| 131. |
- Phalla, Miech, et al.
(författare)
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Growth and survival of reared Cambodian field crickets (Teleogryllus testaceus) fed weeds, agricultural and food industry by-products
- 2016
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Ingår i: Journal of insects as food and feed. - 2352-4588. ; 2, s. 285-292
-
Tidskriftsartikel (refereegranskat)abstract
- This study evaluated survival and growth of Cambodian field crickets (Teleogryllus testaceus) during captivity when fed a set of local weed species, agricultural and food industry by-products. Wild individuals were caught at two locations in Cambodia, kept in pens and fed commercial chicken feed until the second generation off-spring hatched. First larval stage nymphs from this generation were collected and used in a 70-day feeding trial with one control treatment (chicken feed) and 12 experimental treatments (rice bran, cassava plant tops, water spinach, spent grain, residue from mungbean sprout production, and Alternanthera sessilis, Amaranthus spinosus, Commelina benghalensis, Cleome rutidosperma, Cleome viscosa, Boerhavia diffusa and Synedrela nodiflora). The crickets were kept in plastic cages and feed intake, weight and survival of crickets were recorded weekly. Overall survival did not differ between chicken feed and the experimental treatments with the exception of crickets fed B. diffusa, which had lower survival. From day 35 to day 49, survival on A. sessilis was also lower (P<0.05) than on chicken feed. There was no difference in weight between crickets fed chicken feed, cassava tops and C. rutidosperma. However, crickets fed A. sessilis, A. spinosus and B. diffusa weighed less than those fed chicken feed already at day 21. The feed conversion rate ranged from 1.6 to 3.9 and was ≤1.9 in crickets fed chicken feed, cassava plant tops and C. rutidosperma. Thus this study shows that it is possible, using simple means, to rear Cambodian field crickets. Cassava plant tops and C. rutidosperma both have great potential as cricket feed and the other weeds, with the exception of A. sessilis, A. spinosus and B. diffusa, agricultural and food industry by-products tested, also showed potential.
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| 132. |
- Ryding, Sara, et al.
(författare)
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Impulsivity is affected by cognitive enrichment and links to brain gene expression in red junglefowl chicks
- 2021
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Ingår i: Animal Behaviour. - : Academic Press Inc - Elsevier Science. - 0003-3472 .- 1095-8282. ; 178, s. 195-207
-
Tidskriftsartikel (refereegranskat)abstract
- Despite reported findings, explanations for within-species variation in behavioural performance on cognitive tests are still understudied. Cognitive processes are influenced by environmental and genetic differences, where cognitive stimulation and monoaminergic systems are predicted to be important. To explore explanations for individual variation in impulsivity (a behaviour that is negatively correlated with inhibitory control), we experimentally altered the environment of red junglefowl, Gallus gallus, by exposing chicks from newly hatched to 9 weeks old to either (1) both environmental and cognitive enrichment, (2) environmental enrichment without additional cognitive enrichment or (3) neither environmental nor cognitive enrichment. Subsequently, we measured variation in impulsivity and brain gene expression of genes from the dopaminergic system (DRD1 and DRD2) and serotonergic system (5HT2A, 5HT1B, 5HT2B, 5HT2C and TPH). We focused on two aspects of impulsivity, impulsive action and persistence, and their reduction over time. Cognitively enriched chicks tended to have higher initial impulsive action and had higher initial persistence, and our environmentally enriched chicks had slower reduction of impulsive action over time. DRD2 (a dopamine receptor gene) had lower expression in environmentally enriched chicks. Variation in impulsive action tended to correlate with expression of TPH (a gene involved in serotonin synthesis), whereas persistence correlated with both TPH and the dopamine receptor gene DRD1, and tended to correlate with the dopaminergic gene DRD2, regardless of rearing treatment. These results indicate that both environment and links to neurobiology could explain initial individual variation in, and reduction of, impulsivity. Further, distinct neurobiological pathways appear to govern impulsive action versus persistence, supporting the suggestion that impulsivity is a heterogenic behaviour. (c) 2021 The Authors. Published by Elsevier Ltd on behalf of The Association for the Study of Animal Behaviour. This is an open access article under the CC BY license (http://creativecommons.org/licenses/ by/4.0/).
