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Enumeration	Reference	Cover	Find
1.	Chapman, Ben, et al. (author) Partial migration in fishes: causes and consequences. 2012 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 81:2, s. 456-478 Journal article (peer-reviewed)abstract Partial migration, where only some individuals from a population migrate, has been widely reported in a diverse range of animals. In this paper, what is known about the causes and consequences of partial migration in fishes is reviewed. Firstly, the ultimate and proximate drivers of partial migration are reflected upon: what ecological factors can shape the evolution of migratory dimorphism? How is partial migration maintained over evolutionary timescales? What proximate mechanisms determine whether an individual is migratory or remains resident? Following this, the consequences of partial migration are considered, in an ecological and evolutionary context, and also in an applied sense. Here it is argued that understanding the concept of partial migration is crucial for fisheries and ecosystem managers, and can provide information for conservation strategies. The review concludes with a reflection on the future opportunities in this field, and the avenues of research that are likely to be fruitful to shed light on the enduring puzzle of partial migration in fishes.
2.	Chapman, Ben, et al. (author) Partial migration in fishes: definitions, methodologies and taxonomic distribution. 2012 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 81:2, s. 479-499 Journal article (peer-reviewed)abstract Partial migration, where populations are composed of both migratory and resident individuals, is extremely widespread across the animal kingdom. Researchers studying fish movements have long recognized that many fishes are partial migrants, however, no detailed taxonomic review has ever been published. In addition, previous work and synthesis has been hampered by a varied lexicon associated with this phenomenon in fishes. In this review, definitions and important concepts in partial migration research are discussed, and a classification system of the different forms of partial migration in fishes introduced. Next, a detailed taxonomic overview of partial migration in this group is considered. Finally, methodological approaches that ichthyologists can use to study this fascinating phenomenon are reviewed. Partial migration is more widespread amongst fishes than previously thought, and given the array of techniques available to fish biologists to study migratory variation the future of the field looks promising.
3.	Jönsson, Mikael, et al. (author) Foraging success of juvenile pike Esox lucius depends on visual conditions and prey pigmentation 2011 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 79:1, s. 290-297 Journal article (peer-reviewed)abstract Young-of-the-year pike Esox lucius foraging on copepods experienced different foraging success depending on prey pigmentation in water visually degraded by brown colouration or algae. Both attack rate and prey consumption rate were higher for E. lucius foraging on transparent prey in brown water, whereas the opposite was true in algal turbid water. Pigments in copepod prey may have a cryptic function in brown water instead of a photo-protective function even if prey-size selectivity was stronger than selection based on pigmentation in juvenile E. lucius. (C) 2011 The Authors Journal of Fish Biology (C) 2011 The Fisheries Society of the British Isles
4.	Nilsson, Anders, et al. (author) The role of gastric evacuation rate in handling time of equal-mass rations of different prey sizes in northern pike 2000 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 57:2, s. 516-524 Journal article (peer-reviewed)abstract In a laboratory experiment, northern pike Esox lucius gastric evacuation rates did not differ between equal-mass rations of small and large prey. In a comparison between intermediate and large prey, the pike were unable to fit two intermediate prey completely into the stomach at the same time, resulting in two consecutive evacuations, and changes in patterns of gastric evacuation. Thus. total gastric evacuation time was not affected by prey size composition in equal-mass rations. but patterns in evacuation rate may depend on the size ratio between predator and prey. Cumulative manipulation time between strike and complete swallowing of prey differed between equal-mass rations of small. intermediate and large prey, in that small prey took the shortest time to manipulate. Pike had problems striking and redirecting intermediate prey to swallow them head first, and the manipulation times for intermediate prey were as long as for large prey. Since an increased time manipulating prey in the mouth increases risk of predation and intraspecific interactions in Dike, it is concluded that risks associated with long manipulation times, and not only energy per total handling time, determine prey value and prey size preference in this piscivore. (C) 2000 The Fisheries Society of the British Isles.
5.	Nilsson, Anders, et al. (author) Visibility conditions and diel period affect small-scale spatio-temporal behaviour of pike Esox lucius in the absence of prey and conspecifics 2012 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 80:6, s. 2384-2389 Journal article (peer-reviewed)abstract Pike Esox lucius in the absence of prey and conspecifics were shown to have the highest habitat-change activity during dusk and to decrease preference for complex habitats in turbid water. As the behaviours indicate routine responses in the absence of behavioural interactions, E. lucius spatio-temporal distributions should be directly affected and thereby more easily assessed and avoided by prey, with potential consequences for encounter rates.
6.	Olsen, K Håkan, et al. (author) The influence of dominance and diet on individual odours in MHC identical juvenile Arctic charr siblings 2003 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 63:4, s. 855-862 Journal article (peer-reviewed)abstract No difference in attraction was observed in sibling Artic charr Salvelinus alpinus between water scented by dominant or subordinate major histocompability complex (MHC) identical fish observed in a two-choice fluviarium. In a second experiment, MHC identical sibling donors were given different types of food pellets before the preference test. The test fish showed a significant attraction to the sibling given the same kind of food as the test fish itself during the first 6 h of the fluviarium tests. The results suggest that diet has an influence on the odours released and can, in addition to MHC related odours, be used for information relating to group member identity. (C) 2003 The Fisheries Society of the British Isles.
7.	Persson, Anders, et al. (author) Pikeperch Sander lucioperca trapped between niches: foraging performance and prey selection in a piscivore on a planktivore diet 2008 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 73:4, s. 793-808 Journal article (peer-reviewed)abstract The foraging behaviour of planktivorous pikeperch Sander lucioperca during their first growing season was analysed. Field data showed that S. lucioperca feed on extremely rare prey at the end of the summer, suggesting the presence of a bottleneck. In experiments, foraging ability of planktivorous S. lucioperca was determined when fish were feeding on different prey types (Daphnia magna or Chaoborus spp.) and sizes (1). magna of lengths I or 2.5 turn) when they Occurred alone. Front these results, the minimum density requirement of each prey type was analysed. The energy gain for three different foraging strategies was estimated; a specialized diet based on either large D. magna or Chaoborus spp. or I generalist diet combining both prey types. Prey value estimates showed that Chaoborus Spp. Should be the preferred prey, assuming an energy maximizing principle. In prey choice experiments, S. lucioperca largely followed this principle, including D. magna in the diet only when the density of the Chaoborus spp). was below a threshold value. Splitting the foraging bout into different sequences, however, resulted in a somewhat different pattern. During an initial phase, S. lucioperca captured both prey as encountered and then switched to Chaoborus spp. if prey density wits above (he threshold level. The prey selection observed was mainly explained by sampling behaviour and incomplete information about environmental quality, whereas satiation only had marginal effects. It was concluded that the observed diet based on rare prey items wits in accordance with an optimal foraging strategy and may generate positive growth in the absence of prey fish in suitable sizes. (c) 2008 The Authors Journal compilation (c) 2008 The Fisheries Society of the British Isles.
