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Giant freshwater prawn (Macrobrachium rosenbergii (MR)) is a significant aquafarm species commercially cultured in Taiwan. Intensive farming practices have led to the outbreak of Lactococcus garvieae (LG), which causes Lactococcosis in MR. Recently, LG has re‐emerged and the number of mortalities in prawn farms has increased in Taiwan. However, there is no preventative strategy described and a lack of knowledge on virulence factors and pathogenesis from LG in MR. The most virulent strain of L. garvieae from M. rosenbergii was screened in vivo among seven isolates selected for infectivity testing injecting 0.1 mL of 108 CFU/mL bacterial concentration. Among the seven isolates screened, L. garvieae 109‐6 resulted in 100% mortality within 3 days post‐infection. Furthermore, 109‐6 L. garvieae LD50 dosage from in MR was found to be 106 CFU/mL. Subsequently, the most virulent strain 109‐6 was sequenced using MinIon Nanopore sequencing. Results indicated that the LG genome yielded a protein‐coding of 3857 with 59 tRNA and 16 rRNA and no plasmid. Interestingly, the distribution of subsystems in the annotated genome revealed genes related to virulence, defence, and disease among LG 50 genes. Altogether, the virulent strain and its genome data revealed distinctive features of LG, which hinted toward its pathogenicity and could facilitate for better preventive strategies. [ABSTRACT FROM AUTHOR]

Summary: Encapsulation efficiency (EE), structure, antioxidant and antimicrobial activities of liposomes loaded with chitooligosaccharide–gallic acid conjugate (COS–GAL) as affected by cholesterol (CHO) and ascorbyl palmitate (AP) as stabilisers were investigated. In addition, release kinetics and in vitro digestion of selected liposomes were also studied. The higher EE was obtained for liposome (AP/COS–GAL) stabilised by 0.50% AP, when used to encapsulate 0.10% COS–GAL conjugate. The highest EE was noticed for 0.25% CHO when used to encapsulate 1.00% conjugate (CHO/COS–GAL) as compared to the counterparts (P < 0.05). Almost similar antioxidant and antimicrobial activities were noticed for all COS–GAL liposomes and COS–GAL powder. Microstructure study suggested the formation of bilayer in liposomes. CHO/COS–GAL showed a lower release efficiency than the AP/COS–GAL. CHO/COS–GAL was also able to protect conjugate during the in vitro digestion. Therefore, liposomes could be used as a promising carrier of COS–GAL conjugate in both foods as well as medical systems. [ABSTRACT FROM AUTHOR]

The giant freshwater prawn (Macrobrachium rosenbergii) has many advantages in aquaculture, such as fast growth rate, short breeding cycle and good nutrition, which makes it a freshwater shrimp with high economic value. Herein, high-quality chromosome-level genome of both female and male prawns were obtained by combining Illumina paired-end sequencing, PacBio single molecule sequencing technique and High-through chromosome conformation capture (Hi-C) technologies. In ZZ male prawn, a final contig assembly of 3118.58 Mb with a N50 length of 956,237 bp was obtained. In WW female prawn, a final contig assembly of 3333.31 Mb with a N50 length of 1,143,555 bp was obtained. The assembled genome sequences from prawns were anchored to 59 chromosomes. Moreover, the sex chromosomes including W chromosome and Z chromosome were generated in prawn with the length of 36.23 Mb and 27.33 Mb, respectively. The sequence similarity of Z chromosome and W chromosome reached to 74.90%. The high-quality genome resource will be useful for further molecular breeding and functional genomic research of giant freshwater prawns. [ABSTRACT FROM AUTHOR]

Although farmed shrimp contribute to global food security and foreign exchange, the development of genomic resources such as single nucleotide polymorphisms for these shrimp is at slow pace. Public genomic resources like Genbank and Ensembl do not host polymorphism data for shrimp. Therefore, through analysis of the short RNA‐sequence reads generated on pooled‐individual samples, using the latest bioinformatics tools, this study documents data of single nucleotide polymorphisms in two shrimp species, Penaeus vannamei and Penaeus indicus, and presents these data in a searchable user‐friendly webtool, the dbVAST. The webtool also hosts the information about the possible effects that the variations could have on the functioning of the coded protein. This is the first open‐access SNP database of shrimp intended to benefit researchers and academicians by showcasing variations in shrimp transcripts. [ABSTRACT FROM AUTHOR]

Inorganic phosphates have been used in shrimp feeds to meet phosphorus (P) needs, which may be quantitatively affected by the dietary content of P and other minerals and digestibility. In the present study, performance and digestibility were determined simultaneously in juvenile shrimp (Litopenaeus vannamei) during the grow‐out period (4–23 g ind wt). Shrimps were fed plant‐based diets supplemented with different phosphate ingredients: monosodium phosphate (MSP), monoammonium phosphate (MAP), magnesium phosphate (MgP), and monocalcium phosphate (MCP). The total P level in test diets was 0.79%. MSP supplementation was tested at two dietary calcium:phosphorus ratios to check for possible effects upon shrimp performance and digestibility. A negative control diet was tested with a similar formulation without inorganic phosphate supplementation (0.47% total P). Shrimp was reared in a recirculated clear water tank system (35 ppt salinity, 30°C, 100 individuals/m3) with continuous feeding provided by automatic pellet delivery. Feces were sampled 4–5 times daily throughout the trial. A negative control diet produced P limitation and significantly reduced shrimp performances compared to P‐supplemented diets (P < 0.05). Performance of shrimp‐fed diets containing inorganic phosphates varied for feed conversion rate: 1.24–1.34, survival: 87%–94%, growth: 2.50–2.59 g/week, and no significant difference was found among dietary treatments (P > 0.05). Inorganic P supplementation resulted in significantly higher dry matter, crude protein, ash, and P apparent digestibility coefficient (ADC) compared to P limited negative control diet (P < 0.05). In addition, reduced P ADC (P < 0.05) was checked with higher dietary Ca:P ratio. Phosphorus digestibility in test diets showed significant differences: MSP > MCP, MgP, and MSP + CaCO3; MAP > MSP + CaCO3 (P < 0.05). Digestible P (%) could then be calculated in test diets: MgP (4.77 g Pdig/kg of feed), MSP + CaCO3 (4.81 g Pdig/kg of feed), MCP (5.0 g Pdig/kg of feed), MAP (5.13 g Pdig/kg of feed), and MSP (5.30 g Pdig/kg of feed). Digestible P in phosphate sources (%) could then be calculated: 88.2% MSP, 84.2% MAP, 79% MCP, 72.2% MgP, and 71.8% MSP + CaCO3. Shrimp whole body and exoskeleton phosphorus content also showed significantly higher values in P‐supplemented diets compared to control, regardless of the source tested (P < 0.05). It is concluded that tested phosphates were suitable for feeding juvenile shrimp with MSP, MAP, and MgP diets showing high feed efficiency, while MSP and MAP diets resulted in numerically increased growth, coinciding with numerically higher P digestibility in these phosphates. The elevated P digestibility in the phosphates seems related to their water solubility, though MgP, less soluble and digestible in comparison to MSP and MAP, could also produce good performance. [ABSTRACT FROM AUTHOR]

