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The effects of the intensification on the performance of the Amazon River prawn hatchery carried out in a simple recirculation system were investigated. Newly hatched larvae were stocked in 120 L tanks at 80, 100, 120 and 140 larvae L−1 in a closed recirculating system. The experiment used a randomized block design with five replicates. An exponential equation was adjusted to express the relationship between the stocking density and productivity (postlarvae L−1). The development, larval quality, survival and postlarval (PL) dry weight did not significantly differ among the treatments (p > 0.05). When 80 larvae were stocked, the productivity (54 ± 11 PL L−1) was lower than those at higher densities (p < 0.05). Stocking 120 and 140 larvae L−1 resulted in higher productivities (75 ± 18 and 80 ± 17 PL L−1, respectively) with a lower use of Artemia nauplii to produce each postlarvae (~1200 Artemia nauplii PL−1). The maximum mean M. amazonicum postlarval production estimated by the exponential model was 93 PL L−1. This means that despite the increase in stocking density, productivity tends to stabilize. The results showed that M. amazonicum tolerates high intensification in recirculating hatchery systems based on a crushed shell bed biofilter, and the intensification optimizes Artemia use. [ABSTRACT FROM AUTHOR]

Artemia nauplii are high-quality biological feed for aquatic animal breeding, and its quality determines the effectiveness of breeding. The aim of this study was to explore the quality and symbiotic microbial composition of nauplii in different areas. The dormant eggs of Artemia nauplii from Kulundan Lake in Russia, Aibi Lake in Xinjiang, and salt fields in Bohai Bay were selected for incubation, and the relevant indicators of the 29 h incubation period were recorded. A high-throughput sequencing platform was used to analyze the microbial structure of symbiotic bacteria in nauplii between treatments. The PICRUSt2 was used to precalculated the predicted genes and their functions. The hatching rate of Artemia per thousand eggs in Kulundan Lake, Aibi Lake and Bohai Bay was 91.2%, 87.8% and 75.9%, respectively. The Alpha and Beta diversity analysis showed that the richness and evenness of Artemia nauplii in Kulundan Lake were higher than that of in Bohai Bay. At phylum level, Firmicutes, Proteobacteria and Bacteroidota were the dominant symbiotic bacteria of nauplii. But at the genus level, the dominant species of the symbiotic bacteria of nauplii were Bacillus, Pseudomonas and Exiguobacterium. The hatching rate and the abundance of symbiotic bacteria of Artemia nauplii from Kulundan Lake were better than the other two areas. This research might provide a theoretical guidance for the symbiotic bacteria of Artemia nauplii to regulate the feeding health of aquatic animal seedlings, reduce the occurrence of diseases and purify water quality. [ABSTRACT FROM AUTHOR]

AbstractArtemia nauplii are high-quality biological feed for aquatic animal breeding, and its quality determines the effectiveness of breeding. The aim of this study was to explore the quality and symbiotic microbial composition of nauplii in different areas. The dormant eggs of Artemia nauplii from Kulundan Lake in Russia, Aibi Lake in Xinjiang, and salt fields in Bohai Bay were selected for incubation, and the relevant indicators of the 29 h incubation period were recorded. A high-throughput sequencing platform was used to analyze the microbial structure of symbiotic bacteria in nauplii between treatments. The PICRUSt2 was used to precalculated the predicted genes and their functions. The hatching rate of Artemia per thousand eggs in Kulundan Lake, Aibi Lake and Bohai Bay was 91.2%, 87.8% and 75.9%, respectively. The Alpha and Beta diversity analysis showed that the richness and evenness of Artemia nauplii in Kulundan Lake were higher than that of in Bohai Bay. At phylum level, Firmicutes, Proteobacteria and Bacteroidota were the dominant symbiotic bacteria of nauplii. But at the genus level, the dominant species of the symbiotic bacteria of nauplii were Bacillus, Pseudomonas and Exiguobacterium. The hatching rate and the abundance of symbiotic bacteria of Artemia nauplii from Kulundan Lake were better than the other two areas. This research might provide a theoretical guidance for the symbiotic bacteria of Artemia nauplii to regulate the feeding health of aquatic animal seedlings, reduce the occurrence of diseases and purify water quality.

Studies have shown negative short-term effects of early weaning (EW) in finfish larvae but information on long-term effects of EW on growth and subsequent economic loss is lacking. We evaluated the short- and long-term effects of EW and late weaning (LW) on Atlantic cod. Cod larvae were fed with enriched rotifers from 2 to 35 days post-hatch (dph) and weaning carried out from 21 to 35 dph (EW) or with enriched rotifers from 2 to 29 dph followed by enriched Artemia nauplii from 25 to 56 dph and weaning carried out from 45 to 56 dph (LW). At 190 dph, 50 fish from each tank were tagged with an electronic tag and were transferred to sea cages at 10 months old. At the end of 30 months post-hatch, the weight of the fish was recorded. Our results showed a significant short-term effect of the weaning method on the growth of Atlantic cod at 65 dph, but no significant difference at 90 and 190 dph. However, fish from LW showed a significantly higher body weight compared to fish from EW at 30 months post-hatch. A cost analysis indicated substantial benefit for commercial cod farming by using LW and we recommend using LW to gain sizable financial benefit. [ABSTRACT FROM AUTHOR]

Emodin, a compound isolated from Aspergillus terreus, was studied using chromatographic and spectroscopic methods and compound purity (96%) was assessed by TLC. Furthermore, high larvicidal activity against Aedes aegypti-AeA (LC50 6.156 and LC90 12.450 mg/L), Culex quinquefasciatus-CuQ (8.216 and 14.816 mg/L), and Anopheles stephensi-AnS larvae (6.895 and 15.24 mg/L) was recorded. The first isolated fraction (emodin) showed higher pupicidal activity against AeA (15.449 and 20.752 mg/L). Most emodin-treated larvae (ETL) showed variations in acetylcholine esterase, α and β-carboxylesterases, and phosphatase activities in the 4th instar, indicating the intrinsic differences in their biochemical changes. ETL had numerous altered tissues, including muscle, gastric caeca, hindgut, midgut, nerve ganglia, and midgut epithelium. Acute toxicity of emodin on brine shrimp Artemia nauplii (54.0 and 84.5 mg/L) and the zebrafish Danio rerio (less toxicity observed) was recorded. In docking studies, Emodin interacted well with odorant-binding-proteins of AeA, AnS, and CuQ with docking scores of − 8.89, − 6.53, and − 8.09 kcal mol−1, respectively. Therefore, A. terreus is likely to be effective against mosquito larvicides. [ABSTRACT FROM AUTHOR]

