Total Haemocyte Count Research Articles

Evaluation of distiller's dried grains with solubles in diets for Pacific white shrimp, Litopenaeus vannamei, reared under pond conditions

AbstractMost studies evaluating the use of distiller's dried grains with solubles (DDGS) to partially replace the use of soybean meal (SBM) in diets of shrimp Litopenaeus vannamei have been carried out under laboratory conditions, which has significant differences in terms of environmental and culture conditions with the out‐door commercial pond. This study aims to extrapolate the laboratory trials into the out‐door pond condition in order to evaluate the feasibility of incorporating DDGS at various levels (D0 (0%), D5 (5%), D10 (10%), and D 15 (15%)) to replace the use of SBM for 90‐day culture period on the growth, body composition, total hemocyte count, lysozyme activity, and organoleptic characteristics of the shrimp. Seven hundred twenty shrimp (mean initial weight 1.06 ± 0.01 g) were randomly distributed into each of 40 net pens (3 × 2 × 1 per net pen) with 10 replicates per dietary treatment. The results showed an enhancement in biomass, mean weight, and thermal growth coefficient of shrimp fed with 5 and 10% inclusion levels of DDGS. Significant reduction of FCR was also observed with the use of 5 and 10% DDGS to partially replace SBM. There were no severe changes in the total hemocyte count (THC), lysozyme activity, color, aroma, and flavor of the shrimp. However, the texture of shrimp was significantly better with the use of 10 and 15% DDGS in the diet. In summary, regarding all the factors, DDGS is a promising alternative ingredient to replace the use of SBM with 5 and 10% inclusion levels and could modulate better growth, quality, and maintain the health condition of shrimp cultured in out‐door pond conditions.

How do biocidals affect the non-target marine organisms: the short-term effects of antifouling agent sodium pyrithione on Mediterranean mussels (Mytilus galloprovincialis, Lamark 1819).

The metallic pyrithiones are used as antifouling paints for marine vehicles against fouling organisms. However, they are dissolved in marine water and have negative impacts on marine non-target organisms. This study evaluated the adverse effects of sodium pyrithione (NaPT) on Mytilus galloprovincialis using total hemocyte counts (THCs), oxidative stress and antioxidant parameters, and histopathological observations. Mussels were exposed to 0.1 and 1 μg/L NaPT for 96 h. The THC values of the NaPT-exposed mussels significantly decreased (p < 0.05). Lipid peroxidation and advanced oxidative protein products of digestive gland and gill tissues were decreased but only the digestive gland tissues of 0.1 μg/L NaPT values were significantly decreased compared to control groups (p < 0.05). Histological alterations were observed in the gill and the digestive gland tissues revealing malformations and hyperplasia of gill lamella; degenerations and loss of tubules of digestive gland after exposure to NaPT for 96 h. As a result, biocidal sodium pyrithione has adverse effects on the mussels even in short-term exposures and low concentrations.

Temporal dynamics of the immune response in Astacus astacus (Linnaeus, 1758) challenged with Aphanomyces astaci Schikora, 1906

One of the main drivers of biodiversity loss in freshwater ecosystems are alien invasive species. In Europe, pathogen Aphanomyces astaci Schikora, 1906, is considered as one of the most problematic invasive species, as its introduction caused the severe decimation of the European freshwater crayfish stocks. The most affected are the populations of noble crayfish, keystone species native to European freshwaters. Unfortunately, even after decades of research, we do not understand the temporal dynamics of the noble crayfish immune response during Ap. astaci infection. Here, we studied the changes in the immune response of the noble crayfish during a time course challenge with a highly virulent strain of Ap. astaci. We recorded gross symptoms of the disease, changes in the total haemocyte count, gene expression profiles of putative immune response regulators and pathogen load. Additionally, we conducted a preliminary histological analysis of the pathogen dissemination in host tissues. Based on the occurrence of symptoms we propose three stages in the crayfish plague disease progression: asymptomatic stage, symptomatic stage, and finally death of infected individual. Furthermore, based on the qPCR analysis we could differentiate three Ap. astaci growth phases: initial lag phase, followed by exponential growth phase and finally sporulation phase. We observed that all measured immune response parameters were significantly correlated to the observed increase in the pathogen load (qPCR). Altogether, our results point to the absence of a successful immune response in the noble crayfish to a challenge with a highly virulent strain of Ap. astaci. The noble crayfish immune system was not able to suppress the growth of the intruding pathogen. In general, our observations have to be considered in the context of the specific combination of crayfish plague pathogen virulence and disease resistance of the challenged crayfish population, which defines the temporal dynamics of their interaction.

