Indoor Overwintering Research Articles

Establishment of apiary-level risk of American foulbrood through the detection of Paenibacillus larvae spores in pooled, extracted honey in Saskatchewan

Paenibacillus larvae, the causative agent of American foulbrood (AFB), produces spores that may be detectable within honey. We analyzed the spore content of pooled, extracted honey from 52 large-scale (L) and 64 small-scale (S) Saskatchewan beekeepers over a two-year period (2019–2020). Our objectives were: (i) establish reliable prognostic reference ranges for spore concentrations in extracted honey to determine future AFB risk at the apiary level; (ii) identify management practices as targets for mitigation of risk. P. larvae spores were detected in 753 of 1476 samples (51%). Beekeepers were stratified into low (< 2 spores/gram), moderate (2- < 100 spores/gram), and high (≥ 100 spores/gram) risk categories. Of forty-nine L beekeepers sampled in 2019, those that reported AFB in 2020 included 0/26 low, 3/18 moderate, and 3/5 high risk. Of twenty-seven L beekeepers sampled in 2020, those that reported AFB in 2021 included 0/11 low, 2/14 moderate, and 1/2 high risk. Predictive modelling included indoor overwintering of hives, purchase of used equipment, movement of honey-producing colonies between apiaries, beekeeper demographic, and antimicrobial use as risk category predictors. Saskatchewan beekeepers with fewer than 2 spores/gram in extracted honey that avoid high risk activities may be considered at low risk of AFB the following year.

Successful Indoor Mass Storage of Honeybee Queens (Apis mellifera) during Winter

The production of young, mated honeybee queens (Apis mellifera) is essential to replace dead queens or to start new colonies after wintering. Mass storage of mated honeybee queens during winter and their use the following spring is an interesting strategy that could help fulfill this need. In this study, we investigated the survival, fertility, and fecundity of young, mated queens stored massively in queenless colonies from September to April (eight months). The queens were kept in environmentally controlled rooms at temperatures above and below cluster formation. The results show that indoor mass storage of mated queens can be achieved with success when queen banks are stored above cluster temperature. Significantly higher survival of queens was measured when wintering queen banks at 16 °C. Surviving queens wintered at different temperatures above or below cluster formation had similar fertility (sperm viability) and fecundity (egg laying and viable worker population). This study shows the potential of indoor overwintering of honeybee queen banks. The technique we describe could be applied on a commercial scale by beekeepers and queen breeders.

ITRAQ‐based quantitative proteomic analysis reveals metabolic changes in overwintering Scylla paramamosain at two different salinities

Scylla paramamosain is one of the commercially crucial marine crustaceans belonging to the genus Scylla, which is commonly distributed along the coasts of China. Proteomic data are scarce for the mud crab. Salinity is one of the ecological factors that affect S. paramamosain during overwintering. To understand the energy metabolism mechanism adapted to salinity, we analysed the proteomics of S. paramamosain hepatopancreas in response to two different salinities (4‰ and 25‰). A total of 1283 proteins were detected, of which 426 down-regulated proteins and 83 up-regulated proteins were associated with metabolism (p < 0.05). Among these proteins related to metabolic pathways (16 pathways), we identified angiotensin-converting enzyme, trypsin, glutamate dehydrogenase, aminomethyl transferase, hexokinase, pyruvate kinase, glucose-6-phosphate dehydrogenase, L-lactate dehydrogenase, superoxide dismutase, alkaline phosphatase, catalase and xanthine dehydrogenases. Additionally, real-time PCR showed mRNA expression of differentially expressed genes correlated positively with their protein levels. Compared with 25‰ salinity group, 4‰ salinity group was involved in amino acid metabolism, carbohydrate metabolism, energy metabolism, lipid metabolism and inorganic ion metabolism by regulating related proteins, which made the metabolism of the overwintering S. paramamosain more vigorous in the low salt environment, and hepatopancreas consumed more energy to maintain life activities. These data are the first to reveal the molecular mechanism of overwintering S. paramamosain in response to different salinities at the protein level. The study provides important information for the aquaculture production of S. paramamosain during indoor overwintering.

