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Fish stocking continues to be an important and often‐used tool in fisheries management. Mortality of fish may be high in the first few days after stocking due to predation and a lack of appropriate food and habitat. The objective of this study was to develop a conceptual model that may identify stocking locations that can help improve the survival of stocked fish. We identified three factors—predator risk, zooplankton (food) availability and measures of habitat that could be important to the survival of stocked Walleye (Sander vitreus) and White Bass (Morone chrysops) fingerlings in Lake McConaughy, Nebraska. The spatial distribution of these factors was used to create a predictive surface to identify those stocking locations hypothesised to lead to higher survival. Final stocking maps identified the best 12.8% and 13.9% of the predicted area of Lake McConaughy for stocking Walleye and White Bass, respectively. Both maps predicted that the best locations were along the south‐central shoreline of Lake McConaughy. The maps for both species were interestingly similar. These results are likely due to the similarities in predators consuming the stocked species and the zooplankton consumed by fingerlings of both species. Habitat availability may be less important, or other aspects of habitat may need to be considered. Identifying the best locations for stocking based on predation risk and the availability of food and habitat could increase the survival of stocked fishes and help managers reach population objectives. [ABSTRACT FROM AUTHOR]

Observations of fish behavior can provide insights into habitat preferences and use. Black sea bass, Centropristis striata, are a territorial temperate reef finfish species known for their high commercial and recreational value and association with structured habitat. We used underwater action cameras to record video of black sea bass to assess territorial (agonistic, ambush, displacement) and occupancy (station-keeping) behaviors on shelf and bag style oyster aquaculture cages at a shellfish farm, and on boulders at a natural rock reef near Milford, Connecticut in Long Island Sound, Northwest Atlantic. Black sea bass at a variety of life stages were highly associated with cages, including young-of-the-year, and age 1+ fish. The high abundance of black sea bass observed on cages relative to boulders suggests this species has an affinity for the vertical structure created by aquaculture gear. When behaviors were normalized to the total fish sightings, black sea bass showed no significant difference in frequency of behaviors between habitats, indicating that per-fish rates of behavior were similar on cages and boulders. Demonstration of territorial and occupancy behaviors by black sea bass on, and around cages suggests that aquaculture gear provides structured habitat and ecosystem services for this species similar to natural reefs. These results suggest that essential fish habitat descriptions of manmade structures used by black sea bass could be broadened to include aquaculture gear. Our study provides novel information on behavioral interactions of black sea bass with oyster cages that may support aquaculture permitting and consultation processes. [ABSTRACT FROM AUTHOR]

This work investigated the underlying mechanism of thermo-ultrasonic treatment to improve the nutritional properties and emulsion stability of sea bass fish head broth. The effects of ultrasonication on the processing of fish broth were compared with boiling water treatment. The nutritional properties of fish broth mainly include protein, fat, total sugar, 5′-nucleotide and free amino acid content. To achieve a similar effect of nutrient extraction, the thermo-ultrasonic treatment required a shorter time (30 min) than boiling water (120 min). The water-soluble protein, fat and total sugar contents were at their maximum at 120 min of the thermo-ultrasonic treatment. In particular, the fat content increased with the time of thermo-ultrasonic treatment from 0.58% to 2.70%. The emulsion structure of the fish soup was characterized by measuring its color and particle size, using optical microscopy and confocal laser scanning microscopy, and determining its storage stability. Thermo-ultrasonic treatment reduced the particle size of the fish broth emulsion and the fat globules became smaller and more homogeneous. Ultrasonication not only accelerated the nutritional and flavor content of the fish head broth, but also reduced the particle size and enhanced the stability of the emulsified system of the fish broth. The fish head tissue was more severely disrupted by the cavitation effect of an ultrasound, and nutrients migrated more and faster. This was mainly due to the cavitation and mechanical breaking force of the ultrasound on the fish head tissue and the fat globules of the fish broth. Altogether, these findings suggest that the thermo-ultrasonic treatment technique is useful for processing nutrient-rich, storage-stable and ready-to-eat fish head broth. [ABSTRACT FROM AUTHOR]