In this study, shrimp paste was prepared using Antarctic krill and fermented Antarctic krill shrimp paste as raw materials. Two commonly used heating methods, stir‐fried and steaming, were analyzed, the main difference between the two methods being that stir‐frying involves putting the shrimp paste into a wok and stir‐frying it for different periods of time, while steaming involves putting the shrimp paste into a steamer and steaming it for different periods of time. The effects of different salt concentrations and processing techniques on the volatile flavor compounds of shrimp paste were also observed. Electronic nose and gas chromatography–ion mobility spectrometry (GC‐IMS) were employed to analyze the volatile flavor compounds. A total of 52 volatile flavor compounds were detected by GC‐IMS, of which 38 were identified (including monomers, dimers, and polymers). The identified compounds included 11 aldehydes, 6 ketones, 14 alcohols, 2 esters, 2 acids, 1 pyridine compound, and 2 sulfur compounds. In addition, 14 compounds were identifiable. Using the results of the electronic nose analysis, we were also able to differentiate between the volatile flavor compounds in shrimp pastes produced by different processing methods. [ABSTRACT FROM AUTHOR]

As a typical pathogen-associated molecular pattern (PAMP), β-1,3-glucan can engage with pattern recognition receptors (PRRs) to initiate an immune response. In this study, we investigated the effects of dietary β-1,3-glucan on growth performance, antioxidant capacity, immune response, intestinal health, and bacterial resistance in juvenile Macrobrachium nipponense. Prawns were fed with five experimental diets containing 0%, 0.05%, 0.1%, 0.2%, and 0.4% β-1,3-glucan for eight weeks. The findings demonstrated that the inclusion of β-1,3-glucan improved weight gain and survival rate in prawns. Prawns fed with β-1,3-glucan exhibited elevated activities of hepatopancreatic ACP (acid phosphatase), AKP (alkaline phosphatase), and SOD (superoxide dismutase), while MDA (malondialdehyde) content was reduced. Expression levels of PRRs related genes including LGBP (lipopolysaccharide and β-1,3-glucan binding protein), lectin, and LBP (lipopolysaccharide-binding protein) were significantly increased in prawns fed with β-1,3-glucan. Intestinal flora analysis revealed suppression of Cyanobacteria abundance at the Phylum level and enhancement in Rhodobacter abundance at the genus level in prawns fed with a 0.2% β-1,3-glucan diet. Furthermore, prawns fed with 0.1%, 0.2%, and 0.4% β-1,3-glucan demonstrated significantly higher survival rates following Aeromonas hydrophila infection. In conclusion, β-1,3-glucan can activate PRRs to improve immune responses in M. nipponese. Within the range of β-1,3-glucan concentrations set in this experiment, it is recommended to add 0.18% of β-1,3-glucan to the diet, taking into account the positive effect of β-1,3-glucan on the survival rate of M. nipponensecu. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate and compare the effects of biofloc technology (BFT) and clear water (CW) on water quality physiological and productive performance of juvenile freshwater Northern River shrimp, Cryphiops caementarius under three stocking densities (100, 200, and 400 shrimp m−2). Shrimp with an initial body weight of 0.44 ± 0.07 g were stocked in 18 rectangular fiberglass tanks with a water volume 150 L for 290 days. During the experiment, water quality parameters stayed within acceptable ranges for shrimp growth. The highest survival rate was recorded in BFT treatments; however, the growth performance of shrimp in the treatments with the lowest stocking density was higher than that with the highest stocking density, regardless of whether BFT or CW was used. Transcriptional levels of heat shock protein (Hsp70) and superoxide dismutase (SOD) showed significant differences (p < 0.05) between treatments, particularly in BFT. These results indicate that an initial stocking density of 200 shrimp m−2 appears to be appropriate for shrimp juveniles cultured in a BFT system. Thus, this technology emerges as an effective tool for river shrimp farmers looking to increase their stocking densities and improve the efficiency of their production systems in arid zones. [ABSTRACT FROM AUTHOR]

In recent years, with the continuous expansion of aquaculture and the vigorous development of the aquaculture industry, the breeding environment and diseases have become increasingly prominent, and the quality and output of aquaculture products have been affected to a certain extent, which has become one of the important factors restricting the development of aquaculture industry. Clostridium butyricum is a kind of clostridium bacillus, a gram-positive bacterium, strictly anaerobic, which can form spores and produce short-chain fatty acids, biofuel compounds, and biomaterial precursors such as H2, butanol, and 1,3-propanediol in the process of fermenting carbohydrates and sugars. This article reviews the isolation, identification, main biological functions, and mechanism of C. butyricum in the gastrointestinal tract of aquatic animals and summarizes the role of C. butyricum in improving the growth performance, digestibility, survival, immune response, disease resistance, and intestinal structure, as well as regulating the intestinal symbiotic microbiota and metabolic disorders of aquatic animals. To provide insights into the key research directions of C. butyricum in shrimp aquaculture in the future, including research on the relationship between C. butyricum and the host immune system and the possibility of using C. butyricum as an antibiotic substitute for disease prevention and treatment, this study aims to provide a reference for the comprehensive utilization of C. butyricum in shrimp aquaculture and promote the high-quality development of the shrimp aquaculture industry. [ABSTRACT FROM AUTHOR]

To explore the optimal growth and reproduction temperature of Exopalaemon carinicauda, this study tested five temperature gradients (16°C, 20°C, 24°C, 28°C, 32°C) to determine the effects of different temperatures on the growth, digestive enzyme activity, ovarian development performance, ovarian nutrient concentration, vitellogenin, and sex hormone levels of E. carinicauda. The results showed that (1) Between 20° and 32°, the survival rate gradually decreased with the increase of temperature. As the temperature increases, the final body weight and specific growth rate first increase and then decrease (P<0.05), with the fastest growth at 28°; (2) The lipase activity first increases and then decreases with the increase of temperature (P<0.05), reaching a maximum value of 1.22 ± 0.09 U/gprot at 28°. The trypsin activity increased with the increase of temperature and reached a maximum value of 1695.45 ± 163.42 U/gprot at 32°; (3) the gonadosomatic index and ovarian maturation rate increased with increasing temperature; the concentrations of total protein, total cholesterol, and triglycerides generally increased with temperature; the vitellogenin showed a trend of first increasing, then decreasing, and then increasing with the increase of temperature (P<0.05); and (4) at temperatures of 24° and 28°, the concentrations of gonadotropin-releasing hormone were relatively high and close. The highest estradiol concentration was 26.62 ± 1.49 ng/L at temperatures of 28°. These findings indicate that 28° is a suitable temperature for promoting the maturation of the parent shrimp of E. carinicauda and may be recommended for a commercialized culture of this species. [ABSTRACT FROM AUTHOR]

Counting shrimp larvae is an essential part of shrimp farming. Due to their tiny size and high density, this task is exceedingly difficult. Thus, we introduce an algorithm for counting densely packed shrimp larvae utilizing an enhanced You Only Look Once version 5 (YOLOv5) model through a regional segmentation approach. First, the C2f and convolutional block attention modules are used to improve the capabilities of YOLOv5 in recognizing the small shrimp. Moreover, employing a regional segmentation technique can decrease the receptive field area, thereby enhancing the shrimp counter's detection performance. Finally, a strategy for stitching and deduplication is implemented to tackle the problem of double counting across various segments. The findings from the experiments indicate that the suggested algorithm surpasses several other shrimp counting techniques in terms of accuracy. Notably, for high-density shrimp larvae in large quantities, this algorithm attained an accuracy exceeding 98 % . [ABSTRACT FROM AUTHOR]

