Impact of different processing mulberry leaf on growth, metabolism and liver immune function of largemouth bass (Micropterus salmoides)

Large-mouth bass originally lived in rivers and lakes and now is often raised in recirculating aquaculture systems (RAS). However, the shortcoming of RAS is that there is very limited space for swimming fish in a high-density culture environment, thus leading to a lack of exercise. To investigate the effects of exercise training on growth performance, digestive enzymes, stress, and antioxidant capacity of large-mouth bass in a RAS, three training water flow velocities with three replicates were used in the present study: low water velocity: 0.5 body length per second (bl/s) (LV); medium water velocity: 1 bl/s (MV); and high water velocity: 1.5 bl/s (HV). 270 large-mouth bass (average initial body weight 47.51 ± 1.44 g, initial body length 12.71 ± 0.06 cm) were randomly divided into nine tanks (30 fish per tank). After 27 days experiment, the results showed that the growth performance of large-mouth bass, including feed intake, weight gain rate, and specific growth rate, in the HV group was significantly higher compared to the other groups. On the physiological level, the lipase and amylase activities were significantly increased in the HV group compared to the other groups. For the stress response parameters, the cortisol, glucose and lactate concentrations in the HV group were significantly increased, which may indicate higher stress in the HV group. Regarding the antioxidant enzyme activities, the activities of catalase (CAT) and glutathione peroxidase (GSH-PX) in the LV group were significantly higher than those in the HV group, which indicated that fish suffered higher oxidative stress in the LV group. Regarding the immune-related parameters, LZM and ACP activities had no significant differences among the groups, while AKP activities in the MV and HV groups were significantly higher than that in the LV group. Overall, the results demonstrated that exercise training had significant effects on the growth, digestion, stress, and immune response of large-mouth bass. It is suggested that exercise training with 1.5 bl/s can enhance fish growth, however, it also presents a potential risk of inducing stress in fish. Therefore, in rearing large-mouth bass in RAS, the setting of water flow velocity should not only focus on the growth of large-mouth bass but also consider its welfare.

Effects of dietary protein levels with cottonseed protein concentrate inclusion on growth, feed utilization, liver health and intestinal microbiota of juvenile largemouth bass (Micropterus salmoides)

Simple SummaryNowadays, owing to its limited availability and high cost, fish meal is no longer an affordable protein source in fish feed. Therefore, it is necessary to find new sustainable protein sources to replace fishmeal in the diet of fish or in aquafeeds. Recently, yellow mealworm (Tenebrio molitor) has been widely used as a protein source in the formulated feed of broilers, pigs, shrimp and fish, due to its high protein content, excellent amino acid profile and abundant functional substances. In this study, we found that yellow mealworm meal has high digestibility in largemouth bass (Micropterus salmoides) and an appropriate level (less than 19.52%) in the diet can promote growth and improve liver health in largemouth bass. Therefore, we assume that utilization of yellow mealworm in the diet of largemouth bass as a protein source is feasible.This study investigated the effects of yellow mealworm meal (TM) on growth performance, hepatic health and digestibility in juvenile largemouth bass (Micropterus salmoides). The fish were fed with the basic feed and the test feed (70% basic feed and 30% raw materials) containing Cr2O3, and feces were collected for digestibility determination. The fish were fed with five isonitrogenous (47% crude protein) and isolipidic (13% crude lipid) diets, in which fishmeal (FM) was replaced with 0% (TM0), 12% (TM12), 24% (TM24), 36% (TM36) and 48% (TM48) TM. The fish were reared in cylindrical plastic tanks in a recirculating aquaculture system for 11 weeks. The apparent digestibility coefficients (ADC), of dry matter, crude protein and crude lipid, in largemouth bass of TM were 74.66%, 91.03% and 90.91%, respectively. The ADC of total amino acid (TAA) of TM in largemouth bass was 92.89%, and the ADC of essential amino acid (EAA) in TM in largemouth bass was 93.86%. The final body weight (FBW), weight gain rate (WGR) and specific growth rate (SGR) in the TM24 group were significantly higher than those in other groups. Similarly, the highest mRNA expression levels of hepatic protein metabolism genes (pi3k, mtor, 4ebp2 and got) and antioxidant enzyme (glutathione peroxidase, Gpx; catalase, Cat) activities were observed in the TM24 group. Moreover, the expression levels of anti-inflammatory factors (il-10 and tgf) in liver were up-regulated and the expression levels of pro-inflammatory factors (il-8 and il-1β) in liver were down-regulated. Quadratic regression model analysis, based on weight gain rate (WGR) against dietary TM level, indicated that the optimum level of dietary TM replacing FM in largemouth bass diet was 19.52%. Appropriate replacement levels (less than 36%) of FM by TM in the diets can enhance the antioxidant capacity and immunity of largemouth bass. However, high levels of FM substitution with TM (more than 48%) in the feeds can damage the liver health and inhibit the growth of largemouth bass. Notably, largemouth bass has high ADC and high utilization of TM, which indicates that it is feasible to use TM as feed protein source for largemouth bass.