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| 133. |
- van Poucke, Enya, et al.
(författare)
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Play stimulation as a possible means to buffer early stress from commercial hatchery treatment in laying hen chicks
- 2024
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Ingår i: Applied Animal Behaviour Science. - : ELSEVIER. - 0168-1591 .- 1872-9045. ; 274
-
Tidskriftsartikel (refereegranskat)abstract
- In commercial hatcheries, laying hen chicks are exposed to a range of stressors that have previously been shown to induce long-term negative effects on their welfare. It has been suggested that stimulation of play behaviour, a self-rewarding activity associated with positive emotions, may be a way to improve animal welfare. We have previously found that chicks play extensively during their first weeks of life if offered the possibility. Our hypothesis was therefore that stimulating play in chicks could buffer the long-term consequences of stress from commercial hatchery routines. Sixty female Lohmann LSL chicks were hatched at a commercial hatchery and transported for four hours before being randomly allocated to two different treatments. Play-stimulated chicks (PC) were taken out of the home pens and introduced in groups of five into a spacious, object-enriched play arena 3x30 min per week for five weeks starting from 9 days of age. Control chicks (CC) were taken out of the home pens at the same time as PC and placed in cardboard boxes for the same amount of time as PC were allowed to play. Between 46 and 57 days of age,behavioural and corticosterone reactivity tests were conducted. There were no differences between the treatment groups in open field activity, but in a novel object test PC were more active and interacted more with the novel object, indicating reduced fear. There were no differences between the treatment groups in duration of tonic immobility or in corticosterone reaction to a brief restraint. Contrary to our predictions, PC showed a more negative bias compared to CC in a cognitive judgement bias test. In conclusion, play stimulation may reduce fearfulness in early-stressed chickens, but the reason for the opposite reaction in the cognitive judgement bias needs further investigation.
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| 134. |
- Arzel, Céline, et al.
(författare)
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Early springs and breeding performance in two sympatric duck species with different migration strategies
- 2014
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Ingår i: Ibis. - : Wiley-Blackwell Publishing Ltd. - 0019-1019 .- 1474-919X. ; 156:2, s. 288-298
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Tidskriftsartikel (refereegranskat)abstract
- The capacity of migratory species to adapt to climate change may depend on their migratory and reproductive strategies. For example, reproductive output is likely to be influenced by how well migration and nesting are timed to temporal patterns of food abundance, or by temperature variations during the brood rearing phase. Based on two decades (1988–2009) of waterfowl counts from a boreal catchment in southern Finland we assessed how variation in ice break-up date affected nesting phenology and breeding success in two sympatric duck species, Mallard Anas platyrhynchos and Eurasian Teal Anas crecca. In Fennoscandia these species have similar breeding habitat requirements but differ in migration distance; Teal migrate roughly seven times as far as do Mallard. Annual ice break-up date was used as a proxy of spring ‘earliness’ to test the potential effect of climate change on hatching timing and breeding performance. Both species were capable of adapting their nesting phenology, and bred earlier in years when spring was early. However, the interval from ice break-up to hatching tended to be longer in early springs in both species, so that broods hatched relatively later than in late springs. Ice break-up date did not appear to influence annual number of broods per pair or annual mean brood size in either species. Our study therefore does not suggest that breeding performance in Teal and Mallard is negatively affected by advancement of ice break-up at the population level. However, both species showed a within-season decline in brood size with increasing interval between ice break-up and hatching. Our study therefore highlights a disparity between individuals in their capacity to adjust to ice break-up date, late breeders having a lower breeding success than early breeders. We speculate that breeding success of both species may therefore decline should a consistent trend towards earlier springs occur.
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| 135. |
- Bellas, Juan, et al.