State Wildlife Action Plans (SWAPs), including lists of Species of Greatest Conservation Need (SGCN), outline state strategies for protecting species and habitats in the United States. In developing the current, second revision SWAPs, states are increasingly pursuing coordinated landscape conservation approaches. Analyzing SGCN lists in the first revision SWAPs, we found evidence that they already support multistate conservation. Most states address a common set of vertebrate and invertebrate groups, include most of the imperiled species from these groups, do not prioritize endemics over non‐endemics, and often include most imperiled species that are shared with neighboring states. Also, a regional SGCN coordination effort was successful. Although 65% of animals on each SGCN list were assessed as at elevated risk of extirpation by state authorities, only 43% of the combined national list were at elevated risk of global extinction. Over 40% of the combined animal SGCNs are considered globally apparently secure. Plants, snails, freshwater shrimps, and freshwater insects were poorly represented in SGCN lists. For the current SWAP revisions, we recommend improving foundational data on taxonomy, range‐wide distribution, and conservation status; expanded taxonomic coverage in SGCN lists; supporting existing and establishing new interstate initiatives; and diversifying funding mechanisms that target regional cooperation. [ABSTRACT FROM AUTHOR]

Phallocryptus spinosus (Milne-Edwards, 1840) and Branchinectella media (Schmankewitsch, 1873) are two anostracan species co-occurring in several saline lakes of the eastern steppic zone of Algeria. Both species produce resting eggs to persist in their temporary and unstable habitats, constituting a resting eggs bank. B. media has a wide and scattered distribution area, and it is known to prefer cold temperatures (16 °C max). Resting egg banks and hatching patterns of both species have been assessed in seven saline lakes. Results showed that densities of P. spinosus resting eggs were always higher than those of B. media, whatever the lake (F = 4.66, p = 0.0005). They range between 93,000 ± 75 and 1,495,000 ± 366.5 resting eggs m−2 for P. spinosus, and between 670 ± 30 and 365,000 ± 268 resting eggs m−2 for B. media. Hatching percentages of eggs incubated at temperatures of 16 °C and 22 °C, and salinities of 0 and 5 psu, showed that 16 °C and 5 psu was the most suitable combination for B. media, since 38.88 ± 1.93% of eggs hatched under these conditions. For P. spinosus, 81.11 ± 1.92% of eggs hatched at 22 °C and 5 psu. Resting eggs diameters measurements of both species as well as scanning electron micrographs of B. media are provided. [ABSTRACT FROM AUTHOR]

Melanosis in seafood is a natural post-mortem enzymatic process that results from the action of polyphenol oxidase from the animal’s own tissues. It reduces the organoleptic quality of the shrimp and their commercial value. This work concerns prevention of melanosis in pink shrimp (Parapenaeus longirostris) using the latest technology of enzymatic biosensor for sulphite detection. Three application methods (dipping, dusting, and spraying) with four commercial products were tested. Sulphite concentrations (1–3%) were applied for 1–10 min. Parameters measured included residual SO2 levels, pH, melanosis, and odour. Findings showed that the dusting method gave the best sensory scores, but had harmful residual SO2 values. The dipping method provided safe SO₂ levels below normative limits, when using products with 240 g Kg−1 SO₂ content applied at 1.25% bisulphite/seawater for 1 minute. Regarding the spraying method, the results remain promising. Nevertheless, further studies are necessary to understand its potential and limitations fully. [ABSTRACT FROM AUTHOR]

The present study provides length-weight relationships (LWRs) and condition factors (Kn) estimates for ten deep-sea scorpaeniform fishes based on data consisting of new maximum size. The samples were collected from Sakthikulangara Harbour, located on the southwest coast of India, from September 2021 to December 2022. These samples were obtained as bycatch from deep-sea shrimp trawlers operating in the Arabian Sea at depths ranging from 200 to 420 m. The estimated b values ranged from 2.92 (Brachypterois serrulata) to 3.76 (Pterygotrigla arabica). The Kn ranged from 0.56 (Satyrichthys laticeps) to 1.53 (Neomerinthe erostris), with four species exhibiting Kn values higher than 1. The LWR estimates and Kn provided in this study are helpful to understand the growth characteristics of these data limited species and also to revalidate the modeled growth parameters using the Bayesian approach. [ABSTRACT FROM AUTHOR]

In the dark, expansive habitat of the deep sea, the production of light through bioluminescence is commonly used among a wide range of taxa. In decapod crustaceans, bioluminescence is only known in shrimps (Dendrobranchiata and Caridea) and may occur in different modes, including luminous secretions that are used to deter predators and/or from specialised light organs called photophores that function by providing camouflage against downwelling light. Photophores exhibit an extensive amount of morphological variation across decapod families: they may be internal (of hepatic origin) or embedded in surface tissues (dermal), and may possess an external lens, suggesting independent origins and multiple functions. Within Dendrobranchiata, we report bioluminescence in Sergestidae, Aristeidae, and Solenoceridae, and speculate that it may also be found in Acetidae, Luciferidae, Sicyonellidae, Benthesicymidae, and Penaeidae. Within Caridea, we report bioluminescence in Acanthephyridae, Oplophoridae, Pandalidae, and new observations for Pasiphaeidae. This comprehensive review includes historic taxonomic literature and recent studies investigating bioluminescence in all midwater and deep benthic shrimp families. Overall, we report known or suspected bioluminescence in 157 species across 12 families of decapod shrimps, increasing previous records of bioluminescent species by 65%. Mounting evidence from personal observations and the literature allow us to speculate the presence of light organs in several families thought to lack bioluminescence, making this phenomenon much more common than previously reported. We provide a detailed discussion of light organ morphology and function within each group and indicate future directions that will contribute to a better understanding of how deep‐sea decapods use the language of light. [ABSTRACT FROM AUTHOR]

Since 2000, a well‐established population of the invasive oriental shrimp Palaemon macrodactylus has been present in fully marine conditions in the southwestern Atlantic Ocean (~38° S). To assess the physiological performance of this atypical population restricted to fully marine conditions, we conducted a laboratory experiment in which individuals were transferred from 35 ‰S (local seawater) to 2 ‰S; 5 ‰S; 10 ‰S; 20 ‰S; 50 ‰S and 60‰ for short (6 h), medium (48 h), and long (>504 h) acclimation periods. We measured the time course response of relevant parameters in the shrimp's hemolymph; activity of Na+, K+‐ATPase (NKA), and V‐H+‐ATPase (VHA); and muscle water content. Shrimp showed great osmoregulatory plasticity, being able to survive for long periods between 5 ‰S and 50 ‰S, whereas no individual survived after transfer to either 2 ‰S or 60 ‰S. Shrimp hyper‐regulated hemolymph osmolality at 5 ‰S and 10 ‰S, hypo‐regulated at 35 ‰S and 50 ‰S, and isosmoticity was close to 20 ‰S. Compared to 35 ‰S, prolonged acclimation to 5 ‰S caused a decrease in hemolymph osmolality (~34%) along with sodium and chloride concentrations (~24%); the NKA and VHA activities decreased by ~52% and ~88%, respectively, while muscle water content was tightly regulated. Our results showed that the atypical population of P. macrodactylus studied here lives in a chronic hypo‐osmo‐ion regulatory state and suggest that fully marine conditions contribute to its poor performance at the lower limit of salinity tolerance (<5 ‰S). Research Highlights: Shrimp lives in a chronic hypo‐osmo‐ionic regulatory state.Shrimp can tolerate brackish water but not freshwater.An incipient local physiological adaptation to full‐strength seawater is suggested. [ABSTRACT FROM AUTHOR]