8.	Persson, M. E., et al. (author) Fractionation of delta N-15 and delta C-13 for Atlantic salmon and its intestinal cestode Eubothtium crassum 2007 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 71:2, s. 441-452 Journal article (peer-reviewed)abstract Stable isotopes of nitrogen (delta(15) N) and carbon (delta C-13) were measured for Atlantic salmon Salmo salar and their intestinal cestode, Eubothrium crassum, sharing the same diet. Atlantic salmon muscle tissues were enriched in N-15 and depleted in C-13 compared to their prey (sprat Sprattles sprattus sprattus) and their intestinal cestode. There was no significant difference in delta N-15 or delta C-13 between E. crassum and the sprat. Differences in nutrient uptake and intestine physiology between Atlantic salmon and E. crassum are discussed, as well as how these may give rise to different fractionations of stable isotopes between a host and its parasites. Furthermore, Atlantic salmon contained a significantly higher lipid content than their prey, which may partly explain differences in delta C-13 values between the host and its cestode. In addition, cestodes inhabiting lipid-rich hosts were also lipid rich. Larger Atlantic salmon were enriched in N-15 compared to smaller fish. Cestodes inhabiting large hosts were also enriched in N-15 compared to parasites living in smaller hosts. The last two results were explained by larger fish possibly feeding from a higher trophic level, or from larger and older prey, that resulted in both a higher lipid content and an enrichment in N-15. (c) 2007 The Authors Journal compilation (c) 2007 The Fisheries Society of the British Isles.
9.	Romare, Pia (author) An evaluation of horizontal echo sounding as a method for behavioural studies of 0+fish in field experiments 2001 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 58:6, s. 1512-1523 Journal article (peer-reviewed)abstract A 120 kHz echo sounder, with two split-beam transducers, was used horizontally to monitor the behaviour of 0+ roach Rutilus rutilis, from June to August, in field enclosures. 0+ roach outside the vegetated area of the enclosures were registered both as schools and as single swimming fish. Combining echo counting and tracking with direct observation of echograms, an estimate of relative abundance of 0+ roach in the open water volume was obtained also. With this set up, intermediate sized field experiments studying 0+ fish, may be performed during the whole summer season. (C) 2001 The fisheries Society of the British Isles.
10.	Skov, Christian, et al. (author) Evaluation of PIT-tagging in cyprinids. 2005 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 67:5, s. 1195-1201 Journal article (peer-reviewed)abstract Laboratory and field experiments were used to investigate how different marking procedures, with 23 mm PIT (passive integrated transponders) – tags, affected mortality, body condition and tag expulsion in small roach Rutilus rutilus and rudd Scardinus erythrophthalmus (117 to 163 mm total length). In a laboratory experiment mortality was low (≤ 6%) and only occurred among fishes that had their incision closed with sutures. The latter also had a specific growth rate that tended to be lower than the fish tagged without sutures. The different marking procedures did not adversely affect the body condition of fishes either in the laboratory experiment (after 37 days) or in the field experiment (up to 369 days). No tag expulsions were observed among laboratory fishes PITtagged without sutures. Marking without the use of sutures to close the incision, appears to be the most appropriate PIT tagging procedure for small cyprinids.
11.	Skov, Christian, et al. (author) Habitat-choice interactions between pike predators and perch prey depend on water transparency 2007 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 70:1, s. 298-302 Journal article (peer-reviewed)abstract A mesocosm experiment indicated that water transparency influenced antipredator behaviour in young-of-the-year perch Perca fluviatilis, which partly contradicts another study by showing that high transparency decreases rather than increases perch antipredatory use of vegetated habitats when predators are also free to choose habitat. The present study emphasizes the importance of simultaneously considering both prey and predator habitat-choice behaviours when evaluating predator-prey interactions in relation to water visibility.
12.	Turesson, Håkan, et al. (author) Foraging behaviour and capture success in perch, pikeperch and pike and the effects of prey density 2004 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 65:2, s. 363-375 Journal article (peer-reviewed)abstract The effect of school size on capture success in three different piscivores, perch Perca fluviatilis, pikeperch Stizostedion lucioperca and pike Esox lucius, was investigated. Roach Rutilus rutilus were used as prey in a pool experiment where individual predators were presented prey at densities of one, two, four, eight and 16 prey, respectively. Treatments were replicated seven times for each predator species. Perch was at first virtually unable to capture a prey from a school and suffered a significant confusion effect with increasing prey density. The effect, however, was limited in the long run, as the perch was a very effective predator in its hunting strategy where it singled out and repeatedly attacked single prey irrespective of prey density or school size. Pikeperch and pike were able to attack and capture prey at any prey density equally successfully and thus did not suffer from a confusion effect. Neither did these predators receive any apparent advantages from increasing prey density. (C) 2004 The Fisheries Society of the British Isles.