(författare)
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A standardisation of Ciona intestinalis (Chordata, Ascidiacea) embryo-larval bioassay for ecotoxicological studies
- 2003
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Ingår i: Water Research. - 0043-1354. ; 37:19, s. 4613-4622
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Tidskriftsartikel (refereegranskat)abstract
- A standardisation of the ascidian Ciona intestinalis embryo-larval bioassay for marine pollution assessment has been developed. The minimum percentage of embryogenesis success was established to assess the quality of the biological material used; minimum sample size and number of replicates per treatment were also estimated. The suitability of artificial and natural seawater for the incubation of ascidian embryos and larvae was compared, and the optimum conditions of temperature, salinity, pH, density of embryos in the vials and the sperm/egg ratio were investigated. On the basis of the 10th percentile of the distribution of larval abnormalities, we proposed a threshold of 50% normal larvae in the control in order to consider the test of acceptable biological quality. According to our results n = 5 is a sufficiently high replication to detect 5% differences among treatment means with a power of P = 90% and alpha = 0.05, and a sampling size greater than or equal to222 allows a 95% confidence in the estimate with an error of 0.05. Egg density did not affect larval development within the range 1-20 eggs/ml, and the optimum sperm/egg ratio which fertilise 100% of the eggs was 3000-30,000 sperm/egg (i.e. 10(8)-10(7) sperm/ml). There were not significant differences between the two water types tested, and the optimum tolerance ranges were 18-23 degreesC temperature, 34-42 ppt salinity (42 ppt was the highest salinity tested), and 7.4-8.8 pH. The median effective concentration (EC50) of copper (Cu) causing a 50% reduction of normal hatched larvae was 54.2 mug/l (0.85 muM), which shows a sensitivity of this species similar to the commonly used bivalve and sea-urchin tests. The ascidian embryo-larval bioassay is an accurate, reliable, simple and rapid method that can be used in ecotoxicological studies. (C) 2003 Elsevier Ltd. All rights reserved.
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| 136. |
- Beltran-Pardo, Eliana, et al.
(författare)
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Tolerance to Gamma Radiation in the Tardigrade Hypsibius dujardini from Embryo to Adult Correlate Inversely with Cellular Proliferation
- 2015
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:7
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Tidskriftsartikel (refereegranskat)abstract
- Tardigrades are highly tolerant to desiccation and ionizing radiation but the mechanisms of this tolerance are not well understood. In this paper, we report studies on dose responses of adults and eggs of the tardigrade Hypsibius dujardini exposed to gamma radiation. In adults the LD50/48h for survival was estimated at similar to 4200 Gy, and doses higher than 100 Gy reduced both fertility and hatchability of laid eggs drastically. We also evaluated the effect of radiation (doses 50 Gy, 200 Gy, 500 Gy) on eggs in the early and late embryonic stage of development, and observed a reduced hatchability in the early stage, while no effect was found in the late stage of development. Survival of juveniles from irradiated eggs was highly affected by a 500 Gy dose, both in the early and the late stage. Juveniles hatched from eggs irradiated at 50 Gy and 200 Gy developed into adults and produced offspring, but their fertility was reduced compared to the controls. Finally we measured the effect of low temperature during irradiation at 4000 Gy and 4500 Gy on survival in adult tardigrades, and observed a slight delay in the expressed mortality when tardigrades were irradiated on ice. Since H. dujardini is a freshwater tardigrade with lower tolerance to desiccation compared to limno-terrestrial tardigrades, the high radiation tolerance in adults, similar to limno-terrestrial tardigrades, is unexpected and seems to challenge the idea that desiccation and radiation tolerance rely on the same molecular mechanisms. We suggest that the higher radiation tolerance in adults and late stage embryos of H. dujardini (and in other studied tardigrades) compared to early stage embryos may partly be due to limited mitotic activity, since tardigrades have a low degree of somatic cell division (eutely), and dividing cells are known to be more sensitive to radiation.
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| 137. |
- Dessborn, Lisa, et al.
(författare)
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Hatching in dabbling ducks and emergence in chironomids : a case of predator-prey synchrony?