Synthetic pesticides are a considerable issue in both terrestrial and aquatic habitats. Green pesticides derived from fungi, provide an efficient tools and alternative to chemicals. Secondary metabolites from Metarhizium anisopliae were tested against major disease mosquitos such as, Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus, as well as two non-target species, Eudrilus eugeniae and Artemia nauplii. After 24 h of treatment, M. anisopliae derived chemical constituent produced low LC50 values, 54.678, 92.819, and 93.792 µg/ml on Aedes aegypti, for Anopheles stephensi, 80.933, 116.990 and 130.173 µg/ml, for Culex quinquefasciatus, 109.733, 196.540, 182.853 µg/ml in larvae, pupae, and adult, respectively. On the contrary, fungal metabolites are not hazardous to non-target species.. Midgut histology investigations revealed that M. anisopliae metabolites were less harmful to earthworms than chemical pesticides (Permethrin). The treatment of fungal crude extract exhibited minimal toxicity effects on gut tissues, normal epidermis, circular muscle, setae, mitochondrion, and intestinal lumen tissues. M. anisopliae crude metabolites showed a lower toxicity against the non-target species A. nauplii. Our results clearly shows minimal mortality rates were produced by the M. anisopliae derived chemical constituents, LC50 and LC90 values were, 455.947, 5098.233 μg/mL−1. No behavioral changes were observed during the treatment. The primary components of M.anisopliae crude extract identified by GC–MS studies were aucubin (14.356%) and 9, 12-Octadecadienoic acid (z,z)-(75.009%). The presence of key functional groups such as carboxylic acid, amides, and phenol groups was revealed by FT-IR spectral studies, which may be involved in mosquitocidal activity. [ABSTRACT FROM AUTHOR]

The effects of the intensification on the performance of the Amazon River prawn hatchery carried out in a simple recirculation system were investigated. Newly hatched larvae were stocked in 120 L tanks at 80, 100, 120 and 140 larvae L−1 in a closed recirculating system. The experiment used a randomized block design with five replicates. An exponential equation was adjusted to express the relationship between the stocking density and productivity (postlarvae L−1). The development, larval quality, survival and postlarval (PL) dry weight did not significantly differ among the treatments (p > 0.05). When 80 larvae were stocked, the productivity (54 ± 11 PL L−1) was lower than those at higher densities (p < 0.05). Stocking 120 and 140 larvae L−1 resulted in higher productivities (75 ± 18 and 80 ± 17 PL L−1, respectively) with a lower use of Artemia nauplii to produce each postlarvae (~1200 Artemia nauplii PL−1). The maximum mean M. amazonicum postlarval production estimated by the exponential model was 93 PL L−1. This means that despite the increase in stocking density, productivity tends to stabilize. The results showed that M. amazonicum tolerates high intensification in recirculating hatchery systems based on a crushed shell bed biofilter, and the intensification optimizes Artemia use.

The importance of feeding live food in the first stages of fish life is crucial, because the organism is not fully developed, the accessory glands and the enzymatic equipment of the digestive tract are also insufficiently developed. Natural food brings a supply of vitamins, enzymes, and hormones with a major role in the process of digestion and absorption of the food, very important in the ontogenetic development and in increasing the immunity of fish in the larval and postlarval stages. Internationally, over the years, numerous studies have been carried out on the feeding of fish with Artemia, but the present study aims to optimize the process of feeding Artemia nauplii to freshwater fish reared in a recirculating system. This brine shrimp can survive a limited amount of time in fresh water, after which it rapidly decomposes and, due to its high protein content, becomes a water pollutant for the recirculating system. From the point of view of the costs for cyst decapsulating and the energy costs for hatching, they are too costly to afford feeding "ad libitum" with nauplii the fish larvae. The use of the minimum amount of live Artemia nauplii depends on the resistance of the nauplii in fresh water, expressed in a maximum time interval of 3.5 hours, after which vital activity and very low survival are recorded. The optimal Artemia nauplii feeding requirement of starry sturgeon with an average weight of 0.26±0.15 g and an average length of 3.78±0.8 cm is about 2.26% B.W. representing a maximum of 4.5 g wet mass of nauplii administered per 1,000 of larvae daily. [ABSTRACT FROM AUTHOR]

Silver rasbora (Rasbora argyrotaenia) is a new fish species cultured economically for consumption and aquascape. The purpose of this study was to know the effect and determine the optimal concentration of Sardinella lemuru fish oil enrichment on artemia to the survival rate and growth of silver rasbora larvae. Fish larvae were feed by enriched artemia nauplii with different doses per liter water. Larvae feeding artemia enrichment with Sardinella lemuru fish oil in different doses not affect (P > 0.05) on survival, but all growth parameters significantly affected (P < 0.05). Optimal artemia enrichment dose for feeding practical of silver rasbora larvae is 0.5 ml fish oil + 0.5 ml egg yolk. Estimate doses that leads to the maximum length gain is 0.6035 ml fish oil + 0.6035 ml egg yolk. [ABSTRACT FROM AUTHOR]

Zooplanktivory is an important source of nutrients in corals, providing up to 35% of daily metabolic energy requirements in some species. However, little is known about coral zooplanktivory shortly after larval settlement and metamorphosis. In most species it is unclear if, when and under which conditions newly settled polyps are able to capture and ingest prey. This remains a critical knowledge gap, as zooplanktivory could allow coral settlers to replenish energy reserves shortly after metamorphosis, possibly improving settler condition during one of their most vulnerable life stages. Here, we documented the onset of prey (Artemia salina nauplii) capture in ten Caribbean coral species and assessed optimal water flow rates (WFR) for prey capture in five of these species. All species initiated zooplanktivory within six days following metamorphosis, with the exception of Acropora palmata which was never observed capturing nauplii during our 20-day study. Optimal WFR for prey capture varied among species, with Favia fragum displaying maximum prey capture rates in zero flow and Diploria labyrinthiformis most effectively capturing nauplii under WFR of 5–20 cm s−1. Under each species' optimum WFR, prey capture abilities varied considerably, with F. fragum capturing up to one nauplius every two minutes compared to one nauplius every nine minutes in Colpophyllia natans. Using these findings, we make species-specific recommendations to optimize coral husbandry and larval-based restoration practices for these ten coral species. [ABSTRACT FROM AUTHOR]

Studies have shown negative short-term effects of early weaning (EW) in finfish larvae but information on long-term effects of EW on growth and subsequent economic loss is lacking. We evaluated the short- and long-term effects of EW and late weaning (LW) on Atlantic cod. Cod larvae were fed with enriched rotifers from 2 to 35 days post-hatch (dph) and weaning carried out from 21 to 35 dph (EW) or with enriched rotifers from 2 to 29 dph followed by enriched Artemia nauplii from 25 to 56 dph and weaning carried out from 45 to 56 dph (LW). At 190 dph, 50 fish from each tank were tagged with an electronic tag and were transferred to sea cages at 10 months old. At the end of 30 months post-hatch, the weight of the fish was recorded. Our results showed a significant short-term effect of the weaning method on the growth of Atlantic cod at 65 dph, but no significant difference at 90 and 190 dph. However, fish from LW showed a significantly higher body weight compared to fish from EW at 30 months post-hatch. A cost analysis indicated substantial benefit for commercial cod farming by using LW and we recommend using LW to gain sizable financial benefit.

