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Mobile sink (MS) has drawn significant attention for solving hot spot problem (also known as energy hole problem) that results from multihop data collection using static sink in wireless sensor networks (WSNs). MS is regarded as a potential solution towards this problem as it significantly reduces energy consumption of the sensor nodes and thus enhances network lifetime. In this paper, we first propose an algorithm for designing efficient trajectory for MS, based on rendezvous points (RPs). We next propose another algorithm for the same problem which considers delay bound path formation of the MS. Both the algorithms use k -means clustering and a weight function by considering several network parameters for efficient selection of the RPs by ensuring the coverage of the entire network. We also propose an MS scheduling technique for effective data gathering. The effectiveness of the proposed algorithms is demonstrated through rigorous simulations and comparisons with some of the existing algorithms over several performance metrics. [ABSTRACT FROM AUTHOR]

A 60‐day feeding trial was conducted to evaluate the growth, survival, physio‐metabolic and haemato‐biochemical responses of Anabas testudineus reared in (ISW) of varying salinity. Fingerlings (initial weight 6.55 ± 0.08 g) were randomly stocked in triplicate in five treatment groups viz., T1 (0 ppt), T2 (3 ppt), T3 (6 ppt), T4 (9 ppt) and T5 (12 ppt) following a completely randomized design (CRD) with 40/m2 stocking density. No mortality of fish was recorded in any of the treatments during the experimental period. Growth parameters such as weight gain (WG), percentage weight gain (PWG), specific growth rate (SGR) and protein efficiency ratio (PER) were highest (p < 0.05) at 3 ppt salinity followed by 6 and 0 ppt and lowest at 9 and 12 ppt, respectively. Lowest (p < 0.05) feed conversion ratio (FCR) and highest feed efficiency ratio (FER) were observed at 6 ppt salinity with no significant difference from fish at 0 and 3 ppt, respectively. Lowest (p < 0.05) moisture and highest protein and lipid contents were recorded at 3 ppt salinity. Digestive enzyme (protease and amylase) and oxidative stress enzyme (superoxide dismutase, SOD and catalase, CAT) activities were significantly (p < 0.05) higher in high saline groups (T4 and T5). Haemoglobin (Hb), haematocrit (Hct), erythrocytes and leukocytes were higher (p < 0.05) up to 6 ppt (T3) and reduced thereafter. Highest (p < 0.05) serum protein and globulin were recorded at 0 ppt salinity. T5 (12 ppt) group exhibited the highest (p < 0.05) serum glucose, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activity. The present study concluded that A. testudineus can be reared in ISW within an acceptable range of 0–12 ppt salinity. However, salinity above 6 ppt had a negative effect on growth, feed utilization and various physiological parameters related to the well‐being of the fish. Therefore, it can be opined that A. testudineus can be safely considered as a potential cultivable species for inland saline aquaculture up to a salinity of 6 ppt. [ABSTRACT FROM AUTHOR]

Cloud Computing provides a promising platform for executing large scale workflow applications with enormous computational resources to offer on-demand services. Tasks in a workflow may need different type of computing resources such as storage, compute and memory type. However, inappropriate selection of these resources may lead to higher makespan and resource wastage. In this paper, we propose an effective two-phase algorithm for provisioning of cloud resources for workflow applications by using its structural features to minimize makespan and resource wastage. The proposed approach considers the nature of the tasks which may be compute intensive, memory intensive or storage intensive. We assume a realistic cloud model similar to Amazon EC2 that provides virtual machines for different types of workloads. Most importantly, the workflow model used in our approach is assumed to contain limited information about the task which is applicable for real situation. The performance of the proposed work is measured using five benchmark scientific workflows. The simulation results show that the proposed approach outperforms two existing algorithms for all these workflows. [ABSTRACT FROM AUTHOR]

