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An 8-week feeding trial investigated the optimum dietary vitamin K3 requirements of largemouth bass. A total of 600 healthy fish (12.96 ± 0.07 g) were fed diets containing varying levels of vitamin K3 at 0.78 (K0), 5.80 (K5), 10.82 (K10), 15.84 (K15), and 20.85 (K20) mg/kg with four replicates per level. Results showed that dietary vitamin K3 enhanced growth, with weight gain rate and specific growth rate in K15 trials significantly higher than K0 trials (P 0.05). However, the supplementation of vitamin K3 significantly contributed to calcium accumulation in muscle tissues and vertebrae (P 0.05). The antioxidant capacity was improved with the addition of vitamin K3, which was inconsistent with the changes in malondialdehyde and MK-4 (a form of menaquinone) within liver and serum, suggesting that the toxicity of excessive artificial vitamin K3 may account for this difference. Using regression analysis, the appropriate dietary vitamin K3 levels within a largemouth bass diet was determined to be in the range of 9.93–15.22 mg/kg, which will provide a reference for the preparation of vitamin premix and artificial diet for largemouth bass.

This study investigated the effects of replacing fishmeal with Clostridium autoethanogenum protein (CAP) on growth, feed utilization and intestinal histology of largemouth bass (Micropterus salmoides). The control diet contained 350 g/kg fishmeal, and then dietary fishmeal was decreased to 300 g/kg, 250 g/kg, 200 g/kg, 150 g/kg and 100 g/kg by CAP inclusion, respectively (FM-30, FM-25, FM-20, FM-15, FM-10). The largemouth bass (110.0 ± 1.0 g) were fed one of the six diets for 8 weeks. The groups of FM-30, FM-25 and FM-20 showed the similar weight gain (WG) and feed conversion ratio (FCR) to the control (P > 0.05), while the WG of FM-10 group was decreased by 15.9%, and FCR increased by 0.12 when compared to the control (P 0.05). In conclusion, CAP could replace 150 g/kg fishmeal in diet (350 g/kg fishmeal) without adverse effects on growth, feed utilization and intestinal histology of largemouth bass.

The present study was conducted to estimate the optimum requirement of phosphorus in practical diets for largemouth bass (Micropterus salmoides). Six iso-energetic and iso-nitrogenous diets were formulated with the supplementation of monocalcium phosphate (MCP) of 0, 5, 10, 15, 20 and 25 g/kg in basal diet containing 350 g/kg fish meal, respectively. The digestible phosphorus of the six diets was measured as 5.7, 6.7, 7.8, 8.7, 9.3 and 10.0 g/kg, respectively. Each diet was randomly fed to triplicate groups of 25 juvenile fish (initial body weight, 16.0 ± 0.2 g) for 60 days. The results showed that weight gain increased, and feed conversion ratio decreased with the increase of dietary phosphorus. When dietary MCP exceeded 15 g/kg (digestible phosphorus of 8.7 g/kg), the WG and FCR were maintained at the similar values. The crude ash, phosphorus and calcium contents in whole body, apparent digestibility of phosphorus and protein retention also increased with the increasing phosphorus level in diets. Vertebrae phosphorus and calcium levels and plasma phosphorus showed no further increase when dietary MCP reached 20, 20 and 10 g/kg with digestible phosphorus of 9.3, 9.3 and 7.8 g/kg, respectively. Broken-line analysis indicated that the digestible phosphorus requirement for largemouth bass were 8.9, 8.7 and 9.6 g/kg based on weight gain, feed conversion ratio and vertebral phosphorus content. In conclusion, the supplementation of MCP in a diet containing 350 g/kg fish meal improved the growth and feed utilization of largemouth bass, and the digestible phosphorus requirement was suggested to be 8.7–8.9 g/kg with MCP supplementation of 15.0–15.8 g/kg.

Estimating metabolic rate in wild, free-swimming fish is inherently challenging. Here, we explored using surgically implanted heart rate biologgers to estimate metabolic rate in two warmwater piscivores, bowfin Amia calva (Linneaus 1766) and largemouth bass Micropterus salmoides (Lacepede 1802). Fish were surgically implanted with heart rate loggers, allowed to recover for 24 h, exposed to a netting and air exposure challenge, and then placed into respirometry chambers so that oxygen consumption rate (ṀO2 ) could be measured in parallel to heart rate (fH ) for a minimum of 20 h (ca. 20 estimates of ṀO2 ). Heart rate across the duration of the experiment (at 19°C) was significantly higher in largemouth bass (mean ± s.d., 45 ± 14 beats min-1 , range 18-86) than in bowfin (27 ± 9 bpm, range 16-98). Standard metabolic rate was also higher in largemouth bass (1.06 ± 0.19 mg O2 kg-1 min-1 , range 0.46-1.36) than in bowfin (0.89 ± 0.17 mg O2 kg-1 min-1 , range 0.61-1.28). There were weak relationships between fH and ṀO2 , with heart rate predicting 28% of the variation in oxygen consumption in bowfin and 23% in largemouth bass. The shape of the relationship differed somewhat between the two species, which is perhaps unsurprising given their profound differences in physiology and life history, illustrating the need to carry out species-specific validations. Both species showed some potential for a role of fH in efforts to estimate field metabolic rates, although further validation experiments with a wider range of conditions (e.g., digestive states, swimming activity) would likely help improve the strength of the ṀO2 -fH relationship for use in field applications.

