Search results for "juvenil"
showing 10 items of 450 documents
Development and validation of a bioenergetics model for juvenile and adult burbot
2003
Oxygen consumption of juvenile and adult burbot Lota Iota was measured in an intermittent-flow respirometer to determine the effect of temperature and fish body mass on metabolic rate. These results were combined with data from earlier experiments and the 'Wisconsin bioenergetics' model was constructed. The model was validated under laboratory conditions by comparing observed and predicted food consumption and growth of burbot fed on dead vendace Coregonus albula. There was a good correspondence between observed and estimated growth and food consumption under experimental conditions: the mean absolute per cent errors of growth and food consumption were 4.8 and 24.0%. Estimated values with t…
Life in the ice lane: the winter ecology of stream salmonids
2007
Despite the common view that conditions in winter strongly influence survival and population size of fish, the ecology of salmonids has not been as extensively studied in winter as in other seasons. In this paper, we review the latest studies on salmonid winter survival, habitat use, movement and biotic interactions as they relate to the prevailing physical and habitat conditions in rivers and streams. The majority of research conducted on the winter ecology of salmonids has been carried out in small rivers and streams, where temperatures are above zero and where there is no ice. Investigations in large rivers, regulated and dredged rivers, and under conditions of different ice formations a…
Development and habitat selection of a new sanguinicolid parasite of cultured greater amberjack, Seriola dumerili, in the Mediterranean
2009
Abstract This study presents a description of the developmental stages of a new sanguinicolid disease agent (Paradeontacylix ibericus) of cultured Seriola dumerili (greater amberjack) in the Mediterranean, and investigates parasite habitat selection in the definitive host and the development of sanguinicolidosis in experimental, inshore cultures of S. dumerili . Two experimental surveys were carried out using fish captured as wild 0+ juveniles in the aquaculture facilities at Puerto de Mazarron (Spain). Encysted, early post-cercarial stages (schistosomula) were detected in histological sections of the pelvic and thoracic muscles of fish and four subsequent stages of parasite development wer…
Feeding ecology of the loggerhead turtle Caretta caretta in the western Mediterranean
2001
We studied the feeding ecology of juvenile loggerhead turtles Caretta caretta in the western Mediterranean based on the contents of the digestive tract of 54 turtles (range of CCL: 34–69 cm) seized in Barcelona (Spain) in 1991. Turtles had been captured in fishing trawls, but specific information about dates and localities is not available. Despite this limitation, we obtained interesting evidences about the foraging strategies of loggerheads, with potentially important conservation implications. We report 33 new taxa in the diet. Results indicated that western Mediterranean loggerheads feed in an opportunistic way. Numerically, fish made up the most important prey group, followed by pelagi…
Die Diagnose der mitteleuropäischen Urodela (Amphibia) nach der Morphologie des Mundhöhlendaches
1980
AbstractThe pattern of teethrows on the roof of the mouth and the numbers of teeth enable as diagnostic characteristics the determination of the Central European Urodela. Particularly the distinction between T. vulgaris and T. helveticus is now definite in all stages after metamorphose. The degree of development of the vomeromaxillarfold (Triturus) respectively of the vomerfold (Salamandra) indicates whether a specimen is an adult, juvenile or newly metamorphosed one.
Plant regeneration from juvenile and adult Anthyllis cytisoides, a multipurpose leguminous shrub
1997
Summary Anthyllis cytisoides , a legume shrub used for afforestation and reclamation of degraded Mediterranean areas, was successfully micropropagated from expiants of juvenile (cotyledonary nodes and apical buds) and adult origin (axillary buds). Multiple shoot formation was dependent on the presence of benzyladenine in the induction medium. Of the salt formulation and expiants examined, the higher proliferation rates were obtained when axillary buds from adult plants were cultured on a modified Schenk and Hildebrandt medium. Following the preferred protocol, shoot yield reached values greater than 100 shoots per expiant. Plants were easily rooted and transplanted into greenhouse.
The effect of the length of repeated feed deprivation between single meals on compensatory growth of pikeperch Sander lucioperca
2009
Abstract Juvenile pikeperch ( Sander lucioperca ) were reared for 58 days according to one of the following feeding regimes: control (fed once every day); 1 + 1 (fed every other day); 1 + 3 (one-day feeding followed by a three-day feed deprivation); and 1 + 6 (fed once a week). Control fish had significantly higher growth rate than the 1 + 3 and 1 + 6 fish, and consequently the final weight of the controls (125.2 ± SD 30.0 g, n = 4) was higher than that of the 1 + 3 (84.0 ± 17.9 g) and 1 + 6 fish (64.7 ± 7.2 g). Fish in the treatment groups were capable to compensate for the reduced number of feedings by increasing intake relative to the controls when feed was available. This hyperphagic r…
Movement of Metals to New Growing Tissue in the MossHylocomium splendens(Hedw.) BSG
1997
To obtainHylocomium splendens(Hedw.) BSG. that varied in metal (K, Mg, Ca and Zn) content, moss samples were collected from six sites around a zinc contaminated area of Latvia; metal contents were artificially lowered by branch excision. The first fully expanded annual segment (mature segments), together with the unexpanded segment (juvenile segment) were grown in the laboratory with watering from below. The contents of K, Mg, Ca and Zn in new growth were correlated with initial contents in the juvenile+mature segments. However, the concentrations of these metals in the new growth were generally not correlated with those in the pre-experimental segments. The excision of branches from the ma…
Role of genetic polymorphisms in myocardial infarction at young age
2010
Acute myocardial infarction (AMI) in young adult presents a typical pattern of risk factors, clinical, angiographic and prognostic characteristics. In the last years we demonstrated that hemorheological profile is altered in these patients in a persistent way and independently of the number of risk factors and of the extent of coronary lesions. Thus, the hyperviscosity syndrome following AMI could be considered an intrinsic characteristic of these patients. Consequently it is possible to hypothesise the presence of a genetic background at the origin of this predisposition. If this background is able to influence the risk of ischemic heart disease, this should be particularly evident in youn…
Carotid intimal-media thickness and endothelial function in young patients with history of myocardial infarction
2009
AIM: The aim of the study was to evaluate the prevalence of carotid atherosclerosis and endothelial dysfunction in 45 young patients (38 mens and 7 females) with myocardial infarction (MI), age 29-45, mean age 42+/-3 years, to verify its possible role as a marker of coronary atherosclerosis. METHODS: Vascular echography was performed to verify the presence of carotid atherosclerosis and/or endothelial dysfunction in 45 young patients with MI and in 45 healthy control subjects well matched for age and sex. RESULTS: We observed a normal intima media thickness (IMT) only in 30% of patients with juvenile myocardial infarction (JMI) compared with 66% in the control group (P<0.0001) and 34% of pa…