A 60-day feeding trial was carried out to determine the effect of dietary lipid levels on growth and physiometabolic responses to optimize the dietary lipid requirement for maximizing the growth of Genetically Improved FarmedTilapia (GIFT) juveniles reared in inland ground saline water (IGSW) of medium salinity (15 ppt). Formulation and preparation of seven heterocaloric (389.56-449.02 Kcal digestible energy/100 g), heterolipidic (40-160 g/kg), and isonitrogenous (410 g/kg crude protein) purified diets were done for conducting the feeding trial. Random distribution of 315 acclimatized fish (mean weight 1.90 ± 0.01 g) was made in seven experimental groups such as CL4 (40 g/kg lipid), CL6 (60 g/kg lipid), CL8 (80 g/kg lipid), CL10 (100 g/kg lipid), CL12 (120 g/kg lipid), CP14 (140 g/kg lipid), and CL16 (160 g/kg lipid) with 15 fish per triplicate tank (fish density, 0.21 kg/m3). Respective diets were used for feeding the fish at satiation level three times daily. Results indicated that weight gain percentage (WG%), specific growth rate (SGR), protein efficiency ratio, and protease activity significantly increased up to 100 g lipid/kg fed group, and then the values significantly decreased. Muscle ribonucleic acid (RNA) content and lipase activity were highest in 120 g/kg lipid-fed group. RNA/DNA (deoxyribonucleic acid) and serum high-density lipoproteins levels of 100 g/kg lipid-fed group were significantly higher than 140, and 160 g/kg lipid-fed groups. The lowest feed conversion ratio was found in the 100 g/kg lipid-fed group. The amylase activity was significantly higher in 40 and 60 g lipid/kg fed groups. The whole-body lipid level was increased with increasing the dietary lipid levels, whereas, there was no significant difference in whole-body moisture, crude protein, and crude ash contents of all groups. Highest serum glucose, total protein and albumin, and albumin to globulin ratio and lowest low-density lipoproteins level were found in 140 and 160 g/kg lipid-fed groups. Serum osmolality and osmoregulatory capacity did not vary significantly, whereas carnitine palmitoyltransferase-I and glucose-6-phosphate dehydrogenase showed an increased and decreased trend, respectively, with the increasing dietary lipid levels. According to second-order polynomial regression analysis based on WG% and SGR, the optimum dietary lipid for GIFT juveniles in IGSW of 15 ppt salinity was found to be 99.1 and 100.1 g/kg, respectively. [ABSTRACT FROM AUTHOR]

Various single leaf meal can substitute costly de-oiled rice bran (DORB) in farm made feed for carps. However, the use of mixed leaf meal (LM) in fish feed is not reported yet. Therefore, Vigna mungo, Ipomoea aquatica and Hygrophila spinosa leaf meals were blended in an equal proportion to prepare LM. DORB was the major energy source in control diet (C) and LM substituted 50% and 100% of DORB in LM20 and LM40 experimental diets, respectively. In addition, control diet (C), LM20 and LM40 diets were supplemented with limiting amino acids and exogenous carbohydrases and denoted as CE, LM20E and LM40E, respectively. Labeo rohita fingerlings were fed till satiation for 60 days. Fish fed with LM20E diet exhibited maximum growth rates and feed conversion (p <0.05) however these were similar in C and LM40 (p > 0.05). Amylase and aminotransferase activities were positively related with growth indices (p < 0.05). Difference in hematological indices was negligible (except total leukocyte count), and lactate dehydrogenase activities in DORB and LM-based fed groups (p > 0.05) while lower superoxide dismutase activities was observed in LM fed groups (p < 0.05). The present study concluded that LM up to 400 g kg–1 could be incorporated as complete DORB replacer in L. rohita diet, however, 200 g kg–1 LM supplemented with 0.98 g L-lysine kg–1 and 1 g exogenous enzyme kg–1 registered the best growth, nutrient utilization, feed conversion ratio, physio-metabolic responses and hematological status. [ABSTRACT FROM AUTHOR]

