Search Results (599)

Shrimp farming often suffers due to high mortalities and poor growth. Mycotoxins can be one of the causes but often underestimated. BIŌNTE^® QUIMITŌX^® AQUA PLUS, an anti-mycotoxin additive (AMA) was tested to assess its efficacy and determine the best dose for Pacific white shrimp (Litopenaeus vannamei). Four treatments (0, 1, 2, and 3 g/kg of diet) were randomly allocated in 12 aquaria during larval rearing (day 1–20) and 12 fiberglass tanks during subsequent grow-out (day 21–111). Results showed positive impacts on feed conversion, protein efficiency, survival, and growth. A decreasing trend in FCR and increasing trend in PER with the increase in AMA dose. The higher the dose, the better was the immunity as indicated by the survival of shrimp against bacterial challenge. However, the survival and growth showed significant quadratic relationships indicating that the dose of 1.4 g/kg can have the highest daily weight gain (66.7 mg) and the dose of 2.5 g/kg results in the highest survival (60.3%) which is more than double the survival of the control group (27.3%). Therefore, the doses between 1.4 and 2.5 g/kg of feed are recommended for the grow-out phase to enhance growth and survival of shrimp. However, further studies should be conducted in outdoor pond conditions for varying feeding regimes, contamination levels and stocking densities. Full article

Ceratitis capitata (Wiedemann) or medfly is a polyphagous pest of fruit crops worldwide. The Asian-native larval parasitoid Diachasmimorpha longicaudata (Ashmead) is mass-reared at the San Juan Biofactory and is currently released for medfly control in Argentina. Information on parasitoid survival, reproduction, and population growth parameters is critical for optimizing the mass-rearing process and successfully achieving large-scale release. This study provides a first-time insight into the demography of two population lines of D. longicaudata: one mass-reared on medfly larvae of the Vienna-8 temperature-sensitive lethal genetic sexing strain and the other on larvae of the wild biparental medfly strain. The aim was to compare both parasitoid populations to improve mass-rearing quality and to assess performance on medfly in a semi-arid environment, typical of Argentina’s central-western fruit-growing region. Tests were performed under laboratory and non-controlled environmental conditions in semi-field cages during three seasons. Dl_(Cc-bip) females exhibited higher reproductive potential than did Dl_(Cc-tsl) females under lab conditions. However, both Dl_(Cc-bip) and Dl_(Cc-tsl) were found to be similar high-quality females with high population growth rates in warm–temperate seasons, i.e., late spring and summer. Dl_(Cc-bip) females were only able to sustain low reproductive rates in early autumn, a colder season. These results are useful for improving the parasitoid mass production at the San Juan Biofactory and redesigning parasitoid release schedules in Argentina’s irrigated, semi-arid, fruit-growing regions. Full article

Blow flies (Diptera: Calliphoridae) play a crucial role in the decomposition process and serve as important forensic indicators due to their predictable colonization patterns. This review focuses on the dynamics of maggot masses, highlighting their ecological roles, thermoregulation, and implications for forensics. We summarize data on the self-organizing behavior of maggot masses, which is influenced by chemical cues and environmental factors. These masses can generate internal temperatures that exceed ambient levels by 10–20 °C, accelerating larval growth and impacting competition among individuals. This localized heating complicates the estimation of the postmortem interval (PMI), as traditional models may not take these thermal influences into account. Furthermore, maggot masses contribute significantly to nutrient cycling and soil enrichment, while the behavior of the larvae includes both cooperation and competition, which is influenced by the species composition present. This review highlights challenges in PMI estimation due to heat production but also discusses advancements in molecular tools and thermal modeling that enhance accuracy. Ultimately, we identify knowledge gaps regarding species diversity, microbial interactions, and environmental variability that impact mass dynamics, suggesting future research avenues that could enhance ecological understanding and forensic applications. Full article