The purpose of this study is to compare the effects of three live feeds for the larvae of the domesticated strain of mandarin fish (Siniperca chuatsi). Larvae of this strain of mandarin fish with salinity activation ingested Artemia nauplii was firstly observed. The larvae at 3 days post hatch (dph) were reared from first feeding to 9 dph and fed on starving (no food supplied), zebrafish (Danio rerio) (newly hatched larvae), Artemia nauplii and Daphnia magna, respectively. The results showed that the highest survival was found in the newly hatched larvae group (41.7 ± 1.5 %), and the lowest growth was found in the Daphnia group, respectively. A high food intake was found in the Artemia nauplii group, and the npy expression between the Artemia nauplii and newly hatched larvae groups had no significant difference (p＞0.05), whereas they were significantly lower than that of the starving group (p＜0.05). At the first feeding day, the activities of amylase, lipase and trypsin and the target of rapamycin (tor) expression in the Artemia nauplii and newly hatched larvae groups were significantly higher than those of the starving group. These results suggested that larvae of this strain of mandarin fish could feed on the newly hatched larvae and Artemia nauplii, and both of them could be digested, but the digestion might be insufficient in the Artemia nauplii group. Together, this study indicates that larvae of this strain of mandarin fish can ingest and digest Artemia nauplii during first-feeding.

Insecticides can cause significant harm to both terrestrial and aquatic environments. The new insecticides derived from microbial sources are a good option with no environmental consequences. Metarhizium anisopliae (mycelia) ethyl acetate extracts were tested on larvae, pupae, and adult of Anopheles stephensi (Liston, 1901), Aedes aegypti (Meigen, 1818), and Culex quinquefasciatus (Say, 1823), as well as non-target species Eudrilus eugeniae (Kinberg, 1867) and Artemia nauplii (Linnaeus, 1758) at 24 h post treatment under laboratory condition. In bioassays, Metarhizium anisopliae extracts had remarkable toxicity on all mosquito species with LC50 values, 29.631 in Ae. aegypti, 32.578 in An. stephensi and 48.003 in Cx. quinquefasciatus disease-causing mosquitoes, in A. nauplii shows (5.33–18.33 %) mortality were produced by the M. anisopliae derived crude extract. The LC50 and LC90 values were, 620.481; 6893.990 μg/mL. No behavioral changes were observed. A low lethal effect was observed in E. eugeniae treated with the fungi metabolites shows a 14.0 % mortality. The earthworm E. eugeniae mid-gut histology revealed that M. anisopliae extracts had no more harmful effects on the epidermis, circular muscle, setae, mitochondrion, and intestinal lumen tissues than chemical pesticides. By Liquid chromatography mass spectrometry (LC-MS) analysis, camphor (25.4 %), caprolactam (20.68 %), and monobutyl phthalate (19.0 %) were identified as significant components of M. anisopliae metabolites. Fourier transform infrared (FT-IR) spectral investigations revealed the presence of carboxylic acid, amides, and phenol groups, all of which could be involved in mosquito toxicity. The M. anisopliae derived chemical constituents are effective on targeted pests, pollution-free, target-specific, and are an alternative chemical insecticide. [ABSTRACT FROM AUTHOR]

Growth rate, specific weight gain, total body length and survival rate were studied in Heteroclarias fry fed under three (3) different treatments with shell free Artemia naupli, cultured Moina micrura and combination of both, 180 fry measuring 0.2g in weight and0.2cm in length were used in the experiment. Each treatment has two replicates. 30 individual fry were placed in each of the treatment in 50-liter plastic tank for durations for 10 weeks (70 days). Water quality parameters, pH and temperature for each treatment were monitored using pH meter (PHS-3sc) and mercury in glass thermometer (0°c-100°c) respectively. The weights increase of the fry of each treatment was measured weekly using a labtech electronic sensitive scale (0.1g-750g) the body length was also measured using a graduated ruler. Body weight gain was significantly higher (p0.05) from others. Complete replacement of Artemianauplii with Moina micrura produced the lowest body weight gain (12.70 ± 0.05) and percentage survival rate (26.67 ± 3.34%).The result of the overall resarch showed that partial replacement of shell free Artemia nauplii with Moina micrura showed significant growth increase and survival rate and so could be adopted for successful feeding of Heteroclarias fry.

This work reports the fast and effective bio-fabrication of novel platinum-palladium bimetallic nanoparticles (Pt–Pd BNPs) along with their counterparts Pt and Pd monometallic NPs (MNPs) through aqueous Annona muricata leaf extract. The bio-fabrication of the NPs was achieved within 2 h at 100 °C and pH 7 which was established by the occurrence of dark brown color for Pt MNPs and black color for Pd MNPs and Pt–Pd BNPs. NPs were evaluated for their catalytic activity in the reduction of methyl orange (MO), rhodamine-B (rh–B), and methylene blue (MB) textile dyes in presence of sodium borohydride as a reducing agent. Pt–Pd (1:3) BNPs showed higher MO dye degradation (96.84 ± 2.05% in 50 min) followed by Pd MNPs (97.07 ± 1.46% in 60 min), Pt–Pd (3:1) BNPs (97.34 ± 1.17% in 70 min) and Pt–Pd (1:1) BNPs (98.12 ± 1.04% in 80 min). Pd MNPs showed significant catalytic activity in the reduction of rh-B dye by 97.27 ± 1.14% in 12 min followed by Pt–Pd (3:1) BNPs (96.76 ± 2.17% in 18 min), Pt–Pd (1:3) BNPs (96.53 ± 1.97% in 33 min) and Pt–Pd (1:1) BNPs (97.11 ± 2.09% in 39 min). Pt–Pd (1:3) BNPs also showed higher MB dye degradation (96.95 ± 1.57% in 40 min) followed by Pd MNPs (96.22 ± 2.36% in 55 min), Pt–Pd (3:1) BNPs (97.29 ± 1.22% in 75 min) and Pt–Pd (1:1) BNPs (96.45 ± 2.19% in 105 min). However, Pt MNPs showed no catalytic activity. Standard disc diffusion method was used to evaluate the NPs toxicity towards Escherichia coli and Staphylococcus aureus, which showed no inhibitory zones. NPs showed less toxicity compared to potassium dichromate (control) against Artemia nauplii. Among the NPs studied, Pt–Pd (1:1) BNPs showed less toxicity with 100% mortality only at 100 µg/mL concentration followed by Pt MNPs (≥ 80 µg/mL), Pt–Pd (1:3) BNPs (≥ 60 µg/mL), Pt–Pd (3:1) BNPs (≥ 60 µg/mL) and Pd MNPs (≥ 40 µg/mL) after 72 h exposure. These evaluations support the application of bio-fabricated Pt–Pd BNPs as nano-catalysts in textile dyes degradation. [ABSTRACT FROM AUTHOR]