Copyright of Ege Journal of Fisheries & Aquatic Sciences (EgeJFAS) / Su Ürünleri Dergisi is the property of Ege Journal of Fisheries & Aquatic Sciences (EgeJFAS) / Su Urunleri Dergisi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Skin is the largest organ of many animals. Its protective function against hostile environments and predatorial attack makes high mechanical strength a vital characteristic. Here, we measured the mechanical properties of bass fish skins and found that fish skins are highly ductile with a rupture strain of up to 30–40% and a rupture strength of 10–15 MPa. The fish skins exhibit a strain-stiffening behavior. Stretching can effectively eliminate the stress concentrations near the pre-existing holes and edge notches, suggesting that the skins are highly damage tolerant. Our measurement determined a flaw-insensitivity length that exceeds those of most engineering materials. The strain-stiffening and damage tolerance of fish skins are explained by an agent-based model of a collagen network in which the load-bearing collagen microfibers assembled from nanofibrils undergo straightening and reorientation upon stretching. Our study inspires the development of artificial skins that are thin, flexible, but highly fracture-resistant and widely applicable in soft robots. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Fisheries Science & Technology is the property of Tarbiat Modares University Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Natura & Scientia is the property of Semih Kale and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Mugla Journal of Science & Technology is the property of Mugla Journal of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To investigate the effects of brewer's yeast hydrolysate (BYH) on the growth and intestinal bacteria diversity of largemouth bass ( Micropterus salmoides )sthe fish were fed with basal diet supplemented with or without BYH (0, 0.1%, 0.2%) for 8 weeks. The results showed that the weight gain rate, survival rate, hepatosomatic index, organ coefficient and condition factor were not significantly different among the groups, except intraperitoneal fat ratio was significantly reduced in 0.2% BYH group. Totally 25 phyla, 56 classes, 103 orders, 155 families, 216 genera and 1051 operational taxonomic units (OTUs) of bacteria were identified from the 2,057,871 sequences obtained by Illumina MiSeq 16S rRNA sequencing. Among them, Fusobacteria, Firmicutes and Proteobacteria were the most three dominant phyla in the intestines regardless of diets. Furthermore, the richness of Fusobacteria, Cyanobacteria, Tenericutes and Actinobacteria in 0.2% BYH group was significantly lower than those of the control group. Interestingly, the ratio of Bacteroides/Firmicutes was decreased in the groups fed with BYH, this might be related to the modulations of energy absorption and storage, resulting in the decrease of fat deposition in fish body. At the genus level, several bacterial genera ( Plesiomonas , Mycoplasmas , Synechococcus and Peptostreptococcus ) which were potential pathogens of fish were significantly decreased in the groups fed with BYH. By contrast, a significant increase of Cetobacterium which could ferment peptides and carbohydrates to produce vitamin B 12 was observed in fish fed with BYH, indicating that dietary BYH was helpful in propagation of some probiotic bacteria. Taken together, the overall intestinal bacterial diversity was decreased in fish fed with BYH which might promote the growth of some probiotics and inhibit some pathogenic bacteria, suggesting that BYH may serve as feed additive in modulation of the gut bacterial community of largemouth bass to decrease the potential pathogens. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this work was to determine whether juvenile and adult European seabass (Dicentrarchus labrax L.), fed ad libitum manually and with self‐feeding demand feeders, respectively, were able to discriminate between a fish oil‐based diet and a series of diets made with vegetable oils (soybean, linseed, rapeseed and sunflower oil), as well as a fat‐free diet. Adult D. labrax (443.6 ± 108.8 g) selected diets made from soybean (SYO) and rapeseed (RO) in proportions similar to fish oil (FO). Demand levels for the other two diets, sunflower (SUO) and linseed (LO) oils, were significantly lower than FO, whilst juveniles (56.4 ± 11.2 g) displayed a preference for SYO and FO. The lowest demand levels were associated with a fat‐free diet (FF). Selection percentages of the diets for adult and juvenile fish were, respectively, FF—22.96% and 39.76%, SYO—43.02% and 53.26%, LO—36.48% and 36.19%, SUO—39.87% and 37.32%, and RO—46.38% and 40.94%. The animals’ size and feeding method did not significantly affect dietary selection. However, a statistical difference in specific growth rate (1.37% ± 0.26% day−1) for juveniles was only observed for FO+FF combination. For juveniles, no differences were observed in the conversion index. The juvenile group (FO + FF) had the highest food intake (2.00 ± 0.35 g 100 g−1 body weight). Moreover, the groups fed FO + SUO and FO + RO consumed the least. In conclusion, this study shows D. labrax can discriminate between diets where the only difference is the lipid source. These findings should be used to understand the acceptance or rejection of different source oils, which are increasingly being used in aquaculture such as aquafeeds for European seabass. [ABSTRACT FROM AUTHOR]

