-light) (LC50=85.5
mg/L) than at MD (mid-darkness) (LC50=107.6 mg/L) (trimmed Spearman-Karber
method). In addition, when fish were exposed to a sublethal but effective MS-222
concentration (65 mg/L), 7 min passed before 50% a reduction in swimming activity
was observed at ML compared to the 9 min required at MD. As regards recovery, fish
showed activity levels similar to basal levels 10 min after MS-222 removal at ML, but
only 6 min at MD. These results indicated that both toxicity and effectiveness were
higher during the day than at night, coinciding with the diurnal activity pattern
displayed by seabream, which should be taken into account when designing and
applying daily protocols for anaesthesia in aquacultur
Influence of light intensity on plasma melatonin and locomotor activity rhythms in tench
©2005. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
This document is the Accepted version of a Published Work that appeared in final form in Chronobiology International: The Journal of Biological and Medical Rhythm Research.Melatonin production by the pineal organ is influenced by light intensity, as has been
described in most vertebrate species, in which melatonin is considered a synchronizer of
circadian rhythms. In the case of tench, strict nocturnal activity rhythms have been
described although the role of melatonin has not been clarified. In this study we
investigated daily activity and melatonin rhythms under 12:12 light-dark (LD)
conditions with two different light intensities (58.6 and 1091µW/cm2
), and the effect of
one hour broad spectrum white light pulses of different intensities (3.3, 5.3, 10.5,
1091.4 µW/cm2
) applied at mid darkness (MD) on nocturnal circulating melatonin. The
results showed that plasma melatonin in tench under LD 12:12 and high light conditions
displayed a rhythmic variation, where values at MD (255.8 ± 65.9 pg/ml) were higher
than at mid light (ML) (70.7 ± 31.9 pg/ml). Such a difference between MD and ML
values was reduced in animals exposed to LD 12:12 and low light intensity. The
application of one hour light pulses at MD lowered plasma melatonin to 111.6 ± 3.2
pg/ml (in the 3.3-10.5 µW/cm2 range) and to 61.8 ± 18.3 pg/ml (with the 1091.4
µW/cm2 light pulse) and totally suppressed nocturnal locomotor activity. These results
showed that melatonin rhythms persisted in tench exposed to low light intensity
although the amplitude of the rhythm is affected. In addition, it was observed that light
pulses applied at MD affected plasma melatonin content and locomotor activity. Such a
low threshold suggests that the melatonin system is capable of transducing light even
under dim conditions, which may be used by this nocturnal fish to synchronize to weak
night light signals (e.g. moonlight cycles
Feeding entrainment of locomotor activity rhythms, digestive enzymes and neuroendocrine factors in goldfish
©2007. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
This document is the Accepted version of a Published Work that appeared in final form in Journal of PHYSIOL BEHAV. To access the final edited and published work see http://doi: 10.1016/j.physbeh.2006.10.017L.M. VERA, N. DE PEDRO, E. GÓMEZ-MILÁN, M.J. DELGADO, M.J. SÁNCHEZ MUROS, J.A. MADRID, F.J. SÁNCHEZ-VÁZQUEZ. Feeding entrainment of
locomotor activity, digestive enzymes and neuroendocrine factors in goldfish.
PHYSIOL BEHAV 90 (2-3) 518-524, 2007. The existence of food anticipatory activity
(FAA) in animals subjected to daily feeding schedules seems to be mediated by a
feeding-entrainable oscillator (FEO). Such an FEO may help in anticipating meal time
and so optimizing food acquisition and nutrient utilization. In this study we investigated
the existence of FAA and whether digestive enzymes, plasma cortisol, hypothalamic
NPY and gastrointestinal tract (GIT) and plasma melatonin were entrained by periodic
feeding in goldfish. We observed that periodically fed goldfish showed FAA in
locomotor activity as well as in amylase and NPY. Alkaline protease and GIT melatonin
were higher after feeding, whereas plasma cortisol levels were reduced. Plasma
melatonin remained unmodified before and after meal time. These results suggested that
scheduled feeding entrained both behavioral and certain physiological patterns in
goldfish, FAA being of adaptive value to anticipate a meal and prepare the digestive
physiology of fish
Gelsilox: a novel strategy for the study of dynamics alteration in the thiol redox proteome
Comunicaciones a congreso
The feeding of American plaice (Hippoglossoides platessoides), Redfish (Sebastes marinus) and Cod (Gadus morhua) in the Flemish Cap during July 1988
A randomly stratified bottom-trawl survey was realized in the Flemish Cap (NAFO Div. 3M) in July 1988. The stomach contents of three species were studied: 320 of American plaice (Hippoglossoides platessoides), 203 of redfish (Sebastes Marinus) and 468 of cod (Gadus morhua). The cod specimens were classified taking into account age groups; in the case of other species by length classes. The food items, the prey occurrence index and the diversity index were determined too. The Schoener overlap index was calculated to study the intraspecific diet overlap in cod and the interspecific diet overlap between the three species. The relation between predator size (cod) and prey size (redfish) was also studied
Características morfológicas y estructura superficial de montículos submarinos del talud inferior del margen continental canario (O de las Islas Canarias)
Extrusive edifices and structural reliefs, catalogued as mounds and located on the seafloor
to the west of Canary Islands were analyzed by acoustic data obtained with multibeam and
parametric echosounders during several oceanographic expeditions. They were carried out at deep
waters, from 4800 to 5200 m, and they have allowed characterizing 41 newly discovered submarine
structures which occur either as isolated edifices or clustered mounds. These features have circular
to elongated shapes with diameters of 2-24 km and relief heights of 10 to 250 m, showing different
flank slopes of 2-50°. They generally display mounded forms and show morphological elements as
ridges, near-circular rock outcrops, depressions and fault scarps together with mass flow and slide