O_LIThe larval stage in fish development is characterized as a critical period with unusually high mortality rates. Additional stress may be imposed on fish larvae as fresh waters brown in color due to increased inputs of dissolved organic matter from the terrestrial watershed. Both energy transfer and foraging efficacy are predicted to decrease as light availability declines with browning.nC_LIO_LIHere, we investigated the balance between indirect versus direct effects of browning on zooplankton-larval fish interactions. Experimental tanks were established in the laboratory where water color was altered with increasing concentrations of SuperHume (water color measured as absorbance at 440 nm = 1.6 - 10.8 m-1). Phytoplankton and zooplankton densities were monitored across treatments for one month to assess possible changes in community structure leading up to fish spawning (i.e., late Spring in central Virginia, USA). We then introduced larval largemouth bass to the tanks to assess indirect effects on larval fish feeding rate and growth. Additionally, direct effects on the foraging efficiency and selectivity of largemouth bass and bluegill were determined with separate short-term feeding experiments using the same experimental setup.nC_LIO_LIBrowning did not directly alter the ability of larval fish to see and capture prey across our brown water treatments. However, significant indirect effects on larval fish foraging, growth, and survival were observed as phytoplankton and zooplankton densities decreased with increasing water color.nC_LIO_LIOur data suggest lake browning will reduce energy transfer to larval fish, during a critical stage of development, due to a reduction in prey availability but not visual foraging.nC_LI

Fragmentation of river systems by dams can have substantial genetic impacts on fish populations. However, genetic structure can exist naturally at small scales through processes other than isolation by physical barriers. We sampled individuals from five native fish species with varying life histories above and below a dam in the lower Boardman River, Michigan, USA, and used RADseq to investigate processes influencing genetic structure in this system. Species assessed were white sucker Catostomus commersonii, yellow perch Perca flavescens, walleye Sander vitreus, smallmouth bass Micropterus dolomieu, and rock bass Ambloplites rupestris. We detected significant differentiation within each species, but patterns of population structure varied substantially. Interestingly, genetic structure did not appear to be solely the result of fragmentation by the dam. While genetic structure in yellow perch and walleye generally coincided with “above dam” and “below dam” sampling locations, samples from our other three species did not. Specifically, samples from rock bass, smallmouth bass, and, to a much lesser extent, white sucker, aligned with a putative Great Lakes (GL) group that contained mostly individuals sampled below the dam and a putative Boardman River (BR) group that contained individuals sampled both above and below the dam, with some evidence of admixture among groups. We hypothesize that the GL and BR groups formed prior to dam construction and our samples largely represent a mixed stock that was sampled sympatrically outside of the spawning season. Support for this hypothesis is especially strong in smallmouth bass, where GL fish were 151 mm smaller than BR fish on average, suggesting a potential ontogenetic habitat shift of young GL fish into the lower river for feeding and/or refuge. Our study illuminates the complex dynamics shaping genetic structure in fragmented river systems and indicates that conclusions drawn for a single species cannot be generalized.

Predator–prey systems face intensifying pressure from human exploitation and a warming climate with implications for where and how natural resource management can successfully intervene. We hypothesized young salmon migrating to the Pacific Ocean face a seasonally intensifying predator gauntlet when warming water temperature intensifies a multiple predator effect (MPE) from Striped Bass Morone saxatilis and Largemouth Bass Micropterus salmoides. We evaluated this hypothesis using data synthesis and simulation modeling.Contemporary studies based on acoustically tagged fish reaffirmed older observations that Chinook Salmon smolts must transit the Delta before water temperature reaches 20°C or mortality will be nearly 100%. Striped Bass attack rates on tethered smolts were insensitive to distance from shore and water temperature, whereas Largemouth Bass attack rates were highest near shorelines in warm water, supporting the temporal aspect of the hypothesis. Whether the combined effects of the two predators produce an MPE remains unconfirmed due to limitations on quantifying salmon behavior.We used multiple simulation models to try to reconstruct the empirical relationship between smolt survival and water temperature. Simulations reinforced attack rate results, but could not recreate the temperature dependence in smolt survival except at higher than observed temperatures. We propose three hypotheses for why and recommend discerning among them should be a focus of research.We found significant linear relationships between monthly mean inflow to the Delta from each of its two largest tributaries and monthly mean water temperatures along associated salmon migration routes, but these relationships can be nonlinear, with most of the correlation occurring at low inflows when water temperature is largely controlled by air temperature and day length. As the global climate warms, changed circumstances in predator–prey relationships may present important challenges when managing species vulnerable to extinction in addition to presently more abundant species., We build upon previous conceptual models of how intersecting impacts of multiple predators can render former habitats unsuitable to migratory animals and test the conceptual model with a case study. The case study focuses on the potential impacts of two non‐native predators on Chinook Salmon smolts as the young salmon migrate through California's Sacramento‐San Joaquin Delta on their way to the Pacific Ocean.

Largemouth bass (LMB; Micropterus salmoides) recruitment is limited by a critical developmental period during early life stages, but this mechanism may be less important within non-native habitats. We conducted boat electrofishing surveys in four tidal lakes of California’s Sacramento–San Joaquin Delta (SSJD) from 2010 to 2011 to describe introduced LMB recruitment dynamics. We evaluated growth, proximate composition, and health indices of young-of-the-year (YOY) LMB among tidal lakes and developed an integrated count model to determine how factors known to affect LMB recruitment shape SSJD population structure. Our results show a mismatch among growth, nutrition, and YOY abundance, where the tidal lake with the most abundant and fastest-growing LMB had the poorest nutritional status. The warm winter water temperatures and lack of a hatching-cohort growth advantage suggests overwinter starvation plays a less important role in SSJD LMB recruitment than in many native LMB habitats. Collectively, our results suggest that habitat characteristics (submerged aquatic vegetation) and not overwinter mortality shapes SSJD LMB population structure, a mechanism consistent with contemporary hypotheses about the altered fish community structure of the SSJD.