Submitted 2020-06-30 | Accepted 2020-09-01 | Available 2020-12-01 https://doi.org/10.15414/afz.2020.23.mi-fpap.79-87 The present study assessed the effects of two initial stocking densities (low – LD, 4.23 kg m-3, moderate – MD, 8.05 kg m-3) on growth, health and fillet quality of largemouth bass (Micropterus salmoides), and on yield of lettuce (Lactuca sativa) and radicchio (Cichorium intybus group Rubifolium) produced in a low-tech recirculating aquaponic system. A total of 104 largemouth bass (initial body weight: 236 ± 38 g) were randomly stocked in eight 500 L tanks (four per stocking density) and monitored during a 70-day period. Vegetables yield was similar in LD and MD groups. Lettuce yield (6.33 kg m-2) was in line with typical values, whereas radicchio showed a negligible yield (1.34 kg m-2). Likewise, fish final weight (263 g, on average), specific growth rate (0.17% d-1), feed conversion ratio (2.72), and mortality (4.8%) did not differ between treatments. Fish morphometric indices, slaughter results and fillet quality were not affected by stocking density. In conclusion, the production of lettuce was successful in the tested system, whereas the production of radicchio did not achieve satisfactory results. Growth performances of the largemouth bass were poor and further investigations are required to optimize the rearing of this fish species in low-tech aquaponic systems. Keywords: largemouth bass, lettuce, radicchio, water quality, flesh quality References BAßMANN, B. et al. (2017). Stress and welfare of African catfish (Clarias gariepinus Burchell, 1822) in a coupled aquaponic system. Water, 9(7), 504. https://doi.org/10.3390/w9070504 BROWN, T. G. et al. (2009). Biological synopsis of largemouth bass (Micropterus salmoides). Canadian Manuscript Report of Fisheries and Aquatic Sciences, 2884, v + 27 p. CHAVES-POZO, E. et al. (2019). An overview of the reproductive cycle of cultured specimens of a potential candidate for Mediterranean aquaculture, Umbrina cirrosa. Aquaculture, 505, 137–149. https://doi.org/10.1016/j.aquaculture.2019.02.039 CHEN, Y. et al. (2020). Effects of dietary fish oil replacement by soybean oil and L-carnitine supplementation on growth performance, fatty acid composition, lipid metabolism and liver health of juvenile largemouth bass, Micropterus salmoides. Aquaculture, 516, 734596. https://doi.org/10.1016/j.aquaculture.2019.734596 PANTANELLA, E. et al. (2012). Aquaponics vs. hydroponics: production and quality of lettuce crop. Acta Horticulturae, 927, 887-893. https://doi.org/10.17660/ActaHortic.2012.927.109 RAHMAN, M. M (2015). Role of common carp (Cyprinus carpio) in aquaculture production systems. Frontiers in Life Science, 8(4), 399–410. https://doi.org/10.1080/21553769.2015.1045629 RAKOCY, J. E. (2012). Aquaponics: integrating fish and plant culture. In: Tidwell J.H. 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Interactive effect of thermal and hypoxia on largemouth bass (Micropterus salmoides) gill and liver: Aggravation of oxidative stress, inhibition of immunity and promotion of cell apoptosis. Fish & Shellfish Immunology, 98, 923–936. https://doi.org/10.1016/j.fsi.2019.11.056 TIDWELL, J. H. et al. (2000). Species profile – Largemouth bass. Southern Regional Aquaculture Center 722. Retrieved May 20, 2020 from http://aquaculture.ca.uky.edu/aquaculture-publications/12 TIDWELL, J. H. et al. (2007). Effect of stocking density on growth and water quality for largemouth bass Micropterus salmoides growout in ponds. Journal of the World Aquaculture Society, 29, 79–83. https://doi.org/10.1111/j.1749-7345.1998.tb00302.x TYSON, R. V. et al. (2004). Reconciling water quality parameters impacting nitrification in aquaponics: the pH levels. In: Proceedings of the Florida State Horticultural Society 117, 79–83. Retrieved May 20, 2020 from https://journals.flvc.org/fshs/article/view/858557_11 VITULE, J. R. S. et al. (2006). Introduction of the African catfish Clarias gariepinus (Burchell, 1822) into Southern Brazil. Biological Invasions, 8, 677–681. https://doi.org/10.1007/s10530-005-2535-8 WANG, Y. et al. (2019). Effect of stocking density on growth, serum biochemical parameters, digestive enzymes activity and antioxidant status of largemouth bass, Micropterus salmoides. Pakistan Journal of Zoology, 51(4), 1509–1517. http://dx.doi.org/10.17582/journal.pjz/2019.51.4.1509.1517 WATTS, C. et al. (2016). Evaluation of stocking density during second‐year growth of largemouth bass, Micropterus salmoides, raised indoors in a recirculating aquaculture system. Journal of the World Aquaculture Society, 47(4), 538–543. https://doi.org/10.1111/jwas.12315 YILDIZ, H. Y. et al. (2017). Fish welfare in aquaponic systems: its relation to water quality with an emphasis on feed and faeces—A review. Water, 9(1), 13. https://doi.org/10.3390/w9010013 YUAN, J. et al. (2019). 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Bio-affinity ultrafiltration combined with UPLC Q-Exactive Plus Orbitrap HRMS to screen potential COX-2 and 5-LOX inhibitors in mulberry (Morus alba L.) leaf.