The impact of acute and chronic exposure of nonylphenol (NP) on behaviour, histopathology, haematology and biochemical parameters of Labeo rohita (Hamilton, 1822) was investigated in the current study. The 96 h LC 50 of NP for L. rohita was estimated to be 0.548 mg L−1. Acute toxicity of NP induced several behavioural alternations. Further, sub-lethal NP exposure for a period of sixty days to 1/10th (0.0548 mg L−1), 1/15th (0.0365 mg L−1) and 1/20th (0.0274 mg L−1) of 96 h LC 50 resulted a reduction in total erythrocyte count and haemoglobin content whereas the total leukocyte count was observed to increase significantly. Among the biochemical parameters, blood glucose level increased, but there was significant decrease in total serum protein, albumin and globulin level. Significant alterations occurred in the histological architecture of gill tissue in NP exposed groups. The catalase and superoxide dismutase activity in gill tissues were elevated significantly while the concentration dependent inhibition of acetylcholinesterase activity was observed on 20th, 40th and 60th day of NP exposure. An increased glutathione-S-transferase activity in gill tissue was also observed in NP exposed groups. The present ecotoxicological study provides a reliable indication for the obligation to control the use and safe disposal of NP. [Display omitted] • The 96 h LC 50 value of NP for Labeo rohita was estimated as 0.548 mg L−1. • NP induces different types of abrupt behavioural alteration in fishes. • Histological changes were observed in gill and liver tissue of NP exposed fishes. • Haematological parameters were changed significantly after NP exposure. • AChE, SOD, CAT and GST enzyme activity was influenced by NP exposure. [ABSTRACT FROM AUTHOR]

Higher lipid at suboptimum dietary protein level can be a suitable approach to formulate cost-effective feed for cultured fish. However, excess lipid may cause metabolic burden to animals resulted in growth retardation with lipid deposition. Therefore, a feeding trial of 60 days was conducted to assess the effect of glycerol monolaurate (GML) supplemented in varying protein and lipid diets on growth, lipid utilization, antioxidant status and biochemical indices of white-leg shrimp, Penaeus vannamei juveniles reared in inland saline water (ISW). Accordingly, three hetero-lipidic (5–9% lipid), hetero-nitrogenous (30–36% CP), and hetero-energetic (379–400 Kcal DE/100 g) diets with three levels of GML (0%, 0.07% and 0.1%) were formulated for nine diets viz. P 36 L 5 G 0 (36% CP, 5% lipid and 0% GML), P 36 L 5 G 0.07 (36% CP, 5% lipid and 0.07% GML), P 36 L 5 G 0.1 (36% CP, 5% lipid and 0.1% GML), P 33 L 7 G 0 (33% CP, 7% lipid and 0% GML), P 33 L 7 G 0.07 (33% CP, 7% lipid and 0.07% GML), P 33 L 7 G 0.1 (33% CP, 7% lipid and 0.1% GML), P 30 L 9 G 0 (30% CP, 9% lipid and 0% GML), P 30 L 9 G 0.07 (30% CP, 9% lipid and 0.07% GML) and P 30 L 9 G 0.1 (30% CP, 9% lipid and 0.1% GML). Five hundred and forty P. vannamei juveniles (4.02 ± 0.01 g) were randomly distributed following 3 × 3 factorial design. Highest (p < 0.05) weight gain. Specific growth rate, protein efficiency ratio, lipid efficiency ratio, whole body protein with lowest feed conversion ratio, whole body lipid, and hepatopancreas–somatic index was recorded in P 33 L 7 G 0.1 group. Hepatopancreatic amylase and lipase activities increased (p < 0.05) significantly while protease activity decreased in relation to increased levels of dietary lipid. However, supplementing GML resulted in increased (p < 0.05) activity of all digestive enzymes and highest activity was found in 0.1% GML fed group. Lipid metabolic enzyme glucose-6-phosphate dehydrogenase and carnitine palmitoyltransferase-1 activities were found maximum (p < 0.05) in P 33 L 7 G 0.1 group and lowest in P 36 L 5 G 0 group. Hepatopancreatic and branchial superoxide dismutase and catalase activities showed a decreased (p < 0.05) and increased trend with dietary lipid levels, while GML reduced the activities and lowest activity recorded in