13.	Amcoff, P., et al. (author) Alterations of dopaminergic and serotonergic activity in the brain of sea-run Baltic salmon suffering a thiamine deficiency-related disorder 2002 In: Journal of Fish Biology. - : Elsevier. - 0022-1112 .- 1095-8649. ; 60:6, s. 1407-1416 Journal article (peer-reviewed)abstract Baltic salmon Salmo salar females displaying wiggling behaviour had significantly lower (P<0.05) hepatic and ovarian thiamine (vitamin B1) concentrations than the normal females, confirming that they suffered from a thiamine deficiency. A significantly (P<0.05) increased monoaminergic activity was found in the telencephalon and the hypothalamus of the wiggling individuals as indicated by [5-hydroxyindoleacetic acid (5-HIAA)]: [5-hydroxytryptamine (5-HT)] and [3,4-dihydroxyphenylacetic acid (DOPAC)]: [dopamine (DA)] ratios. The 5-HIAA concentrations of wiggling individuals were significantly (P<0.05) higher in the telencephalon and the hypothalamus compared to normal fish. Wiggling fish showed significantly (P<0.05) higher concentrations of the DA metabolite DOPAC in the hypothalamus and the brain stem compared to normal fish. Furthermore, the brain stem in wiggling fish contained significantly (P<0.05) less 5-HT than in normal individuals, which was also reflected in a significant (P<0.05) increase in the (5-HIAA): (5-HT) ratio. These results demonstrate an increased serotonergic and dopaminergic activity in wiggling compared to normal fish. The altered monoaminergic activity may be directly related to altered brain thiamine metabolism, but a general stress caused by thiamine deficiency and an inability to regulate swim bladder inflation may contribute. Furthermore, a changed brain monoaminergic activity may contribute to the behaviour characterizing wiggling fish.
14.	Watz, Johan, 1977-, et al. (author) Temperature-dependent prey capture efficiency and foraging modes of brown trout Salmo trutta 2012 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 81:1, s. 345-350 Journal article (peer-reviewed)abstract Prey capture success and foraging mode were studied in brown trout Salmo trutta at temperatures ranging from 5·7 to 14·0° C. At low temperatures, there was a positive correlation between prey capture success and the proportion of time that the fish spent holding feeding stations. This correlation was not found at temperatures >10° C.
15.	Jaensson, Alia, et al. (author) Effects of copper on olfactory-mediated endocrine responses and reproductive behaviour in mature male brown trout Salmo trutta parr to conspecific females 2010 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 76:4, s. 800-817 Journal article (peer-reviewed)abstract In the present study, the effects of copper (CuSO4) on the ability of mature male brown trout Salmo trutta parr to detect and react both physiologically and behaviourally to female pheromones were studied. The study was composed of two parts. In the first experiment, priming effects of the female pheromone prostaglandin F2α (PGF2α) were evaluated by determining the amount of milt produced and the blood plasma levels of 11-ketotestosterone (11-KT) and 17α,20β-dihydroxy-4-pregnen-3-one (17,20β-P) after the PGF2α exposure. In the second experiment, male parr were placed in a large stream tank together with a group of adult males and ovulated females and their individual behaviours were recorded. In the priming experiment, the amount of expressible milt was significantly lower, less than half, in groups exposed during 4 days to 10 or 100 µg l−1 copper compared with control parr only exposed to water. No significant differences were observed in plasma levels of 11-KT and 17, 20β-P. During the behavioural experiment, exposed parr spent less time with the female and had a lower number of courting events. Blood plasma levels of 11-KT were, however, significantly higher in the group exposed to 100 µg l−1 copper compared with the control group. Furthermore, the exposed group spent significantly less time swimming upstream than did the control group. The present study demonstrates that exposure to copper affects reproductive behaviours and endocrinology of S. trutta male parr.
16.	Ah-King, M., et al. (author) Why is there no sperm competition in a pipefish with externally brooding males? Insights from sperm activation and morphology 2006 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 68:3, s. 958-962 Journal article (peer-reviewed)abstract Nerophis ophidion sperm activation and morphology were investigated with the aim of explaining the apparent lack of sperm competition in this syngnathid with externally brooding males. Nerophis ophidion sperm were activated by a mixture of ovarian fluid and sea water, but not by sea water alone. This indicated that sperm were not shed into the water but needed to be released near the eggs, which probably restrained sperm competition. (c) 2006 The Fisheries Society of the British Isles.
17.	Ahnesjo, Ingrid, et al. (author) The biology of Syngnathidae : pipefishes, seadragons and seahorses 2011 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 78:6, s. 1597-1602 Journal article (other academic/artistic)
18.	Ahnesjö, Ingrid (author) Behavioural temperature preference in a brooding male pipefish Syngnathus typhle 2008 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 73:4, s. 1039-1045 Journal article (peer-reviewed)abstract In the broad-nosed pipefish Syngnathus typhle, brooding males positioned themselves significantly more often towards the warmer part (18 degrees C) of an aquarium. whereas females were indifferent in this respect. This behavioural temperature preference may increase male brooding rate and indirectly influence patterns of mating competition. (c) 2008 The Author Journal compilation (c) 2008 The Fisheries Society of the British Isles.
19.	Ahnesjö, Ingrid (author) Fewer Newborn Result In Superior Juveniles In The Paternally Brooding Pipefish Syngnathus-Typhle L 1992 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 41:Suppl. B, s. 53-63 Journal article (peer-reviewed)
20.	Ahnesjö, Ingrid (author) Seahorses and Their Relatives 2010 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 77:1, s. 308-309 Review (other academic/artistic)
21.	Bakke-McKellep, A. M., et al. (author) Effects of dietary soybean meal and photoperiod cycle on osmoregulation following seawater exposure in Atlantic salmon smolts 2006 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 69:5, s. 1396-1426 Journal article (peer-reviewed)abstract Atlantic salmon Salmo salar juveniles were fed either fishmeal-based diets (FM) or diets in which soybean meal (SBM) partly replaced the FM from first feeding on. The fish were kept at continuous daylight during the juvenile stage. During the last 3 weeks before reaching 100 g body mass, all fish were subjected to 12L:12D. Starting at 100 g body mass, groups of 60 fish from each feeding background were subjected to continuous light for 12 weeks (short winter), or a square-wave photoperiod cycle to stimulate parr to smolt transformation with 8L:16D during the first 6 weeks, and then continuous light during the last 6 weeks (long winter). After the 12 weeks, 20 fish from each treatment were subjected to 0, 24 or 96 h seawater exposure at a water salinity of 34. Hypo-osmoregulatory ability at seawater exposure was assessed by mortality, intestinal pathology, plasma ion concentrations and osmolality, gill Na+/K+-ATPase activity and element concentrations in the cytoplasm of distal intestinal enterocytes using X-ray microanalysis. The hypo-osmoregulatory capacity was higher in fish kept at short winter than at long winter, apparently due to more rapid development of gill Na+/K+-ATPase activity. Fish fed SBM suffered typical soybean meal-induced histological alterations of the distal intestine and apparent reductions in digestive function in the more proximal gastrointestinal regions. The net osmoregulatory capacity of these fish was maintained, as indicated by higher gill Na+/K+-ATPase activity and lower plasma Na+, Ca2+ and osmolality compared to the FM-fed fish. Thus, feeding SBM did not impair the hypo-osmoregulatory ability of the Atlantic salmon following seawater exposure.