The Effect of Hyperthermia on the Immune Response of Vannamei Shrimp Infected with IMNV

The purpose of this study was to determine the effect of hyperthermia on the immune response of shrimp infected by IMNV. Vannamei shrimp were challenged with IMNV and reared at temperatures 30ºC (Sk30), 31ºC (S31), 32ºC (S32) and 33ºC (S33) repectively. The temperature of shrimp without IMNV infection was 300C as control. During the study, shrimp immune response measurements were Total Hemocyte Count (THC), Differential Hemocyte Count (DHC), Respiratory Burst (RB) activity and Phenoloksidase (PO) activity. Generally, the results showed that the response of shrimp decreased along with hyperthermic condition. Shrimp infected with IMNV, decreased immune response especially at temperatures of 32ºC and 33ºC.

Transcriptomic analysis of the antioxidant responses and immunomodulatory effects of dietary melatonin in red swamp crayfish (Procambarus clarkii)

This study aimed to investigate the effects of dietary melatonin (MT) levels on the antioxidant capacity, immunomodulatory, and transcriptional regulation of red swamp crayfish. Six experimental diets with different levels of MT (0, 22.5, 41.2, 82.7, 165.1, and 329.2 mg/kg diet) were fed to juvenile crayfish for 60 d. The transcriptome data of the control group and the group supplemented with dietary MT at 165.1 mg/kg were obtained using RNA-seq. In total, 3653 differentially expressed genes (2082 up-regulated and 1571 down-regulated) were identified. Pathways and genes related to antioxidant immune and growth performance were verified by qRT-PCR. The total hemocyte count, phagocytosis rate, and respiratory burst were significantly increased in the MT (165.1 mg/kg) group compared to the control group. Analysis of antioxidant immune-related enzymes in the hepatopancreas demonstrated that dietary MT (165.1 mg/kg) significantly increased activities of catalase, superoxide dismutase, glutathione reductase, and glutathione peroxidase and significantly decreased aspartate aminotransferase and alanine aminotransferase activity. At the transcriptional level, dietary MT up-regulated expression levels of genes associated with antioxidant immune and development, which included toll-like receptors, Crustin, C-type lectin, and so on. To conclude, MT could be used as a supplement in crayfish feed to increase immunity and antioxidant capacity and according to the broken line regression, the ideal MT concentration was the 159.02 mg/kg. Overall, this study demonstrates the role of melatonin in the antioxidant responses and immunomodulatory of Procambarus clarkii, laying the foundation for the development of melatonin as a feed additive in the aquaculture of this species.

Functional Effects of Hydrolyzable Tannins on the Growth, Health Status, and Hepatopancreas Histology of Pacific White Shrimp Penaeus vannamei Reared under Commercial Pond Conditions

