Knowledge on how an insect’s behavior changes in response to chemical substances in the environment can ultimately contribute to the development of biologically harmless pest controls. One of the links between sensory processing systems in the brain and motoric output is thought to be the neurons mediating the pre-processed information from the brain to act on motor circuits in the ganglia of insects. In the present study, the noctuid moth Heliothis virescens was the insect of study, and the thoracic ganglion of in total 88 preparations was stained with fluorescent dye to systematically study the descending neurons mediating information out of their brains. Performing mass-staining of the thoracic ganglion have contributed to knowledge on the areas where these neurons originates or projects. Visualizing the stained neurons in a confocal microscope showed condensed staining of dendrites of descending neurons in the anterior-ventral part of the lateral protocerebrum and in the lateral accessory lobes. Knowing that processing of chemosensory information might result in activities of behavioral relevance, it was especially interesting to see whether projection neurons making up the olfactory axis in the lateral protocerebrum overlapped spatially with dendrites of descending neurons eventually terminating in motor systems in the thoracic ganglia. Double staining of both the antennal lobe and the thoracic ganglion were therefore performed in the same individual, in 31 preparations. Three dimensional reconstruction and registration of descending neurons into the digital standard brain atlas (SBA) of H.virescens supported the spatial position of descending neurons in the anterior-ventral part of the lateral protocerebrum. The SBA containing the descending neurons was visually compared to a separate SBA containing the olfactory axis in the lateral protocerebrum, indicating no or minimal spatial overlap between the olfactory axis and the dendrites of descending neurons. This highlights the need for a detailed examination to discover if sensory information can be transferred to motor systems via 3rd order neurons local to the protocerebrum.

The use of ballan wrasse (Labrus bergylta) for the treatment of salmon lice (Lepeophtheirus samonis) in salmon farming is rapidly growing due to resistance to chemical treatments. The demand for high quality and large amounts of ballan wrasse has thus led to the development of ballan wrasse farming. Due to the small size of the newly hatched larvae, the first-feeding of the larvae has become a bottleneck area. The size and nutritional properties of the live feed chosen can greatly affect both growth and development. Using copepods as live feed in the first part of the feeding regime should give a positive effect on the larval growth and development as they are the natural prey of marine fish larvae and are nutritional superior to rotifers.The aim of this study was to use 1H-NMR to examine the differences in larval metabolic composition as a function of the different types of live feed, as well as to find the most suited method for preparation of ballan wrasse samples for metabolic analysis. To examine this, ballan wrasse larvae was fed using four different feeding regimes. The live feed used was different between the four groups for the first 30 days post hatch. After this all groups were fed the same diet. Larvae in the Copepod group were fed only the copepod Acartia tonsa. The Cop7 was fed copepods the first 7 days, then enriched rotifers. The RotMG group was fed enriched rotifers, and the RotChl group was fed unenriched rotifers. After 30 days post hatch, all treatments was fed enriched Artemia before weaning to formulated feed. Results from the present study indicate that the use of copepods in first-feeding of ballan wrasse resulted in an increase in growth compared to larvae fed rotifer diets. Metabolic analysis of the larvae show that changes in the levels of certain metabolites can be used as biomarkers for growth and development. Differences seem to be correlated to feed composition, with TMAO and taurine standing out as reliable biomarkers for growth differences

Photoperiodic manipulation of reproductive events in fish is suggested to secure all-year supply of fish fry in the Nepalese aquaculture. This could significantly improve food security and decrease poverty in Nepal. In order to achieve this, knowledge about the teleost melatonin system and reproduction is needed. The present study examined blood plasma profiles of the hormone melatonin in silver carp (Hypophthalmichthys molitrix) in Nepal during natural and manipulated photoperiods. Plasma melatonin levels throughout the natural 24-hour light-dark cycle were low during the light period, and increased several folds during the dark period. Peak level was reached early in the dark period, 2.5 hours after onset of darkness. Thereafter levels decreased prior to sunrise. When the silver carps were exposed to continuous darkness, the diurnal rhythmical melatonin levels observed during natural light-dark cycle were sustained. The melatonin levels during the time of the natural light period were low, and increased significantly during the time of the natural dark period, even if the fish were deprived of time signals in the light-dark cycle. In another experiment, silver carps were subjected to a period of two hours darkness at different times during the natural light period. Darkness at morning and midday did not increase plasma melatonin levels, whereas darkness during late light-phase gave a significant increase in plasma melatonin levels. The findings in this study suggest that melatonin synthesis from the pineal gland in silver carp is controlled by an endogenous biological clock. Plasma cortisol levels were measured, and were relatively high. However, it is suggested that cortisol may not have influenced the plasma melatonin levels and fluctuations in the silver carps in the present study significantly.