Purpose. Largemouth bass (Micropterus salmoides), a fish species native to freshwaters of North America, is a promising object of aquaculture all over the world. This is evidenced by the fact that this species is currently actively cultivated in aquaculture of more than 50 countries worldwide, on all continents, with the exception of Antarctica and Australia, both for recreational fishing and as a table fish. If we consider the history of breeding and cultivation of the largemouth bass, we can note a tendency to a continuous expansion of the stages of cultivation and transition from polyculture to monoculture. For example, in the first half of the last century, fish farms in the United States raised mainly juveniles of largemouth bass for stocking to natural water bodies, but currently most farms use the full production cycle from fry to marketable fish. In addition, earlier largemouth bass was used in many countries mainly as an additional object of aquaculture (biomeliorator) to increase the production of common carp, but now, thanks to the development of recreational fishing, it is increasingly becoming the main object of aquaculture, which is facilitated by the intensification of cultivation methods. Nowadays, there are many methods of growing largemouth bass, from the simplest, extensive, when fish are raised on natural food supply, to most intensive using flow-through aquaculture systems and off-season spawning. On the territory of Ukraine, it may be effective to use pond aquaculture of largemouth bass, which begins from the production of larvae and fry at fish farms. This stage of fish farming will be discussed in this article. Findings. This article contains brief information on method of natural spawning of largemouth bass, filling ponds with water, selection of broodstock and norms for their stocking to spawning ponds, spawning behavior of fish, peculiarities of caring for larvae and fry, sorting juveniles, as well as minimizing injuries during manipulations with fish. Practical value. Information from this review can be used for development of a new method for production of largemouth bass larvae and fry at warm-water pond farms in Ukraine, taking into account climatic conditions and local specificities of aquaculture. Key words: Largemouth bass, Micropterus salmoides, recreation fishing, sport fishing, pond fish farm, aquaculture, biomeliorator, larvae, fry, polyculture, monoculture, intensification, perspective species.

The feeding method is of great significance for aquaculture production and cost. In recent years, research on intelligent feeding, a method based on fish appetite, has been trending. Few studies, however, have focused on fish welfare issues that can result from intelligent feeding. In this study, an adaptive feeder based on a practical intelligent feeding method was designed to evaluate whether this intelligent feeding method would impair fish welfare compared to traditional automatic feeding. The results indicated that the amount of residual feed and size inhomogeneity in the traditional group was significantly higher than that in the intelligent group. The results of the growth indicator showed that the weight gain rate (WGR) in the intelligent feeding group was significantly higher (30.17%) than in the traditional feeding group. Although no significant differences were observed in the survival rate (SR), the condition factor (CF) and the hepatosomatic index (HSI), the specific growth rate (SGR) in the intelligent feeding group was significantly increased by 8.33% while the feed conversion rate (FCR) was reduced by a remarkable 17.07% compared to the traditional feeding group. Moreover, intelligent feeding significantly improved the pepsin activity of the bass. In terms of immunity and antioxidant capacity, however, the fish in the intelligent feeding group had a significantly lower lysozyme (LZM) level than those fed with the traditional method. For superoxide dismutase (SOD), the intelligent group also displayed a lower activity value, although it was not significant. The intelligent feeding group had 0.14 nmol/mg protein higher malondialdehyde (MDA) activity than the traditional group. Regarding stress, although no statistical significance was observed, the cortisol level in the intelligent group was 1.9 ng/ml higher than in the traditional group. Together, these data suggested that the intelligent feeding method can significantly improve fish growth but may also result in stress and suppress innate immunity.

Molecular markers were used as indicators in assessing the genetic diversity of a fish, they allow for direct observation of genetic information and estimation of genetic relationships between the population and species. In the present study, eleven SCoT primers and ten ISSR primers were used to estimate the genetic diversity among the four mullet species namely Mugil cephalus, Liza ramada, Liza grana, and Valamugil seheli collected from four different Egypt governorates Alexandria, Ismailia, Port Said and Damietta. The two markers SCoT and ISSR successfully amplified amplicons with a total number of 176 and 132 of which 153 and 111 were polymorphic, representing a percentage of polymorphism of 86.9% and 84.1% polymorphic amplicons/ primer, respectively. The similarity indices ranged from 0.47 to 0.84, 054 to 0.92 and 0.52 to 0.86 for SCoT, ISSR and combined, respectively. Cluster analysis based on similarity matrices of SCoT, ISSR and combined dendrograms revealed some similarities; for example, the grouping of the Mugile cephallus (Alexandria, Ismailia and Port Said) together and the grouping Valamugil seheli (Ismailia and Damietta) based on the three dendrograms. Also, Liza ramada, Liza garana (Damietta) and Mugile cephallus ( Damietta) were clustered together based on the three dendrograms. From gene sequencing and NCBI Blast analysis identified of gene location in fish genomes. The NCBI blast tool was used to align our gene with the NCBI database and it revealed that this sequence is highly similar to a sequence located on fish species called Dicentrarchus labrax (the European bass). Also, the sequence is located on Chr1 near a gene called “Type II keratin E3”.