P 33 L 7 G 0.1 group. Shrimps of 9% lipid group exhibited highest serum malondialdehyde, glucose, cholesterol and triglyceride levels but 0.1% GML significantly showed the lowest levels that other groups. Higher hemocyanin and total protein observed in 33% dietary protein and 0.1% GML fed group. Therefore, 33% protein, 7% lipid with 0.1% GML is optimum for maximum growth performance, lipid utilization, whole body protein, and antioxidative status of white-leg shrimp, P. vannamei juveniles reared in ISW of 10 ppt. • Effect of glycerol monolaurate (GML) was evaluated in white shrimp, P. vannamei reared in ISW. • Dietary 0.1% GML in sub-optimum protein high lipid/energy (33% CP and 7% lipid) is suitable for P. vannamei. • Highest amylase, protease and lipase and CPT-1 and G 6 PDH activities were found in 0.1% GML group. • Shrimps of 0.1% GML group exhibited the lowest CAT, SOD, and MDA content. [ABSTRACT FROM AUTHOR]

Nutritional components are multifarious amongst different producers, whereas they are just designed for fish farming but not suitable for improving the reproductive performance of brood fish. Climbing perch, Anabas testudineus is one of the candidate species for freshwater aquaculture in Asia. However, there is little knowledge available about the nutrient requirement of A. testudineus broodstock. Therefore, a feeding trial was conducted for 90-days to optimize the dietary protein requirement for reproductive performances of A. testudineus female broodstock. Six iso-energetic (around 400 Kcal digestible energy/100 g), iso-lipidic (8%) and hetero nitrogenous (25–50% crude protein, CP) semi-purified diets namely, 25% CP (T 25), 30% CP (T 30), 35% CP (T 35), 40% CP (T 40), 45% CP (T 45) and 50% CP (T 50) were prepared for feeding the fish of respective group twice daily. Three hundred and sixty (360) adults A. Testudineus (average body weight 18.67 ± 0.09 g) with female and male ratio of 1:1 were randomly distributed in six treatments in triplicate with the stocking density of 20 fish/ tank (500 L water volume) following a completely randomized design. Results indicated that the gonado-somatic index and viscero-somatic index increased significantly (p < 0.05) up to 40% CP then reduced gradually. But intraperitoneal fat content decreased with increasing dietary protein levels. T 40 group showed lowest hepato-somatic index. The absolute fecundity was highest (p < 0.05) in 35% dietary protein fed group but found similar (p > 0.05) between T 30 and T 45 group. Estradiol was significantly lowest (p < 0.05) but highest 17α, 20β di-hydroxy progesterone level were observed in 35% CP fed group. Cortisol was found highest (p < 0.05) in T 40 , T 45 andT 50 groupand lowest in T 35 group. Histological observations revealed that the females with higher proportion of vitellogenic oocytes were from 35% to 40% protein-fed groups. After induced spawning, significantly (p < 0.05) higher fecundity of spawning, rate of fertilization and hatching, and survival of larvae were observed in 40% CP fed group. Second-order polynomial regression analysis of fertilization rate (%) and larval survival (%) estimated 39.07–39.21% dietary protein is optimum for gonadal development, oocyte maturation and reproductive performance of female A. testudineus broodstock. • 39.07–39.21% dietary CP is optimum for maximum reproductive performance of Anabas testudineus female broodstock. • 40% CP exhibited highest GSI, spawning fecundity, oil globule diameter and fertilization rate. • Very high (>45%) and low (<30%) dietary CP reduced the reproductive performance of fish. [ABSTRACT FROM AUTHOR]