Mulberry (Morus alba) leaves improved the growth and intestinal health in largemouth bass (Micropterus salmoides) fed a cottonseed protein concentrate-based diet

Dietary Morus alba L. leaf supplementation improves hepatic lipid accumulation of laying hens via downregulating CircACACA

An 8-week feeding trial was conducted to explore the effects of replacement of dietary fishmeal by cottonseed protein concentrate (CPC) on growth performance, liver health, and intestine histology of largemouth bass. Four isoproteic and isolipidic diets were formulated to include 0, 111, 222, and 333 g/kg of CPC, corresponding to replace 0% (D1), 25% (D2), 50% (D3), and 75% (D4) of fishmeal. Two hundred and forty largemouth bass (15.11 ± 0.02 g) were randomly divided into four groups with three replicates per group. During the experiment, fish were fed to apparent satiation twice daily. Results indicated that CPC could replace up to 50% fishmeal in a diet for largemouth bass without significant adverse effects on growth performance. However, weight gain rate (WGR), specific growth rate (SGR), feed efficiency (FE), and condition factor (K) of the largemouth bass were significantly decreased when 75% of dietary fishmeal that was replaced by CPC. The whole body lipid content was increased with the increasing of dietary CPC levels. Oil red O staining results indicated that fish fed the D4 diet showed an aggravated fat deposition in the liver. Hepatocytes exhibited serious degeneration, volume shrinkage, and inflammatory cells infiltration in the D4 group. Intestinal villi appeared shorter and sparse with severe epithelial damage in the D4 group. The transcription levels of anti-inflammatory cytokines, such as transforming growth factor β (tgf-β), interleukin 10 (il-10), and interleukin 11 β (il-11β), were downregulated in the D4 group. The lipid metabolism-related genes carnitine palmitoyl transferase 1 (cpt1), peroxisome proliferator-activated receptor α (pparα), and target of rapamycin (TOR) pathway were also significantly downregulated in the D4 group. It was concluded that suitable replacement of fishmeal by less than 222 g CPC/kg diet had a positive effect on growth performance of fish, but an excessive substitution of 75% fishmeal by CPC would lead to the suppressed growth, liver inflammation, and intestinal damage of largemouth bass.