Transcriptome analysis of genes and pathways associated with metabolism in Scylla paramamosain under different light intensities during indoor overwintering

BackgroundScylla paramamosain is one of the commercially crucial marine crustaceans belonging to the genus Scylla, which is commonly distributed along the coasts of China, Vietnam, and Japan. Genomic and transcriptomic data are scarce for the mud crab. Light intensity is one of the ecological factors that affect S. paramamosain during indoor overwintering. To understand the energy metabolism mechanism adapted to light intensity, we analyzed the transcriptome of S. paramamosain hepatopancreas in response to different light intensities (0, 1.43, 40.31 μmol·m− 2·s− 1).ResultsA total of 5052 differentially expressed genes were identified in low light group (LL group, 3104 genes were up-regulated and 1948 genes were down-regulated). A total of 7403 differentially expressed genes were identified in high light group (HL group, 5262 genes were up-regulated and 2141 genes were down-regulated). S. paramamosain adapts to different light intensity environments through the regulation of amino acids, fatty acids, carbon and energy metabolism. Different light intensities had a strong impact on the energy generation of S. paramamosain by influencing oxygen consumption rate, aerobic respiration, glycolysis/gluconeogenesis pathway, the citrate cycle (TCA cycle) and fatty acid degradation.ConclusionLow light is more conducive to the survival of S. paramamosain, which needs to produce and consume relatively less energy to sustain physiological activities. In contrast, S. paramamosain produced more energy to adapt to the pressure of high light intensities. The findings of the study add to the knowledge of regulatory mechanisms related to S. paramamosain metabolism under different light intensities.

GC‐MS‐based metabolomics reveal that light intensity during indoor overwintering affects the metabolism of Scylla paramamosain

The mud crab (Scylla paramamosain) is among the most economically important seawater crustacean species. Overwintering is one of an important stage for aquatic animals, and light intensity has an important effect on the conservation of Scylla paramamosain during overwintering. Here, S. paramamosain were exposed to three different light intensities (0, 1.43 and 40.31 μmol m−2 s−1) for four months. Then, GC-MS-based metabolomic analyses of the hepatopancreas were performed to assess differences in the metabolites produced by S. paramamosain exposed to different light intensities. The weight gain rate (WGR) was also compared among treatment groups. The LL group displayed significantly greater WGRs than the HL group. A total of 117 and 128 significantly different metabolites (SDMs) were identified in LL group and HL group respectively (VIP > 1 and p < .05). The identified SDMs were associated with the amino acid metabolism, the carbohydrate metabolism, the fatty acid metabolism, the nucleotide metabolism and membrane transport. The results suggested that light intensity affected the metabolic pathways in S. paramamosain by influencing the citrate cycle (TCA cycle), the biosynthesis of amino acids and unsaturated fatty acids, ABC transporters, and the purine metabolism. Further integrated analyses of key metabolic pathways showed that the metabolism of S. paramamosain was more vigorous under light conditions.

The iTRAQ-based quantitative proteomics reveals metabolic changes in Scylla paramamosain under different light intensities during indoor overwintering

Light intensity is one of the ecological factors that appreciably affects the metabolism of Scylla paramamosain during overwintering. This study adopted the isobaric tag for relative and absolute quantitation (iTRAQ) method to investigate metabolic changes of S. paramamosain under three illumination levels (0, 1.43 and 40.31 μmol m−2·s−1) for four months during indoor overwintering. The iTRAQ identified 3282 proteins, among which 267 exhibited significant differential expression (122 upregulated and 145 downregulated) in the low light group, and 299 with significant differential expression (252 upregulated and 47 downregulated) in the high light group. Analysis of these results showed that there were different metabolic regulatory patterns under different light intensities. Low light is more conducive to the survival of S. paramamosain, which needs to produce and consume relatively less energy to sustain physiological activities. Thus, the essential proteins associated with physiological activities were significantly upregulated, while those related to energy production were significantly downregulated. In contrast, high light exerts a certain stress on the survival of S. paramamosain and required more energy to cope with this stress, which forced a significant upregulation of proteins related to stress response and energy production. The findings of this study highlighted the metabolic regulatory mechanisms of S. paramamosain under different light intensities.