In the present study, the functional effects of hydrolyzable tannins (HT) extracted from the sweet chestnut tree Castanea sativa were evaluated either by directly incorporating them into the diet or by using a top-dressing application on the growth, body composition, total hemocyte counts, lysozyme activity, and histomorphological condition of the hepatopancreas of Pacific white shrimp Penaeus vannamei. Shrimp was confined in hapa nets installed within commercial outdoor ponds for 90 days. Eight experimental diets included a basal formulated diet (BD) with varying inclusion levels of HT (BD-0%, BD-0.1%, BD-0.2%, and BD-0.3%), a low fish meal (FM) diet with reduction on the inclusion level of FM from 10% to 7.5% and labeled as LFM 0.3% HT, a top-dressing HT application (TC) on basal diet (BDTD-0.4% HT), and a commercial diet (CDTD-0% HT and CDTD-0.4% HT). The final body weight (FBW), percentage weight gain (PWG), thermal growth coefficient (TGC), average daily growth (ADG), and feed conversion ratio (FCR) were significantly better in the group of shrimp fed with BD-0.3% HT compared to BD-0% HT. The administration of CD-0.4% HT was able to enhance the growth performance of shrimp compared to BD-0% HT and CD without HT. Higher protein and fat contents were found in the body of shrimp fed with graded levels of HT compared to shrimp fed with BD or CD without HT. Numerically, the direct inclusion and top-dressing process of HT increased the total hemocyte count and lysozyme activity in shrimp. Both BDTD-0.4% HT and CDTD-0.4% HT were also able to support a better hepatopancreatic condition with reference to histomorphology and integrity. These results indicated that BD-0.3% HT inclusion could significantly improve the growth performance and prevent the alteration in health and histomorphological condition of the hepatopancreas of shrimp P. vannamei cultured in hapa nets under commercial farm conditions, but also 0.4% HT could be used as a supplementation dosage for the top-dressing process in diets.

Exploring the combined interplays: Effects of cypermethrin and microplastic exposure on the survival and antioxidant physiology of Astacus leptodactylus

Plastic waste and micro/nanoplastic particles pose a significant global environmental challenge, along with concerns surrounding certain pesticides' impact on aquatic organisms. This study investigated the effects of microplastic particles (MPPs) and cypermethrin (CYP) on crayfish, focusing on biochemical indices, lipid peroxidation, oxidative stress, hematological changes, and histopathological damage. After determining the LC50–96 h value (4.162 μg/L), crayfish were exposed to sub-lethal concentrations of CYP (1.00 ppb (20%) and 2.00 ppb (50%)) and fed a diet containing 100 mg/kg MPPs for 60 days. Hemolymph transfusion and histopathological examinations of the hepatopancreas were conducted. The results showed significant alterations in crayfish. Total protein levels decreased, indicating protein breakdown to counteract contaminants, while total cholesterol and triglyceride levels declined, suggesting impaired metabolism. Glucose levels increased in response to chemical stress. The decline in total antioxidant capacity highlighted the impact of prolonged xenobiotic exposure and oxidative stress, while increased CAT, SOD, and MDA activities helped mitigate oxidative stress and maintain cellular homeostasis. The elevated total hemocyte count, particularly in semi-granular cells, suggests their active involvement in the detoxification process. Further research is needed to fully understand the implications of these effects.

Combined effects of microfibers and polychlorinated biphenyls on the immune function of hemocytes in the mussel Mytilus coruscus

Numerous studies have shown that microplastics can interact with other pollutants in the environment to produce synergistic effects, leading to more serious impacts. To date, there is little consensus on the combined effects of microfibers (MFs) and polychlorinated biphenyls (PCBs, Aroclor 1254), two legacy and alarming environmental pollutants. There is an urgent need to assess the impact of combined exposures on bivalve immune defences. In this study, we assessed the immune response of the mussels (Mytilus coruscus) hemocyte to MFs and PCBs alone and in combination by using flow cytometry. M. coruscus were exposed to MFs (1000 pieces/L) and PCBs (PCBs) (100 ng/L and 1000 ng/L) alone or in combination for 14 consecutive days and recovered for 7 days. The hemocyte of M. coruscus was collected on day 7, 14 and 21. MF exposure alone had no effect on the hemocyte. The total hemocyte count (THC), esterase (EA), lysosomal contents (LC), mitochondrial number (MN) and mitochondrial membrane potential (MMP) of mussels showed a decreasing trend with increasing PCB concentrations, both individually and in combination; The decreases in EA, MN and MMP were associated with the induction of reactive oxygen species (ROS). Hemocyte mortality (HM) was associated with a decrease in THC. Combined exposure to MFs and PCBs would exacerbate the effects on hemocyte immunity. These new findings improve our understanding of the toxic effects of MFs and organic chemical pollutants, and demonstrate the potential mechanism of PCBs to bivalves through changes in hemolymph immunity-related indicators.