A 60-day feeding trial was conducted to find out the effect of bile acid supplemented diets with varying protein and lipid levels on growth performance, body composition, antioxidant status and physio-biochemical responses of genetically improved farmed tilapia (GIFT) juveniles reared in inland saline water (ISW) of 10 ppt. Three hetero-nitrogenous (38–32% crude protein, CP), hetero-lipidic (8–14% lipid) and hetero-caloric (409–439 Kcal digestible energy/100 g) diets were supplemented with three levels (0%, 0.05% and 0.1%) of bile acid to prepare nine experimental diets viz. P 38 L 8 B 0 (38% CP, 8% lipid and 0% bile acid), P 38 L 8 B 0.05 (38% CP, 8% lipid and 0.05% bile acid), P 38 L 8 B 0.1 (38% CP, 8% lipid and 0.1% bile acid), P 35 L 11 B 0 (35% CP, 11% lipid and 0% bile acid), P 35 L 11 B 0.05 (35% CP, 11% lipid and 0.05% bile acid), P 35 L 11 B 0.1 (35% CP, 11% lipid and 0.1% bile acid), P 32 L 14 B 0 (32% CP, 14% lipid and 0% bile acid), P 32 L 14 B 0.05 (32% CP, 14% lipid and 0.05% bile acid) and P 32 L 14 B 0.1 (32% CP, 14% lipid and 0.1% bile acid). Four hundred and five acclimated GIFT juveniles (2.51 ± 0.01 g) were randomly distributed in nine treatment groups in triplicate (stocking density 15 fish/tank, 300 L) following 3 × 3 factorial design. Results indicated that body lipid, feed conversation ratio (FCR), amylase and lipase activities, gill and liver superoxide dismutase (SOD) and catalase (CAT) activities and serum glucose (GLU), total protein, triacylglycerol (TAG), total cholesterol (T-CHO), and low density lipoprotein cholesterol (LDL-CHO) were significantly (p < 0.05) increased and weight gain percentage (WG%), specific growth rate (SGR), protease activity and high density lipoprotein cholesterol (HDL-CHO) were significantly (p < 0.05) decreased with increasing dietary lipid levels and more pronounced effect was found in fish fed 32% protein and 14% lipid. Dietary bile acid significantly (p < 0.05) increased WG%, SGR, protein efficiency ratio, lipase activity and HDL-CHO and significantly (p < 0.05) decreased FCR, gill and liver SOD and CAT activities and serum GLU, TAG, T-CHO, and LDL-CHO with more pronounced effect by 0.05% dietary bile acid. In conclusion, feeding of 35% crude protein, 11% lipid and 0.05% bile acid can cause better growth performance, antioxidant status and physio-biochemical responses of GIFT juveniles reared in ISW of 10 ppt. This information will be useful in formulating the bile acid supplemented eco-friendly low protein high lipid (LPHL) feed for profitable culture of GIFT in ISW. • Effect of dietary bile acid was evaluated in GIFT juveniles reared in ISW. • Dietary 0.05% bile acid with 35% crude protein and 11% lipid is suitable for GIFT. • Lowest activities of oxidative stress enzymes and MDA found in 0.05% bile acid fed group. • Higher dietary bile acid did not improve the growth performance and nutrient utilization. [ABSTRACT FROM AUTHOR]

Addition of suboptimum protein and higher lipid in the diet can be a better strategy to develop an environment friendly feed for cultured species. But very high amount of dietary lipids can cause metabolic burden to the species leading to growth retardation and lipid accumulation in the body of the animals. In this context, a feeding trial of 60 days was conducted to find out the effect of L -carnitine supplemented diets with different protein and lipid levels on growth, feed conversion, nutrient utilization, body composition, antioxidant status and physio-metabolic responses of Penaeus vannamei juveniles reared in inland saline water (ISW) of 10 ppt salinity. Three hetero-nitrogenous (36.17, 33.13, 30.11% crude protein, CP), hetero-lipidic (5.12, 8.15, 11.17% lipid) and hetero-caloric (378–411 Kcal digestible energy or DE/100 g) diets were supplemented with three levels (0%, 0.05% and 0.1%) of L -carnitine to prepare nine experimental diets viz. P 36 L 5 C 0 (36% CP, 5% lipid and 0% L -carnitine), P 36 L 5 C 0.05 (36% CP, 5% lipid and 0.05% L -carnitine), P 36 L 5 C 0.1 (36% CP, 5% lipid and 0.1% L -carnitine), P 33 L 8 C 0 (33% CP, 8% lipid and 0% L -carnitine), P 33 L 8 C 0.05 (33% CP, 8% lipid and 0.05% L -carnitine), P 35 L 8 C 0.1 (33% CP, 8% lipid and 0.1% L -carnitine), P 30 L 11 C 0 (30% CP, 11% lipid and 0% L -carnitine), P 30 L 11 C 0.05 (30% CP, 11% lipid and 0.05% L -carnitine) and P 30 L 11 C 0.1 (30% CP, 11% lipid and 0.1% L -carnitine). Six hundred and seventy-five (675) acclimated P. vannamei juveniles (average body weight, 4.02 ± 0.01 g) were randomly distributed to nine treatments viz. P 36 L 5 C 0 , P 36 L 5 C 0.05 , P 36 L 5 C 0.1 , P 33 L 8 C 0 , P 33 L 8 C 0.05 , P 33 