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To understand the growth and survival during the postlarval stage of Macrobrachium rosenbergii, commonly known as the giant freshwater prawn, two experiments were performed which explored the differences in growth and survival rates between wild and captive postlarvae and the effect of temperature on survival and growth. The postlarvae reared at 27 and 30°C grew significantly throughout the experimental periods. The survival rates in the wild and captive postlarvae were similar at approximately 60%. The highest survival rate of 58% was found at 27°C.

The global concern over trace and heavy metal contamination in aquatic environments necessitates the development of effective remediation strategies. Using aquatic plants for heavy metal removal is a relatively economical and sustainable technology worldwide. This study involved collecting sediment and aquatic plant samples (Acanthus ilicifolius, Typha elephantina, and Cynodon dactylon) from a highly urbanized estuary to analyze metal concentrations in sediment, assess ecological risks, and explore the phytoremediation potential. Trace and heavy metals were detected using Energy Dispersive X-ray Fluorescence Spectroscopy (EDXRF). The sediment metal concentrations were found in decreasing order of Fe, Ti, Mn, Rb, Zr, Zn, Sr, Cu, Co, and As. Fe, Sr, and As concentrations were below certified values, whereas Cu, Zn, and Rb exceeded them. Cumulatively, the pollution load index (PLI) values were close to 1 (0.845), indicating that the study area is likely experiencing metal pollution. The Contamination Factor (CF) values, ranging from 1 to 3, indicated a moderate degree of sediment pollution for Ti, Mn, Cu, Zn, and Rb. The Enrichment Factor (EF) values similarly showed moderate enrichment for these metals, with Cu exhibiting the highest degree of enrichment. Ecological risk assessment highlighted the only metal, Cu, as posing the greatest risk among the studied metals. In terms of phytoremediation potential, the bioconcentration factor (BCF) followed the decreasing order of C. dactylon > A. ilicifolius > T. elephantina for most metals, with low BCF values (<1) indicating low accumulator potential. However, the translocation factor (TF) values for Zn (1.464) and Rb (1.299) in A. ilicifolius species were greater than 1, indicating low accumulation potential but hyper-metabolizing capabilities, allowing the plant to accumulate metals in its aerial parts, making it effective for phytostabilization. [ABSTRACT FROM AUTHOR]

Microbial communities have been documented as playing many pivotal roles, and contributing to the growth or health performance of animal hosts. Thus, many studies are currently looking for potential beneficial bacteria "probiotics" from diverse environments, including wild species. The present study aimed to investigate the diversity and potential metabolic functions of bacterial communities in the gastrointestinal tract of wild spiny lobsters. The gastrointestinal (GI) tracts of two wild lobster species (Panulirus ornatus and Panulirus homarus) were dissected aseptically and analyzed through high-throughput sequencing, followed by PICRUSt analysis. The results exposed that the most dominant phyla inhabiting both lobster species at the post-puerulus and juvenile stages were Proteobacteria, Firmicutes, Bacteriodota, Patescibacteria, and Verrucomicrobiota, while at the genus level, the GI tracts were mostly dominated by Photobacterium, Candidatus Bacillopora, Vibrio, and Catenococcus at the post-peurulus stage, and Vibrio, Catenococcus, Acanthopleuribacter, Acinetobacter, Pseudoalteromonas, Grimontia, and Photobacterium at the juvenile stage. Further metagenomic prediction analysis discovers many potential probiont properties indicated by the detection of marker genes corresponding to many important metabolic activities, such as antimicrobial compounds (streptomycin, vancomycin, carbapenem, tetracycline, novobiocin, penicillin, cephalosporin, ansamycines, butirosin, and neomycin), antioxidants (e.g., flavonoids and carotenoids), and several important digestive enzymes (e.g., lipase, protease, and amylase). These results suggest that GI tracts of wild spiny lobsters are potential sources to discover novel probionts for aquaculture purposes. Further studies, such as the isolation of the natural product-producing bacteria, or cloning of the beneficial compound-identified genes, are highly recommended to develop novel probiotic strains for aquaculture purposes. [ABSTRACT FROM AUTHOR]

Reliance on fish meal can be reduced by incorporating plant-based ingredients, making aquaculture more economical, sustainable and environmental friendly. In this study, the efficacy of plant protein ingredients (PPI) such as mustard oil cake (MOC), soybean meal (SBM) and rice bran (RB) as Partial substitute of fishmeal (FM) was investigated for a commercially important fish, Labeo rohita in cages for 90 days. Three experimental diets, labeled as Diet 1, Diet 2, and Diet 3, were formulated to be isonitrogenous (with protein content ranging from 32.20 to 32.29%) and iso-caloric (with gross energy ranging from 4.12 to 4.17 kcal/g). These diets contained different proportions of PPI (45, 68, and 79%) and FM (46, 23, and 11%, respectively). Square-shaped cages with a volume of 1m3 (1 m × 1 m × 1 m) were stocked with 40 fish/m3 each with an average initial weight of 52.97 g in triplicates. Fish were hand-fed to apparent satiation twice daily for 7 days a week at a feeding rate of 5% in the initial month and 3% for the rest of the culture period. 50% of the caged fish was sampled monthly to monitor growth performance and at the termination of the experiment, all the fish was harvested to measure production economics performance. The results indicated improved growth performance and higher feed utilization at Diet 2, yielding significantly (p < 0.05) higher fish production compared to Diet 3, while these parameters were insignificant with Diet 1. By replacing FM with PPI, the total feed cost compared to Diet 1 was reduced to 20.62 and 32.76% for Diet 2 and Diet 3, respectively. The replacement of 50% FM in Diet 2 also yielded a 15.61% higher total economic net return than the Diet 1 group. However, a higher inclusion rate of PPI in Diet 3 potentially reduced fish growth, with a consequent decline of 41.61% total economic net return compared to the Diet 1 group. In conclusion, the replacement of 50% FM in Diet 2 compared to Diet 1 returned a higher benefit-cost ratio (1.72) among the feeding groups. Therefore, this FM replacement experiment suggested a 50% FM replaced diet as an unconventional, cost-effective, and readily available novel protein source without compromising the inherent nutritional quality of fish and feed in the cage culture of L. rohita. The results could be widely applicable to the fastgrowing approach of cage culture technology across Asia and beyond. [ABSTRACT FROM AUTHOR]