In this study, Bacillus amyloliquefaciens strain L11 was used as potential probiont in preliminary in vivo assay using Artemia and blue crab juveniles as final host. Strain L11 at 108 CFU mL-1 was found able to penetrate into gnotobiotic Artemia as early as 6h exposure. The survival rate of Artemia incubated with strain L11 at concentration of 106 CFU ml-1 and challenged with V. harveyi was 62 ± 1%. The numbers of Vibrios in Artemia were reduced at the end of the challenge assay. The in vivo assay using blue crab juveniles, demonstrated that strain L11 at 106 CFU mL-1 showed significant survival (42 ± 1 %) compared with group challenged with V. harveyi with no probiont added (12 ± 1 %) after five days of exposure. Strain L11 also able to reduce the number of Vibrios and increased the weight of the juveniles.

The present study investigated the effect of polysaccharide gel (PG) extracted from the rind of durian fruit which is encapsulated with Bacillus subtilis as a feed and co-inoculation with Artemia nauplii in the induction of immune response in Danio rerio after Vibrio immersion challenge (5 days). The total RBC count, lysozyme activity test, weight, and length analysis revealed that the zebra fishes fed with the PG encapsulated probiotics had more immune induction activity, survival, and growth than the non-encapsulated groups. When the expression of the immune-related genes was measured, the studies revealed the significant upregulation (P < 0 .05) of interleukin 1 beta (Il1b), lysozyme (lyz), tumor necrosis factor-alpha (TNF-α), superoxide dismutase (SOD) genes in fish fed with PG encapsulated probiotics with A. nauplii showed an immense effect on the induction of immune response compared to other feeds.

Insecticides can cause significant harm to both terrestrial and aquatic environments. The new insecticides derived from microbial sources are a good option with no environmental consequences. Metarhizium anisopliae (mycelia) ethyl acetate extracts were tested on larvae, pupae, and adult of Anopheles stephensi (Liston, 1901), Aedes aegypti (Meigen, 1818), and Culex quinquefasciatus (Say, 1823), as well as non-target species Eudrilus eugeniae (Kinberg, 1867) and Artemia nauplii (Linnaeus, 1758) at 24 h post treatment under laboratory condition. In bioassays, Metarhizium anisopliae extracts had remarkable toxicity on all mosquito species with LC50 values, 29.631 in Ae. aegypti, 32.578 in An. stephensi and 48.003 in Cx. quinquefasciatus disease-causing mosquitoes, in A. nauplii shows (5.33–18.33 %) mortality were produced by the M. anisopliae derived crude extract. The LC50 and LC90 values were, 620.481; 6893.990 μg/mL. No behavioral changes were observed. A low lethal effect was observed in E. eugeniae treated with the fungi metabolites shows a 14.0 % mortality. The earthworm E. eugeniae mid-gut histology revealed that M. anisopliae extracts had no more harmful effects on the epidermis, circular muscle, setae, mitochondrion, and intestinal lumen tissues than chemical pesticides. By Liquid chromatography mass spectrometry (LC-MS) analysis, camphor (25.4 %), caprolactam (20.68 %), and monobutyl phthalate (19.0 %) were identified as significant components of M. anisopliae metabolites. Fourier transform infrared (FT-IR) spectral investigations revealed the presence of carboxylic acid, amides, and phenol groups, all of which could be involved in mosquito toxicity. The M. anisopliae derived chemical constituents are effective on targeted pests, pollution-free, target-specific, and are an alternative chemical insecticide.

The aim of this study was to investigate the tolerance of Hypsolebias radiseriatus larvae to different salinities, and the effects of different prey concentrations and water salinities on the larviculture of this species. Salinity tolerance was tested by subjecting newly-hatched larvae to 96 hours of osmotic shock testing (experiment I) and gradual acclimatization (experiment II) of the following salinities: freshwater (control), 2, 4, 6 and 8 g of salt L-1. A third experiment (experiment III) evaluated three water salinities (S0 - freshwater, S2 - 2 g of salt L-1 and S4 - 4 g of salt L-1) and three initial daily prey concentrations (100, 300 and 500 artemia nauplii larva-1). In experiments I and II, survival was only influenced by the salinity of 8 g of salt L-1 (p < 0.01). After 35 days, weight was only influenced by prey concentration (p < 0.05), with the highest value being with 500 artemia nauplii larva-1. The lowest survival was for 4 g of salt L-1 and for 100 artemia nauplii larva-1. H. radiseriatus larviculture can be carried out in salinity of up to 2 g of salt L-1 and initial daily prey concentrations with 500 artemia nauplii larva-1. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the tolerance of Hypsolebias radiseriatus larvae to different salinities, and the effects of different prey concentrations and water salinities on the larviculture of this species. Salinity tolerance was tested by subjecting newly-hatched larvae to 96 hours of osmotic shock testing (experiment I) and gradual acclimatization (experiment II) of the following salinities: freshwater (control), 2, 4, 6 and 8 g of salt L-1. A third experiment (experiment III) evaluated three water salinities (S0 - freshwater, S2 - 2 g of salt L-1 and S4 – 4 g of salt L-1) and three initial daily prey concentrations (100, 300 and 500 artemia nauplii larva-1). In experiments I and II, survival was only influenced by the salinity of 8 g of salt L-1 (p < 0.01). After 35 days, weight was only influenced by prey concentration (p < 0.05), with the highest value being with 500 artemia nauplii larva-1. The lowest survival was for 4 g of salt L-1 and for 100 artemia nauplii larva-1. H. radiseriatus larviculture can be carried out in salinity of up to 2 g of salt L-1 and initial daily prey concentrations with 500 artemia nauplii larva-1.