Periphylla periphylla (Scyphozoa, Coronatae) is a deep sea jellyfish first described by Péron & Lesueur in 1809. It is distributed in all of the world’s oceans except for the Arctic. P. periphylla avoids light and is well adapted to a life in the dark. It performs diel vertical migrations (DVM) in the water column.Relatively recently, since first observation in Lurefjorden near Bergen in the 1970s, it has established dense populations in several Norwegian fjords including the Trondheimsfjord, the focus of this study. The main goal of this thesis was to estimate the current biomass of the P. periphylla population in the inner Trondheimsfjord (Beitstadfjorden), which has three smaller basins with different depths. Most of the data was collected by a Lightweight Video Profiling Platform (LVPP) which provided information on the vertical distribution of jellyfish, their numbers, and the size (CD: coronal diameter) of each individual. The population in Verrabotn, the shallowest and innermost basin of Beitstadfjorden, had a higher percentage of large individuals (CD >121 mm) than the other basins. Most of the jellyfish individuals in the other two basins tended to be small, with CD ≤ 40 mm. However, the total biomass estimated at each location was mainly made up by large P. periphylla. Comparing the present biomass estimate with a previous one in 2007, it appeared that the population had decreased.However, the presence of large numbers of small individuals of different sizes suggests that a successful local recruitment is still taking place.

Insects are guided to potential host plants by visual and olfactory signals. Upon arrival they encounter various taste stimuli, ultimately deciding whether the plant is a proper food or oviposition source. The detection of gustatory stimuli by contact chemosensilla has been studied in several insect species, and intracellular recordings from neurons in the subesophageal ganglion (SOG) in Heliothis virescens have revealed responses to several taste qualities mediated by different appendages. However, how the gustatory information is further processed in higher gustatory areas and how it may lead to taste-related behavior is poorly understood. Important questions are where gustatory neurons project in the protocerebrum and how they process information mediated by different appendages, i.e. the coding of taste identity and location. These topics were investigated in the present study using intracellular recordings combined with fluorescent staining techniques. The recordings were carried out in vivo from single neurons in the protocerebrum of the moth Heliothis virescens, while concurrently stimulating the contact chemosensilla of the antennae and the proboscis with gustatory and mechanosensory stimuli. The protocerebral neurons showed large diversity in their response tuning breadth, some responding specifically to one tastant applied at one appendage, whereas others responded to several tastants applied at one, two or three appendages. Some of the neurons were successfully stained, all of them partially or entirely located in the protocerebrum. In addition, some of the neurons targeted the SOG/tritocerebrum, the antennal mechanosensory and motor center (AMMC) and the antennal lobes (ALs). The present results point to different processing streams of taste information in the protocerebrum, where the narrowly tuned neurons seem to participate in a labelled line (LL) and the others in an across fiber pattern (AFP) mechanism. Moreover, the important role of the gustatory system for influencing behavior is substantiated by the widespread gustatory innervation of the protocerebrum. These projections suggest a role for the gustatory system in modulating the activity of other sensory systems, in addition to the coding of taste information.