Salinity and temperature significantly affect the growth and production of giant freshwater prawn Macrobrachium rosenbergii. This research investigated the effect of these two vital parameters on behaviour, survival, haemocyte-based cellular immunity, and proximate composition of M. rosenbergii. Adolescent prawns were exposed at five different salinities (0, 5, 10, 15, 20 ppt) and temperatures (22, 26, 30, 34, 38 °C) at a stocking of 6-ind/25-L glass tank with three replication and nursed up to 168 h. Prawn showed normal behaviour and movement up to salinity of 10 ppt, while rising salinity to 20 ppt associated with abnormal behaviour caused 50% mortality within 72 h and showed complete mortality after 96 h. Prawns exposed at 22–30 °C exhibited normal behaviours, while uplifting temperature to 34 °C showed unusual behaviour and mortality. Further increase of temperature to 38 °C, survival rapidly decreased to 33.33% after 24 h, and complete mortality happened within 72 h. Total haemocyte count and differential haemocyte count did not exhibit significant variation at salinity ≤ 10 ppt and temperature ≤ 30 °C, while there was a significant declination at higher salinities (≥ 15 ppt) and temperatures (≥ 34 °C). Interestingly, after a significant fall in protein content at 30 °C, it started to increase at higher temperatures. Meanwhile, a significant decrease in lipid content was recorded at salinity ≥ 15 ppt. Water quality measurements were within acceptable norms for prawn aquaculture throughout the experiment. According to this study, prawns' growth, behaviour, and immune system were mostly unaffected by saline levels up to 10 ppt and temperatures below 30 °C; thus, ranges could be adopted for climatically altered coastal environments. [ABSTRACT FROM AUTHOR]

Object detection adopting deep-learning has strongly promoted the development of intensive aquaculture. However, shrimp larvae, as an important aquatic organism, are more difficult to be detected than others. On the one hand, they have indeed small sizes, which will cause them to be easily ignored due to the background noise pollution. On the other hand, affected by environmental factors and the fact that shrimp larvae like to move fast as jumping, the images of shrimp larvae often appear blurry. In order to obtain better shrimp larvae detection performance, we propose an improved anchor-free method called CAGNet in this paper. Compared with YOLOX_s, three structures including backbone, neck, and head have been improved in the proposed method. Firstly, we ameliorate the backbone by adding a coordinate attention module to extract more location information and semantic information of shrimp larvae at different levels. Secondly, an adaptively spatial feature fusion module is introduced to the neck. It can adaptively integrate effective shrimp larvae features from different levels and suppress the interference of conflicting information arising from the background. Moreover, in the head, we use GIoU module instead of conventional IoU for more accurate bounding box regression. We conducted experiments by collecting shrimp larvae data from a real aquaculture farm. Compared with the general object detection methods and previous related research, CAGNet has achieved better performance in Precision, Recall, F1 Score, and AP@0.5:0.95. Hence, the proposed method can be effectively applied to shrimp larvae detection in intensive aquaculture. [ABSTRACT FROM AUTHOR]

This study investigated the effects of exogenous enzyme supplementation, specifically phytase and protease, in fish meal–free and phosphorus-limited diets for juvenile Litopenaeus vannamei through two feeding trials. The trials aimed to assess shrimp growth performance and apparent nutrient digestibility simultaneously in a clear-water recirculating tank system (34 ppt, 30 °C) employing a continuous feeding regime, with feces being collected on a daily basis throughout the feeding trials. In the first feeding 50-day feeding trial shrimp (3.4 g initial body weight) were fed diets supplemented with phytase (1000 and 2000 FTU/kg) and phytase together with protease (1000 FTU/kg + protease and 2000 FTU/kg + protease), in addition to animals fed a positive control (supplemented inorganic phosphate) and a negative control diet without supplementation. In the second shrimp feeding trial (4.3 g initial body weight), in addition to negative and positive controls, shrimp were fed increasing levels of phytase (1000, 2000, 3000, 4000 and 8000 FTU/kg) over a 42-day experimental period. Both feeding trials showed beneficial effects phytase addition compared to the negative control, with significant improvements (P < 0.05) observed at dietary phytase levels of 2000 FTU/kg and above. Gains were obtained in growth performance (observed weekly growth of 1.46 and 1.86 g/week for shrimp fed the negative control and diet supplemented with 3000 FTU/kg, respectively), and apparent phosphorus digestibility increasing from 41.7% in animals fed the negative control diet to 52.9% in animals fed the 3000 FTU/kg supplemented. Results indicated that phytase supplementation yielded significant improvements in shrimp growth performance and phosphorus digestibility compared to the negative control. Notably, the observed benefits were evident at specific dietary phytase levels. However, the addition of protease supplements did not demonstrate any discernible effects on shrimp performance under the experimental conditions. Overall, these findings underscore the potential of phytase supplementation as a means to enhance nutrient utilization and promote optimal growth in L. vannamei. Further investigations are warranted to explore the full range of benefits and mechanisms associated with protease supplementation in shrimp diets. [ABSTRACT FROM AUTHOR]

Vibriosis is a disease that frequently infects shrimp and financially devastates the shrimp industry worldwide. Because of the detrimental effects of antibiotic use in shrimp disease management, such as the emergence of various antibiotic-resistant bacteria, decreased antibiotic efficacy due to long-term use, and residues remaining in sediments, water, and shrimp body tissues, researchers are developing alternatives to vibriosis disease control through biocontrol technologies that are more effective, economical, and environmentally friendly. Biological agents such as microalgae, viruses, fungi, and bacteria are used in several biocontrol technologies. Despite its widespread use, several aspects of bacteria-based Vibrio biocontrol remain poorly known, including the most effective pathogen suppression mechanism and how it interacts with shrimp as a host. In this review, the development of biocontrol technologies for vibriosis in shrimp, especially those that use bacteria as agents, such as green water technology, biofloc, probiotics, and synbiotics, as well as the biocontrol mechanism of action and its interactions with the host and opportunities for further studies, are discussed to enrich our understanding of controlling Vibrio in shrimp in the future. [ABSTRACT FROM AUTHOR]