Marine pollutant Phenanthrene (PHE) exposure causes immunosuppression of hemocytes in crustacean species, Scylla paramamosain

Phenanthrene (PHE), a representative polycyclic aromatic hydrocarbons (PAHs), is widely found in aquatic environments, which exhibits high toxicity to aquatic organisms and has a substantial impact on overall health. In order to investigate the immunosuppressive effects of PHE exposure on marine crustacean species, the Scylla paramamosain was exposure to different concentrations of PHE, which was 0 μg/L (control group), 0.7 μg/L, 7 μg/L, or 70 μg/L PHE with 35 individuals in every group, respectively. The results showed that the color of hemocytes gradually deepened with increasing PHE concentration, and the total hemocyte count (THC) was activated and increased after PHE exposure analyzed by Flow cytometry. Meanwhile, compared with the control group, cryostat sections of hepatopancreas showed cell infiltration, cell steatosis, eosinophilic masses and vacuolization in PHE groups. The superoxide dismutase (SOD) activity was decreased immensely in PHE exposure groups, meanwhile, the acid phosphatase (ACP) activity and glutathione (GSH) activities were increased after PHE exposure compared with control group. Moreover, the expression profile of Crustin, TLR, MCM7, JAK, caspase, Moyosin and P53 were up-regulated significantly after 7th day PHE exposure in all treatment groups by Q-PCR. Those data illustrated that PHE exposure could inhibit the immune function of mud crab by causing hepatopancreas damage, induce the activity of antioxidant enzymes and the expression of immune genes. These data provide a scientific basis for evaluating the impact of PAH pollution on marine organisms.

Effects of abamectin on nonspecific immunity, antioxidation, and apoptosis in red swamp crayfish (Procambarus clarkii)

Abamectin, a pesticide of 16-member macrocyclic lactones, is widely applied in agriculture. As an important environmental factor, pesticides pose a great threat to defense system in aquatic animals. Procambarus clarkii is one of the most important economic aquatic animals in China. It is necessary to explore the defense mechanism of P. clarkii to abamectin. In this study, P. clarkii were exposed to 0, 0.2, 0.4, 0.6 mg/L abamectin, immune- and antioxidant-related enzymes activities, genes expression levels, and histological observations were used to analyze the defense capacity of P. clarkii to abamectin. With increasing abamectin concentration, reactive oxygen species (ROS) level and malondiadehyde (MDA) content increased significantly. Meanwhiile, acid phosphate (ACP), alkaline phosphatase (AKP) activities, total haemocyte counts (THC), and Crustin expression level decreased significantly, superoxide dismutase (SOD), catalase (CAT) activities, total antioxidant capacity (T-AOC), and GPX expression level also decreased significantly. Hematoxylin & eosin (H&E) observation showed that with increasing abamectin concentration, hepatopancreas were damaged, especially membrane structure. Through TUNEL observation and apoptosis-related genes (PcCTSL, Bcl-2, Bax, BI-1, PcCytc, caspase-3) expression levels, with increasing abamectin concentration, apoptosis rate increased significantly. Results of this study indicated that abamectin caused oxidative damage to P. clarkii, resulting in damage to defense system, suppression of nonspecific immunity and antioxidation, and promotion of apoptosis. It provided theoretical basis for healthy P. clarkii culture, and for further study on defense mechanism of aquatic animals to pesticides.