Dietary valine modulates hepatic immune responses in largemouth bass (Micropterus salmoides) against Aeromonas veronii infection: Integrated regulation of antioxidant defense, ER stress and autophagy.

Largemouth Bass Micropterus salmoides are commonly stocked throughout their native range, but survival of stocked fish is variable and often low. Hatchery fish may have difficulty switching to natural forage; therefore, providing feeding experience with natural prey in the rearing environment could result in improved growth and survival of Largemouth Bass after stocking. We conducted pond experiments to evaluate differences in growth and survival of Largemouth Bass reared in raceways and fed pellets or in ponds and fed either Bluegill Lepomis macrochirus prey or Fathead Minnow Pimephales promelas prey. Largemouth Bass reared on one of these three diets were stocked into ponds containing Bluegill prey. After 2 months, pellet-reared Largemouth Bass were significantly smaller than fish reared either on Fathead Minnows or Bluegills, whereas fish reared on either Fathead Minnows or Bluegills were similar. Fathead Minnow-reared Largemouth Bass had lower survival than Bluegill-reared fish, but no other survival differences were observed. To determine possible mechanisms influencing differential growth and survival of juvenile Largemouth Bass, we also conducted laboratory experiments examining the influence of prior feeding experience (pellets, Bluegills, or Red Shiners Cyprinella lutrensis) on foraging behavior and prey capture success in pools. Largemouth Bass reared on live forage captured prey faster, ingested more prey, and had higher capture efficiencies than did fish reared on pellets. Combined, pond and laboratory experiments show prior acclimation to live prey may ultimately be beneficial to increasing growth of stocked hatchery Largemouth Bass and could result in increased recruitment. We recommend additional exploration of acclimation of Largemouth Bass fingerlings to natural prey, preferably Bluegills, prior to stocking to determine whether hatchery managers should consider alternative rearing techniques.

Largemouth bass can hatch over a 70-d period, and among fish less than 90 d old, those hatched earlier can grow faster than those hatched later. Because faster growth of age-0 largemouth bass has been positively linked with fish consumption, it has been suggested that faster growth of largemouth bass hatched earlier was also due to higher fish consumption. We determined hatching-date-specific diets and growth of largemouth bass up to about 180 d old, collected in summer and fall 1987 in a North Carolina reservoir. Frequency of fish consumption for age-0 largemouth bass of all sizes tended to decrease as the growing season progressed. Largemouth bass that hatched earlier, however, were piscivorous at a younger age and maintained a higher level of piscivory late in the growing season than did fish that hatched later. Dietary differences that were hatching-date-dependent seemed to be due to seasonal decrease in prey fish availability. The growth advantage for fish hatched earlier was primarily expressed for fish less than about 85 d old. No growth differences related to hatching date were observed among fish older than 85 d. Studies are needed to determine whether the faster growth of fish hatched earlier results in lower mortality and ultimately in greater recruitment.

Fish growth can be highly variable among populations of the same species due to differences in abundance, system productivity and watershed characteristics. Because of this, understanding factors that influence fish growth and body condition is important to managers for fish conservation, to meet angler desires and to support local economies. As ecosystems respond to a changing climate, species compositions can change. In north temperate lakes, this is often exemplified by an increase in largemouth bass (LMB). These lakes are often managed for multiple fish species concurrently, making standardized fishery‐independent LMB data limited, creating challenges for managing this species. As such, a better understanding of factors influencing LMB body condition and growth may become critically important in the future. We assessed LMB age, length, and weight data to test for abiotic and biotic lake characteristics explaining variation in LMB body condition, asymptotic length, and mean length at age metrics in Wisconsin from 1994 to 2022. Macrophyte species composition and lake classification relationships were the two primary predictors of variation in LMB growth. Lakes with degraded macrophyte communities were associated with larger individual LMB sizes as were lake class types that contained cool water and riverine characteristics. Our results provide fisheries managers with options when dealing with diverse angler desires and a heterogenous landscape of lakes. Where available, macrophyte species composition data can be consulted by managers to identify opportunities to provide a trophy fishing experience in a system that otherwise would be undervalued. As populations of LMB increase in Wisconsin lakes, a better understanding of how to effectively reach goals set by managers, and what realistic goals might be, is required, and understanding what lake characteristics can explain variation of body condition gives insight to that end.