The fan mussel Pinna nobilis is the largest bivalve species in the Mediterranean Sea and provides numerous ecosystem services. It is classified as critically endangered by IUCN (International Union for Conservation of Nature) due to severe mass mortality events throughout the Mediterranean. The aims of this work are as follows: (i) to assess the current recruitment potential of the species, (ii) to enhance recruitment by keeping juveniles in controlled conditions before releasing them back into the sea, and (iii) to assess the health status of recruits. In the period 2022–2023, larval collectors were set up in the Gulf of Trieste as part of the LIFE Pinna project. The collected individuals were kept in aquaria in two different facilities under different conditions: (a) a closed system with constant water temperature, live phytoplankton, and commercial food and (b) an open system with ambient seawater temperature and commercial food. A clear temporal and spatial variability in recruitment was observed: 13 recruits were found in 2022 and 50 recruits in 2023. The live specimens were between 0.5 and 8 cm in size upon collection and larger in 2023. The growth and survival rate did not differ significantly between the two systems, but the average monthly growth and survival rate were related to the initial size of the juveniles. Full article

The effects of Lys and Ile supplementation in a barley-based substrate on growth performance and nutrient deposition in Tenebrio molitor larvae were evaluated. Six trays per treatment containing sixty larvae were assigned to five treatments in two 21-day periods: barley (B); an 85% barley and 15% soybean meal mixture (BS) and B supplemented with synthetic Lys (BL), Ile (BI) or a combination of both (BLI), as potential limiting amino acids (AA) for larval growth. Supplementing AAs was provided in agar cubes twice per week. Larval performance was measured, and larvae were analyzed for nutrient content and AA profile. Final larval weight increased (p = 0.042) in BS and BL compared to B, with intermediate values for BI and BLI. Larval contents (mg/larva) in total AAs and seven key AAs (sum of Lys, Met, Cys, Thr, Trp, Val and Ile) were higher in BS-fed larvae than in BL and BLI, with the lowest values for BI and B (p < 0.001). Barley supplementation with Lys improved larval AA content, although the levels remained lower than those observed with BS. Conversely, Ile supplementation had no apparent effect on overall AA deposition compared to Lys alone, suggesting the presence of additional limiting AAs for optimal larval growth. Full article

The drastic surge in Sardine landings in Korea underscores the urgent need for sustainable upcycling strategies. However, research on the feasibility of using sardine (SD) in food waste (FW)-based substrates during the cultivation of black soldier fly (Hermetia illucens) larvae (BSFL) remains limited. Thus, we aimed to investigate the effect of incorporating varying SD contents (0, 25, 50, 75, and 100%), into which 4-day-old (third-instar) larvae weighing approximately 0.02 g were introduced and reared for 12 days in triplicate. SD inclusion in the substrate had a dose-dependent effect on BSFL growth; higher concentrations (≥50%) markedly inhibited key growth indices, including a significant reduction in total biomass (p < 0.05). Incorporating SD into the diet dose-dependently enriched the biomass with eicosapentaenoic acid and docosahexaenoic acid while reducing the relative proportions of saturated and monounsaturated fatty acids (p < 0.05). Proteobacteria and Firmicutes were the dominant phyla in the intestinal microbiota of BSFL. Further, SD inclusion altered the gut microbial community structure. Increased SD concentration in the diet led to a progressive reduction in unique genera, indicating decreased microbial diversity at higher inclusion levels. Overall, incorporating SD into FW for BSFL cultivation is feasible; however, optimizing substrate composition—particularly moisture and nutrient balance—is necessary to enhance larval growth and productivity. Full article

The present study explored the seasonal dynamics of spat settlement and growth of the Mediterranean mussel (Mytilus galloprovincialis) in the semi-enclosed and eutrophic Maliakos Gulf (Central Aegean, Greece), a coastal system within the Natura 2000 network (GR 2440002, Natura 2000). Spat collectors were deployed at three mussel farms representing different locations in the gulf (north, south, and inner west) and at multiple depths over a year. The results revealed a clear reproductive cycle, with spawning initiated in early January and spat settlement occurring from March to June. Settlement intensity was highest in shallower waters during the beginning of the season (March) and in the end (June), while depth had no significant effect mid-season. Mussel size and weight varied significantly with season and location, with the largest individuals observed during spring and early summer at the north and south sites. Environmental monitoring depicted strong nitrogen enrichment and phosphorus limitation, driven by inputs from the Spercheios River and surrounding agricultural activities. During winter, elevated chlorophyll-a concentrations likely supported early larval development, while nutrient imbalances threaten long-term ecosystem stability. These findings underscore the importance of area- and season-specific management of spat collectors and call for integrated monitoring and regulation of nutrient inputs to safeguard the ecological integrity of the gulf and ensure sustainable mussel farming. Full article