22.	Bergek, Sara, et al. (author) Panmixia in Zoarces viviparus: implications for environmental monitoring studies 2012 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 80, s. 2302-2316 Journal article (peer-reviewed)abstract In this study, the genetic population structure of the eelpout Zoarces viviparus was investigated by using microsatellites. Samples were collected at 10 sites in the Baltic Sea, covering a distance of c. 90 km. Ten newly developed microsatellite loci were used to infer the population structure. No global spatial genetic differentiation was found (global F-ST = 0.0001; D-est = -0.0003), indicating strong gene flow at this scale, nor any clear pattern of isolation by distance. The results suggest that gene flow among the studied populations of Z. viviparus is stronger than usually thought, which might be caused by environmental homogeneity. This is important for planning and evaluating monitoring activities in this species and for the interpretation of ecotoxicological studies. Strong migration might lead to wrong conclusions concerning the pollution in a given area. Therefore, reference stations should be placed at a larger distance than presently practiced.
23.	Bergek, Sara, 1979-, et al. (author) Population differentiation in perch Perca fluviatilis : environmental effects on gene flow? 2010 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 76:5, s. 1159-1172 Journal article (peer-reviewed)abstract Environmental parameters were used to investigate barriers to gene flow and genetic differentiation in the Eurasian perch (Perca fluviatilis L.) at a small geographical scale in an archipelago system. Significant genetic differentiation was found among locations. Distance per se did not play a major role in the reduction of gene flow. Instead, the largest genetic differences between populations correlated with major changes in environmental conditions, such as temperature at time of spawning. The results show that genetic divergence can arise between populations in habitats thought to be highly connected, and that environmental variables can influence the level of gene flow between populations, including those that are at small spatial scales (tens of kilometres). The importance of a landscape approach when investigating genetic differentiation and defining barriers to gene flow is highlighted.
24.	Björklund, Mats, et al. (author) Genetic differentiation in pikeperch (Sander lucioperca): the relative importance of gene flow, drift and common history 2007 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 71:Suppl B, s. 264-278 Journal article (peer-reviewed)abstract To investigate the relative importance of homogenizing factors, such as gene flow, and diversifying factors, such as drift, genetic variation in pikeperch (Sander lucioperca) in two Fennoscandian regions (North and South) was analysed with microsatellites. Allelic richness and the degree of differentiation were significantly higher in the North (FST = 0·20) than in the South (FST = 0·064). In northern areas, assignments of genotypes were almost exclusively to the population of origin, but in southern areas, the proportion of correct assignments was significantly lower. Most samples exhibited significant heterozygote deficits, and the level of relatedness was higher than expected from randomness. These combined results suggest that there has been more gene flow between populations in southern areas than in northern areas, where the importance of genetic drift has been greater. Effective population sizes were small (c. 100) and did not differ between areas. The effect of a common history appears minor, and thus processes such as genetic drift and gene flow have been more influential in shaping the patterns of genetic diversity in this species.
25.	Charlier, Johan, et al. (author) Census (NC) and genetically effective (Ne) population size in a lake-resident population of brown trout Salmo trutta 2011 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 79:7, s. 2074-2082 Journal article (peer-reviewed)abstract Census (NC) and effective population size (Ne) were estimated for a lake-resident population of brown trout Salmo trutta as 576 and 63, respectively. The point estimate of the ratio of effective to census population size (Ne:NC) for this population is 0·11 with a range of 0·06–0·26, suggesting that Ne:NC ratio for lake-resident populations agree more with estimates for fishes with anadromous life histories than the small ratios observed in many marine fishes
26.	Clark, T.D., et al. (author) Calibration of a hand-held haemoglobin analyser for use on fish blood 2008 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 73:10, s. 2587-2595 Journal article (peer-reviewed)abstract The HemoCue haemoglobin analyser consistently overestimated haemoglobin concentration ([Hb]) in the blood of all fish species (sockeye salmon Oncorhynchus nerka, Chinook salmon Oncorhynchus tshawytscha, Pacific bluefin tuna Thunnus orientalis and chub mackerel Scomber japonicus) by 22–50% (9·9–36·0 g l−1) over a [Hb] range of 20–160 g l−1. The systematic nature of the overestimation, however, allowed the formulation of an accurate calibration equation that can be used to correct values of [Hb] measured by the HemoCue in field studies.
27.	Clevestam, P. D., et al. (author) Too short to spawn? : Implications of small body size and swimming distance on successful migration and maturation of the European eel Anguilla anguilla 2011 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 78:4, s. 1073-1089 Journal article (peer-reviewed)abstract Individual net fat reserves after migration and reproductive investments were calculated for migrating female silver eels Anguilla anguilla (n = 387) collected in the outlet region of the Baltic Sea during the autumn run. It is estimated that 20 center dot 4% of the A. anguilla had completely exhausted all initial fat reserves and that 45 center dot 0% of A. anguilla were within 90% of complete energy depletion after migration and reproduction. This study concludes that a combination of body size and distance (6900 km) to the spawning area in the Sargasso Sea explains the results. An increase in the costs of migration due to heavy infection with Anguillicoloides crassus was also evaluated in an additional scenario with results showing that 26 center dot 4% of the A. anguilla had completely depleted all fat reserves. It is hypothesized that a large proportion of female silver A. anguilla from the Baltic Sea catchment area will have inadequate or suboptimal reserves for successful migration and reproduction.