Evaluation of Galleria mellonella immune response as a key step toward plastic degradation

BackgroundPlastic's remarkable durability presents a significant challenge for our planet, leading to widespread environmental damage. However, some organisms, such as Galleria mellonella larvae, have shown a unique capability to consume and degrade plastic, offering potential solutions to plastic pollution. In this study, we investigated the response of G. mellonella larvae to different diets, including artificial diet (AD), polyethylene low density mixed with AD (PELD + AD), and PELD alone. Using various microscopy techniques, we examined the larvae's hemocyte hemogram and mid-gut characteristics to understand their immune response and digestive system when exposed to plastic.ResultsThe results revealed that PELD-only feeding negatively impacted hemocyte immunity, resulting in a significant decrease in total hemocyte counts compared to AD and AD + PELD feeding. Moreover, plastic consumption induced differential hemocyte alterations, affecting specific cell types. The presence of phagosomes in larval hemocytes and mid-gut cells during PELD-only feeding suggested active involvement in plastic breakdown.ConclusionsThese findings highlight the potential of G. mellonella larvae as a model organism to study responses to pollutants, emphasizing the urgent need to address plastic pollution's global threat. Further investigation is warranted to explore larval deformities, weight loss, and appetite changes, potentially influencing mortality rates and enzyme biochemistry. Understanding the impacts of plastic ingestion on G. mellonella larvae is crucial to develop effective strategies for mitigating plastic pollution's ecological implications.

Assessment of Bacillus subtilis fermented Caulerpa microphysa byproduct as feed additive on the growth performance, immune regulation and disease resistance of white shrimp (Litopenaeus vannamei)

In this study, the immunomodulatory and antioxidant activity of fermented Caulerpa microphysa byproduct (FCMB) by Bacillus subtilis was evaluated, and its potential as a feed additive for white shrimp (Litopenaeus vannamei) was explored. In vitro experiments showed that the FCMB supernatant contained polysaccharides, polyphenols and flavonoids, and exhibited antioxidant properties as assessed by various antioxidant assays. Additionally, the FCMB supernatant was found to increase the production rate of reactive oxygen species and the activity of phenoloxidase in hemocytes in vitro. Furthermore, the results of the in vivo feeding trial showed that dietary 5 g kg−1 FCMB significantly improved the weight gain and specific growth rate of white shrimp after 56 days of feeding. Although there were no significant differences in total hemocyte count, phagocytosis, superoxide anion production rate, and phenoloxidase activity among the experimental groups, upregulation of immune-related genes was observed, particularly in the hepatopancreas and hemocytes of shrimps fed with 5 g or 50 g FCMB per kg feed, respectively. In the pathogen challenge assay, white shrimp fed with 5 % FCMB exhibited a higher survival rate compared to the control group following Vibrio parahaemolyticus challenge. Therefore, it is concluded that the fermented byproduct of C. microphysa, FCMB, holds potential as a feed additive for enhancing the growth performance and disease resistance against V. parahaemolyticus in white shrimp.

Growth inhibitory, immunosuppressive, cytotoxic, and genotoxic effects of γ-terpinene on Zeugodacus cucurbitae (Coquillett) (Diptera: Tephritidae)

γ-Terpinene, a monoterpene widely present in essential oils of many medicinal and aromatic plants with numerous biological properties, was evaluated for its insecticidal activity against melon fruit fly, Zeugodacus cucurbitae (Coquillett). Different concentrations (5, 25, 125, 625, and 3125 ppm) of γ-terpinene along with control were fed to larvae of melon fly. The number of pupae formed and adults emerged declined significantly after treatment. Morphologically deformed adults and pupae were also observed. The developmental duration too prolonged in treated larvae. Food assimilated, mean relative growth rate, larval weight gain, and pupal weight also declined. In the larvae treated with LC30 and LC50 concentrations, there was a decline in the titers of phenoloxidase and total hemocyte count, and variations were observed in the differential hemocyte count, suggesting an immunosuppressive effect of γ-terpinene on melon fly. Both concentrations also led to an increase in the apoptotic and necrotic cells as well as decrease in the viable hemocytes in the circulating hemolymph of treated larvae. Comet parameters (tail length, % tail DNA, tail moment, and olive tail moment) of γ-terpinene fed larvae increased significantly. Given the observed effects of γ-terpinene on normal developmental and nutritional physiology, its immunosuppressive properties, and its potential for genome damage, it can be considered for incorporation into integrated pest management strategies for controlling Z. cucurbitae.