Dissolved oxygen (DO) is a crucial water quality characteristic in the cultivation of vannamei shrimp. Increasing the DO concentration in shrimp ponds can be carried out using the aeration method with a tool called an aerator. In this study, types of fine-pore aeration tubes are chosen. This aerator offers multiple benefits, such as superior aeration efficiency, effortless installation, and minimal clogging. In practice, fine-pore aeration tubes can be arranged according to needs, so the layout used can influence the resulting aeration performance. This research uses the computational fluid dynamics (CFD) method to analyze DO distribution, water circulation, and aeration performance ( K L a 20 , SOTR, and SOTE) produced in various aerator layouts, namely straight-type, ring-type, and square-type, in a vannamei shrimp pond. The results show that the straight-type layout has the best DO distribution because it is spread throughout the pond area. The square-type layout has the best water circulation because it has the largest area with water velocities of less than 5 cm/s. The optimal aeration performance was achieved with the straight-type layout, which demonstrated a K L a 20 value of 3.16 h−1, SOTR value of 19.20 kg/h, and SOTE of 29.30%. [ABSTRACT FROM AUTHOR]

The effects of dietary mannan oligosaccharide (MOS) supplementation in a biofloc system on growth performance, whole‐body proximate composition, whole‐body fatty acids, nonspecific immune parameters, antioxidant enzyme activities, digestive enzyme activity, and gut microbiota of brown shrimp, Farfantepenaeus aztecus, were investigated. Shrimp were fed five diets containing different levels of MOS doses (MOS0: basal diet, MOS1: 0.1%, MOS2: 0.2%, MOS3: 0.3%, and MOS4: 0.4%) during the 90‐day trial. The results indicated that all MOS‐supplemented shrimp showed significantly higher growth rates and better feed utilization than shrimp fed the control diet. Experimental diets had varying effects on the nonspecific immune parameters and antioxidant enzyme activities, indicating that MOS supplementation resulted in significant differences in the parameters except for respiratory burst activity. Significantly higher protease activity was observed in shrimp fed MOS1 and MOS2 diets compared with MOS0, MOS3, and MOS4 diets. Shrimps fed MOS2 and MOS3 diets had the highest lipase and amylase activities among all groups. Proteobacteria were the most abundant phylum in all groups and were higher at increasing MOS doses. In conclusion, these results suggest that supplementing the diet of brown shrimp in the biofloc system with 3 g kg−1 of MOS may improve production parameters. [ABSTRACT FROM AUTHOR]

The water quality is vital for the vannamei shrimp pond's productivity. Manual monitoring at Gunung Anyar's vannamei shrimp pond is timeconsuming, ineffective, and potentially harmful. In this research, we developed a real-time monitoring system for the water quality of the vannamei shrimp pond. This monitoring system is integrated with a solarbased aerator. To address this, water quality monitoring in a solar-based aerator system tracks the degree of acidity (pH), temperature, and total dissolved solids (TDS) remotely using a website and real-time mobile phone Android application with 98.57% accuracy and 1.43% error. Seven days of data revealed the degree of acidity between 6.92 and 7.34 is indicated poor conditions of the pond While the temperatures from 23.59 °C to 38.32 °C, and TDS from 628.65 to 652.34 ppm indicate the good condition of the shrimp pond. This real-time monitoring system can help vannamei shrimp farmers monitor the actual conditions of their ponds. [ABSTRACT FROM AUTHOR]

Determination of protein and lipid requirements is crucial in prawn species aquaculture. The present study investigated the impact of six diets with different protein and lipid levels (T1, 30/08; T2, 30/12; T3, 35/08; T4, 35/12; T5, 40/08; and T6, 40/12), in triplicate, on the zootechnical performance and body composition of juvenile Macrobrachium macrobrachion over 56 days. These protein and lipid levels were chosen based on the requirements of other freshwater prawn species. The stocking density was one individual per liter. Results show that prawn survival was lower in T6 (with 40% protein and 8% lipid) compared to all others. The treatment T3 (35% protein and 8% lipid) shows higher survival (with 40.0 ± 24.0%) but not significantly different from other diets. The specific growth rate obtained in the present study was not different between diets. Negative values were recorded for treatments T2, T3, and T4 (30%, 35%, and 35% proteins and 12%, 8%, and 12% lipids, respectively) and positive values for treatments T1, T5, and T6 (30%, 40%, and 40% proteins and 8%, 8%, and 12% lipids, respectively). The protein efficiency coefficient (PEC) and the lipid efficiency coefficient (LEC) did not differ between treatments; however, there was a trend for these coefficients to be lower in T4, T5, and T6 (35%, 40%, and 40% proteins and 12%, 8%, and 12% lipids, respectively) compared with the other diets. The highest protein efficiency rates were recorded with the T3 and T4 treatments (35% proteins and 8% and 12% lipids, respectively), while the best lipid level was obtained with T4 (35% proteins and 12% lipids). According to dose–response models, the optimal protein/lipid ratio requirements for M. macrobrachion juveniles can be estimated at 35/8. This study is the first to provide relevant information on the nutritional needs of juveniles of African native freshwater prawn M. Macrobrachion. Further research is needed to optimize nutritional requirements at early stages of development. [ABSTRACT FROM AUTHOR]

Chitin biomass is the second largest biomass resource on Earth but under-utilized. In this study, pretreated shrimp shells were converted into value-added platform chemical 5-hydroxymethylfurfural (HMF) using microwave hydrothermal treatment. Under the combined pretreatment of acid decalcification at room temperature and microwave-assisted alkali deacetylation, the HMF yield could reach 1.8 wt%. The key process parameters, including the holding temperature, holding time, and pH value, were evaluated and optimised. The highest HMF yield of 6.5 wt% was obtained at 202.6°C at a holding time of 5.8 min and a pH value of 1.5. This result demonstrates the potential of synchronously treating waste and recycling it, thereby offering a highly promising valorisation strategy for chitin-biomass utilisation. [ABSTRACT FROM AUTHOR]

Comma shrimp, or cumaceans, are diverse benthic crustaceans, yet they are one of the groups with the poorest fossil record, hindering our understanding of the evolution of the group in deep time. Here, we describe a new species of fossil comma shrimp, Makrokylindrus itoi sp. nov., from the Plio‐Pleistocene of Japan. The singular fossil is exceptionally preserved, including details of the carapace, cuticle, and some appendages, and it represents the first known fossil of the family Diastylidae and only the fourth fossil crown group cumacean known to date. We suggest that the scarce and sparsely known fossil record of cumaceans likely reflects a lack of recognition due to their small size and unfamiliar anatomy, making fossil cumaceans easy to misidentify, be confused with crustacean larvae of unknown affinities, or be interpreted as fragments of other crustaceans (taxonomic bias), rather than a lack of fossilization potential (taphonomic bias). [ABSTRACT FROM AUTHOR]