- 2009
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Ingår i: Hydrobiologia. - : Springer Netherlands. - 0018-8158 .- 1573-5117. ; 636:1, s. 319-329
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Tidskriftsartikel (refereegranskat)abstract
- It has been hypothesized that dabbling ducks (Anas spp.) time breeding to coincide with annual regional peaks in emerging dipterans, especially Chironomidae, which are important prey for newly hatched ducklings. However, this hypothesis has never been evaluated in a replicated lake-level study, including year effects in emergence patterns. We collected duck and invertebrate data from 12 lakes during the nesting seasons 1989-1994 in a watershed in southern Finland. The oligotrophic study lakes are typical of the boreal Holarctic, as are the three focal duck species: mallard Anas platyrhynchos L., widgeon Anas penelope L and teal Anas crecca L. Hatching of ducklings showed a clear peak in relation to ambient phenology (annual ice-out date of lakes), whereas chironomid emergence was more erratic and showed no clear peak at the lake level, although total watershed-level emergence was somewhat higher before and long after the duck hatching peak. Thus, we find no evidence that ducklings hatch in synchrony with abundance peaks of emerging chironomids. There was large within-year temporal variation in chironomid emergence among lakes, but this was not correlated with ambient temperature. The rank of individual lakes with respect to the abundance of emerging chironomids was consistent among as well as within years, a predictability that ought to make adaptive lake choice by ducks possible. On the lake level, there was a positive correlation between the total amount of emerging chironomids and brood use. We argue that emergence patterns of chironomids on typical boreal lakes are neither compressed nor predictable enough to be a major selective force on the timing of egg-laying and hatching in dabbling ducks. Despite spatial (among-lake) patterns of abundance of emerging chironomids being predictable within and among years, the observed pattern of brood use suggests that other factors, e.g. habitat structure, also affect lake choice.
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| 138. |
- Engwall, Magnus, 1965-, et al.
(författare)
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Cytochrome P450IA induction by a coplanar PCB, a PAH mixture, and PCB-contaminated sediment extracts following microinjection of rainbow trout sac-fry
- 1994
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Ingår i: Aquatic Toxicology. - : Elsevier BV. - 0166-445X .- 1879-1514. ; 30:4, s. 311-324
-
Tidskriftsartikel (refereegranskat)abstract
- The 7-ethoxyresorufin-O-deethylase (EROD)-inducing potencies of a coplanar polychlorinated biphenyl (PCB) (3,3',4,3',5-pentachlorobiphenyl, IUPAC No. 126), a mixture of five polycyclic aromatic hydrocarbons (benzo(k)fluoranthene, benz(a)anthracene, benzo(a)pyrene, indeno(1,2,3-cd)pyrene and chrysene), and lipophilic compounds extracted from the sediments in a PCB-contaminated lake and from sediments in lakes up- and downstream, were studied in rainbow trout sac-fry in a 43-day study. The compounds/extracts were injected into the yolk sacs of newly hatched sac-fry and hepatic EROD activities and mortality rates were measured at various times after the injections. Five livers from each group were also examined by transmission electron microscopy. All the compounds/extracts induced hepatic EROD activities in the sac-fry. Ten days after injection the EROD activity caused by PCB No. 126 (1.3 ng per embryo) was 40-fold compared to the control activity. This was the highest induction rate observed in the experiment. For the sediment extracts, the highest induction rates were observed at the first sampling occasion, which for these groups was on day 24. The extract from the Lake Jarnsjon sediment was more potent as an EROD inducer than the extracts of sediments from the lakes up- and downstream from Lake Jarnsjon. None of the sediment extracts caused any significant mortality. In sac-fry injected with the PAH mixture, EROD was only slightly induced. The highest dose of PAHs (10 mu g per embryo) caused about 90% mortality by 24 days after injection. When the livers were examined by transmission electron microscopy, morphological alterations (e.g. hepatocyte degeneration and hypertrophy) were seen in the groups injected with Lake Jarnsjon sediment extract, PCB No. 126 and the highest dose of the PAH mixture (10 mu g per embryo).