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 BAsMANN, 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. (Ed), Aquaculture production systems. India: Wiley-Blackwell (pp. 343–386). https://doi.org/10.1002/9781118250105.ch14 SAS (Statistical Analysis System). 2013. SAS/STAT(R) 9.2 User’s Guide, second ed. SAS Institute Inc., Cary, NC, USA. Retrieved May 10, 2020 from http://support.sas.com/documentation/cdl/en/statug/63033/HTML/default/viewer.htm#glm_toc.htm SOMERVILLE, C. et al. (2014). Small-scale aquaponic food production. Integrated fish and plant farming. Rome: FAO Fisheries and Aquaculture Technical Paper No. 589. Retrieved May 15, 2020 from http://www.fao.org/3/a-i4021e.pdf SUAREZ, M. D. et al. (2014). Influence of dietary lipids and culture density on rainbow trout (Oncorhynchus mykiss) flesh composition and quality parameter. Aquaculture Engineering, 63, 16–24. http://dx.doi.org/10.1016/j.aquaeng.2014.09.001 SUN, J.-L. et al. (2020). 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). Analysis of the growth performances, muscle quality, blood biochemistry and antioxidant status of Micropterus salmoides farmed in in-pond raceway systems versus usual-pond systems. Aquaculture, 511, 734241. https://doi.org/10.1016/j.aquaculture.2019.734241

The carnivorous largemouth bass Micropterus salmoides has been introduced to many regions and poses a threat to native aquatic organisms due to predation, resulting in a significant decrease in biodiversity. Under conditions of prey scarcity, the largemouth bass is thought to consume smaller conspecifics. However, little is known about this species’ dietary reliance on intraspecific predation and its impact on the population structure. We investigated the length–frequency distribution of largemouth bass and estimated their reliance on intraspecific predation using stable carbon and nitrogen isotopes in an agricultural pond with no available prey fish. Almost all individual largemouth bass were collected via the pond drainage system. Within the largemouth bass population, the dominant length class was composed of fish measuring 100–160 mm standard length (SL), whereas few individuals measuring < 100 mm SL (first-year juveniles) were collected. The results from a Stable Isotope Analysis in R mixing model indicated that all four length classes (105–146, 165–180, 216–246, and 300–337 mm SL) of largemouth bass fed mainly on juvenile conspecifics and on red swamp crayfish (Procambarus clarkii). First-year juveniles could have been predated by other individuals of various sizes. The dominant 100–160 mm SL length class may have experienced a weak predation pressure when they were in the first-year juvenile class. Consequently, the largemouth bass population was unbalanced, with few first-year juveniles (< 100 mm SL) and dominance of a 100–160 mm SL length class.

Juvenile striped bass (age-1) of distinct genetic ancestry were re-discovered in the Saint John River, New Brunswick in 2014 after a 35 yr hiatus of recognition. These juveniles were determined to be highly genetically divergent from all possible source populations, hypothesized to be of Saint John River ancestry, and thus considered evidence of the continued existence of the native stock. Successful recruitment of strong year classes of striped bass within the Saint John River, however, appears to be infrequent. We acoustically tagged and tracked juvenile and sub-adult striped bass (n = 37; age 2-4) in the Saint John River in both 2015 and 2016, and identified summer feeding and overwintering habitats that established an in-river residency. Following decades of poor or no recruitment of the native striped bass stock, it is now imperative that managers quickly include monitoring of juvenile and sub-adult striped bass and protection of their habitats in the conservation and recovery efforts for Saint John River striped bass.

ConspectusSilica-alumina catalysts, including zeolites and amorphous silica-aluminas (ASAs), are among the most widely used solid acid catalysts and supports to produce petrochemicals, fine chemicals, and renewable energy. The coordination, distribution, and interactions of aluminum in ASAs have an enormous impact on their acidic properties and catalytic performance. Unsaturated tetracoordinated aluminum (AlIV) species are commonly accepted as the key sites in generating catalytically active Bronsted acid sites (BASs) in silica-alumina catalysts. Extensive efforts focus on increasing the concentration of AlIV as the main route to enhance their Bronsted acidity for efficient catalysis. However, increasing the AlIV concentration either weakens the acid strength in zeolites or lowers Bronsted acidity in ASAs at high Al/Si ratios, impeding acidity enhancement of these popular catalysts."Pentacoordinated aluminum (AlV) species" are potential unsaturated Al species like AlIV but rarely observed in silica-aluminas, and thus, are widely considered unavailable for BAS formation or surface reactions. In this Account, we will describe novel strategies for the controlled synthesis of AlV-enriched ASAs using flame-spray pyrolysis (FSP) techniques and highlight the contribution of AlV species in acidity enhancement, together with their structure-activity relationship in the conversion of biomass-derived compounds into valuable chemicals. Using various in situ and advanced 2D solid-state NMR (SSNMR) experiments, the studies of the acidic properties and local structure of AlV-enriched ASAs reveal that AlV species can highly populate on ASA surfaces, promote BASs formation, and facilitate adaptable tuning of BASs from moderate to zeolitic strength by synergy with neighboring Al sites. Moreover, the BASs with enhanced acidity can work jointly with surface Lewis acid sites or metal active species for bifunctional catalysis on AlV-enriched ASAs. Compared to zeolites, these AlV-enriched ASAs are highly active in acid-catalyzed biomass conversion, including alcohol dehydration and sugar conversion reactions, as well as in promoting the performance of supported metal catalysts in chemoselective hydrogenation of aromatic ketones. These new insights provide a state-of-the-art strategy for strongly enhancing the acidity of these popular silica-alumina catalysts, which offers an interesting potential for a wide range of acid and multifunctional catalysis.