The addition of Navicula sp. to shrimp nurseries can improve the growth of Penaeus vannamei reared in biofloc systems. However, the contribution of microalgae to the biofloc formation and the effective contribution to shrimp nutrition remain unknown. In this study, Navicula sp. was added to biofloc nursery systems of P. vannamei at distinct time frequencies for evaluating its nutritional contribution to shrimp growth. Nursery rearing was carried out in bioflocs for 35 days at a stocking density of 3000 post-larvae m−3. Shrimp were fed using a commercial feed plus fresh culture of Navicula sp. at different frequencies: no addition of Navicula sp. (WN – control), the addition of 10 × 104 cells mL−1 of the diatom every 5, 10 and 15 days (N5, N10 and N15, respectively). Food sources relative contribution to P. vannamei development was estimated using a Bayesian mixture model. The isotopic discrimination factor (Δ15N and Δ13C) for each food source was determined experimentally. After 35 days of culture, survival (∼93 %) was similar across all treatments but there was a significant difference in weight gain and feed conversion ratio. The N10 treatment (0.50 ± 0.05 g, 0.99 ± 0.01) exhibited better growth parameters when compared to the WN treatment (0.33 ± 0.07 g, 11.46 ± 0.30). Biofloc was the food source most assimilated by shrimp followed by Navicula sp. and commercial feed. Contribution of Navicula sp. was higher in the N5 treatment. In the treatments with diatom addition, an inverse correlation was observed between the relative contributions of biofloc and Navicula sp., indicating that Navicula sp. is not in the biofloc composition, but it is directly consumed by P. vannamei post-larvae. Biofloc and Navicula sp. exhibited larger contributions to the growth of shrimp, reinforcing the importance of natural food sources to the aquaculture of P. vannamei post-larvae. [ABSTRACT FROM AUTHOR]

We document the first record of Kishinouyepenaeopsis incisa (Wang & Liu in Liu & Wang, 1987) (Decapoda, Penaeidae) from the west coast of Peninsular Malaysia. Five specimens were initially collected during a trawling survey in April 2014, followed by another 17 specimens collected during sampling sessions from February 2023 to August 2023. Previously, this species was known to occur only in South China and Bangladesh. We provide detailed morphometric and meristic data, along with brief diagnostic characters, supported by genetic analysis that corroborates the species identity and distribution. [ABSTRACT FROM AUTHOR]

To maximize camouflage across visually heterogeneous habitats, animals have evolved a variety of strategies, including polyphenism, color change, and behavioral background matching. Despite the expected importance of behavioral processes for mediating camouflage, such as selection for matching substrates, behavior has received less attention than color traits themselves, and interactions between color change and behavior are largely unexplored. Here, we investigated behavioral background matching in green and red chameleon prawns (Hippolyte varians) over the course of a color change experiment. Prawns were housed on mismatching green and red seaweeds for 30 days and periodically given a choice test between the same seaweeds in y-choice trials over the experiment. We found that, as prawns change color and improve camouflage (to the perspective of a fish predator), there is a reinforcing shift in behavior. That is, as prawns shift from red to green color, or vice versa, their seaweed color preference follows this. We provide key empirical evidence that plasticity of appearance (color) is accompanied by a plastic shift in behavior (color preference) that reinforces camouflage in a color changing species on its natural substrate. Overall, our research highlights how short-term plasticity of behavior and longer-term color change act in tandem to maintain crypsis over time. [ABSTRACT FROM AUTHOR]

A freshwater prawn M. sundaicum, is an obligate species to acidic peat swamp. Up to the present, M. sundaicum has only been reported in the West Kalimantan, the Riau Archipelago, and Jambi Provinces in Indonesia. The aim of this research is to determine the distribution and habitat preferences of peat swamp prawn in Selat Panjang Island, Riau Province, Indonesia. The samples were collected in seven peat swamp rivers by hand net. The study yielded one hundred specimens. The acidic peat swamp is a perfect habitat for M. sundaicum. This study provided the basic information about peat swamp prawn in Selat Panjang Island, especially their distribution and habitat preferences. [ABSTRACT FROM AUTHOR]

Background: Enterocytozoon hepatopenaei (EHP) is a microsporidian parasite that infects Pacific white shrimp (Penaeus vannamei). EHP infection causes severe growth retardation and subsequent economic losses, thereby posing a major challenge in shrimp farming. Understanding the diversity of microbiota in EHP-infected shrimp hepatopancreas (HP) is essential, as the organ plays a crucial role in nutrient storage, absorption and growth. Methods: A metagenomic approach was employed, targeting the V3-V4 conserved region of the 16S rRNA gene to gain insights into the microbiome dynamics of P. vannamei HP in response to EHP infection. Operational Taxonomic Units (OTUs) were identified from the sample reads using sequence similarity based on the 16S bacterial reference database (Greengenes) and the OTUs were clustered together using UCLUST at a cut-off of 97% identity. Result: The analysis revealed a varied OTU abundance between healthy and EHP-infected HP samples. Higher levels of pathogenic Vibrionales, Pseudoalteromonadaceae, Vibrio and Photobacterium damselae were found in EHP-infected HP samples, linked to Acute Hepatopancreatic Necrosis Disease (AHPND) and White Feces Syndrome (WFS) in shrimp, suggesting a possible pathobiome interaction in conjugation with EHP. Furthermore, specific taxa like Sphingomonadaceae, Chitinophagaceae, Cytophagaceae, Verrucomicrobiaceae, Xanthomonadaceae, Pseudomonas and Kaistobacter were more abundant in healthy P. vannamei HP, suggesting their potential as health biomarkers to assess the overall health status of the shrimp. [ABSTRACT FROM AUTHOR]

In this work, effects of constant and time-dependent vaccination rates on the Susceptible–Exposed–Infected–Recovered–Susceptible (SEIRS) seasonal model are studied. Computing the Lyapunov exponent, we show that typical complex structures, such as shrimps, emerge for given combinations of a constant vaccination rate and another model parameter. In some specific cases, the constant vaccination does not act as a chaotic suppressor and chaotic bands can exist for high levels of vaccination (e.g., > 0.95). Moreover, we obtain linear and non-linear relationships between one control parameter and constant vaccination to establish a disease-free solution. We also verify that the total infected number does not change whether the dynamics is chaotic or periodic. The introduction of a time-dependent vaccine is made by the inclusion of a periodic function with a defined amplitude and frequency. For this case, we investigate the effects of different amplitudes and frequencies on chaotic attractors, yielding low, medium, and high seasonality degrees of contacts. Depending on the parameters of the time-dependent vaccination function, chaotic structures can be controlled and become periodic structures. For a given set of parameters, these structures are accessed mostly via crisis and, in some cases, via period-doubling. After that, we investigate how the time-dependent vaccine acts in bi-stable dynamics when chaotic and periodic attractors coexist. We identify that this kind of vaccination acts as a control by destroying almost all the periodic basins. We explain this by the fact that chaotic attractors exhibit more desirable characteristics for epidemics than periodic ones in a bi-stable state. [ABSTRACT FROM AUTHOR]