deposits located at the vicinity of the edifices. Two types of extrusive features are evidenced by the
morphological and seismic data analyses, the first one probably corresponds to high velocity
extrusions that reach the seafloor surface and the second one is probably formed by the
combination of faulted structures and low velocity extrusions that produce singular domes in the
shallower sedimentary records. Based on both analyses, extrusive phenomena represent the
dominant mechanism for mound field evolution in the Canary lower slope region.Versión del edito
List of Species as recorded by Canadian and EU Bottom Trawl Surveys in Flemish Cap
A list of species has been prepared with all records in each haul of both Canadian (1977-1985) and EU (1988-2002 and 2003-2012) bottom trawl surveys. Even though sampling intensity and taxonomic interest changed with time, the three periods can be considered almost homogeneous. Main change occurred when the EU survey increased the depth range, from 730 to 1460 meters depth, and all invertebrates were recorded
Características geomorfológicas del Pasaje de Lanzarote (Región oriental de las Islas Canarias)
The Passage of Lanzarote is an example of a wide oceanic corridor. It extends between the
eastern Canary Islands and the Western Africa continental margin. Seafloor morphology of this
passage has been analyzed with the aim to know the morphogenetic processes related to both the
oceanography and the geology. Multibeam bathymetric data and high and very high resolution
seismic profiles obtained in the SUBVENT2 cruise have been used. Five main morphological groups
were analyzed: (a) Volcanic or diapiric submarine hills; (b) Tectonic features on the continental slope
(linear scarps and a rhomboid-like depression) related to normal faults at the top of buried diapirs;
(c) Giant circular depressions initially triggered by submarine venting at the top of diapirs; (d)
Sedimentary instabilities and canyons (gullies, canyons, mass transport deposits) that are present
specially on the Fuerteventura-Lanzarote ridge must be related to the high energy geological
processes, both constructive and dismantling, associated to the evolution of these volcanic domains;
and (e) Contouritic features both erosive (central channel, contourite channels) and depositional
(mounded and plastered drifts) that occur in the central part of the bottom surface of the passage,
and are generated by the interaction of the MW and the interface MW-AAIW with the seafloor.Versión del edito
Interstellar MHD Turbulence and Star Formation
This chapter reviews the nature of turbulence in the Galactic interstellar
medium (ISM) and its connections to the star formation (SF) process. The ISM is
turbulent, magnetized, self-gravitating, and is subject to heating and cooling
processes that control its thermodynamic behavior. The turbulence in the warm
and hot ionized components of the ISM appears to be trans- or subsonic, and
thus to behave nearly incompressibly. However, the neutral warm and cold
components are highly compressible, as a consequence of both thermal
instability in the atomic gas and of moderately-to-strongly supersonic motions
in the roughly isothermal cold atomic and molecular components. Within this
context, we discuss: i) the production and statistical distribution of
turbulent density fluctuations in both isothermal and polytropic media; ii) the
nature of the clumps produced by thermal instability, noting that, contrary to
classical ideas, they in general accrete mass from their environment; iii) the
density-magnetic field correlation (or lack thereof) in turbulent density
fluctuations, as a consequence of the superposition of the different wave modes
in the turbulent flow; iv) the evolution of the mass-to-magnetic flux ratio
(MFR) in density fluctuations as they are built up by dynamic compressions; v)
the formation of cold, dense clouds aided by thermal instability; vi) the
expectation that star-forming molecular clouds are likely to be undergoing
global gravitational contraction, rather than being near equilibrium, and vii)
the regulation of the star formation rate (SFR) in such gravitationally
contracting clouds by stellar feedback which, rather than keeping the clouds
from collapsing, evaporates and diperses them while they collapse.Comment: 43 pages. Invited chapter for the book "Magnetic Fields in Diffuse
Media", edited by Elisabete de Gouveia dal Pino and Alex Lazarian. Revised as
per referee's recommendation
The Interactive Role of Hydrocarbon Seeps, Hydrothermal Vents and Intermediate Antarctic/Mediterranean Water Masses on the Distribution of Some Vulnerable Deep-Sea Habitats in Mid Latitude NE Atlantic Ocean
In this work, we integrate five case studies harboring vulnerable deep-sea benthic habitats in different geological settings from mid latitude NE Atlantic Ocean (24–42° N). Data and images of specific deep-sea habitats were acquired with Remoted Operated Vehicle (ROV) sensors (temperature, salinity, potential density, O2, CO2, and CH4). Besides documenting some key vulnerable deep-sea habitats, this study shows that the distribution of some deep-sea coral aggregations (including scleractinians, gorgonians, and antipatharians), deep-sea sponge aggregations and other deep-sea habitats are influenced by water masses’ properties. Our data support that the distribution of scleractinian reefs and aggregations of other deep-sea corals, from subtropical to north Atlantic could be dependent of the latitudinal extents of the Antarctic Intermediate Waters (AAIW) and the Mediterranean Outflow Waters (MOW). Otherwise, the distribution of some vulnerable deep-sea habitats is influenced, at the local scale, by active hydrocarbon seeps (Gulf of Cádiz) and hydrothermal vents (El Hierro, Canary Island). The co-occurrence of deep-sea corals and chemosynthesis-based communities has been identified in methane seeps of the Gulf of Cádiz. Extensive beds of living deep-sea mussels (Bathymodiolus mauritanicus) and other chemosymbiotic bivalves occur closely to deep-sea coral aggregations (e.g., gorgonians, black corals) that colonize methane-derived authigenic carbonates.Versión del edito
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