Effects of dietary melatonin on antioxidant and immune function of the Pacific white shrimp (Litopenaeus vannamei), as determined by transcriptomic analysis

Melatonin (MT) is regarded as an antioxidant and immunostimulant that can efficiently scavenge free radicals and activate antioxidant enzymes. The aim of this study was to investigate the effects of dietary MT on the growth performance and immune function of the Pacific white shrimp (Litopenaeus vannamei). Six groups of L. vannamei were supplemented with dietary MT at 0, 22.5, 41.2, 82.7, 165.1, and 329.2 mg/kg levels for 2 months. RNA-Seq analysis was performed to obtain transcriptome data of the control group and the group supplemented with dietary MT at 82.7 mg/kg BW. In total, 1220 DEGs (799 up-regulated and 421 down-regulated) were identified. Pathways and genes related to growth performance and immune function were verified by real-time quantitative polymerase chain reaction. The total hemocyte count, phagocytosis rate, and respiratory burst were significantly increased in the MT (82.7 mg/kg BW) group as compared to the control group. Analysis of antioxidant-related enzymes in the hepatopancreas showed that dietary MT (82.7 mg/kg BW) significantly increased activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase, while dietary MT at 41.2 mg/kg BW significantly increased activities of glutathione S-transferase, lysozyme (LZM), and phenoloxidase (PO). At the transcriptional level, dietary MT up-regulated expression levels of genes associated with antioxidant immunity and growth, which included PO, SOD, LZM, GPx, chitin synthase, ecdysone receptor, calcium–calmodulin dependent protein kinase I, and retinoid X receptor. In conclusion, dietary MT may improve the growth performance and immune function of L. vannamei to some extent.

The Influence of Adding Api-Api Mangrove Leaf Extract as an Immunostimulant on Vaname Shrimp Against Vibriosis Disease Caused by Vibrio parahaemolyticus Bacteria

Vanname shrimp cultivation is one of the most developed aquacultures in Indonesia and makes it one of the commodities with the highest foreign exchange inputs for the Indonesian state from the fisheries sector. Disease attack is one of the main causes of failure in vaname shrimp culture, especially disease attacks caused by Vibrio parahaemolyticus bacteria. Avicennia alba mangrove leaf extract is known to have active compounds that can act as antibacterial. This research was conducted by mixing Avicennia alba mangrove leaf extract with doses of 150 ppm (VA), 250 ppm (VB) and 350 ppm (VC) into commercial feed by re-pelletting. Positive control (KV+) treatment used commercial vitamins added to the feed. The vaname shrimp used was 60 days old with an average initial weight of 8.9 grams. The aquariums used were 15 pieces with a size of 60 x 30 x 40 cm and a volume of 54 liters of water. The white shrimp challenge test with Vibrio parahaemolyticus bacteria with a concentration of 106 Cfu/ml as much as 0.2 ml. The clinical symptoms of white vaname shrimp include pale white hepatopancreas, blackened tail, grippy swimming legs, necrosis in some parts of the body, necrosis of the tail, blackened and necrotic rectum, broken intestines that are partially brown and starting to turn white, empty intestines, presence of white feces. appears in the aquarium, decreased appetite, as well as not actively swimming. The results showed that Avicennia alba leaf extract had an effect on absolute weight growth (W), growth rate (GR), specific growth rate (SGR), survival rate (SR), total haemocyte count (THC) and phagocytic activity of white shrimp. The dose of 350 ppm VC treatment was the most influential dose as an immunostimulant in this study.