SamandragInsekt nyttar luktesansen til mange formål som er avgjerande for overlevnad og reproduktiv suksess. Ein veksande kunnskapsbase tyder på at miksturar av nokre få biologisk relevante plantevolatiler kan vekke atferdsmessige responsar i insekt medan einskilde volatiler har liten effekt. Mykje forsking er gjort på nevral prosessering av binære duftblandingar i det primære luktesenteret til insekt, men ein veit lite om korleis informasjon om blandingar av mange komponentar vert handsama i høgare ordens hjernesentra. Denne studien tok sikte på å utforske prosessering av informasjon om biologisk relevante plantedufter og komplekse duftblandingar i høgare ordens luktesentra i nattflyarten Heliothis virescens. Insekt vart stimulerte med primære plantedufter og komplekse duftblandingar medan intracellulære registreringar vart utførte på høgare ordens nevron i laterale og superiore protocerebrum. Nokre nevron vart òg karakteriserte morfologisk ved intracellulær fargeinjeksjon, og eit av desse nevrona vart rekonstruert digitalt i tre dimensjonar og registrert inn i eit standard hjerneatlas som er konstruert for denne arten. Nevrofysiologiske analyser viste at duftblandingane vekte responsar med høgare sannsyn enn enkeltdufter i desse høgare ordens nevrona. Mange nevron skilde mellom blandingar og enkeltkomponentar ved å svare med ulik styrke på dei to typane stimuli, men det var ikkje noko fast forhold mellom responsmønstera eit nevron utviste for ei blanding og responsmønstera nevronet utviste for komponentane i blandinga. Resultata viste òg at mange nevron kunne skilje mellom to komplekse blandingar som var kjemisk nært slekta. Blandingane vakte dei sterkaste responsane I storparten av nevrona, men eit nevron svarte spesifikt på berre éin primær odorant. Desse resultata tyda på at informasjon om primære plantedufter vert integrerte i høgare ordens nevron på ein ikkje-lineær måte som er spesifikk for kvar duftblanding og kvart enkelt nevron. Vidare utviser høgare ordens nevron primært synergi for duftblandingar, men informasjon om spesifikke enkeltdufter er òg bevart i høgare hjernesentra.

One major challenge in Asian aquaculture is the limited availability of carp fries. In order to establish out of season supply of fries, knowledge about the pineal melatonin clock and calendar function, and its influence on the reproductive system, is needed. Three experiments were carried out to examine pineal melatonin dynamics of mrigal carp (Cirrhinus mrigala), under natural outdoor, and manipulated photoperiods. Plasma melatonin profile of the mrigal carp kept under natural outdoor photoperiod reached a peak early in the dark phase, and then showed a tendency of falling plasma melatonin levels until daytime levels were reached at first light. The second experiment intended to induce production of melatonin at different times during the light phase, and gave production of melatonin only in late afternoon. This indicates a refractory period of the pineal gland during daytime, and that production of melatonin might be controlled by a circadian clock. In the third experiment, animals were exposed to continuous darkness. The resulting plasma melatonin profile was in accordance with subjective darkness and light, with a peak late in the dark phase. This further supports the assumption that a circadian clock controls pineal melatonin production and secretion in the mrigal carp.

The Black legged Kittiwake (<i>Rissa tridactyla</i>) is one of the more extensively studied seagull species, and much of their nesting behaviour and physiology concerning the breeding period has already been examined to a high degree. Its habitat choice is such that it has been able to cover much of the costal habitats on the northern hemisphere, from Spain in the south to Svalbard in the north. For this reason it encounters a high degree of variability when it comes to environmental challenges during its breeding season, leading to large fluctuations in inter-annual breeding success. As the environmental factor play such an important role in conservation, the ability to accurately estimate its effects on sea-bird populations, is of outmost importance. One step towards acquiring such knowledge is to measure the effects on the nestling, when exposing their parents to a known increase in energy expenditure; a procedure attempted in this study.Long-lived species, like the Kittiwake, have long been thought to maximize their fitness by restricting parental investment to a fixed level in each breeding attempt. By manipulating parental flight wing size at the start of the hatching period, we induced a handicap on the experimental nests. By measuring body condition (BCI) of parents and chicks, in addition to the baseline corticosterone (CORT) levels of the nestlings, this study aimed to investigate whether or not the offspring in the experimental nests would suffer any detrimental effects from increased foraging costs to their parents, by wing-clipping, in comparison to offspring of unmanipulated parents; and whether or not offspring gender played any role in this context. The offspring of wing-clipped parents showed no significant detrimental effects, neither on body condition or CORT levels in relation to the control nests. With regard to the CORT levels, the data actually suggested a more positive outcome, significantly lower CORT levels for larger nestlings, in the experimental nests than what was found for the control nests. Both males and females seemed to experience the same investment, as there was found no significant difference in size, BCI or CORT levels between them. The effect on the parents also did not show any significant difference between the groups on BCI or weight loss. Neither father nor mother showed any appreciable difference in their investment, measured as their BCI or on weight loss, although mothers was found to loos a larger proportion of their body mass, suggesting that they are willing to assist in a larger extent during chick rearing, in comparison to fathers. There was also detected a difference in nest attendance, where the treatment actually appeared to give a significant difference, with wing-clipped couples sing a longer time between each nest attention swap. Despite the results on the nest attendance, the lack of a considerable detrimental effect from the wing-clipping procedure could not be detected on neither parents nor the offspring. This study was therefore unable to say anything definitive with regard to parental investment theories. It would seem that the experimental procedure in this case was too weak to give a significant handicap, whether this was from the procedure itself, environmental factors or other, so far, unknown effectors.Although this study failed in its investigation on parent nestling tradeoffs, and gender relations regarding this; It has however, found a very strong correlation (P = 0.006) between handling time during blood sampling and CORT levels in time intervals below the 3 minutes. Suggesting that the widely accepted limit of 3 minutes handling time when sampling the baseline CORT level, might not be valid with regard to chicks during their growth face.