BPAF (Bisphenol AF), one of the primary substitutes for BPA (Bisphenol A), is widely used in the production of plastics, optical fibers, and other materials. During the use of these products, BPAF inevitably enters the environment and exerts toxic effects on animal growth, development, reproduction, immunity, neurology, and genetics. This study employed marine medaka (Oryzias melastigma) as the experimental model to evaluate the toxicological impacts of BPAF on early development. Embryos were exposed to four BPAF concentrations (0, 1 μg/L, 10 μg/L, and 100 μg/L) for 14 days (embryonic to larval stages), followed by phenotypic measurements, behavioral analysis, and gene expression detection. The results demonstrated that BPAF exposure induced developmental malformations and reduced survival rates in marine medaka embryos, with embryo survival negatively correlated with BPAF concentrations. Additionally, BPAF significantly decreased embryonic heart rates, and the 100 μg/L BPAF group exhibited prolonged embryo hatching time and reduced hatching success. In newly hatched larvae, BPAF exposure led to decreased body length, reduced heart rates, and significant suppression of swimming activity, characterized by increased resting time and reduced swimming distance. BPAF exposure altered the expression levels of genes associated with cardiovascular function (e.g., tbx2b, arnt2), the HPT axis (e.g., tg, dio3a, trh, trhr2, tpo), and neurodevelopment (e.g., ache, elavl3, gfap) in the medaka larvae. These transcriptional perturbations are proposed as potential molecular mechanisms underlying the observed phenotypic effects, including reduced heart rates and suppressed swimming behavior in the study. Molecularly, BPAF exposure significantly disrupted the expression of genes related to the cardiovascular system, HPT axis, and nervous system. Full article

Cephus fumipennis, a significant pest of highland spring wheat, damages crops through larval boring and feeding within wheat stalks. This activity disrupts nutrient and water transport, causing severe yield reductions. To find microbial biocontrol agents targeting this pest, primary entomopathogenic microorganisms were isolated and identified from naturally infected, deceased C. fumipennis larvae. Morphological examination and ITS-based phylogenetic analysis tentatively identified the isolate as the entomopathogenic fungus Clonostachys sp. (strain CF01). Third-instar larvae of C. fumipennis were inoculated with conidial suspensions of the CF01 strain at concentrations of 1 × 10⁵, 1 × 10⁶, 1 × 10⁷, and 1 × 10⁸ spores/mL. Spore suspensions of different concentrations demonstrated pathogenicity against third-instar larvae of C. fumipennis. The optimal growth conditions for strain CF01 were identified as follows: PPDA medium, 25 °C, fructose as the carbon source, and yeast extract as the nitrogen source. Photoperiod exhibited no significant effect on either mycelial growth or sporulation. These findings indicate that the CF01 strain possesses considerable potential for the biocontrol of C. fumipennis. Full article

Copepods play a critical role in aquatic food chains and are a key source of food in aquaculture, so optimizing their culture conditions is essential for their large-scale production. The objective of this study was to determine the optimal culture parameters of the copepod Oithona nana as a function of total population growth and the different stages of its life cycle. To this end, four experiments were carried out in quadruplicate, evaluating the effects of temperature, salinity, photoperiod and optimal microalgal concentration of Isochrysis galbana. Each experiment lasted 15 days. Temperatures of 20, 24, 28 and 32 °C were tested; salinity levels of 20, 25, 30 and 35 PSU; photoperiods of 12L:12D, 16L:8D and 24L:0D; and concentrations of I. galbana of 1 × 10⁴, 5 × 10⁴, 10 × 10⁴, 15 × 10⁴ and 20 × 10⁴ cells/mL. Results indicated that the optimal temperature for the culture of O. nana, with significant differences compared to the other treatments, was 28 ± 1 °C. Regarding salinity, the optimal level for the total development of the population was 25 ± 2 PSU, while to maximize the percentage of copepodites, the most appropriate levels were 30 and 35 PSU. The light-dark regimen of 16L:8D promoted the highest total density of individuals, while 12L:12D and 16L:8D favored development of nauplii and copepodites. Finally, optimal concentrations of I. galbana that generated the highest densities of O. nana at all stages of its life cycle were 15 × 10⁴ and 20 × 10⁴ cells/mL. These findings provide key information for the development of optimized cultures of O. nana, which can improve its availability as a food source in aquaculture systems and favor the success of larval cultures in species of commercial interest. Full article