Columnaris disease generates substantial losses of many freshwater fish species; one is the hybrid striped bass. The ubiquitous aquatic bacterium Flavobacterium columnare can be highly effective in biofilm formation on fish skin and gills. Previous research showed a difference between columnaris disease susceptibility of hybrid striped bass (Morone saxatilis × M. chrysops) and white bass (M. chrysops). To understand these differential susceptibilities and possible mucosal relationship, we assessed total bacterial growth and biofilm formation with mucus derived from each moronid parental species: white bass and striped bass (M. saxatilis). Differential susceptibility was confirmed of the other parent species, the striped bass (M. saxatilis). In addition to intraspecies investigations, individual hybrid striped bass mucosal affects were also studied for deferential responses to bacterial growth and biofilm formation. Species- and concentration-dependent differences were detected in the total growth of the bacteria to host mucus. Our data suggest that bass mucus can significantly affect biofilm formation with the F. columnare isolate tested. There appears to be a correlation between the bacteria's response of growth and biofilms and bass species susceptibility. This study provides insight into our understanding of the host-pathogen interaction between F. columnare and moronids.

Coptodon zilli and Micropterus salmoides were introduced into Lake Naivasha in 1929 and 1959 respectively. The reasons for the introduction were to boost the fisheries and for recreational fishing respectively. However, the numbers of the two fish species in the lake have been declining over the years. It is therefore necessary to assess various aspects of their growth such as length-weight relationship, condition factor, sex ratio and length at first maturity to inform management and policy making for enhanced recovery and establishment of their populations. Length-weight relationship, condition factor, sex ratio and length at first maturity of the fish were studied from October 2016 to November 2018. A total of 303 fish samples; 193 C. zilli and 110 M. salmoides were studied. Results showed that C. zilli and M. salmoides had an allometry coefficient value of 2.9 and 3.1 and condition factor (K) value of 1.77 and 1.39 respectively. The sex ratios (male: female) of C. zilli and M. salmoides were 1.1:1 and 1.3: 1 respectively. The shortest total length for mature C. zilli and M. salmoides recorded were 12 cm and 26.5 cm while 21.8 cm and 51 cm were for the longest respectively. The fish growth pattern therefore failed to obey the cube law of b=3 thus exhibiting allometric growth. The two fish species were found to be in good condition with K factor above 1. It can therefore be concluded that the fish are generally in a good condition though the early maturity especially for C. zilli could be a sign of pressure either from environmental factors or human induced. Domination of the species by males, although a common feature in African lakes, is a case for concern since it presents uncertainty on the future of the fisheries. Restocking of Lake Naivasha with the two fish species should be considered and proper fishing practices enforced

Largemouth bass (LMB) were fed diets developed to substitute fishmeal (FM) using a blend of alternative proteins. Diets included a FM control (FMC), two FM-free formulae (FMF), one of which (FFF) was formulated using an algal oil replacing fish oil (FO) and, for comparative purposes, a commercial LMB feed (COM). Fish (densities of 3.11±0.29 kg m-1) were arbitrarily distributed into one of eight tanks configured as a recirculating system (RAS; 28.3±0.76 oC; DO2: 7.7±1.19 mg L-1) and tanks randomly assigned to one of the four treatments (i.e. each treatment was tested in duplicate). Animals were fed 3x daily to apparent satiation and group weighed every 3 weeks for 18 weeks. No differences were observed in feed consumption between groups (P >0.05) but LMB fed the COM diet were heavier (P 0.05). Results from the present study show that, with prudent dietary control, complete replacement of FM/FO in LMB diets is attainable and verifiable, without compromising growth performance or consumer acceptance of the final product.

Diets were manufactured for largemouth bass (LMB) replacing fishmeal (FM) with poultry by-product meal (PBM), soybean meal (SBM), and a hydrolyzed soy meal. Experimental diets included a FM control (FMC), and three FM-free formulations containing equal amounts of PBM and SBM with fish oil (diet F2), Algal meal DHA (F3) or a soy protein concentrate (SPC). A commercial LMB diet was included for reference. Fish (n=20 per group) were randomly dispersed into one of 20 tanks with group weights of ±5%, and densities of 7.39±0.17 kg m-3. Tanks were maintained as a RAS (28.3±0.76 oC, DO2 at 7.7±1.19 mg L-1) and randomly assigned to one of the five diets (n=80 fish per diet). Animals were fed to apparent satiation 3x daily for 12-weeks. Groups were weighed every 3 weeks and feed consumption recorded for calculation of FCRs. At trial end all fish were weighed and measured individually and 3 fish per tank employed for various analyses and comparisons against pre-trial samples. At trial end no differences (P > 0.05) were observed between groups for growth, SGR, or condition. FCR differed between the commercial and F3 diets (P < 0.05). F2 fed fish had higher (P < 0.05) visceral fat than F3 fed fish. Survival was 98-100% across all groups. Results indicate that judicious dietary manipulations may allow elimination of FM from LMB diets without compromising overall performance.