In Silico and In Vivo Potential of Fraction Red Betel Leaf as an Immunostimulant Agent in White-leg Shrimp

Production of white-leg shrimp (Litopenaeus vannamei) in aquaculture with advanced technology ultimately results in high mortality rates in cultivation. Infectious diseases, including Vibrio spp., can cause mortality with necrosis symptoms in the white-leg shrimp hepatopancreas. Disease prevention through enhancing immunity is highly effective in controlling diseases in shrimps. The current study aimed to obtain information on the compounds present in the fraction of Piper (P.) crocatum as an immunostimulant agent used in silico. The current study investigated the absorption, distribution, metabolism, excretion, and toxicity (ADME/T), and determined the optimal fraction dosage of P. crocatum when injected as an immunostimulant substance. In this study, in silico analysis was conducted by accessing several servers, while the shrimp’s immune response was evaluated using a completely randomized design experiment with four treatments (10 individuals/container) and three replications, including 0 (control), 0.5 µg/g, 1 µg/g, and 1.5 µg/g. The shrimp’s immunity was examined by injecting the P. crocatum fraction initially, followed by a second injection 24 hours later. Shrimp hemolymph was collected before the injection of the P. crocatum fraction and 24 hours after the injection. Hemolymph was collected at both time intervals to assess total hemocyte count (THC), differential hemocyte count (DHC), and phenoloxidase (PO) as the immune response of shrimp before and after administration of P. crocatum fraction. Two compounds were confirmed immunostimulant agents in a fraction of P. crocatum, 2-Amino-1,3,4-octadecanetriol, and erucamide. The immune response values for THC (14.17 ± 2.45 × 106 cells mL-1), DHC hyaline (53 ± 4.5%), semi-granular cells (52 ± 4.0%), and granular cells (43 ± 40%), and PO (0.112 ± 0.016 units/λ=490) at a concentration of 1.5 µg/g showed a significant increase in number and percentage compared to the control. These results indicate the presence of two compounds in fraction one P. crocatum, as candidates for immunostimulant agents. Administration of 1.5 µg/g of a fraction of P. crocatum is the appropriate dose as an immunostimulant agent when administered via injection method for white-leg shrimp.

Host-parasite relationship Octopus tehuelchus – Aggregata valdessensis in Patagonian coast, southwestern Atlantic Ocean

Histopathology associated with the apicomplexan Aggregata valdessensis in the wild population of Octopus tehuelchus was studied. Moreover, to analyze the impact of the prevalence and infection intensity on the dorsal mantle length, sex, maturity stages, condition index and total hemocyte counts on wild O. tehuelchus, Generalized Linear Models (GLMs) were applied. Kruskal–Wallis (KW) test was used to compare growth parameter (RNA/DNA ratios) in infected and uninfected octopuses. Lesions including hypertrophy of host cells and destruction of the tissue organ architecture as well as the replacement of host tissue by parasites were associated with infection. The infection caused an inflammatory defensive response in form of hemocytic infiltration.. The prevalence of apicomplexan increased with octopus dorsal mantle length (GLM, t = 2.68; p = 0.007). Infection intensity was significantly higher in male octopus (GLM, t = 2.69; p = 0.009) and decreased at higher temperatures in both sexes (GLM, t = -2.42; p = 0.018). The digestive gland condition index did not significantly vary with infection intensity, and no significant relationship between total hemocyte counts and coccidian infection was found (Lineal Model, t = 0.46; p = 0.64). The acid nucleic ratio was significantly lower in octopuses infected by A. valdessensis (Kruskal Wallis test, H = 4.8; p = 0.02), suggesting a detrimental effect on O. tehuelchus growth caused by the coccidian.

Immunosuppressive effect of Plantago major on the innate immunity of Galleria mellonella.