To explore the molecular response of fish larvae to nutritional manipulation, the partial sequences of bone morphogenetic protein (BMP1, BMP2, BMP4, BMP5, and BMP10) genes were obtained, and their expressions were quantified on golden pompano Trachinotus ovatus at 28 days post hatching. Artemia nauplii were separately enriched with Nannochloropsis and Algamac 3080, and non-enriched Artemia nauplii were used as a control feed. The lowest jaw deformity rate occurred in fish fed Algamac 3080 enriched Artemia nauplii. The expression level of BMP4 of fish fed Algamac 3080 enriched Artemia nauplii was significantly lower than those fed Nannochloropsis enriched and non-enriched Artemia nauplii. The lowest expression level of BMP10 was found in fish fed non-enriched Artemia nauplii, and the highest expression of BMP10 was observed in fish fed Algamac 3080 enriched Artemia nauplii. Correlation analysis indicates that nutritional manipulations can significantly affect the expression level of BMP4 and BMP10 genes. The concentration of dietary docosahexaenoic acid (DHA) can significantly affect the expression level of BMP10. This study indicates that the use of Algamac 3080 enriched Artemia nauplii results in fast fish growth and low jaw deformity, and BMP4 and BMP10 gene expressions were closely related to jaw deformity in golden pompano larvae.

Major challenges in culture of Atlantic halibut larvae have been slow growth during the late larval stages and inferior juvenile quality due to pigmentation errors and incomplete eye migration during metamorphosis. The hypothesis of this study was that feeding on‐grown Artemia would alleviate these problems. Artemia were grown for 3–4 days on Origreen or Origo. The growth and nutrient composition of Artemia nauplii and on‐grown Artemia were analysed, and both Artemia types were fed to Atlantic halibut larvae, on‐grown Artemia from 15 days post‐first feeding (dpff). The body length of Artemia increased with 20%–70% in response to on‐growing. In all experiments, protein, free amino acids and the ratio of phospholipid to total lipid increased, while lipid and glycogen decreased. The fatty acid composition improved in some cases and not in others. The micronutrient profiles were not negatively affected in on‐grown Artemia. All these changes are thought to be beneficial for marine fish larvae. The final weight of Atlantic halibut postlarvae was similar, and 90% of the juveniles had complete eye migration in both groups. It is concluded that the present version of Artemia nauplii probably covers the nutrient requirements of Atlantic halibut larvae. [ABSTRACT FROM AUTHOR]

This study reports on the bioactive potential of silver nanoparticle synthesized from seaweed, Cladophora fascicularis aqueous extract. C. fascicularis assisted silver nanoparticles (Cf-AgNPs) was characterized by UV–visible spectroscopy, XRD, FT-IR, FESEM, TEM, and EDX analysis. The Cf-AgNPs exhibited a maximum absorption peak at 427 nm. The carboxyl (–C=O) and amine (N–H) groups of C. fascicularis extract is answerable for the synthesis of Cf-AgNPs. The microscopic analysis confirmed that the synthesized Cf-AgNPs are spherical in shape with an average size of 45 nm. The Cf-AgNPs exhibited a dose depended antibacterial activity against Aeromonas hydrophila. Noteworthy bacterial inhibition (19 mm) was observed at 150 µg/ml, whereas, the lowest activity (10 mm) was recorded at 25 µg/ml. Similarly, Cf-AgNPs significantly (P < 0.05) enhanced the protein leakage in A. hydrophila by increasing the membrane permeability. The considerable amount of ROS activity was noticed in the test bacterium A. hydrophila when treated with 150 µg/ml of Cf-AgNPs. The toxicity investigation results revealed that the synthesized Cf-AgNPs were not acutely toxic to Artemia nauplii even at a higher concentration (150 μg/ml). These results underline that Cf-AgNPs effectively inhibited the growth of A. hydrophila and showed the non-toxic effect with outstanding biocompatibility. [ABSTRACT FROM AUTHOR]

Vibrio species represent the predominant and significant pathogen in global marine fish and shellfish aquaculture. Vibrio species are ubiquitously presented in Artemia cyst hatcheries, and their notable colonization in live prey, particularly Artemia nauplii, leads to the transmission of these pathogens into the digestive system of larval organisms, causing serious problems in Vibriosis in marine aquaculture. To eliminate the Vibriospecies in Artemia nauplii, trichloroisocyanuric acid (TCCA) was used for sterilization of the nauplii. In this study, 3 different concentrations, including 0.5 ppm (FA group), 1.0 ppm (FB group) and 1.5 ppm (FC group) of TCCA were used to treat nauplii for 25 min, and then genomic DNA of the different groups were extracted followed by metagenomic next-generation sequencing (NGS). Bioinformatics analysis was applied and the results indicated that Proteobacter constituted the predominant component within each group at the phylum level, albeit accounting for only 58.68% in the FB group, which was significantly lower than in other groups (>86%). The relative abundance of Vibrio species at genus level showed that when compared with the control group, the FB group (15.8%) was reduced by 25.5%. Beta diversity showed differences between the FB group and the other groups, suggesting that treatment with 1.0ppm TCCA for 25 min would obviously reduce the Vibrio in Artemia nauplii. In conclusion, the Vibrio species were significantly reduced after treatment with TCCA, indicating that TCCA might be an alternative to antibiotics used for live food sterilization in marine aquaculture.

In this study, Bacillus amyloliquefaciens strain L11 was used as potential probiont in preliminary in vivo assay using Artemia and blue crab juveniles as final host. Strain L11 at 108 CFU mL-1 was found able to penetrate into gnotobiotic Artemia as early as 6h exposure. The survival rate of Artemia incubated with strain L11 at concentration of 106 CFU ml-1 and challenged with V. harveyi was 62 ± 1%. The numbers of Vibrios in Artemia were reduced at the end of the challenge assay. The in vivo assay using blue crab juveniles, demonstrated that strain L11 at 106 CFU mL-1 showed significant survival (42 ± 1%) compared with group challenged with V. harveyi with no probiont added (12 ± 1%) after five days of exposure. Strain L11 also able to reduce the number of Vibrios and increased the weight of the juveniles. [ABSTRACT FROM AUTHOR]

Abstract The practice of indoor larviculture can be an alternative to enhance the rearing of arapaima larvae, improving their survival and the supply of arapaima juveniles for the grow-out stage. We aimed to evaluate different live microcrustaceans as feed for arapaima larvae to verify groups that can be safely used in laboratory trials, as well as in commercial larviculture. Arapaima larvae (39.45 ± 7.04 mg and 2.09 ± 0.13 cm) were housed in 12-L circular tanks (n = 4 tanks; 30 larvae per tank) in a static water system. The tanks were cleaned twice a day, when 50% of the water was changed. Fish were fed three types of live feed 9 times/day: brine shrimp Artemia sp. nauplii (AR), Cladocera-rich zooplankton (CZ), and Ostracoda-rich zooplankton (OZ) for 15 days. Fish fed CZ and AR showed a similar fast growth rate with low mortality rates. The OZ fed Arapaima larvae presented intact Ostracoda in their rectums. This findins, demonstrates their poor digestibility, which resulted in poor growth and low survival. Ostracoda-rich zooplankton must be avoided in arapaima larviculture until 8 days after they begin swimming to the water surface or 17 days after hatching. Highligths • Cladocera-rich zooplankton and Artemia sp. nauplii were suitable live feed sources to arapaima larvae providing fast growth rates with low mortality; • Ostracoda-rich zooplankton were well consumed by arapaima larvae; • The presence of intact ostracoda in the arapaima rectum demonstrates its low digestibility; • Arapaima larvae fed ostracoda-rich zooplankton presented poor growth and low survival. [ABSTRACT FROM AUTHOR]