To investigate whether incorporation of small peptides into diets could change the growth performance, muscle quality and liver health of the largemouth bass, four diets were designed: SP0⁺ group (positive control group) was formulated according to the nutritional requirement of the largemouth bass. In SP0⁻ group (negative control group), the crude protein level was decreased by 30 g/kg compared with SP0⁺ group; SP20 group was added 20 g/kg small peptides based on the SP0⁻ group, and its crude protein level did not reach that of SP0⁺ group. In SP65 group, 65 g/kg small peptides were added on the basis of SP0⁻ group to obtain same crude protein level as SP0⁺ group. Fish were fed with these four different diets for 9 weeks. Results showed that, compared with the negative control group, the addition of 20 g/kg small peptides had no significant effect on the weight gain rate and feed coefficient of the largemouth bass; adding 65 g/kg small peptides could significantly increase the weight gain rate and reduce the feed coefficient (p

Steam cooking is a popular way of preparing fish and the end temperature plays a key role in the quality of the cooked fish. In this study, the lipid and protein oxidation, and the related changes in volatile compounds and in vitro digestibility of large-mouth bass ( Micropterus salmoides ) steam cooked to a core temperature of 45℃, 55℃, 65℃, 75℃, and 85℃ were investigated. Steaming caused a significant increase in the peroxide value (PV) and the thiobarbituric acid-reactive substances (TBARS) value, accompanied by the decreased proportion of unsaturated fatty acids like oleic acid and linoleic acid, which was related to the lipid oxidation and the increase in volatile aldehydes as indicated by the partial least squares analysis. The protein oxidation can be reflected by the significant decrease of total thiol groups, combined with the aggregation as shown in SDS-PAGE and the increase in particle size at pre-digestive phase. And the aggregation of proteins further caused the decreased digestibility of fish meat at the gastric phase, especially when the core temperature was above 75℃. Furthermore, steaming significantly decreased the aerobic count, and no coliform or generic E. coli was detected in steamed samples. Thus the core temperature of 65-75℃ was recommended for the consideration of food oxidation and microbial safety.

Striped Bass, Morone saxatilis (Walbaum, 1792), is an anadromous fish species that supports fisheries throughout North America and is native to the North American Atlantic Coast. Due to long coastal migrations that span multiple jurisdictions, a detailed understanding of population genomics is required to untangle demographic patterns, understand local adaptation, and characterize population movements. This study used 1,256 single nucleotide polymorphism (SNP) loci to investigate genetic structure of 477 Striped Bass sampled from 15 locations spanning the North American Atlantic coast from the Gulf of St. Lawrence, Canada, to the Cape Fear River, United States. We found striking differences in neutral divergence among Canadian sites, which were isolated from each other and US populations, compared with US populations that were much less isolated. Our SNP dataset was able to assign 99% of Striped Bass back to six reporting groups, a 39% improvement over previous genetic markers. Using this method, we found (a) evidence of admixture within Saint John River, indicating that migrants from the United States and from Shubenacadie River occasionally spawn in the Saint John River; (b) Striped Bass collected in the Mira River, Cape Breton, Canada, were found to be of both Miramichi River and US origin; (c) juveniles in the newly restored Kennebec River population had small and nonsignificant differences from the Hudson River; and (d) tributaries within the Chesapeake Bay showed a mixture of homogeny and small differences among each other. This study introduces new hypotheses about the dynamic zoogeography of Striped Bass at its northern range and has important implications for the local and international management of this species.

A 12-week feeding trial was conducted to evaluate the effects of replacing fish meal by chicken haemoglobin powder in largemouth bass diets. Four isonitrogenous (48%) and isolipidic (12%) diets were formulated to replace 0% (control), 9.80%, 19.61% and 29.41% of fish meal with chicken haemoglobin powder. Each diet was fed to triplicate groups of fish (initial weight: 49.50 ± 0.07 g) twice daily. The fish specific growth rate was significantly reduced when diet replacement level was up to 19.61%, which may be related to the feed intake and apparent digestibility coefficient of protein and amino acids. Meanwhile, the feed efficiency ratio and protein efficiency ratio were not significantly decreased until the replacement level up to 29.41%. The activity of CCP was significantly reduced when 19.61% of fish meal was replaced. Meanwhile, the activity of lysozyme and serum protein content was significantly altered in fish fed with the diets up to 29.41% replacement. Additionally, the red blood cell count and haemoglobin content was significantly decreased when the replacement level was up to 19.61%. In overall, the diet with 9.80% of chicken haemoglobin powder was more suitable for largemouth bass.

Aquafeeds for carnivorous species face a nutritional–technological conundrum: containing sufficient starch to meet specific manufacturing requirements for binding, extrusion and expansion, but ideally containing as little starch as possible owing to their limited ability to utilise carbohydrates. The present study evaluated the effects of dietary starch with different amylose to amylopectin ratios and resistant starch contents on growth performance, hepatic glycogen accumulation and glucose metabolism of an important cultured carnivorous finfish, largemouth bass (Micropterus salmoides). A common starch source (α-cassava starch (CS)) was tested as is or after being enzymatically de-branched at three different inclusion levels in diets for largemouth bass. Results showed that the increased dietary starch levels compromised performance and high dietaryα-CS content led to obvious liver damage. However, the growth performances of fish fed the diets with de-branched starch (DS) were improved, and no manifest liver damages were observed even at the higher inclusion level. The increasing dietary starch contents significantly increased hepatic glycogen accumulation, but not when DS was used. High dietary starch content, without regard to starch sources, had no effect on the expression of glucose metabolism-related genes, except for down-regulation of insulin receptor expression. However, the use of dietary DS promoted the expression of genes involved in the insulin pathway and glycolysis. In conclusion, this study showed that the use of starch sources with a high amylose to amylopectin ratio and resistant starch in the feed for cultured carnivorous finfish could alleviate the hepatic glycogen deposition through regulating the insulin pathway and glycolysis.