Effect of light intensity on digestion and immune responses, plasma cortisol and amino acid composition of Scylla paramamosain during indoor overwintering

Overwintering is one of an important stage for aquatic animals, and light intensity has an important effect on the conservation of Scylla paramamosain during overwintering. Three different light intensity levels (0, 1.43 and 40.31 μmol m−2 s−1) were used to explore the effects of light intensity on digestion and immune responses, plasma cortisol and amino acid composition of S. paramamosain. This is the first report that the adult S. paramamosain can be effect by the light intensity. The results showed that S. paramamosain has a strong stress response under high light intensity. Compared with darkness condition, digestive enzyme activity was higher under light condition. S. paramamosain reared under low light conditions had enhanced immunity, and it raised in light conditions exhibited superior qualities to those cultured in dark conditions. The results of this study demonstrated that low light levels are most suitable for breeding and improving the quality of S. paramamosain.

Effects of light intensity on growth performance, biochemical composition, fatty acid composition and energy metabolism of Scylla paramamosain during indoor overwintering

A long-term experiment was carried out to explore the effects of light intensity on growth performance, biochemical composition, fatty acid composition and energy metabolism of Scylla paramamosain. S. paramamosain were cultured under three illumination levels (0, 1.43 and 40.31 μmol m−2 s−1) in a recirculating water system of crab compartments for four months. S. paramamosain were fed to satiation once daily (17:00). The photoperiod was set at 10 L: 14 D (07:00–17:00). Results showed that the best growth of S. paramamosain was observed at the 1.43 μmol m−2 s−1 light intensity. The amount of energy substances was higher at the 1.43 μmol m−2 s−1 and 40.31 μmol m−2 s−1 light intensities. The amount of total unsaturated fatty acids (∑UFA) and total polyunsaturated fatty acids (∑PUFA) was significantly higher at the 1.43 μmol m−2 s−1 and 40.31 μmol m−2 s−1 light intensities (p < 0.05). However, total saturated fatty acids (∑SFA) were significantly higher at 0 μmol m−2 s−1 (p < 0.05). The concentrations of hepatic glycogen, blood glucose (GLU), total cholesterol (T-CHO) and triglyceride (TG) were significantly elevated at the 1.43 μmol m−2 s−1 light intensity, whereas the highest concentrations of muscle glycogen and lactic acid (LD) were at the 40.31 μmol m−2 s−1 light intensity (p < 0.05). Activities of hexokinase (HK) and pyruvate kinase (PK) were markedly higher at the 40.31 μmol m−2 s−1 light intensity, while the highest lactic dehydrogenase (LDH) activity was observed at 0 μmol m−2 s−1 and at 1.43 μmol m−2 s−1 for succinate dehydrogenase (SDH) (p < 0.05). Compared with 0 μmol m−2 s−1 and 40.31 μmol m−2 s−1, 1.43 μmol m−2 s−1 was more suitable for the breeding of S. paramamosain.

Effects of salinity on the ions important and sodium‐potassium ATPase in osmoregulation, cortisol, amino acids, digestive and immune enzymes in Scylla paramamosain during indoor overwintering

Overwintering is an important part of the conservation of Scylla paramamosain, and salinity has an important effect on the conservation of S. paramamosain during overwintering. Three salinities (4‰, 12‰ and 25‰) were selected as the overwintering salinities to reveal the effects of different salinities on the relevant important ions in osmotic pressure regulation, plasma cortisol, digestive enzymes, immune enzymes and amino acids of S. paramamosain during indoor overwintering. Results indicated that after overwintering, Cl-, Na+ and the osmotic pressure of serum have the highest salinity at 25‰, and the lowest salinity at 4‰. Na+/K+-ATPase activity and cortisol were found to increase with decreasing salinity. The activity of digestive and immune enzymes was highest at 25‰, and was the lowest at 4‰. The amount of total amino acids (TAA), umami amino acids (UAA) and essential amino acids (EAA) in 25‰ were significantly higher than in 4‰ and 12‰. After overwintering, the essential amino acid index (EAAI) in the salinity range of 12–25‰ was 54.04–59.00, compared to 48.56–54.04 in the salinity range of 4–12‰. As a result, S. paramamosain at 25‰ had higher digestion and immunity than at 4‰ and 12‰, due to requiring more energy for osmotic pressure adjustment. In addition, S. paramamosain at 25‰ had the best meat quality. The results of this study are helpful for aquaculture production for indoor overwintering of S. paramamosain.