Greater plantain (Plantago major), a medicinal plant species, is used in folk medicine for the treatment of various diseases in many countries of the world. Different studies have shown that the bioactive components contained in the plant have a dual effect. It was also reported that in vivo and in vitro studies showed different results. The aim of the study was to determine the effects of P. major extract on the hemocyte-mediated and humoral immune responses of the invertebrate model organism Galleria mellonella, which is widely used in immune studies. In the evaluation of these effects, total hemocyte count, encapsulation, melanization, phenoloxidase, superoxide dismutase, catalase, malondialdehyde and total protein parameters were evaluated. The results of the study showed that the total hemocyte count did not change, that the encapsulation responses decreased, that the melanization responses and phenoloxidase activity increased and that the superoxide dismutase activity decreased. As a result, it was determined that high doses of P. major had negative effects on cell-mediated immunity and antioxidant defence and positive effects on melanization. High doses and continuous use of P. major may have negative effects on living things.

Black Soldier Fly (Hermetia illucens) as an Alternative to Marine Ingredients Elicits Superior Growth Performance and Resistance to Vibrio harveyi Infection for Pacific White Shrimp (Litopenaeus vannamei)

To assess the feasibility of incorporating insect meal and oil into diets for Pacific white shrimp Litopenaeus Vannamei, a trial was conducted to measure growth and feed performance metrics within balanced iso-nitrogenous and iso-lipid (36% protein and 6% lipid) experimental diets formulated with standard commercially sources ingredients. Incremental levels of BSF larval meal (BSFM, 0.5 to 5%) were used to partially substitute the use of fishmeal (FM) in the diet. In addition, next group of dietS were designed by using incremental levels of BSF larval oil (BSFO (0.5 to 5%) with 0.5% BSFM as a reference to partially and completely replace the use of fish oil (FO) within the diet. Ten dietary treatments were evaluated as four replicates in 40 Hapa ponds assigned randomly. Shrimp of initial mean weight of 0.97 g were fed by hand over 90 days with feed intake based on an FCR of 1.5 and all parameters recorded to determine response. Inclusion of up to 5% of both BSF meal and oil improved performance with respect to growth rate and feed utilization efficiency FCR. Total hemocyte counts and lysozyme activity reflected these trends displaying advantages of BSF diet groups compared to the basal fed group of L. Vannamei. After the growth trial, a disease challenge test was undertaken using an infection model with Vibrio harveyi at a concentration of 105 CFU shrimp-1 under controlled laboratory settings. As such, several indices of health status were recorded that included hemocyte counts, lysozyme activity as well as histopathology of the hepatopancreas that is a prime indicator of the progression of disease and a reflection on health status. Insect meal and oil inclusions increased survival from 40% to 60 - 80% and in accordance, raised the immune response and improved histopathological profiles of hepatopancreas tissues.

The effect of reactive oxygen species (ROS) in immunity and WSSV infection of Scylla paramamosain

Reactive oxygen species (ROS) are typically regarded as being generated by the cellular respiratory chain or by cells under pathological damage, which play a crucial role as signaling molecules in promoting hemocytes circulation and normal cellular physiological functions. In this study, the antioxidant N-acetylcysteine (NAC) was used to reduce ROS in vivo and in vitro, which to analyze the effect of ROS on innate immunity and viral infection of mud crab. The total hemocyte count (THC), phenoloxidase (PO), superoxide dismutase (SOD) activity, immune-relative genes were analyzed, respectively. Moreover, the effect of ROS on WSSV infection was analyzed by THC and hemocytes apoptosis. The data showed that NAC could effectively remove and inhibit intracellular ROS. The THC of NAC group was reduced at 12 h and 24 h compared with that of control. And the inhibition of ROS by NAC could increase the SOD activity with control group, while increased the PO activity caused by early WSSV infection. And NAC could up-regulate the expression of MCM7, JAK, TLR and proPO significantly, while down-regulate the expression of Astakine, proPO, caspase and p53. Similarly, NAC could inhibit WSSV-induced apoptosis of S. paramamosain hemocytes. The data illustrated that ROS participates in the interaction between hemocytes and virus infection by regulating innate immunity. Especially, after NAC inhibited ROS, the expression of hemocytes proliferation gene Astakine was also inhibited, which may indicate that ROS is related to the process of hemocytes proliferation. The data will show a preliminary exploration on the regulatory role of ROS in crustacean immune system.