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| 139. |
- Eriksson, Andreas N.M., et al.
(författare)
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Changes in cardiac proteome and metabolome following exposure to the PAHs retene and fluoranthene and their mixture in developing rainbow trout alevins
- 2022
-
Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 830
-
Tidskriftsartikel (refereegranskat)abstract
- Exposure to polycyclic aromatic hydrocarbons (PAHs) is known to affect developing organisms. Utilization of different omics-based technologies and approaches could therefore provide a base for the discovery of novel mechanisms of PAH induced development of toxicity. To this aim, we investigated how exposure towards two PAHs with different toxicity mechanisms: retene (an aryl hydrocarbon receptor 2 (Ahr2) agonist), and fluoranthene (a weak Ahr2 agonist and cytochrome P450 inhibitor (Cyp1a)), either alone or as a mixture, affected the cardiac proteome and metabolome in newly hatched rainbow trout alevins (Oncorhynchus mykiss). In total, we identified 65 and 82 differently expressed proteins (DEPs) across all treatments compared to control (DMSO) after 7 and 14 days of exposure. Exposure to fluoranthene altered the expression of 11 and 19 proteins, retene 29 and 23, while the mixture affected 44 and 82 DEPs by Days 7 and 14, respectively. In contrast, only 5 significantly affected metabolites were identified. Pathway over-representation analysis identified exposure-specific activation of phase II metabolic processes, which were accompanied with exposure-specific body burden profiles. The proteomic data highlights that exposure to the mixture increased oxidative stress, altered iron metabolism and impaired coagulation capacity. Additionally, depletion of several mini-chromosome maintenance components, in combination with depletion of several intermediate filaments and microtubules, among alevins exposed to the mixture, suggests compromised cellular integrity and reduced rate of mitosis, whereby affecting heart growth and development. Furthermore, the combination of proteomic and metabolomic data indicates altered energy metabolism, as per amino acid catabolism among mixture exposed alevins; plausibly compensatory mechanisms as to counteract reduced absorption and consumption of yolk. When considered as a whole, proteomic and metabolomic data, in relation to apical effects on the whole organism, provides additional insight into PAH toxicity and the effects of exposure on heart structure and molecular processes.
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| 140. |
- Hake, M., et al.
(författare)
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The impact of water level fluctuation on the breeding success of the Black-throated Diver Gavia arctica in South-west Sweden
- 2005
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Ingår i: Ornis Fennica. - 0030-5685. ; 82:1, s. 1-12
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Tidskriftsartikel (refereegranskat)abstract
- We evaluated the impact of water level fluctuation on the breeding success of the Black-throated Diver in South-west Sweden by using results from a one-year study of 43 lakes (49 pairs) in 1996 and surveys of a population of 16-22 pairs at the lake system Fegen-Svansjoarna in 1997-2000. At this lake system, the water level is regulated (for hydropower production) with a maximum amplitude of 1.75 m. In 1997 2000, an attempt was made to maintain a stable water level during the period 1 May-15 June. Flooding was the most important cause of breeding failure at the 43 lakes, whereas no failure could be related to this factor at Fegen-Svansjoarna. In the 43 lakes, the change in median water level during incubation was +6 cm for five flooded nests, compared to -5 cm for 14 hatched clutches and -6 cm for 13 clutches that failed because of other or unknown causes. The mean breeding success at Fegen-Svansjoarna was on the same level as for South-west Sweden in general during 1997-2000 (0.44 and 0.38 chicks per pair and year, respectively), but was higher than for the four years before the attempt to keep the water level stable (0.22 chicks). We conclude that flooding is a main cause of nesting failure, that rainfall is the main factor behind the water level fluctuations, and that the regulation of the water level for hydropower production may have an additional negative impact on some takes. Control of the water level during the incubation period may help to reduce the risk of failure caused by flooding, and Our results support previous recommendations to allow for a rise of only a few centimetres or a lowering of a maximum of 20-30 cm during the incubation period.
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