Antheraea pernyi (Lepidoptera: Saturniidae) is an economically important silk-producing insect, whose gut microbiota play a crucial role in growth, development, and nutrient metabolism. This study focused on the entire larval developmental stages of A. pernyi. Using the Illumina MiSeq high-throughput sequencing platform, we performed 16S rRNA gene amplicon sequencing on the gut microbiota of laboratory-reared A. pernyi larvae, analyzing in detail the composition and diversity characteristics of the gut microbial communities across all five instars (1st to 5th instar). Additionally, functional predictions were conducted to explore the potential roles of these microbiota during larvae development. The study revealed that the core gut microbiota of A. pernyi larvae primarily consisted of Actinomycetota (39.78%), Cyanobacteriota (32.46%), Bacillota (18.08%), and Pseudomonadota (9.02%). Among these, Actinomycetota dominated in the 1st to 4th-instar larvae, while Cyanobacteriota became the predominant phylum in the 5th instar. Linear discriminant analysis effect size identified statistically significant biomarkers across different instar larvae of A. pernyi. Alpha diversity analysis showed that gut microbiota diversity initially increased and then decreased with larval development, peaking in the 3rd instar, and reaching its lowest level in the 5th instar. Principal coordinate analysis (PCoA) of beta diversity indicated that the gut microbiota structures of the 1st to 4th instars were similar but significantly differed from that of the 5th instar. Functional prediction analysis based on the KEGG database revealed that Carbohydrate metabolism and Amino acid metabolism-related genes were significantly lower in the 5th instar compared to other instars, while Energy metabolism and Cofactor and vitamin metabolism-related genes were significantly higher. This study offers valuable insights for the development of gut microbial resources in Lepidoptera insects. Full article

The widespread use of rare earth elements (REEs) in agriculture, particularly Lanthanum (La), raises concerns about their ecological impact on non-target organisms. We investigated the direct and indirect effects of La on the insect pest Spodoptera littoralis and its host plant, Brassica rapa. Direct exposure to La-supplemented diets reduced larval growth, survival, and egg production. Interestingly, a transgenerational effect was observed, where larvae from La-exposed parents exhibited increased resilience, showing no performance reduction on the same diets. Indirectly, La accumulation in plants mediated a hormetic response in herbivores, increasing larval weight at low concentrations but reducing it at high concentrations, while modulating their oxidative stress and detoxification gene expression. From the plant perspective, La exposure amplified herbivory-induced calcium signalling and altered the expression of key genes related to calcium and reactive oxygen species pathways. These findings reveal the complex ecological risks of La accumulation in agroecosystems, affecting both plants and insects directly and through novel transgenerational effects. Full article

Tachypleus tridentatus is a rare and endangered marine organism with considerable scientific and economic value. It has existed on Earth for about 450 million years and its continuation to the present day may be related to its unique immune system. Owing to its drastic population decline, diverse technical approaches are required for its recovery, and the development and growth of its larvae are crucial in this context. Vibrio parahaemolyticus is a common marine pathogen that impairs the healthy growth of marine organisms. The peak period of V. parahaemolyticus occurrence is from May to November, which significantly overlaps with the T. tridentatus spawning period from April to September. However, the response mechanisms of juvenile T. tridentatus to V. parahaemolyticus stress remain unknown. Hence, in this study, we aimed to investigate these response mechanisms through acute toxicity assays, histological observations, and transcriptome analysis. The results showed that the 48 h LD₅₀ of V. parahaemolyticus-infected T. tridentatus larvae was determined to be 1.31 × 10⁸ CFU/g. Histological analysis showed that V. parahaemolyticus damaged the larval tissue. In addition, RNA sequencing (RNA-Seq) identified 2347 differentially expressed genes (DEGs; 1440 upregulated and 907 downregulated genes) and 243 enriched signaling pathways. Functional enrichment analysis revealed the enrichment of immunoregulatory pathways, including the Wnt signaling pathway, ECM-receptor interaction, aminoacyl-tRNA biosynthesis, and Toll and Imd signaling pathways. Seventeen DEGs were randomly selected for real-time RT-PCR (RT-qPCR) validation, and their expression patterns were consistent with those obtained via RNA-Seq. The study of the response mechanism of T. tridentatus larvae to V. parahaemolyticus stress provides scientific references for the protection of T. tridentatus habitats and the recovery of its population size. Full article