28.	Conrad, J L, et al. (author) Behavioural syndromes in fishes : a review with implications for ecology and fisheries management 2011 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 78:2, s. 395-435 Journal article (peer-reviewed)abstract This review examines the contribution of research on fishes to the growing field of behavioural syndromes. Current knowledge of behavioural syndromes in fishes is reviewed with respect to five main axes of animal personality: (1) shyness-boldness, (2) exploration-avoidance, (3) activity, (4) aggressiveness and (5) sociability. Compared with other taxa, research on fishes has played a leading role in describing the shy-bold personality axis and has made innovative contributions to the study of the sociability dimension by incorporating social network theory. Fishes are virtually the only major taxon in which behavioural correlations have been compared between populations. This research has guided the field in examining how variation in selection regime may shape personality. Recent research on fishes has also made important strides in understanding genetic and neuroendocrine bases for behavioural syndromes using approaches involving artificial selection, genetic mapping, candidate gene and functional genomics. This work has illustrated consistent individual variation in highly complex neuroendocrine and gene expression pathways. In contrast, relatively little work on fishes has examined the ontogenetic stability of behavioural syndromes or their fitness consequences. Finally, adopting a behavioural syndrome framework in fisheries management issues including artificial propagation, habitat restoration and invasive species, may promote restoration success. Few studies, however, have examined the ecological relevance of behavioural syndromes in the field. Knowledge of how behavioural syndromes play out in the wild will be crucial to incorporating such a framework into management practices.
29.	Demandt, Marnie, et al. (author) Loss of genetic variability in reintroduced roach (Rutilus rutilus) populations 2007 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 70:Suppl.B, s. 255-261 Journal article (peer-reviewed)abstract Genetic variation at five microsatellite loci and in mtDNA was surveyed in reintroduced and 'control' populations of roach (Rutilus rutilus) in Sweden. Microsatellite allelic richness and allele size ranges were significantly reduced in reintroduced populations, and mtDNA diversity was nearly significantly reduced in reintroduced populations. These measures of genetic variability were strongly correlated with lake characteristics that influence population size and food availability.
30.	Eklöv, Peter, et al. (author) Pike predators induce morphological changes in young perch and roach 2007 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 70:1, s. 155-164 Journal article (peer-reviewed)abstract The morphological response of two 1 year-old prey species, perch Perca fluviatilis and roach Rutilus rutilus to the presence of predatory pike Esox lucius, was tested in a 6 week aquarium experiment. The growth of perch was higher than that of roach but there was no difference in growth of prey between predator and control treatments. The presence of pike caused morphological changes in both perch and roach. Perch showed an increase in body depth during the experiment whereas the morphological response of roach to pike was more related to a displacement of the dorsal and pelvic fins and width of the anal fin. Differences in morphological responses of perch and roach to pike can be interpreted by their overall differences in antipredator strategies.
31.	Forseth, Torbjörn, et al. (author) Thermal growth performance of juvenile brown trout Salmo trutta : no support for thermal adaptation hypotheses 2009 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 74:1, s. 133-149 Journal article (peer-reviewed)abstract Using thermal growth data from eight populations of anadromous and lake-feeding brown trout Salmo trutta, hypotheses of adaptation to local optima and countergradient variation in growth were tested. The adaptation to local optima hypothesis suggests that natural selection can shift optimal performance temperatures to match the prevailing temperature in a new or changed thermal niche. In contradiction, the countergradient variation hypothesis suggests that populations from hostile environments perform better than conspecifics from benign environments at all temperatures. In this study, growth capacity varied between populations but there was no significant correlation between any of the estimated thermal performance parameters (e.g. lower and upper thermal growth limits, optimal temperature for growth and maximum growth capacity) and natural climatic conditions among populations. Hence, S. trutta growth response to temperature lends no support for either of the two suggested thermal adaptation hypotheses. Instead, growth capacity among populations tended to correlate positively with female size at maturity.
32.	Goncalves, Ines, 1982, et al. (author) The relationship between female body size and egg size in pipefishes 2011 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 78:6, s. 1847-1854 Journal article (peer-reviewed)abstract Comparing five species of pipefish, egg size was significantly larger in species with brood pouches (Syngnathus typhle, Syngnathus acus and Syngnathus rostellatus) than in species without brood pouches (Entelurus aequoreus and Nerophis ophidion). Egg size correlated positively with female body size in species with brood pouches, but was similar across female sizes in the species lacking pouches. These results may reflect differences in offspring competition as a consequence of variable offspring relatedness within a brood, due to the mating systems adopted by the different species and the presence or absence of a brood pouch.
33.	Gräns, Albin, 1979, et al. (author) Behavioural fever boosts the inflammatory response in rainbow trout Oncorhynchus mykiss 2012 In: Journal of Fish Biology. - : Wiley. - 1095-8649 .- 0022-1112. ; 81:3, s. 1111-1117 Journal article (peer-reviewed)abstract Behavioural fever, manifested as an increased preferred temperature, was shown in rainbow trout Oncorhynchus mykiss following an injection of bacterial lipopolysaccharide. Simulated behavioural fever, through a 2·5° C water temperature rise following bacterial lipopolysaccharide injection, enhanced the expression of the cytokine interleukin-1β, in comparison with an untreated group held at the initial temperature. The present findings show that an important mediator in the immune response can be boosted through behavioural fever in fishes.
34.	Guenard, G., et al. (author) An experimental study of the multiple effects of brown trout Salmo trutta on the bioenergetics of two Arctic charr Salvelinus alpinus morphs 2012 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 81:4, s. 1248-1270 Journal article (peer-reviewed)abstract This study investigated the importance of competition with brown trout Salmo trutta as a driver of the morphological and behavioural divergence of two morphs of Arctic charr Salvelinus alpinus. The morphs originated from two lakes differing in absence or presence of the competitor. The bioenergetics and behaviour of S. alpinus were quantified in replicate experimental enclosures (mean volume: 150 m(3)) stocked with 15 S. alpinus of one morph or the other and in the absence or presence of nine S. trutta. The presence of S. trutta decreased growth rate, affected food consumption and increased activity costs in S. alpinus, but provided little support for the hypothesis that competition with S. trutta is a major driver of the divergence of the two S. alpinus morphs. Both morphs responded similarly in terms of mean growth and consumption rates per enclosure, but the association between individual morphology and growth rate reversed between allopatric and sympatric enclosures. While the activity patterns of the two morphs were unaffected by the presence of S. trutta, their swimming speed and activity rate differed. Since the profound differences in the structure of the physical habitat of the source lakes provided a more likely explanation for the difference observed among these two morphs than interspecific competition, it is hypothesized that physical habitat may sometimes be a significant driving force of the phenotypic divergence.