The present investigation deals with the extracellular metabolites from the soil bacterium against the devastating vector, Aedes aegypti. The testing of cell-free supernatant (CFS) of the soil bacterium, SA5 against third instar larvae of A. aegypti revealed LC50 and LC90 values (µL/mL) of 45.43 and 77.77, respectively. Histopathological analysis of third instar larvae of A. aegypti treated with CFS (1500 µL) after 24 h showed highly damaged epithelial cells, midgut and cortex regions. The brine shrimp toxicity of the effective CFS of SA5 strain on Artemia nauplii, exhibited only low lethality effect (33%). The bacterial genomic DNA of the effective SA5 strain was found to possess 1330 bp and was identified as Acidovorax sp. strain (MF581272) through molecular characterization. The FTIR, HPLC and GC-MS analyses of the CFS of Acidovorax sp. revealed 18 functional groups, 12 peaks and 10 compounds, respectively. The SDS-PAGE analysis of the extracellular protein from the CFS revealed their molecular weight range as 15-165 kDa. In view of the rerecorded potent anti-mosquitocidal property of the metabolites of the Acidovorax sp., further studies on their active principles are warranted. [ABSTRACT FROM AUTHOR]

Abstract The interactions of the probiotics Bacillus subtilis , Lactococcus lactis and Lactobacillus plantarum with the yeast Saccharomyces cerevisiae were examined in terms of probiotic and biochemical characteristics. Yeast supernatant had a positive effect on the aggregation biofilm formation capacity and hydrophobicity of probiotics, and resulted in increased lactic acid levels, reduced pH values as well as lower RS and FAN levels of probiotics. The effect of probiotics supernatants on yeast was more complex but best results were obtained in the yeast: probiotic CFS ratio of 1:2 for B. subtilis and of 2:1 for the other probiotics. The observed effects depended on the volume ratio of the cell free supernatant to the culture it was applied on. Best results were obtained by the volume ratio probiotic: yeast of (2:1) for B. subtilis and of (1:2) probiotic: yeast for L. plantarum and L. lactis. These ratios were used for further evaluation in vitro against V. anguillarum , resulting in reduced survival and attachment properties of the pathogen. Moreover, the administration of the corresponding combination of bacteria and yeast to Artemia nauplii greatly improved their survival following a challenge with the pathogen. Our results demonstrate that yeast enhances the protective effect of probiotics in a strain specific manner. Highlights • Yeast had a positive effect on probiotic properties of lactic acid bacteria. • The positive effect depended on the volume ratio probiotic: yeast. • Yeast and probiotics caused reduced survival and attachment of Vibrio anguillarum. • Bacteria and yeast improved survival of Artemia nauplii following a Vibrio challenge. [ABSTRACT FROM AUTHOR]

The effects of feeding on a commercial diet and lecithin‐enriched (EN) Artemia franciscana nauplii for improving co‐feeding strategies of Neotropical green terror cichlid (Aequidens rivulatus) larvae were conducted. For this purpose, eight groups of fish in triplicates were assigned with two different diets (unenriched Artemia [UN] and EN Artemia) and four feeding regimes (1, 5, 10 and 25 days feeding with UN and EN diets and then a 10% daily replacement Artemia nauplii with commercial diet). The crude lipid (21.4%) and total polar lipid (12.96% of total crud lipid) levels significantly increased in enriched Artemia nauplii (p < 0.05). The highest amount of saturated fatty acids (SFA) were in enriched and UN Artemia nauplii (41.74% and 49.64% respectively) but the highest level of monounsaturated fatty acids (MUFA) (25.69%) and polyunsaturated fatty acids (PUFA) (49.11%) were obtained in commercial diet. Growth performance of fish fed 10 EN and 5 EN had significantly higher values of total weight (120.67, 120.31 mg), %WG (584.48, 580.50%) and SGR (7.69, 7.67%) respectively (p < 0.05). Nevertheless, fish fed 25 EN had significantly higher FCE (190.4%), PER (3.95) and NPU (202.5), in comparison with other groups. In terms of body composition, the EN Artemia nauplii led to increased lipid contents in 25 EN, 10 EN and 5 EN treatments. In conclusion, the results of this study revealed that feeding regimes of 10 EN and 5 EN could improves survival and growth performance of Neotropical green terror cichlid, A. rivulatus larvae. [ABSTRACT FROM AUTHOR]

To explore the molecular response of fish larvae to nutritional manipulation, the partial sequences of bone morphogenetic protein (BMP1, BMP2, BMP4, BMP5, and BMP10) genes were obtained, and their expressions were quantified on golden pompano Trachinotus ovatus at 28 days post hatching. Artemia nauplii were separately enriched with Nannochloropsis and Algamac 3080, and non-enriched Artemia nauplii were used as a control feed. The lowest jaw deformity rate occurred in fish fed Algamac 3080 enriched Artemia nauplii. The expression level of BMP4 of fish fed Algamac 3080 enriched Artemia nauplii was significantly lower than those fed Nannochloropsis enriched and non-enriched Artemia nauplii. The lowest expression level of BMP10 was found in fish fed non-enriched Artemia nauplii, and the highest expression of BMP10 was observed in fish fed Algamac 3080 enriched Artemia nauplii. Correlation analysis indicates that nutritional manipulations can significantly affect the expression level of BMP4 and BMP10 genes. The concentration of dietary docosahexaenoic acid (DHA) can significantly affect the expression level of BMP10. This study indicates that the use of Algamac 3080 enriched Artemia nauplii results in fast fish growth and low jaw deformity, and BMP4 and BMP10 gene expressions were closely related to jaw deformity in golden pompano larvae. [ABSTRACT FROM AUTHOR]