Urban and agricultural runoffs can transport contaminants and pesticides into freshwater ecosystems, particularly in the developing tropics. For instance, organophosphate and pyrethroids pesticides, such as Roundup, Malathion, and Permethrin, have been found in tropical streams. The uncontrolled application of these pesticides has become a growing concern due to their adverse effects on various non-targeted organisms. Unfortunately, most studies have focused on a few selected model species, ignoring the effects on other non-target organisms, which may play an important role in tropical lotic ecosystems. In addition, the biological characteristics of aquatic crustaceans, including their morphology, physiology, and behavior, make them susceptible to toxic chemicals. For this reason, this study used the widely distributed freshwater shrimp Xiphocaris elongata as a model organism to determine the acute toxicity of Permethrin, Malathion, and Roundup. Our results show that the proportion of mortality of X. elongata in each concentration group became progressively higher as the concentration of exposure increased. We also found that the synthetic pyrethroid Permethrin was the most toxic pesticide tested, with a median lethal concentration (LC50) value for 96 h of 3.96 × 10−6 µg·L−1, followed by organophosphate Malathion (8.87 µg·L−1) and Roundup (748.92 µg·L−1). Experiments with this freshwater shrimp showed a good control performance and reproducibility for the tested pesticides. This study demonstrated that X. elongata is a suitable test organism that can be a representative bioindicator of pesticide toxicity in tropical streams. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the impact of adding fermented herbal extracts (FHE) derived from mulberry leaf (Morus alba), Javanese turmeric (Curcuma xanthorrhiza), and fingerroot (Boesenbergia rotunda) to the diet of tiger shrimp (Penaeus monodon) on their growth, moulting performance, feed efficiency, and nutrient retention. The main feed used in this trial was a commercially manufactured pellet; then, five different doses of FHE supplementation were used: 0 mL/kg feed (P0, control), 50 mL/kg feed (P1), 100 mL/kg feed (P2), 150 mL/kg feed (P3), and 200 mL/kg feed (P4). Weight gain, average daily gain, and length gain of shrimps fed P2 were significantly higher than that of those fed the control diet. A similar result was observed in moulting performance. The application of P2 showed superior results in enhancing the feed efficiency of cultured shrimp. Thus, the protein and energy retention of P. monodon was significantly better in P2 treatment groups. P0 had the lowest crude protein, while shrimp on the P2 and P3 diets had the highest crude protein content of any treatment group. Crude lipid content was lower in shrimp fed diets supplemented with FHE compared to those fed the control diet. In addition, higher energy contents were found in P1 and P2 treatment groups. Based on the findings, it is recommended that the juvenile tiger shrimp diet contain 100 mL/kg of FHE for the best effects. [ABSTRACT FROM AUTHOR]

The use of aquaponic systems has grown in recent years, but few of these systems have integrated the production of prawns and short-cycle vegetables. This study evaluated the potential for producing microgreens (beet, amaranth, arugula, and red cabbage) integrated with Amazon River prawns (Macrobrachium amazonicum) in an aquaponic system. Four seeding densities (5, 10, 15, or 20 seeds/cell) were assessed in two treatments: one using prawn wastewater and the other using plain dechlorinated water (control). Water quality, prawn growth performance, and microgreen productivity were monitored over 13 days, revealing optimal conditions for both prawns and microgreens in the aquaponic system. Amaranthus paniculatus yielded 374.00 g/m2 in prawn wastewater compared to 231.34 g/m2 in the control, while Beta vulgaris produced 1734.39 g/m2 in wastewater versus 1127.69 g/m2 in the control. Similarly, Brassica oleracea (2180.69 g/m2) and Eruca sativa (2109.46 g/m2) had higher yields in the prawn aquaponics system. These findings demonstrate that integrating prawn cultivation in aquaponic systems significantly enhances microgreen production compared to traditional methods. This integrated approach not only improves yields but also offers a more sustainable production model. Significant variation in productivity and growth metrics among species treatments underscores the viability and need for more systematic aquaponic procedures. [ABSTRACT FROM AUTHOR]

The abundance dynamics of short-lived marine species often exhibit large-amplitude fluctuations, potentially driven by unknown but important species interactions and environmental effects. These complex dynamics pose challenges in forecasting and establishing robust reference points. Here, we introduce an empirical dynamic modeling (EDM) framework using time-delay embeddings to recover unspecified species interactions and environmental effects, and use walk-forward simulations with varying harvest rates to estimate maximum sustainable yield (MSY). Firstly, we apply our framework to simulated data under various dynamics scenarios and demonstrate the statistical robustness of EDM-based MSY. Secondly, we apply our framework to abundance and catch time series (>30 years) of federally managed brown shrimp stocks in the US Gulf of Mexico. We identify nonlinear signals and achieve high prediction accuracy in the empirical dynamics of brown shrimp. Lastly, based on the EDM of brown shrimp dynamics, we obtain MSY for timely and effective management. Our results highlight the utility of EDM in deriving reference points for short-lived species, particularly in situations where stock abundance and catch dynamics are influenced by unobserved species interactions and environmental effects in a complex ecosystem. [ABSTRACT FROM AUTHOR]

(1) Background: Genotype-by-environment interaction (G×E) can adversely impact genetic improvement programs. The presence of G×E is mainly measured as the genetic correlation between the same trait measured in different environments where departure from unity can be taken as presence of G×E. (2) Methods: To understand the extent of G×E in shrimp production, a review and meta-analysis was conducted using the results from 32 peer-reviewed studies. (3) Results: Of these, 22 G×E studies were conducted on Pacific white shrimp (Litopenaeus vannamei) with fewer studies reported in other shrimp species. The most frequently studied traits were growth and survival, with relatively few studies on traits of economic importance. The meta-analysis demonstrated a moderately high genetic correlation (rg = 0.72 ± 0.05) for growth, indicating low to moderate levels of G×E with some re-ranking of breeding values across environments. However, substantial G×E was evident for survival where only a moderate genetic correlation (rg = 0.58 ± 0.07) was observed for survival across different environments. A re-ranking of breeding values is likely for this trait and genetic improvement of shrimp for survival in one environment may not be effective in other environments. The results from ANOVA-based studies show that G×E accounted for 6.42 ± 1.05% and 7.13 ± 3.46% of the variation for growth and survival traits, respectively. (4) Conclusion: The significance of G×E necessitates tailored genetic improvement programs in commercial shrimp breeding. We discuss the scope and challenges of G×E for shrimp breeding programs, including opportunities of implementing G×E in genomic selection programs. [ABSTRACT FROM AUTHOR]

As climate change transforms marine environments globally, species distributions correspondingly shift to locations where conditions have become or remain favourable. The ability to model these distributional shifts has been facilitated by species distribution models (SDMs). However, current SDM approaches have largely ignored climate‐driven changes in species interactions, which ultimately can have an important influence on species distributions. In this study, we utilize a long‐term, large‐scale dataset spanning 48 years and approximately 30 degrees latitude across the Canadian Atlantic shelf. We examine how climate influences the distribution and predation patterns of two invertebrates, northern shrimp Pandalus borealis and snow crab Chionoecetes opilio, aiming to evaluate the impacts of climate change on prey distributions. We found that both invertebrate species have a pronounced predicted response to climate change, with a northern shift in the distribution of northern shrimp and an overall reduction in abundance of both snow crab and shrimp associated with warming temperatures. Including predatory interactions as predictors in the SDMs (either directly via predator densities or via estimated predation rates) improved prediction accuracy for northern shrimp but not for snow crab. This is consistent with the ecology of these two species, as northern shrimp is more vulnerable to predation than snow crab. We found that the projections of future northern shrimp distributions are sensitive to the predicted spatial distribution and abundance of predators, highlighting the inherent complexity of predicting species response to climate change. Collectively, these results contribute to a broader literature that seeks to improve the capabilities of models to predict the effects of species interactions on species distributions under changing ecological conditions. [ABSTRACT FROM AUTHOR]