35.	Höjesjö, Johan, 1967, et al. (author) Movement and home range in relation to dominance; a telemetry study on brown trout Salmo trutta 2007 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 70:1, s. 257-268 Journal article (peer-reviewed)abstract By combining behavioral observations on adult resident brown trout Salmo trutta in the laboratory with radio telemetry studies in a natural stream. information on movement and space use in relation to social status was obtained. Dominant individual longer distances and also tended to have larger home ranges than subordinates during the summer. In general. home ranges were larger during daytime than at night. Fish were not strictly territorial since the average overlap in interquartile range was 36%. during the summer. During the spawning period, the brown trout moved to specific spawning areas resulting in an increased overlap (89%) in space Use. Subordinate individuals now tended to increase both home range and interquartile range and were also less frequently observed in spawning areas relative to dominants.
36.	Jansson, Håkan, et al. (author) Genetic relationships among species of hagfish revealed by protein electrophoresis 1995 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 47:4, s. 599-608 Journal article (peer-reviewed)abstract Hagfish species of the genera Myxine, Eptatretus and Pnramyxine were analysed for genetic variation by allozyme electrophoresis and isoelectric focusing of general proteins. Large genetic differences were observed between samples of supposed conspecifics of Myxine circifrons from off the Californian coast, and also within one sample of Paramyxine sp. from Sagami Bay, Japan. The results are convincing evidence of the existence of additional sympatric species in these two areas. In general, the highest genetic identities were found between species within the subfamilies Myxininae and Eptatretinae. Within Eptatretinae, the Japanese species Eptatietus burgeri was genetically more similar to Japanese species of Paramyxine than to American species of Eptatretus. Thus, our data indicate that the generic status of Paramyxine should be reconsidered. (C) 1995 The Fisheries Society of the British Isles.
37.	Jensen, O. P., et al. (author) Foraging, bioenergetic and predation constraints on diel vertical migration : field observations and modelling of reverse migration by young-of-the-year herring Clupea harengus 2011 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 78:2, s. 449-465 Journal article (peer-reviewed)abstract Diel vertical migration (DVM) of young-of-the-year (YOY) herring Clupea harengus and one of their major predators, pikeperch Sander lucioperca, was examined using bottom-mounted hydroacoustics in Himmerfjarden, a brackish bay of the Baltic Sea, in summer. In contrast to previous studies on DVM of C. harengus aggregated across size and age classes, YOY C. harengus showed a reverse DVM trajectory, deeper at night and, on average, shallower during the day. This pattern was observed consistently on five acoustic sampling occasions in 3 years and was corroborated by two out of three trawl surveys. Large acoustic targets (target strength >-33 dB, probably piscivorous S. lucioperca > 45 cm) showed a classic DVM trajectory, shallow at night and deeper during the day. Variability in YOY C. harengus vertical distribution peaked at dawn and dusk, and their vertical distribution at midday was distinctly bimodal. This reverse DVM pattern was consistent with bioenergetic model predictions for YOY C. harengus which have rapid gut evacuation rates and do not feed at night. Reverse DVM also resulted in low spatial overlap with predators.
38.	Jonsson, Bror, et al. (author) A review of the likely effects of climate change on anadromous Atlantic salmon Salmo salar and brown trout Salmo trutta, with particular reference to water temperature and flow 2009 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 75, s. 2381-2447 Journal article (peer-reviewed)abstract The present paper reviews the effects of water temperature and flow on migrations, embryonic development, hatching, emergence, growth and life-history traits in light of the ongoing climate change with emphasis on anadromous Atlantic salmon Salmo salar and brown trout Salmo trutta. The expected climate change in the Atlantic is for milder and wetter winters, with more precipitation falling as rain and less as snow, decrease in ice-covered periods and frequent periods with extreme weather. Overall, thermal limits for salmonids are species specific. Scope for activity and growth and optimal temperature for growth increase with temperature to an optimal point before constrain by the oxygen content of the water. The optimal temperature for growth decreases with increasing fish size and varies little among populations within species, whereas the growth efficiency may be locally adapted to the temperature conditions of the home stream during the growth season. Indirectly, temperature influences age and size at smolting through its effect on growth. Time of spawning, egg hatching and emergence of the larvae vary with temperature and selective effects on time of first feeding. Traits such as age at first maturity, longevity and fecundity decrease with increasing temperature whilst egg size increases with temperature. Water flow influences the accessibility of rivers for returning adults and speed of both upstream and downstream migration. Extremes in water flow and temperature can decrease recruitment and survival. There is reason to expect a northward movement of the thermal niche of anadromous salmonids with decreased production and population extinction in the southern part of the distribution areas, migrations earlier in the season, later spawning, younger age at smolting and sexual maturity and increased disease susceptibility and mortality. Future research challenges are summarized at the end of the paper.
39.	Jonsson, Bror, et al. (author) Migratory timing, marine survival and growth of anadromous brown trout Salmo trutta in the River Imsa, Norway 2009 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 74:3, s. 621-638 Journal article (peer-reviewed)abstract The aim of the paper was to study sea migration, growth and survival of brown trout Salmotrutta of the River Imsa, 1976–2005. The migratory S. trutta were individually tagged and fishleaving or entering the river were monitored daily in traps located near the river mouth. Themean annual duration of the sea sojourn was 6–9 months for first-time migrants moving to seabetween January and June. It was 8–18 months for those migrating to sea between July andDecember. Veteran migrants stayed 12 months or less at sea and most returned to the river inAugust. Early ascending fish stayed the longest in fresh water because most returned to sea inApril to May. The day number of 50% cumulative smolt descent correlated negatively withmean water temperature in February to March and the February North Atlantic Oscillationindex (NAOI). Mean annual sea growth during the first 2 years after smolting was higher for S.trutta spending the winter at sea than those wintering in the River Imsa. First year's sea growthwas lower for S. trutta descending in spring than autumn. For first-time migrants, it correlatednegatively with the February NAOI of the smolt year. Sea survival was higher for spring thanautumn descending first-time migratory S. trutta with a maximum in May (149%). Number ofanadromous S. trutta returning to the river increased linearly with the size of the cohort movingto sea, with no evidence of density-dependent sea mortality. Sea survival of S. trutta smoltsmoving to sea between January and June correlated positively both with the annual number ofAtlantic Salmo salar smolts, the specific growth rate at sea, and time of seaward migration inspring. This is the first study indicating how environmental factors at the time of seawardmigration influence the sea survival of S. trutta.