Effects of salinity on growth, nutrient composition, fatty acid composition and energy metabolism ofScylla paramamosainduring indoor overwintering

Three salinities (4‰, 12‰ and 25‰) were selected to determine the effects of different salinities on the growth, survival, nutrition and energy metabolism of Scylla paramamosain during indoor overwintering. Growth performance (survival rate, condition factor, hepatopancreatic index, weight gain rate and specific growth rate), nutrient composition (ash, moisture, crude fat, crude protein and total nitrogen), fatty acids, energy metabolites (glycogen, glucose, triglycerides, cholesterol and lactic acid) and energy metabolic enzymes (hexokinase, pyruvate kinase, lactate dehydrogenase and succinate dehydrogenase) were measured and calculated. The results showed that S. paramamosain exhibited the best growth and survival at 25‰ and worst at 4‰ after overwintering. In addition to consuming crude fat, excess protein was also broken down to provide energy in the 4‰ and 12‰ groups. The content of unsaturated fatty acids in the 25‰ group was higher after overwintering. Glycogen and glucose consumption and triglycerides, cholesterol and lactic acid production were lowest in the 25‰ group. The activity of hexokinase, pyruvate kinase, lactate dehydrogenase and succinate dehydrogenase was highest in the 4‰ group and lowest in the 25‰ group. The activity of hexokinase, pyruvate kinase, lactate dehydrogenase and succinate dehydrogenase in the hepatopancreas was higher than in the muscle. In conclusion, S. paramamosain uses less energy, has more unsaturated fatty acids and has a higher survival rate at a salinity of 25‰ after overwintering. The results of this study provide helpful information the indoor overwintering S. paramamosain in aquaculture production systems.

Effects of treatments with Apivar® and Thymovar® on V. destructor populations, virus infections and indoor winter survival of Canadian honey bee (Apis mellifera L.) colonies

Efficacies of two miticides, Apivar® and Thymovar®, were evaluated as a fall treatment against V. destructor. The effect of treatment with miticides was further evaluated by monitoring both viral load and rate of indoor overwintering survival of colonies of European honey bees (Apis mellifera L.) in the vicinity of Saskatoon, Saskatchewan, Canada. Forty-five colonies were randomly assigned to three treatment groups with 15 hives per group: Group 1; 2 strips of Thymovar® (thymol); Group 2; 2 strips of Apivar® (Amitraz); and Group 3; no treatment (control). Significant decreases in the rates of colony infestation (Mites per hundred bees, MPHB) by V. destructor were observed (p < 0.05) between colonies of bees treated with Apivar® in October 2013 when compared to control colonies. Efficacy of Apivar® and Thymovar® against V. destructor after treatment for 22 days were 76.5 and 26.7%, respectively. After 22 days, concentrations of the two miticides in bees were 15.4 ng amitraz/g wet mass (wm) and 64,800 ng thymol/g wm. There were no significant differences (p > 0.05) in the percentage of colonies infected by deformed wing virus (DWV) and Israeli acute paralysis virus (IAPV) either before or after treatment with Apivar® or Thymovar® in October 2013 and 7 months post treatment in April 2014. Only the Apivar® treatment group showed IAPV infections in April 2014. The group treated with Apivar® exhibited a better overwintering rate of survival (93%), than hives treated with Thymovar® (67%). These results suggest volatile miticides like Thymovar® should be avoided in geographical areas with colder fall temperatures.

진주조개 Pinctada fucata martensii의 실내월동을 위한 저온노출에 따른 생리적 변화

With the aim of developing and indoor overwintering technique for Pearl oyster, Pinctada fucata martensii, the metabolic rates of young oysters (52.4-83.0 mm in shell length) were measured for 2 weeks at water temperatures of 8, 10, 12, and . The filtration rate (FR) ranged 0 to (mean, to ), with significant changes observed over thme except for the case of a water temperature of . Respiration rate (R) ranged from 0 to (mean, 0 to ), with significant respiratory disorders observed at temperatures below ; in contrast, the rate increased on the day of the experiment in the case of a temperature of 14. No significant difference was observed among the different water temperatures in terms of excretion rate (E) or absorption efficiency (Abs.eff), except for a significant decrease in aerobic metabolism in the case of water temperature of . The estimated scope for growth (SFG) ranged from -9.1 to (mean. to ). A significant energy Joss was found at , with negative SFG observed throughout the experiment and a gradual energy decrease observed over time at water temperatures of and 120C. However. SFG remained positive throughout the experiment in the case of . The estimated minimum energy requirement, assessed from energy expenditure, is (mean, ). In conclusion, the lowest temperature suitable for indoor overwintering is above .