Jack-knife shrimp Haliporoides sibogae is a target species for boat seine fishery in the waters off south-western Kyushu, Japan. Reproduction, including ovarian maturation, size at sexual maturity, and spawning season of this species were studied using females collected from Kagoshima Bay, southern Japan. The present study also explored an alternative maturity index by conducting a microscopic examination of oocytes. Histological analysis of the ovaries validated six oocyte developmental stages. Ovarian development was asynchronous, indicating multiple spawning throughout a reproductive season. On the basis of the developmental stage of the most advanced oocytes, ovarian maturity was categorized into three stages: immature, maturing and mature. Females containing oocytes exhibiting cortical crypts were defined as mature. The gonadosomatic index (GSI) significantly increased as ovarian maturation progressed, and all females with a GSI of ≥ 6% were determined to be mature. The minimum size at sexual maturity was estimated to be 24.0 mm in carapace length. The spawning season extended from November to May, with February being the peak. Moreover, microscopically, the oocytes with spherical bodies on the periphery all had cortical crypts. Therefore, observation of oocytes using a microscope was considered an effective method to easily identify mature females. [ABSTRACT FROM AUTHOR]

The present work was aimed at evaluating whether females of a freshwater shrimp, Neocaridina davidi (Bouvier, 1904), allocate differentially to reproduction when reared in the presence of males and in the presence of brothers/non-brothers. Ovarian growth was evaluated in three consecutive maturation cycles. The composition of biochemical reserves was determined in the eggs (i.e., embryos) laid at the end of the first cycle, in 20-day-old juveniles produced at the end of the second cycle, and in the mature ovary of females at the end of the third cycle. When reared in the absence of males, females took longer to mature the ovaries and stored less proteins, triglycerides, and cholesterol in the mature ovary. Females reared with brothers took longer to mature the ovaries than females reared with non-brothers, with no differences in the biochemical composition of their mature ovaries. The eggs produced by females mated to brothers showed a lower carotenoid content, higher cholesterol content, and a tendency towards lower energy content than those produced by females mated to non-brothers. These results suggest that females are capable of recognizing kin and modulate primary reproductive effort, in terms of ovarian and egg biochemical composition, according to male presence and genetic relatedness. [ABSTRACT FROM AUTHOR]

The non-indigenous mysid Neomysis americana (S.I. Smith, 1873) is reported here, for the first time, along the Bay of Biscay in the Loire estuary, France in 2021. This species, originating from North-American estuaries, was initially discovered in Europe in 2010 (Wadden Sea) and first reported in France in 2017 (Seine estuary). The absence of long-term monitoring makes it impossible to know precisely the arrival of this non-indigenous species in the Loire estuary. However, this species is present in high abundance, suggesting an arrival prior to 2021. Its introduction might even be prior to or concomitant to the Seine estuary discovery, suggesting an introduction via the ballast water of the commercial vessels. [ABSTRACT FROM AUTHOR]

The effect of different drying methods (oven drying, fluid bed drying, and freeze drying) on the fatty acid composition, astaxanthin content, antioxidant activity, and colour values of giant red shrimp (Aristaeomorpha foliacea) processing wastes were investigated. These results showed that freeze drying was the most effective method in preserving the quality of shrimp processing waste (SPW), resulting in higher levels of EPA and DHA, astaxanthin content, antioxidant activity, and desired reddish colour characteristics compared to other methods. These findings highlight the potential of freeze drying as a suitable technique for converting SPW into high value products. [ABSTRACT FROM AUTHOR]

The current study was to examine the significance of primary productivity and phytoplankton density in semi-intensive and intensive shrimp (L. V annamei) ponds located at Haleyangadi, Mangaluru (Taluk), Dakshina Kannada (District), Karnataka. Primary production metrics were examined biweekly throughout a span of 90 days, starting from the time of stocking to harvest (November 2021 to February 2022). A total of 8 species from 3 classes were found in semi-intensive ponds, whereas 12 species from 4 classes were identified in intensive shrimp ponds during the course of the study. The gross primary production in intensive shrimp ponds varied from 239.583 to 302.083 mg C/m³/hr. The gross primary production in semi-intensive ponds varied from 192.708 to 348.950 mg C/m³/hr. During the research period, it was noted that net productivity was quite low, suggesting that a significant proportion of the organic matter produced by photosynthesis was utilized for respiration. [ABSTRACT FROM AUTHOR]

Large branchiopod crustaceans are flagship species of temporary water bodies, especially in arid and semi-arid regions. Less information is available about the large branchiopods of tropical Asia compared to other parts of the world such as the Americas. To reduce this disparity, we surveyed large branchiopods from the semi-arid region of Maharashtra state, India. Sampling at 29 sites over four years revealed nine species representing four orders. This is the highest diversity ever reported from a single regional study in India. Anostracans were the most commonly occurring group, whereas the spinicaudatans Leptestheria cf. nobilis Sars, 1900 , L. jaisalmerensis Tiwari, 1962 , and Eulimnadia michaeli Nayar & Nair, 1968 were very rare. Leptestheria jaisalmerensis had been known previously only from its type locality nearly 1,200 km north of our study region. Congeneric assemblages of the anostracans Streptocephalus dichotomus Baird, 1860 + S. simplex Gurney, 1906 and the spinicaudatans Leptestheria cf. nobilis + L. jaisalmerensis were collected. Temporary aquatic habitats are threatened due to adverse anthropogenic activities, especially in developing countries like India. The endemic species of large branchiopods in the Indian subcontinent should be red-listed, as is done elsewhere. [ABSTRACT FROM AUTHOR]

Species of Plesionika Spence Bate, 1888 holds significant importance in the commercial harvesting of deep-sea shrimps along the southern coasts of India. Despite Plesionika quasigrandis Chace, 1985 being a crucial resource on the southwest coast of India, there is a need for comprehensive information on its food and feeding habits. We investigated the diet of P. quasigrandis in relation to sex, size, and season. The species exhibited a diet primarily consisting of crustaceans, foraminiferans, and detritus. Both males and females showed a noteworthy reliance on detritus, as indicated by an index of preponderance values exceeding 45.8. The species displayed active scavenging behaviour alongside predatory dietary habits. We observed a decrease in feeding intensity from pre-monsoon to post-monsoon in both males and females. Permutational multivariate analysis of variance (PERMANOVA) revealed significant differences in the diets of P. quasigrandis , considering the combined effects of size and sex (P < 0.01). No significant distinctions were noted in the diet composition between males and females in relation to season. [ABSTRACT FROM AUTHOR]

The current systematics of the large branchiopod crustaceans are reviewed in relation to other crustacean groups and from class to genus level. Calmanostraca and Diplostraca are raised to superorder, and †Kazacharthra and Notostraca are both treated as orders. Problems and needs regarding the systematics of large branchiopods are presented and discussed, with suggestions for moving forward, stressing the need for modern methods and defensible taxonomic definitions. Subdividing taxonomic categories may or may not be warranted, but should never be based on only one gene, or on limited taxon sampling. Furthermore, splitting species out as new genera, when the original genus is poorly defined can only lead to future problems. [ABSTRACT FROM AUTHOR]