| 1. |
- Chapman, Ben, et al.
(författare)
-
Partial migration in fishes: causes and consequences.
- 2012
-
Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 81:2, s. 456-478
-
Tidskriftsartikel (refereegranskat)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.
(författare)
-
Partial migration in fishes: definitions, methodologies and taxonomic distribution.
- 2012
-
Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 81:2, s. 479-499
-
Tidskriftsartikel (refereegranskat)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.
(författare)
-
Foraging success of juvenile pike Esox lucius depends on visual conditions and prey pigmentation
- 2011
-
Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 79:1, s. 290-297
-
Tidskriftsartikel (refereegranskat)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.
(författare)
-
The role of gastric evacuation rate in handling time of equal-mass rations of different prey sizes in northern pike
- 2000
-
Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 57:2, s. 516-524
-
Tidskriftsartikel (refereegranskat)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.
(författare)
-
Visibility conditions and diel period affect small-scale spatio-temporal behaviour of pike Esox lucius in the absence of prey and conspecifics
- 2012
-
Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 80:6, s. 2384-2389
-
Tidskriftsartikel (refereegranskat)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.
(författare)
-
The influence of dominance and diet on individual odours in MHC identical juvenile Arctic charr siblings
- 2003
-
Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 63:4, s. 855-862
-
Tidskriftsartikel (refereegranskat)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.
(författare)
-
Pikeperch Sander lucioperca trapped between niches: foraging performance and prey selection in a piscivore on a planktivore diet
- 2008
-
Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 73:4, s. 793-808
-
Tidskriftsartikel (refereegranskat)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.
(författare)
-
Fractionation of delta N-15 and delta C-13 for Atlantic salmon and its intestinal cestode Eubothtium crassum
- 2007
-
Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 71:2, s. 441-452
-
Tidskriftsartikel (refereegranskat)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
(författare)
-
An evaluation of horizontal echo sounding as a method for behavioural studies of 0+fish in field experiments
- 2001
-
Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 58:6, s. 1512-1523
-
Tidskriftsartikel (refereegranskat)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.
(författare)
-
Evaluation of PIT-tagging in cyprinids.
- 2005
-
Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 67:5, s. 1195-1201
-
Tidskriftsartikel (refereegranskat)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.
|
|