40.	Kalogirou, Stefan, 1981, et al. (author) Feeding ecology of indigenous and non-indigenous fish species within the family Sphyraenidae 2012 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 80:7, s. 2528-2548 Journal article (peer-reviewed)abstract The feeding ecology of two common indigenous (Sphyraena viridensis and Sphyraena sphyraena) and one abundant non-indigenous sphyraenid species, Sphyraena chrysotaenia, of Indo-Pacific Ocean origin, was investigated in an area of the eastern Mediterranean Sea. The stomach contents of 738 individuals of varying size, collected during the period December 2008 to August 2009, were examined. The dietary analyses revealed that all three species were specialized piscivores with a diet consisting of >90% fish, both by number and mass. Concurrent sampling of the fish assemblage made it possible to calculate selectivity as well as diet breadth and overlap of these strict piscivores. Even though several prey species were found in the stomachs of the three predators examined, selectivity towards Atherina boyeri was highly significant. For all species examined, >70% of the diet by mass was made up by three indigenous species of commercial value: Spicara smaris, Boops boops and A. boyeri. Diet breadth and size of prey increased with increasing body size for all predators. With increased body size, the diet overlap between indigenous and non-indigenous species decreased. This could be attributed to increased diet breadth and the specific life-history characteristics of indigenous species developing into larger individuals. During winter, the condition factor of the non-indigenous species was significantly lower than that of the indigenous, indicating that winter conditions in the Mediterranean Sea may limit its further expansion north and westward. With this study, the gap in knowledge of the feeding preferences of the most abundant piscivorous species found in coastal areas of the study region is filled. Additionally, the results indicate that non-indigenous species familial affiliation to indigenous ones does not facilitate invasion success.
41.	Kaspersson, Rasmus, 1978, et al. (author) Density-dependent growth rate in an age-structured population: a field study on stream-dwelling brown trout Salmo trutta 2009 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 74:10, s. 2196-2215 Journal article (peer-reviewed)abstract A field experiment during autumn, winter and spring was performed in a small stream on the west coast of Sweden, aiming to examine the direct and indirect consequences of density-dependent intercohort competition in brown trout Salmo trutta. Individual growth rate, recapture rate and site fidelity were used as response variables in the young-of-the-year (YOY) age class, experiencing two different treatments: presence or absence of yearlings and over-yearlings (age ≥ 1+ year individuals). YOY individuals in stream sections with reduced density of age ≥ 1+ year individuals grew significantly faster than individuals experiencing natural cohort structure. In the latter, growth rate was negatively correlated with density and biomass of age ≥ 1+ year individuals, which may induce indirect effects on year-class strength through, for example, reduced fecundity and survival. Movement of YOY individuals and turnover rate (i.e. proportion of untagged individuals) were used to demonstrate potential effects of intercohort competition on site fidelity. While YOY movement was remarkably restricted (83% recaptured within 50 m from the release points), turnover rate was higher in sections with reduced density of age ≥1+ year individuals, suggesting that reduced density of age ≥1+ year individuals may have released favourable microhabitats.
42.	Kolm, Niclas, et al. (author) Differential investment in the Banggai cardinalfish : can females adjust egg size close to egg maturation to match the attractiveness of a new partner? 2003 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 63:S1, s. 144-151 Journal article (peer-reviewed)abstract To test whether females can change their egg investment according to the different attractiveness ( i.e. size as measured by standard length, Ls) of a new mate after eggs have already matured in response to an earlier mate, female Banggai cardinalfish Pterapogon kauderni were first allowed to produce eggs for small (unattractive) or large (attractive) males. Then, when spawning was initiated, but prior to actual spawning, their partner was switched to either a significantly larger or a significantly smaller partner, respectively. A strong positive correlation between egg size and days until spawning with the second male was found for the females initially paired to a small and then a large male. Within a few days, these females apparently increased their egg size to match the attractiveness of their new male. No correlation between days until spawning and egg size in females initially paired to a large and then a small male, however was found, so apparently females were unable to adjust egg size in response to a decrease in mate attractiveness. Consequently, it is suggested that females can increase their egg size investment even after the onset of egg maturation and that this change can be quite rapid.
43.	Kolm, Niclas, et al. (author) Do egg size and parental care coevolve in fish? 2005 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 66:6, s. 1499-1515 Journal article (peer-reviewed)abstract A phenomenon that has attracted a substantial theoretical and empirical interest is the positive relationship between egg size and the extent of parental care in fishes. Interestingly, despite the effort put into solving the causality behind this relationship over the past two decades it remains largely unsolved. Moreover, how general the positive relationship between egg size and parental care is among fishes is also poorly understood. In order to stimulate research exploring egg size and parental care variation in fishes, the potential selective forces from both natural and sexual selection on egg size and parental care are discussed. Recent empirical findings on how oxygen requirements and developmental times may differ between differently sized eggs are incorporated into a critical view of the current theory of this field. Furthermore, it is suggested that the up to now neglected effects of sexual selection, through both mate choice and sexual conflict, can have strong effects on the relationship between egg size and parental care in fishes. In light of the recent developments of comparative and experimental methods, future approaches that may improve the understanding of the relationship between egg size and care in fishes are suggested.
44.	Kotrschal, Alexander, et al. (author) Inside the heads of David and Goliath : environmental effects on brain morphology among wild and growth-enhanced coho salmon Oncorhynchus kisutch 2012 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 81:3, s. 987-1002 Journal article (peer-reviewed)abstract Transgenic and wild-type individual coho salmon Oncorhynchus kisutch were reared in hatchery and near-natural stream conditions and their brain and structure sizes were determined. Animals reared in the hatchery grew larger and developed larger brains, both absolutely and when controlling for body size. In both environments, transgenics developed relatively smaller brains than wild types. Further, the volume of the optic tectum of both genotypes was larger in the hatchery animals and the cerebellum of transgenics was smaller when reared in near-natural streams. Finally, wild types developed a markedly smaller telencephalon under hatchery conditions. It is concluded that, apart from the environment, genetic factors that modulate somatic growth rate also have a strong influence on brain size and structure.