Purpose. To review scientific sources on the technological and biological characteristics of the use of brine shrimp (Artemia) in the feeding of sturgeon juvenilse (Acipenseridae). To highlight the common biotechnological bases of the enrichment of brine shrimp with biologically active substances necessary for the full development of sturgeon juveniles. Findings. The review of scientific papers showed that the technology is the use of brine shrimp in the feeding of sturgeon speices not only had not lost its relevance in aquaculture, but also continued to evolve in response to new challenges. The review contains a description of the peculiarities of the biological structure of brine shrimp eggs and methods of their quality assessment in the field. It describes the nutritional characteristics of Artemia. It is shown that brine shrimp is the best food organism for the use in the feeding of sturgeon fingerlings. The calculation scheme for Artemia decapsulation and incubation is provided. The main technological stages of of the preparation of shrimps before their use in feeding – activation, hydration, decapsulation, incubation, dehydration were described. The effect of brine shrimp nauplia enriched with biologically active substances enriched brine shrimp on sturgeon juveniles was highlighted. Practical value. Fish farm owners search for cost-effective, easy to use, and available food that is preferred by sturgeon juveniles (Acipenseridae). Brine shrimp nauplii obtained from cysts can be readil used to feed fish just after one-day incubation. Instar I (the nauplii that just hatched and contain large yolk reserves in their body) and instar II nauplii (the nauplii after first moult and with functional digestive tracts) are more widely used in aquaculture, because they are easy for operation, rich in nutrients, and small, which makes them suitable for feeding fish larvae as live feed or after drying. The generalized information will be important for scientists studying the peculiarities of the feeding of sturgeon juvenile including natural foods. The data on the application of the biotechnology of brine shrimp use for the feeding of sturgeon juveniles will be useful for fish farmers. The importance of the use of Artemia for the feeding of sturgeon juveniles is due to its biological and economic characteristics and is diescribed in the article. The ability of the brine shrimp to produce dormant eggs, known as cysts, facilitated the extensive use of Artemia in aquaculture. The cysts may be stored for long periods and hatched on demand to provide a convenient form of live feed for larval fish. Brine shrimp nauplii constitute the most widely used food item, and over 2000 tonnes of dry Artemia cysts are marketed worldwide annually.

The effects of using n-3 LC-PUFA -enriched Artemia nauplii and newly hatched Artemia on survival and resistance to pH stress in larvae of angel fish (Peterophylum scalar) were examined In tow 20 days period. In the first step of the experiment the larvae with an average weight of 0.86 ±0.03mg were fed with tow diets (enriched Artemia nauplii and newly hatched Artemia) for 20 days. At the end of the first step of the experiment, the significantly (p

Vector-borne diseases like malaria, filariasis, and dengue are transmitted by mosquitoes and they cause global mortality and morbidity due to an increased resistance against commercial insecticides. The present study was aimed to evaluate the neurobehavioral toxicity, knock-down effect, histopathology, ovicidal, adulticidal, and smoke toxicity effect of Aspergillus terreus extract against three mosquito species, namely Anopheles stephensi, Culex quinquefasciatus , and Aedes aegypti (Diptera: Culicidae). The isolated fungal strain was identified as A. terreus (GenBank accession no: KX694148.1) through morphological and molecular (phylogenetic) analysis. The morphological changes in the treated fourth instar larvae shown the demelanization of cuticle and shrinkage of the internal cuticle of anal papillae. The time duration of extract exposure against the larvae determines the level of toxicity. The extract treated larvae were displayed excitation, violent vertical and horizontal movements with aggressive anal biting behavior as the toxic effect on the neuromuscular system. The results of the biochemical analysis indicated that a decrease in the level of acetylcholinesterase, α-carboxylesterase, and β-carboxylesterase in extract treated fourth instar larvae of all tested mosquito species. The findings of histopathological investigation shown the disorganization of the abdominal region, mainly in mid, hindgut, and gastric caeca, loss of antenna, lateral hair, caudal hair, upper and lower head hairs in the mycelium extract treated An. stephensi, Cx. quinquefasciatus , and Ae. aegypti. The ovicidal bioassay test results showed the mosquito hatchability percentage was directly related to the concentrations of mycelium extract. Nil hatchability of mosquito eggs was noticed at 500 μg/ml concentration. The adulticidal activity of fungal mycelia ethyl acetate extract resulted in a dose-dependent activity (15 and 30 min recovery periods). The higher concentration of extract (1000 mg/L) acted as a repellent, the adult mosquitoes showed restless movement, uncontrolled/anesthetic flight at last died. The better adulticidal activity was observed in the ethyl acetate extract against An. stephensi, Cx. quinquefasciatus followed by Ae. aegypti with the best score of LD50 and LD90 values and nil mortality was found in the control. The results of smoke toxicity assay of the mycelia extract exhibited significant mortality rate against Ae. aegypti (91%), Cx. quinquefasciatus (89%), and An. stephensi (84%). In addition, the present investigation reported the stability and toxic effects of A. terreus mycelium ethyl acetate extract on Artemia nauplii. The swimming speed (0.88 mm s-1) of A. terreus was reduced with ethyl extract 24 h treatment whereas, the control A. nauplii showed the normal speed of 2.96 mm s-1. Altered behavior and swimming movement were observed in the 8 h A. terreus mycelium extract treated A. nauplii. A pale yellow color substance (metabolites) was found in the mid-gut region of the mycelial extract exposed A. nauplii. The outcome of the present study, suggest that the A. terreus metabolites might serve as an alternative, cost-effective, eco-friendly, and target specific mosquitocidal agent in the future. [ABSTRACT FROM AUTHOR]

Abstract: Microalgae concentrates are important for hatchery operations but have been found to contain high concentrations of bacteria. Therefore, this study investigated the effects of four thermal disinfection and sterilisation treatments, low‐temperature long‐time (LTLT; 62–65°C, 30 min), high‐temperature short‐time (HTST; 72–75°C, 15 s), ultra‐high‐temperature (UHT; 120–150°C, 1–3 s) and high‐temperature high‐pressure (HTHP; 121°C, 0.2 MPa, 15 min), on concentrates of the microalgae, Chaetoceros gracilis, Chlorella vulgaris (fortified with eicosapentaenoic acid and docosahexaenoic acid) and Nannochloropsis oculata. The concentrates had reduced bacterial counts following LTLT, HTST and UHT and were completely sterilised by HTHP. Furthermore, cell dispersibility was retained in all treatment groups except HTHP‐treated C. gracilis. Rotifers that were cultured with HTHP‐treated C. vulgaris and N. oculata experienced significant population increases, whereas the survival rate and growth of Artemia nauplii significantly improved when supplied with HTHP‐treated N. oculata, indicating that HTHP enhances the digestibility of this microalga. HTHP did not affect the total lipid content and fatty acid composition of the microalgae. These results suggest that HTHP‐treated C. vulgaris and N. oculata could be used for the nutritional enrichment of rotifers and Artemia, while avoiding the risk of bacterial contamination, and would have an increased shelf life at room temperature. [ABSTRACT FROM AUTHOR]