Hyperpigmented melanistic skin lesions (HPMLs) of smallmouth bassMicropterus dolomieuare observed in the Potomac and Susquehanna rivers, Chesapeake Bay watershed, USA. Routine, nonlethal population surveys were conducted at 8 sites on the mainstem Susquehanna River and 9 on the Juniata River, a tributary of the Susquehanna River, between 2012 and 2018, and the prevalence of HPMLs was documented. A total of 4078 smallmouth bass were collected from the mainstem Susquehanna River and 6478 from the Juniata River. Lesions were primarily seen in bass greater than 200 mm, and prevalence in the Susquehanna River (8%) was higher (p < 0.001) than in the Juniata River (2%). As part of ongoing fish health monitoring projects, smallmouth bass were collected at additional sites, primarily tributaries of the Susquehanna (n = 758) and Potomac (n = 545) rivers between 2013 and 2018. Prevalence in the Susquehanna River (13%) was higher (p < 0.001) than the Potomac (3%). Microscopically, HPMLs were characterized by an increased number of melanocytes in the epidermis or within the dermis and epidermis. RNAseq analyses of normal and melanistic skin identified 3 unique sequences in HPMLs. Two were unidentified and the third was a viral helicase (E1). Transcript abundance in 16 normal skin samples and 16 HPMLs showed upregulation of genes associated with melanogenesis and cell proliferation in HPMLs. The E1 transcript was detected in 12 of the 16 melanistic areas but in no samples from normal skin. Further research will be necessary to identify the putative new virus and determine its role in melanocyte proliferation.

Purpose. Modern fisheries of Ukraine faces many challenges, among which the adaptation to climate changes as well as the development of recreational fishery and international fishing tourism can be highlighted. The main purpose of the adaptation can be formulated as an improvement of fishery activities due to an increase in average annual temperatures and prolongation of the active growth period of aquatic organisms. Moreover, in the majority of developed countries all around the world, there is a tendency of the transition from perception of fish as a food product to the perception of fish as an object of recreational services. This makes possible to exploit fish stocks more effectively and sparingly, with only a little harm for fish. As a new object of aquaculture that has high adaptive potential to increases in average annual temperatures and takes an important place in recreational fishing across the world, we can consider the largemouth bass (Micropterus salmoides). This fish species, which is native to freshwaters of North America, is currently reared in aquaculture in more than 50 countries, mainly for recreational and sport fishing. The development of methodologies for largemouth bass aquaculture in Ukraine could contribute to more effective fisheries management and to development of recreational fishing services. This in turn would result in income growth to local and general budgets and would contribute to more effective investment raising. Findings. The article contains brief information on the outlooks of reproduction and cultivation of the largemouth bass in Ukrainian aquaculture, ecological and fisheries characteristics of this species with the description of its natural habitats, feeding, growing potential of different age groups, and breeding process in its natural range. Moreover, this review mentions attempts of largemouth bass introduction to Ukrainian water bodies occurred in XІХ-ХХ centuries, and possible reasons of its total and partial failures. Furthermore, this article assesses the potential impact of the largemouth bass on local ichthyofauna and aquaculture conditions, and considers the measures aimed on the prevention of uncontrolled spread of this species during cultivation. Practical value. Information provided in this review can be further used for development of the methodology of largemouth bass aquaculture in Ukraine as well as for popularization of this species for recreational fishing and the development of international fishing tourism.

Environmental effects monitoring in marine ecosystems are challenging, particularly in dynamic macrotidal settings like the Bay of Fundy. Environmental DNA provides a useful tool for determining species presence in such challenging places to access and sample. Moreover, recent studies showing a link between eDNA concentration and fish density/biomass reveal the great promise for eDNA tools to improve biodiversity assessments in marine environments. Three mesocosm experiments were conducted to assess the accuracy and precision of a handheld point‐of‐need (PoN) tool for quantitative polymerase chain reaction (qPCR) assay for eDNA detection of striped bass (Morone saxatilis) versus conventional laboratory‐based eDNA techniques. The first of these experiments determined that striped bass eDNA was reliably detected using either of the laboratory‐based or PoN platforms, with some variation observed in the estimates of eDNA concentrations derived from each. Next, a time series experiment established that eDNA in water samples collected within a 24‐hrs period of exposure to striped bass was reliably and consistently detectable with either platform. Our final experiment found that the relationship between eDNA concentrations and manipulated striped bass stocking densities was significant and positive based on results from each of the laboratory‐based or PoN platforms. Our results validate and advance eDNA approaches toward environmental monitoring efforts and demonstrate the potential for real‐time eDNA tools to quantify and identify the spatial and temporal distribution of species‐at‐risk in an open ocean environment.