Turkey ranked first in sea bass farming in Europe, and almost all extra-EU seabass come from this country. The share of Turkish sea bass in the fish consumption of Europeans has increased significantly, and assessment of potential health risks of trace metals via sea bass, cultured by Turkey, became important. The Netherlands is the main buyer of the Turkish sea bass. Therefore, potential health risks were determined for Turkish and Dutch consumers. In the study, the concentrations of lead (Pb) and mercury (Hg) were below the limits, but the level of cadmium (Cd) was above the guidelines, in spring and winter. Dietary intake and potential health risk were found higher for the Dutch consumer, but all target hazard quotients (THQs) and total THQ (TTHQ) values were well below 1, showing no significant health risk due to the consumption of sea bass, cultured and exported by Turkey. It was determined that these sea basses can be safely consumed in quite high amounts, such as at least 31 meals a month. Se/Hg molar ratios were all above 1 and selenium health benefit values (Se-HBVs) were positive, indicating that selenium (Se) had a protective effect on Hg toxicity and positive health effects. Considering the average annual intake in Turkey and Netherlands, the consumption of sea bass, cultured by Turkey, is safe. Since the risk levels of communities may differ due to their eating habits, it is important to determine the public health impacts of the international fish trade. [ABSTRACT FROM AUTHOR]

The aim of the work was to monitor the presence of Listeria monocytogenes in cold-smoked fish products (trout, salmon, and sea bass) marketed in Italy. Cold-smoked sea bass is a new product that has not yet been commercialized and was collected from the production facility. Monitoring data have shown that cold-smoked products can be contaminated by L. monocytogenes , the presence of which has been highlighted mainly by enrichment culture (presence in 25 g). The isolated Listeria were serotyped and belonged mainly to low-virulence serotypes (1/2c), followed by serotypes 1/2a, 1/2b, and 4b. Furthermore, considering the ability of L. monocytogenes to grow in these products due to their chemical–physical characteristics (pH > 6.0, Aw > 0.97) and long shelf life at 4°C, an additional aim was to verify the activity of different bioprotective starters, including Lactilactobacillus sakei (LAK-23, Sacco srl, Via Alessandro Manzoni 29/A, 22071 Cadorago, CO, Italy), Carnobacterium spp., Lacticaseibacillus casei (SAL 106), and Lacticaseibacillus paracasei (SAL 211), in cold-smoked sea bass. All starters were bacteriocin producers. For this experiment, smoked sea bass samples were intentionally inoculated with a mixture of three different strains of L. monocytogenes and of each starter culture. After inoculation, the smoked sea bass were vacuum-packed and stored at 6 ± 2°C for 60 days, simulating the typical abuse storage temperature of markets and home refrigerators. At 0, 15, 30, 45, and 60 days, the sea bass samples were analyzed to evaluate the effectiveness of the starters against L. monocytogenes. Listeria monocytogenes growth was prevented only by the addition of the LAK-23 starter. Indeed, at the end of the shelf life, the amount of L. monocytogenes observed was similar to that in the inoculum. Consequently, the use of this starter can allow the inclusion of cold-smoked sea bass or smoked fish products in category 1.3 of Regolamento CE 2073/2005, which are products that do not support the growth of this microorganism. Finally, the activity of the LAK-23 starter did not produce an off flavor or off odor in the smoked sea bass. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Fisheries Science & Technology is the property of Tarbiat Modares University Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Fisheries Science & Technology is the property of Tarbiat Modares University Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Guadalupe Bass, Micropterus treculii is endemic to the Hill Country region of central Texas, US, and its entire native distribution is within Texas, including portions of the Brazos, Colorado, Guadalupe, and San Antonio River basins. Currently, the genetic integrity of Guadalupe Bass populations are threatened by hybridization with introduced, nonnative Smallmouth Bass, M. dolomieu. Species-isolating mechanisms (or lack thereof) are not well understood for these two species. To identify potential mechanisms influencing hybridization in Guadalupe Bass populations, our objectives were to characterize: (1) spawning season and duration, (2) nesting habitat, (3) courtship behaviors (including color pattern changes), and (4) parental care pattern. The reproductive ecology (spawning season, nest sites) and behavior (courtship, parental care) of Guadalupe Bass were found to be similar to what has been reported in Smallmouth Bass, possibly contributing to continued potential for hybridization. Guadalupe and Smallmouth Bass share 12 reproductive behaviors and similar color patterns during courting and spawning interactions. This study is the first to report an individual male Guadalupe Bass simultaneously courting and spawning with two to four females in one nest, suggesting the need for further investigation of links between hybridization potential, sex ratio and population structure in Guadalupe Bass. We recommend investigation of female mate choice and sexual competition comparing Guadalupe Bass and Smallmouth Bass. Additionally, future conservation efforts should focus on nesting habitat in existing pure strain Guadalupe Bass populations. [ABSTRACT FROM AUTHOR]