L 8 C 0.1 , P 30 L 11 C 0 , P 30 L 11 C 0.05 and P 30 L 11 C 0.1 in triplicate following 3 (protein-lipid levels) × 3 (dietary levels of L -carnitine) factorial design. The shrimp fed with 33% protein, 8% lipid and 0.05% L -carnitine showed significantly (p < 0.05) the highest weight gain percentage, specific growth rate, protein efficiency ratio, lipid efficiency ratio, and protease activity and the lowest feed conversion ratio. The hepatopancreas somatic index (HPSI) value, whole body lipid content and activities of amylase and lipase significantly (p < 0.05) increased with increase in dietary lipid level with the highest values found in 11% lipid fed group, but dietary L -carnitine caused the decreasing trend of HPSI and increasing trend of lipase respectively with the lowest and the highest values in 0.05% L -carnitine fed group. Similarly, the 0.05% L -carnitine fed group showed significantly higher body lipid content and amylase activity than its non-supplemented counterpart. Body moisture content significantly decreased with increase in dietary lipid level with the lowest value in 11% lipid fed group. However, dietary L -carnitine did not affect the body moisture level. The 33% protein, 8% lipid and 0.05% L -carnitine fed group exhibited significantly higher Carnitine palmitoyl transferase-I and glucose-6-phosphate-dehydrogenase activity than non-supplemented groups. The shrimp of 11% lipid fed group showed significantly lowest serum total protein and the highest serum glucose, cholesterol and triglycerides, gill and hepatopancreatic superoxide dismutase (SOD) and catalase (CAT) and hepatopancreatic malondialdehyde (MDA). But, 0.05% L -carnitine fed group showed significantly higher serum total protein and lower serum glucose, cholesterol and triglycerides and lower tissue SOD, CAT and MDA. In conclusion, P. vannamei juveniles reared in 10 ppt ISW and fed with 33% crude protein, 8% lipid and 0.05% L -carnitine diet can exhibit better growth performance, body lipid content, antioxidant status and physio-metabolic responses. This information will be useful in formulating the L -carnitine supplemented eco-friendly low protein high lipid or energy (LPHL or LPHE) feed for profitable culture of P. vannamei in ISW. • Effect of dietary L -carnitine was evaluated in white shrimp, P. vannamei. • Dietary 0.05% L -carnitine in low protein high energy/lipid (LPHE/LPHL) (33% crude protein and 8% lipid) is suitable for P. vannamei culture in ISW. • Lowest SOD, CAT and hepatopancreatic MDA content were exhibited in 0.05% L-carnitine fed group. • Higher level of dietary L -carnitine reduced the growth performance and nutrient utilization of P. vannamei. [ABSTRACT FROM AUTHOR]

A study was performed to evaluate the efficacy of shrimp shell meal derived natural astaxanthin (SSM), supplemented with its commercial variant on gonadal maturation and vitellogenin gene (Vtg.) expression in reproductively active adults of the high-value ornamental cichlid discus (Symphysodon aequifasciatus) reared under captivity. Four isonitrogenous (50% crude protein), isolipidic (9% ether extract), and isocaloric (400 kcal digestible energy/100 g) experimental diets viz. control (commercial grade astaxanthin, without SSM), T1 (15% SSM + commercial astaxanthin), T2 (20% SSM + commercial astaxanthin), T3 (25% SSM + commercial astaxanthin) were prepared and fed to satiation level twice daily for the entire experimental period of 90 days. Results revealed significant (p < 0.05) linear, quadratic, and overall trends, wherein GSI increased with an increase in the proportion of SSM in the diet, with higher GSI recorded in T2 and T3 treatment groups (testis and ovary, respectively), which were significantly (p < 0.05) different from other groups. The overall linear and quadratic trends of HSI differed significantly (p < 0.05) with the variability in proportions of natural and commercial astaxanthin combinations and were found highest in the T2 treatment group. Cholesterol, FSH, LH, 11-KT, 17β- Estradiol, and 17α-20β DHP levels increased with an increasing proportion of natural astaxanthin and recorded the