SammendragDen dominerende planktonorganismen i Atlanterhavet og Barentshavet er den calanoide kopepoden Calanus finmarchicus. Den er en nøkkelart i den marine næringskjeden, og har evnen til å lagre store mengder fett, som kan være den viktigste opptaksruten for lipofile forurensende stoffer til høyere trofiske nivå. C. finmarchicus er derfor betraktet som en økologisk relevant forsøks art.Ettersom en upassende respons til miljøbestemte og fysiologisk stimuli, som en årsak av toksiske effekter av forurensende stoffer, kan ha atskillige konsekvenser for overlevelse, selv på konsentrasjoner under dødelig nivå, er det viktig å undersøke adferds indikatorer for akvatisk toksisitet. Det ble totalt gjennomført fire eksponerings serier, hvor eksponerings media var WAFs basert på fersk og forvitret råolje. Eksponeringstiden var 24, 48, 72 og 96 timer. Endringer i flukt respons som en årsak av narkose indusert av olje eksponering ble målt. Parameterne som ble målt var flukt respons frekvens, flukt respons latens tid og utmattende effekter av repetitive hydrodynamiske forstyrrelser. Resultatet fra forvitret og fersk råolje eksponeringer viser at det skjer en nedgang i flukt respons frekvenser selv på konsentrasjoner langt under dødelig nivå, for alle eksponerings tider. Det ble derimot ikke funnet noen klar korrelasjon mellom råolje eksponering og endinger i latens tid eller utmattende effekter av repetitiv hydrodynamiske forstyrrelser.Tilstedeværelsen av signifikant reduksjon i flukt respons frekvenser i C. finmarchicus indikerer at endringer i flukt adferd kan fungere som endepunkt for toksiske effekter, av kjemikalier med konsentrasjoner under dødelig nivå, og kan blir brukt som en økologisk relevant biomarkør.

As human induced disturbance in alpine ecosystems have increased, more knowledge is needed about the long-term effects of restoration efforts in such environments. There are benefits with using native species in restoration in alpine ecosystems, but the establishment success of native species compared to non-native species, and their effect on the establishment of native species has not been evaluated in detail. We examined ten disturbed alpine sites 21 years after seeding with a commercial seed mix, with regard to vegetation cover, species richness and soil conditions, and compared them with reference sites in close vicinity. After 21 years seeded sites had more vegetation cover, but native vegetation cover and species richness was larger in reference sites. Soil material did have a significant effect on vegetation cover, with less vegetation establishing as dominating soil particle size increased. However, native vegetation cover remained the same with increasing soil material. The effects of a native species, Festuca ovina, was compared with the effects of the main ingredient from the commercial seed mix used in 1989, Festuca rubra, on the establishment of the native Betula nana. Festuca rubra established slightly better than F. ovina on all soil types in the greenhouse experiment, but had larger plant size. B. nana experienced competition from both Festuca species, but less from F. ovina. The species F. ovina facilitated for B. nana on coarse soil. Even though these findings indicate that the native F. ovina is the best alternative with regard to establishment of a native species in the greenhouse, these patterns may not always be expected in nature due to other environmental factors, like wind. However the findings in this study indicate that using native species is the best alternative in alpine ecosystem restoration.