Three experiments assessed the effects of cold-shock induced triploidy on (1) the incidence of abnormal cell cleavage during embryogenesis, (2) hatching success and the proportion of live yolk-sac larvae in normally cleaved versus abnormally cleaved embryos, and (3) survival of triploid larvae of spotted sand bass (Paralabrax maculatofasciatus). All spawns were obtained by hormonal induction (LHRHa). Triploidy was induced by cold shock shortly after fertilization. In experiment 1, the percentage of abnormal cell cleavage was significantly higher (P < 0.05) in the cold-shocked group than in the control group, while the hatching rate and the proportion of live yolk-sac larvae were significantly lower (P < 0.05). In experiment 2, when normally and abnormally cleaved embryos from the control and cold-shocked groups were incubated separately, normal cleaved embryos in the cold-shocked group showed a significantly higher hatching rate and proportion of live yolk-sac larvae than abnormally cleaved embryos in the same group. No difference was observed in the control group. In experiment 3, a significant decrease (P < 0.05) in the triploidy count was observed throughout the larval period. Final survival was drastically lower for triploid larvae compared to cold-shocked diploids and untreated eggs. Low triploidy percentages at the end of the larval period would seriously hinder the development of triploid sand bass culture. Three experiments assessed the effects of cold-shock induced triploidy on (1) the incidence of abnormal cell cleavage during embryogenesis, (2) hatching success and the proportion of live yolk-sac larvae in normally cleaved versus abnormally cleaved embryos, and (3) survival of triploid larvae of spotted sand bass (Paralabrax maculatofasciatus). All spawns were obtained by hormonal induction (LHRHa). Triploidy was induced by cold shock shortly after fertilization. In experiment 1, the percentage of abnormal cell cleavage was significantly higher (P < 0.05) in the cold-shocked group than in the control group, while the hatching rate and the proportion of live yolk-sac larvae were significantly lower (P < 0.05). In experiment 2, when normally and abnormally cleaved embryos from the control and cold-shocked groups were incubated separately, normal cleaved embryos in the cold-shocked group showed a significantly higher hatching rate and proportion of live yolk-sac larvae than abnormally cleaved embryos in the same group. No difference was observed in the control group. In experiment 3, a significant decrease (P < 0.05) in the triploidy count was observed throughout the larval period. Final survival was drastically lower for triploid larvae compared to cold-shocked diploids and untreated eggs. Low triploidy percentages at the end of the larval period would seriously hinder the development of triploid sand bass culture. [ABSTRACT FROM AUTHOR]