45.	Kvarnemo, C., et al. (author) Evidence of paternal nutrient provisioning to embryos in broad-nosed pipefish Syngnathus typhle 2011 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 78:6, s. 1725-1737 Journal article (peer-reviewed)abstract In two experiments, radioactively labelled nutrients (either H-3-labelled amino-acid mixture or C-14-labelled glucose) were tube-fed to brooding male Syngnathus typhle. Both nutrients were taken up by the males and radioactivity generally increased in the brood pouch tissue with time. Furthermore, a low but significant increase of H-3-labelled amino acids in embryos was found over the experimental interval (48 h), whereas in the C-14-glucose experiment the radioactivity was taken up by the embryos but did not increase over the experimental time (320 min). Uptake of radioisotopes per embryo did not differ with embryo size. A higher uptake mg(-1) tissue of both H-3-labelled amino acids and C-14-labelled glucose was found in smaller embryos, possibly due to a higher relative metabolic rate or to a higher surface-area-to-volume ratio compared to larger embryos. Uptake in embryos was not influenced by male size, embryonic developmental advancement or position in the brood pouch. It is concluded that brooding males provide amino acids, and probably also glucose, to the developing embryos in the brood pouch.
46.	Kvarnemo, Charlotta, 1963, et al. (author) Investment in testes, sperm-duct glands and lipid reserves differs between male morphs but not between early and late breeding season in Pomatoschistus minutus 2010 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 76:7, s. 1609-1625 Journal article (peer-reviewed)abstract This study of the sand goby Pomatoschistus minutus, a nest-holding fish with paternal care, focused on gonadal investment among males of different sizes collected early and late in the breeding season. All males caught at the nest had breeding colour, whereas trawl-caught fish consisted of males both with and without colour. The absence or presence of breeding colour was a good predictor of testes investment. Compared to males with breeding colour, males without colour were smaller in body size but had extraordinarily large testes. In absolute terms, testes mass of males without breeding colour was on average 3.4 times greater than those of males with breeding colour. Since small colourless males are known to reproduce as sneaker males, this heavy investment in testes probably reflects that they are forced to spawn under sperm competition. Contrary to testes size, sperm-duct glands were largest among males with breeding colour. These glands produce mucins used for making sperm-containing mucous trails that males place in the nest before and during spawning. Since both sneakers and nest-holders potentially could benefit from having large glands, this result is intriguing. Yet, high mucus production may be more important for nest-holders, because it also protects developing embryos from infections. There was no significant effect of season on body size, testes or sperm-duct glands size, but colourless males tended to be less common late in the season. Possibly this may indicate that individual small colourless males develop into their more colourful counterparts within the breeding season.
47.	Lefébure, Robert, et al. (author) A temperature-dependent growth model for the three-spined stickleback Gasterosteus aculeatus 2011 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 79:7, s. 1815-1827 Journal article (peer-reviewed)abstract Specific growth rates of individually reared juvenile three-spined sticklebacks Gasterosteus aculeatus were investigated under laboratory conditions to parameterize a complete temperature-dependent growth model for this species. To test the applicability of experimentally derived optima in growth response rates to natural conditions, the effects of commercial pellets and natural prey on growth rates were investigated. In addition, to test for seasonal effects on growth, laboratory trials were performed in both spring and winter. Growth took place from 5 to 29° C with a temperature for optimum growth reaching a sharp peak at 21° C. Modelled optimal temperature for maximum growth was estimated to be 21.7° C and lower and upper temperatures for growth were estimated to be 3.6 and 30.7° C, respectively. There were no significant differences in growth rates between fish reared on invertebrates or commercial pellets. Seasonal effects on growth were pronounced, with reduced growth rates in the winter despite similar laboratory conditions. On average, 60% higher growth rates were achieved at the optimum temperature in summer compared to the winter. The strong seasonality in the growth patterns of G. aculeatus indicated here reduces the applicability of the model derived in this study to spring and summer conditions.
48.	Lindberg, Magnus, et al. (author) Post-release and pre-spawning behaviour of simulated escaped adult rainbow trout Oncorhynhus mykiss in Lake ovre Fryken, Sweden 2009 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 74, s. 691-698 Journal article (peer-reviewed)abstract Using radio telemetry, the present study simulated the escape of 48 adult rainbow trout Oncorhynchus mykiss from a net-cage fish farm in the Lake ovre Fryken, Sweden. The post-release dispersal of O. mykiss was fast, showed long-range dispersal behaviour, low winter survival and lacked the ability to find suitable spawning habitats. Thus, the present study suggested that reproducing for the first time may be an obstacle to the establishment of escaped farmed O. mykiss.
49.	Lindqvist, Charlotte, et al. (author) Male broad-nosed pipefish Syngnathus typhle do not locate females by smell 2011 In: Journal of Fish Biology. - London : Academic Press. - 0022-1112 .- 1095-8649. ; 78:6, s. 1861-1867 Journal article (peer-reviewed)abstract Broad-nosed pipefish Syngnathus typhle were used to investigate whether males used scent in their search for mates. When the males in an experiment had access to olfactory cues only, they did not locate females better than they located males. Thus, S. typhle, was less successful in mate search when visual cues were absent.
50.	Ljunggren, L, et al. (author) Influence of visual conditions on foraging and growth of juvenile fishes with dissimilar sensory physiology 2007 In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 70:5, s. 1319-1334 Journal article (peer-reviewed)abstract The influence of turbidity on foraging and growth of young-of-the-year (YOY) of two percid species with relatively dissimilar sensory physiology, perch Perca fluviatilis and pikeperch Sander lucioperca was tested. A littoral mysid, Neomysis integer, was used as prey. Functional response was investigated indoors at two levels of turbidity, 3 NTU (clear) and 25 NTU (turbid). Growth and consumption rate were studied both during day and night in outdoor experiments at similar turbidity levels. Pikeperch were not affected by turbid conditions in either of the experiments. Foraging of perch, on the other hand, was significantly negatively affected by higher turbidity in the functional response experiments and during the night-time in the outdoor experiments. As opposed to pikeperch, consumption rates of perch decreased markedly during nights. Perch also grew more slowly in the treatments with turbid water. The dissimilar reactions of the two species indicate that sensory physiological adaptations and foraging behaviour are important factors that partly can explain disparate reactions of YOY fishes to the level of turbidity.

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