Abstract: Brine shrimp Artemia, the most common live food organism used in larviculture, can reproduce either oviparously (production of dormant cysts) or ovoviviparously (direct production of nauplii), depending on environmental conditions. Ovoviviparous Artemia nauplii have seldom been considered as a source of live food in aquaculture, partly due to the convenience and the developed techniques associated with the production and use of the dormant cysts. In many countries in Africa, however, hatchery managers do not have access to a reliable supply of affordable good quality cysts. In this study, we therefore demonstrated the potential of a system designed for the continuous ovoviviparous production of nauplii at low salinity, using Great Salt Lake Artemia franciscana and micronized agricultural material as feed. The suitability of the produced nauplii was tested by feeding them directly to Clarias gariepinus larvae in comparison with oviparous nauplii and decapsulated cysts. Higher survival (100%), better protein efficiency ratio (2.6 ± 0.1) and food conversion ratio (1.0 ± 0.1) was observed in larvae fed with the ovoviviparous nauplii (p < 0.05). Overall, we conclude that the ovoviviparous nauplii could serve as an alternative live food for larval fish. If optimized, the system could be validated for integration in hatcheries. [ABSTRACT FROM AUTHOR]

Typical harmful micro-algal species constantly occurred in high density in marine aquaculture ponds in Xiangshan and Sanmen Bay, Zhejiang Province. Fates of the microalgal cells influenced by activity of the cultured animals largely determined the effects of the harmful microalgae. However, it is difficult to detect the in situ process. In this paper, toxic activities of three harmful microalga, namely Prymnesium parvum, Pleurochrysis elongata, Karlodinium veneficum, which were isolated from the local ponds, were comparatively studied based on brine shrimp toxic bioassays. Different lethal activities of live cells, cell debris, cellular extracts, and cell free mediums prepared by different process were analyzed. The results showed that, (1) all of the three microalgal species had density and time dependent lethal effects on Artermia nauplii, while P. parvum was the most toxic one and had acute lethal effects in 5 h. No such acute lethal effects were observed in P. elongata or K. veneficum; (2) live cells, cell debris and cellular extracts of P. parvum had the same lethal pattern. Prymnesins, toxin from P. parvum, is probably not exotoxic active; For P. elongata, toxic activity mainly came from live cells and cell debris; For K. veneficum, toxic activity was relatively lower compared with the other two species. However, Karlotoxin, toxin from K. veneficum, is exotoxic active. Physical disturbance triggered K. veneficum cells actively releasing toxins, which made it an active predator. [ABSTRACT FROM AUTHOR]

This study investigates the effects of first feeding regime on growing, survival, and gene expression (appetite, digestion, absorption, and growth) and digestive enzymes activity in Chinese perch (Siniperca chuatsi) larvae. The fish larvae at 3 days post-hatch (DPH), were fed with prey fry (newly hatched zebrafish Danio rerio)/ Artemia naupli from 3 to 15 DPH for different time periods as follows: (A)only prey fry;(B) 3–5 DPH Artemia /6–15 DPH prey fry;(C) 3–7 DPH Artemia /8–15 DPH prey fry; (D) a combination of Artemia and prey fry. Final performance parameters (total length, body weight, survival rate), gene expression and digestive enzymes were measured and compared among treatments at 15 DPH. The groups fed only prey fry (group A) (53.67 ± 1.76%) and combination of Artemia and prey fry (group D) (61.22 ± 1.18%), respectively, showed significantly (P < 0.05) higher survival specific growth rate (SGR TL) than other groups. Brain expression of npy and agrp were not significantly affected under different feeding regimes. The groups fed with Artemia till 7 DPH followed by feeding with prey fry till 15 DPH (group C) showed significantly (P < 0.05) higher pomc and cck expression level than the other groups. The expression of amy , ctrb , and pl was significantly higher in larvae fed combination of Artemia and prey fry (group D). pep had a high expression level in both group A and D. The highest expression of two genes related to intestinal development and maturation (alp , lap3 , anpep) were observed in the fish fed a combination of Artemia and prey fry, but there was no significant difference compared to group A. The expression of absorption and growth (mtor , pept1 and igf-1) increased with combination of Artemia and prey fry in larval diet (group D), indicating a more efficient functionality of digestive structures. In conclusion, feeding with combination of Artemia and prey fry could be suggested as an economical feeding regime for first feeding of Chinese perch larvae as comparable growth to prey fry were achieved, and better survival. • Four first feeding regimes were analyzed in Chinese perch larvae. • Improving survival and digestive enzyme activity of Chinese perch larvae. • Rearing on prey fry and Artemia in combination improved intestinal development and growth. • Appetite and digestion of Chinese perch larvae in different first feeding regime. [ABSTRACT FROM AUTHOR]

Mosquitoes can transmit the terrible diseases to human beings. Soil-borne fungal products act as potential source for low-cost chemicals, used for developing eco-friendly control agents against mosquito-vector borne diseases. The prime aim of study was to check the larvicidal potential of fungus mycelia (by ethyl acetate solvent) extract from Penicillium daleae (KX387370) against Culex quinquefasciatus and Aedes aegypti and to test the toxicity of brine shrimp Artemia nauplii, by observing the physiological activity. The ethyl acetate extract of P. daleae mycelia (after 15 days) from Potato dextrose broth (PDB) medium revealed better result with least LC50 and LC90 values of I-IV instars larvae of Cx. quinquefasciatus (LC50 = 127.441, 129.087, 108.683, and 93.521; LC90 = 152.758, 158.169, 139.091, and 125.918 μg/ml) and Ae. aegypti (LC50 = 105.077, 83.943, 97.158, and 76.513; LC90 = 128.035, 106.869, 125.640, and 104.606 μg/ml) respectively. At higher concentration (1000 μg/ml) of extracts, mortality begins at 18 h of exposure and attained 100% mortality after 48 h exposure. Overall, the activity was depends on the dose and time of exposure to the extracts. The stereomicroscopic and histopathological analysis of Ae. aegypti and Cx. quinquefasciatus larvae treated with mycelium ethyl acetate extract showed complete disintegration of abdominal region, particularly the midgut and caeca, loss of cuticular parts and caudal hairs. Morphological characterization of the fungi was performed and taxonomically identified through 5.8s rDNA technique. The phylogenetic analysis of rDNA sequence was carried out to find out the taxonomic and the evolutionary sketch of isolate in relation to earlier described genus Penicillium. Behavior and swimming speed alteration was analyzed together with mortality. The results of the experiment indicates that swimming behavior recorder (SBR) is a appropriate tool to detect individual swimming speed of the A. nauplii organisms, since the values have been obtained in accordance with control monitored results showed the 2.75 mm s-1 and after 24 h treated found to be 0.72 mm s-1, respectively. The extract-exposed to A. nauplii showed changes in body structures, i.e., intestine enlargement, eye formation, outer shell malformations and loss of antennae. In the present study, we aimed to investigate the toxicity of the ethyl acetate extract of P. daleae on A. nauplii larvae by performing the mortality, behavior and alterations in swimming responses. This is the first time report on the larvicidal efficacy of P. daleae ethyl acetate extract against Cx. quinquefasciatus and Ae. aegypti larvae.