highest values in the treatment T2 with an overall significant linear and quadratic trend as compared to other treatments. Most of the oocytes of T2 and T3 groups were in the vitellogenic phase, i.e., primary, secondary, and tertiary yolk stages. More spermatids were visible in testicular tubules in T2, followed by T3 and T1. The abundance of Vtg. mRNA was significantly (p < 0.05) evident in T2, followed by T1, then in control. Further increase in SSM inclusion caused a downregulation in the expression of this gene in the T3 group. The dietary combination of SSM @200 g/kg diet with its synthetic/commercial variant exhibited optimum performance at combination levels of 77.5 and 22.5 mg/kg, respectively, evidenced in terms of changes in steroid hormone profiles, gonadal maturation and vitellogenin gene expression in comparison to the control, which contained the dietary synthetic/commercial variant of astaxanthin alone. These inferences are presumably a milestone in the captive broodstock development of this high-value ornamental cichlid, S. aequifasciatus, with an added advantage of cost-effectiveness. The study would help the utilisation of economically important bio-waste in combination with commercial variants for effective value addition in the ornamental fish feed industry. [Display omitted] • Shrimp shell meal (SSM) is good source of protein and natural astaxanthin for fish diet. • Effective dose of synthetic and SSM derived natural astaxanthin is 77.5 and 22.5 mg/kg in feed. • Dietary incorporation of natural and synthetic asataxanthin enhanced gonadal maturation and upregulate Vtg. gene expression. • Study will be helpful in formulation of cost effective quality feed for brood stock maturation in fish. [ABSTRACT FROM AUTHOR]

The present experiment was designed to evaluate the effect of graded level of zinc on Vitellogenin gene (Vtg) expression and antioxidant enzymes in threatened catfish, Clarias magur (C. magur). One hundred and eighty female C. magur with an average weight of 145 ± 5 g were allocated in twelve cemented tanks with dimension 4.5 × 2 × 1 m for a period of 60 days. Fish were distributed in four groups with three replicates following the completely randomised design. The first group treated as control (C) fed with basal diet contained normal zinc level, and remaining groups were fed with basal diets having 50, 200 and 300 mg/kg zinc acetate and treated as T1, T2 and T3 respectively. To evaluate the effect of dietary zinc supplementation on Vtg gene expression, three sampling were carried out, I sampling (April, before starting the experimental trail), II sampling (May, after 1 month of feeding trail) and III sampling (June before breeding season). In the present study, a dose-dependent relationship between Vtg gene expression and zinc inclusion in the diet of threatened catfish, C. magur, was reported. Vtg gene expression increased in all groups from I sampling to II sampling but the highest Vtg gene expression was found in T1 group and the lowest in T3 group at II sampling. Vtg gene expression among the treatments differs significantly (P < 0.05) in each sampling. Accumulation of zinc was measured by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) in C. magur and it was reported that the significantly higher (P < 0.05) zinc was accumulated in the liver and ovary of T3 group as compared to other groups. The antioxidant enzyme activities (superoxide dismutase, SOD, catalase and GST) were also measured in different tissues (liver, gill and ovary) to evaluate the effect of extra-supplementation of zinc on the antioxidant status. In T3 group, SOD, catalase and GST activities were significantly higher than those in other groups. In the current study, serum glucose level was also measured and it was found in increasing trend with inclusion of zinc in the diet of C. magur. In the present study, it can be concluded that the zinc exhibits beneficial effect only up to 50 mg/kg. Thus, it is concluded that supplementation of zinc at 200 mg/kg or more disrupts Vtg gene expression and antioxidant status., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)