Growth, fat metabolism and hepatic health in largemouth bass fed varying fat-level diets

Background: Asthma is a chronic inflammatory disease of the airways. Inhaled corticosteroids are very important in anti-inflammatory treatment, but to a great extent they cannot control asthma alone. In addition to corticosteroids, long-acting β₂ agonists and leukotriene antagonists are used for asthma control. Objective: In this study, the effect of the addition of formoterol and montelukast on asthma control in patients with moderately persistent asthma who were symptomatic while using a low dose of inhaled budesonide was compared. Methods: At the beginning of the study, 40 symptomatic patients with moderately persistent asthma used 400 µg/day budesonide for a 4-week training period, and were then divided randomly into two groups, each composed of 20 persons. For the first group’s treatment regime, inhaled formoterol (9 µg) twice a day was added, and for the second group’s treatment regime, one-dose oral montelukast (10 µg) was added. These patients were followed up for 8 weeks. The patients’ peak expiratory flow (PEF) values measured in the morning and at night, changes in PEF, forced expiratory volume in 1 s, asthma symptom score and the symptom-relieving therapy used during the 12-week study period were recorded and evaluated in the clinic at the very beginning and at the end of each period. Results: Before the study, the morning PEF value of the group for whom formoterol was added to budesonide (FB) was 266.3 ± 59.3 liters/min, and in the group for whom montelukast was added to budesonide (MB), it was 262.8 ± 53.8 liters/min (p > 0.05). After the 8-week treatment period, the morning PEF values were found to be 320.5 ± 54.4 liters/min in the FB group and 293.3 ± 52.4 liters/min in the MB group; at the end of the study, it was seen that although there was an increase in morning PEF of 54.2 ± 15.2 liters/min in the FB group, there was an increase of only 30.5 ± 25.3 liters/min in the MB group (p < 0.0001). Before the study, night PEF values were 287 ± 56.6 liters/min in the FB group and 283 ± 48.5 liters/min in the MB group (p > 0.05). At the end of the treatment, the night PEF values were found to be 331.5 ± 56.1 liters/min in the FB group and 310 ± 53.1 liters/min in the MB group. At the end of the study, it was observed that although there was an increase in night PEF of 44.5 ± 23.3 liters/min in the FB group, there was an increase of only 27 ± 24.1 liters/min in the MB group (p < 0.001). Although asthma symptom scores and the use of symptom-relieving drugs showed similarities between the two groups at the beginning of the study, after treatment, the FB group had better results than the MB group with respect to these two parameters (p < 0.0001 for both). It was also seen that the two treatments are tolerated equally well. Conclusion: FB treatment, which causes a considerable improvement in lung function, showed better asthma control than MB treatment in patients with moderately persistent asthma.

Age and growth data are frequently used to monitor and manage important North American sport fishes such as Largemouth Bass Micropterus salmoides. Continental and regional growth standards have been developed for this species to assess fish growth over time and across space. However, Largemouth Bass age and growth data are infrequently collected in Arizona and the reliability of age estimates derived from typical structures (e.g., scales, otoliths) in the Southwest is uncertain. Our objectives were to 1) compare precision and bias of age estimates from scales with those from otoliths and 2) estimate Largemouth Bass growth in several southwestern warmwater reservoirs by using otoliths. We collected Largemouth Bass from three Arizona reservoirs—Alamo, Peña Blanca, and Roosevelt—by boat electrofishing in spring 2021. We removed scales and sagittal otoliths from fish and then prepared and independently aged them three times. We compared differences in precision and bias between scales and otoliths using reader agreement percentages, confidence ratings, average coefficients of variation, and age-bias plots. We used age estimates from Largemouth Bass otoliths to calculate mean lengths-at-age at capture and relative growth indices based on published growth standards in each reservoir. Largemouth Bass scale age estimates were less precise, overestimated ages of younger fish, and underestimated age of older fish compared with those of otoliths. Growth was lower in Peña Blanca Lake than in the other two reservoirs according to mean length-at-age estimates, and relative growth indices suggested that Largemouth Bass growth in all three reservoirs was above average at younger ages, but less so at older ages. The results from this study add to a growing body of literature supporting the use of otoliths for estimating age and growth of Largemouth Bass.