Plant growth-promoting rhizobacteria (PGPR) offer a sustainable strategy for enhancing crop productivity and suppressing phytopathogens. In this study, seven bacterial isolates obtained from the rhizosphere of healthy tomato plants were evaluated for their antagonistic activity against the fungal pathogen Passalora fulva, the leaf miner Tuta absoluta, and their effects on tomato growth. In vitro dual-culture assays revealed that isolates IQR1, IQR2, IQR3, and IQR5 significantly inhibited P. fulva mycelial growth, with inhibition rates exceeding 35%. Volatile organic compounds (VOCs) produced by the bacterial isolates exhibited considerable antifungal activity, with IQR5, IQR1, and IQR2 achieving over 84% inhibition. Molecular identification based on 16S rDNA sequencing indicated that these isolates belong to distinct taxa: Leucobacter aridicolis (ON799334.1) (genus Leucobacter), Paenochrobactrum sp. (JF804769.1) (genus Paenochrobactrum), an uncultured bacterium (JQ337400.1) (genus Psychrobacter), and marine bacterium AK6_052 (KF816539.1) (genus Brevundimonas). Under greenhouse conditions, isolates IQR3, IQR5, and IQR1 reduced disease incidence of P. fulva to 20–26%. The same isolates also promoted plant growth, enhancing stem height and collar diameter. In addition, IQR5 significantly reduced T. absoluta larval density and foliar damage, with the number of larvae per leaflet decreasing to 1.42, compared to 3.20 in the control. These findings highlight the potentials of these rhizobacterial strains—particularly IQR5—as effective biocontrol agents and biofertilizers for integrated pest and disease management in tomato cultivation. Full article

To systematically elucidate the chronological patterns of embryonic development and morphological changes in the larval and juvenile stages of Silurus glanis, and provide fundamental biological insights into this species, in this study, fertilized eggs were obtained through artificial spawning induction technology. After removing adhesiveness from fertilized eggs using trypsin, a detailed developmental study was conducted. The study systematically analyzed the chronological sequence of embryonic development and the morphological change patterns of larval and juvenile fish. The results showed the following: The fertilized eggs of S. glanis are yellow, spherical, and sticky, and the stickiness allows eggs to attach to spawning substrates, enhancing hatching success. The egg diameter after water absorption was (2.88 ± 0.13) mm. The embryonic development took 47 h and 55 min, with a total accumulated temperature of 1245.56 h degrees Celsius, the developmental process includes seven stages and twenty-six periods, namely the zygophase stage, cleavage stage, blastula stage, gastrula stage, neurula stage, organogenesis stage, and hatching stage. At a temperature of (26.0 ± 0.9) °C, the hatched individuals went through the pre-yolk sac larval stage, late larval stage, juvenile fry stage, and juvenile stage. In the pre-yolk sac larval stage, otoliths appeared in the bilateral otic vesicles, a pair of barbel primordia emerged under the mandible, a short and thin straight intestine formed in the abdominal cavity, and the oral fissure first appeared. In the late larval stage, the fin rays were initially formed, the intestine became thicker and longer, the oral fissure, anus, and cloaca were formed, and the larvae could float and start feeding on exogenous food. In the juvenile fry stage, the differentiation of various organs was basically complete, the nostrils became larger, and both the anal fin and caudal fin had dark black markings. In the juvenile stage, the maxillary barbels elongated, the mucus layer thickened on the body and back, the abdomen is light white, and it had the external morphological characteristics of an adult fish. By measuring and calculating the total length, body length, body height, and head length of S. glanis larvae and juveniles (0–40 days), the results showed that the growth characteristics conformed to the following fish growth formula: TL = 0.0141x² + 0.8096x + 8.2421 (R² = 0.9916), where x denotes days after hatching. This study has preliminarily mastered the chronological patterns of the embryonic development, growth, and formation of the morphological characteristics in larval and juvenile S. glanis, providing scientific data and laying a theoretical foundation for the division of early developmental stages, reproduction, hatching, and fry cultivation. Full article