Anti-Leishmanial drug therapy faces significant challenges related to cytotoxicity and drug resistance. Thus, new and efficient anti-Leishmanial drugs need to be identified. Due to their broad-spectrum antimicrobial and also immunomodulatory activities, antimicrobial peptides (AMPs) have attracted considerable attention. In this study, we comparatively assessed the anti-Leishmanial activities of two recently identified AMPs (dicentracin-like and moronecidine-like) and the well-known AMP piscidin from the hybrid striped bass. AMPs were first assessed against Leishmania major promastigotes using MTS. Subsequently, macrophages were infected with L. major and treated with AMPs to evaluate anti-amastigotes activity of AMPs, and non-infected macrophages were treated with AMPs to determine cytotoxicity against mammalian cells using MTS. The induction of factors limiting L. major growth (IL-12, TNF-α and reactive oxygen species (ROS)) by AMPs was measured by ELISA and dichlorofluorescin-diacetate (DCFH-DA) assay, respectively. Piscidin was more efficacious against L. major promastigotes as compared to dicentracine-like or moronocidin-like peptides, whereas, dicentracine-like and moronocidin-like peptide exhibited a higher activity against L. major amastigotes compared to piscidin. In turn, piscidin was most cytotoxic in non-infected macrophages compared to the other two AMPs. A direct association was observed between hydrophobicity of AMPs and their anti-promastigote and cytotoxic activities. Dicentracine-like or moronocidin-like peptides induced higher levels of IL-12, TNF-α and ROS in macrophages compared to piscidin. Collectively, our results suggest that dicentracine-like and moronocidin-like peptides represent potentially promising multi-functional therapeutic agents that might not only directly kill L. major but also induce anti-Leishmania factors that can limit L. major growth and intracellular survival. [ABSTRACT FROM AUTHOR]

To investigate whether mechanoreception is used in non-visual feeding in larval striped bass (Morone saxatilis), the ontogeny of superficial neuromasts along the lateral line was described using the vital stain FM1-43FX and fluorescent microscopy. The number of neuromasts visible along one flank increased from 11 at first feeding [5 to 7 days post-hatch (dph)] to >150 by the juvenile stage (27 dph). A neomycin dose response (0, 1, 2 and 5 mmol l-1) was evaluated for neuromast ablation of bass aged 10, 13, 17 and 20 dph. Using these same age groups, the ability of bass to catch Artemia salina prey in both dark and light tank-based feeding trials was compared between larvae with neuromasts ablated using neomycin (5 mmol l-1) and controls. Neomycin significantly reduced the incidence of feeding in the light and dark. Among larvae that fed, those in the dark treated with neomycin caught fewer Artemia (~5 prey h-1; P<0.05) than controls (16 prey h-1 at 10 dph; 72 prey h-1 at 20 dph). In the light, by contrast, neomycin treatment had no significant effect on prey capture by larvae age 13 to 20 dph, but did inhibit feeding of 10 dph larvae. Verification that neomycin was specifically ablating the hair cells of superficial neuromasts and not affecting either neuromast innervation, olfactory pits, or taste cells was achieved by a combination of staining with FM1-43FX and immunocytochemistry for tubulin and the calcium binding proteins, S100 and calretinin. [ABSTRACT FROM AUTHOR]

Skeletal deformities are important traits for aquaculture as they induce slow growing and low market value. We studied their genetic determinism and their interactions with the environment at the ongrowing stage in 5839 European sea bass from a partial factorial mating of 33 sires and 23 dams, reared in four sites. All families were mixed, and fish were first reared in one site (site B) until 35 g mean weight, then distributed to the four sites. A posteriori reconstruction of pedigree with microsatellites was used. Deformities were scored internally at slaughtering, and externally from photographs. Site B, where all fish were initially stocked until 35 g and exposed to forced swimming because of fast water current showed the highest rate of deformities with 83% and 65% from internal and external scoring respectively. Heritability on the underlying scale was h2 = 0.25 ± 0.03 across all sites, and varied little between sites, while genetic correlations of deformities between sites were always high (>0.85). Genetic correlations between deformities and daily growth coefficient were variable between sites( rA = 0.50 ± 0.09, 0.43 ± 0.10, 0.32 ± 0.10, 0.18 ± 0.10 for sites A, B, C, D respectively) and were positively linked with the average growth rate in each site. These results pointed out that there could be a relation between growth rate and the evolution of deformities at the grow-out stage. [ABSTRACT FROM AUTHOR]