We observed episodic zooplanktivory by largemouth bass (Micropterus salmoides; LMB) ≥ 150 mm total length (TL) on the cladoceran Daphnia spp. over two decades in a small oligotrophic lake. While zooplanktivory is beneficial for young-of-year and juvenile LMB, dietary utilization of Daphnia by adults is unusual because zooplankton are not energetically favorable and the LMB buccal cavity is poorly adapted for filter feeding. We classified the threshold of ≥ 38 Daphnia per feeding event as an episode of zooplanktivory based on data from a zooplankton specialist, the bluegill sunfish (Lepomis macrochirus). In this study, 1718 LMB were caught, marked, sampled, and released. Gut contents at the time of capture were collected via gastric lavage. We captured the same 612 LMB 3 or more times. Of these, approximately 26% had at least one episode of zooplanktivory and approximately 6% had multiple episodes. There was no relationship between the population sizes of Daphnia and LMB, but the yearly percentage of individual LMB with at least one episode of zooplanktivory significantly increased with LMB population density. Episodes of zooplanktivory were more likely to occur later in the season when Daphnia were more abundant in the lake. The probability of an individual LMB having a repeat episode of zooplanktivory was not significantly different from expected; however, the probability of a LMB not having a single episode was significantly greater than expected by random chance signifying that some LMB were better than others at eliminating Daphnia from their diets. The probability of episodic zooplanktivory significantly decreased with increasing fish TL and weight but significantly increased with increasing Daphnia abundance. LMB without episodes of zooplanktivory achieved significantly greater maximum weight and body condition factor than those with them, but there was no statistical difference in their maximum TL or longevity (duration between first and final capture of the same LMB). In contrast, LMB with episodes of zooplanktivory had significantly greater instantaneous growth rates than those without. These results suggest that LMB within the resource-limited lake partitioned prey resources when some LMB sporadically targeted under-utilized, energetically unfavorable prey.

Adjustments to rearing practices should be justified with increases in production, stocking success, or angler satisfaction. Largemouth bass (Micropterus salmoides) production was assessed between hatchery ponds where fish were restricted to an invertebrate diet or received supplemental fathead minnow (Pimephales promelas) forage during 2015. At harvest, age-0 bass yield was 4.5 times greater and average fish length was 38 mm longer, in the pond that received fathead minnow. In 2016, a second study evaluated the timing of minnow supplementation that included earlier stockings of small fathead minnow (30 mm) minnows. With earlier supplementation, bass yield was 2.3 times greater and fish averaged 14 mm longer at harvest. Bass survival was approximately 38% higher during 2015 when supplementation occurred and 25% higher during 2016 when minnow supplementation began earlier. Our findings show invertebrate forage was probably limiting bass production in hatchery ponds and supplementing with appropriately-sized fathead minnows increased age-0, largemouth bass production.

Barriers in the estuaries of the rivers prevent the immigration of glass eels (Anguilla anguilla) arriving on the European coast every spring. This leads to an unnatural accumulation of migrating glass eels below the barriers, and this may lead to additional losses in glass eels by piscivorous fish. The proportion of predation losses can be estimated using mark-recapture techniques and abundance estimates in combination with stomach content analysis of piscivorous fish. Nonetheless, whether tagging transparent glass eels increases predation risk and what the digestion rate of glass eel is in piscivorous fish are unknown. This study aimed to determine whether there is an increased predation risk for tagged glass eel; it also studies glass eel digestion status in piscivorous fish after appointed time frames. A laboratory experiment with 48 trials was conducted. Tagged (visible implanted elastomer, VIE) and untagged glass eels were exposed to small (19.1-24.4 cm) and large (31.9-43.5 cm) sea bass (Dicentrarchus labrax) during a 2 h trial. In 48% of the trials, successful predation was present and 13% showed clear predation attempts in which bass did not capture glass eels. No significant difference was found in predation rate between tagged and untagged glass eels and between red and blue tagged glass eels. Large sea bass predated more, but all sizes consumed glass eel under laboratory conditions. Stomach content analysis showed intact glass eel bodies 4-6 h after ending the 2 h trial and parts of glass eel bodies up to 16-18 h. This study showed that tagging does not increase predation in mark-recapture studies using VIE-tags in transparent glass eel. It also shows that the proportion of predation in relation to local glass eel abundance can be estimated if stomach content analysis is conducted within 4-6 h after predation.

European sea bass (Dicentrarchus labrax) migrate towards habitats where salinity can reach levels over 60‰, notably in Mediterranean lagoons. D. labrax are genetically subdivided in Atlantic and Mediterranean lineages and have evolved in slightly different salinities. We compared Atlantic and West-Mediterranean populations regarding their capacity to tolerate hypersalinity with a focus on the involvement of the intestine in solute-driven water reabsorption. Fish were analyzed following a two-week transfer from seawater (SW, 36‰) to either SW or hypersaline water (HW, 55‰). Differences among lineages were observed in posterior intestines of fish maintained in SW regarding NKA activities and mRNA expressions of nkaα1a, aqp8b, aqp1a and aqp1b with systematic higher levels in Mediterranean sea bass. High salinity transfer triggered similar responses in both lineages but at different magnitudes which may indicate slight different physiological strategies between lineages. High salinity transfer did not significantly affect the phenotypic traits measured in the anterior intestine. In the posterior intestine however, the size of enterocytes and NKA activity were higher in HW compared to SW. In this tissue, nka-α1a, nkcc2, aqp8ab and aqp8aa mRNA levels were higher in HW compared to SW as well as relative protein expression of AQP8ab. For aqp1a, 1b, 8aa and 8b, an opposite trend was observed. The sub-apical localization of AQP8ab in enterocytes suggests its role in transepithelial water reabsorption. Strong apical NKCC2/NCC staining indicates an increased Na+ and Cl- reuptake by enterocytes which could contribute to solute-coupled water reuptake in cells where AQP8ab is expressed.