Search results for "Salve"

The influence of temperature on growth and proximate body composition of under yearling Lake Inari arctic char (Salvelinus alpinus (L.))

1997

The growth of underyearling Lake Inari arctic char was studied in groups of fish held at 5.9, 8.7, 12.1, 15.1 and 18.0 °C for 31 days. Growth rate increased with increasing water temperature, reached a peak at 15.1 °C, and then declined. The temperature influence on relative growth was expressed as a non-linear function. There were differences in body composition between fish reared at different temperatures: percentage water being highest at the lowest temperature, whereas energy content was highest in the fish held at the three highest temperatures. The body wet weight explained most of the variance in water content and it is suggested that this may also apply to other body constituents.

Adaptive radiation along a thermal gradient: preliminary results of habitat use and respiration rate divergence among whitefish morphs.

2014

Adaptive radiation is considered an important mechanism for the development of new species, but very little is known about the role of thermal adaptation during this process. Such adaptation should be especially important in poikilothermic animals that are often subjected to pronounced seasonal temperature variation that directly affects metabolic function. We conducted a preliminary study of individual lifetime thermal habitat use and respiration rates of four whitefish (Coregonus lavaretus (L.)) morphs (two pelagic, one littoral and one profundal) using stable carbon and oxygen isotope values of otolith carbonate. These morphs, two of which utilized pelagic habitats, one littoral and one …

Lake size and fish diversity determine resource use and trophic position of a top predator in high-latitude lakes

2015

Prey preference of top predators and energy flow across habitat boundaries are of fundamental importance for structure and function of aquatic and terrestrial ecosystems, as they may have strong effects on production, species diversity, and food-web stability. In lakes, littoral and pelagic food-web compartments are typically coupled and controlled by generalist fish top predators. However, the extent and determinants of such coupling remains a topical area of ecological research and is largely unknown in oligotrophic high-latitude lakes. We analyzed food-web structure and resource use by a generalist top predator, the Arctic charr Salvelinus alpinus (L.), in 17 oligotrophic subarctic lakes…

Introduction of Mysis relicta (Mysida) reduces niche segregation between deep-water Arctic charr morphs

2019

This is a post-peer-review, pre-copyedit version of an article published in Hydrobiologia. The final authenticated version is available online at https://doi.org/10.1007/s10750-019-3953-4. Niche diversification of polymorphic Arctic charr can be altered by multiple anthropogenic stressors. The opossum-shrimp (Mysis relicta) was introduced to compensate for reduced food resources for fish following hydropower operations in Lake Limingen, central Norway. Based on habitat use, stomach contents, stable isotopes (δ13C, δ15N) and trophically transmitted parasites, the zooplanktivorous upper water-column dwelling ‘normal’ morph was clearly trophically separated from two sympatric deep-water morphs…

Moviments socials i comunicació al País Valencià (1991-2011)

2015

El tractament de la comunicació en la mobilització social ha estat tractat en la teoria sociològica de manera constant però molt poques vegades ha estat considerat un aspecte central. Per la seua banda els enfocaments teòrics centrats en la comunicació solen tractar la comunicació en els seus efectes en els públics. Les teories crítiques al respecte, se centraran en la capacitat dels mitjans per produir desmobilització. Aquest treball se centra en un període concret caracteritzat per una alta volatilitat social al País Valencià, entre 1991, quan l'ajuntament de la capital passa a mans de la dreta, i 2011, any en què es produeixen les mobilitzacions massives del "15M". Amb l'estudi empíric d…

Nutritional quality of littoral macroinvertebrates and pelagic zooplankton in subarctic lakes

2021

Littoral benthic primary production is considered the most important energy source of consumers in subarctic lakes. We analyzed essential fatty acid (EFA) and amino acid (EAA) content of 23 littoral benthic macroinvertebrate taxa as well as cladocerans and copepods from pelagic and littoral habitats of 8–9 subarctic lakes to compare their nutritional quality. Pelagic crustacean zooplankton had significantly higher EFA and total FA content (on average 2.6‐fold and 1.6‐fold, respectively) than littoral macroinvertebrates in all our study lakes. Specifically, docosahexaenoic acid (DHA), one of the most important EFA for juvenile fish, was almost exclusively found in pelagic copepods. In littor…

Filosofia e Salvezza

2014

Una riflessione sul modo di pensare il divino alla luce dei diversi modi di intendere la salvezza in rapporto alla contingenza, alla finitezza, alla mortalità

La salvezza della città e la bella speranza in Platone

2011

Environmental and biological factors are joint drivers of mercury biomagnification in subarctic lake food webs along a climate and productivity gradi…

2021

Subarctic lakes are getting warmer and more productive due to the joint effects of climate change and intensive land-use practices (e.g. forest clear-cutting and peatland ditching), processes that potentially increase leaching of peat- and soil-stored mercury into lake ecosystems. We sampled biotic communities from primary producers (algae) to top consumers (piscivorous fish), in 19 subarctic lakes situated on a latitudinal (69.0-66.5 degrees N), climatic (+3.2 degrees C temperature and +30% precipitation from north to south) and catchment land-use (pristine to intensive forestry areas) gradient. We first tested how the joint effects of climate and productivity influence mercury biomagnific…

The natural history of Echinorhynchus bothniensis Zdzitowiecki and Valtonen, 1987 (Acanthocephala) in a high Arctic lake.

2015

The acanthocephalan Echinorhynchus bothniensis Zdzitowiecki and Valtonen, 1987 differs from most other species in the genus Echinorhynchus Zoega in Muller, 1776 by infecting mysids (order Mysida) instead of amphipods (order Amphipoda) as intermediate hosts. Here we report on the occurrence of E. bothniensis in mysids (Mysis segerstralei Audzijonytė et Vainola) and in its fish definitive hosts in a high Arctic lake. Out of 15 907 sampled mysids, 4.8% were infected with a mean intensity of 1.05 worms (range 1-5), although there was notable variation between samples taken in different years and sites. Larger mysids appear more likely to be infected. Of five fish species sampled, charr,Salvelin…