Penaeus Monodon Research Articles

The structure, conduct, and performance of the hatchery segment of the aquaculture value chain in Bangladesh

IntroductionSeed production has experienced significant growth in Bangladesh over the last decade, driven by the increasing number of hatcheries. The hatchery segment plays a crucial role in the overall growth and development of aquaculture in the country. Understanding its structure, conduct and performance is essential for assessing its impact on the productivity and profitability of aquaculture farms. However, there is a limited number of methodologically rigorous studies focusing on the hatchery segment in Bangladesh. The study aimed to fill the gap in the exiting literature by conducting a methodologically analysis of the hatchery segment of aquaculture value chain in Bangladesh.MethodsThis study was conducted in seven of the main aquaculture producing districts in southern Bangladesh. A comprehensive structured survey was conducted between May and August 2022 with 66 enterprises, including 42 carp+catfish, 16 tilapia, and 8 crustacean hatcheries.Results and discussionThe major findings and their implications are as follows. (1) The number of hatcheries increased by 15% over the past decade, with a 27% increase in fish hatcheries and a 47% decrease in crustacean hatcheries. (2) Carp and tiger shrimp were the most commonly produced fish and crustacean seeds, contributing 67% and 99% of volume and 66% and 97% of sales value, respectively. (3) The hatcheries were family-owned and operated enterprise, and generated a total 2,491 full time equivalent (FTE) jobs. (4) Hatcheries used 86% of their broodstock annually and replaced them regularly for improving quality and avoiding inbreeding. (5) 18% of hatcheries reported facing diseases and/or water quality problems, but mean economic loss was only 0.71% of seed sales value, which is a low level of loss and waste. (6) Average annual net profit margin was relatively modest, averaging 54% of the gross revenue, which suggests the existence of competitive seed production and marketing. The results showed that the hatchery segment in southern Bangladesh appears to be dynamic, well developed, efficient, and relatively competitive.

Docking Studies on Biomolecules from Marine Microalga Skeletonema costatum Against Hemolysin Protein of Bioluminescence Disease-Causing Vibrio harveyi.

Grow-out and hatchery units of shrimps are being impacted by disease-causing bacterial pathogens and predominantly marine Vibrios. The use of chemicals for governing bacterial pathogens in the aquaculture practices is developing resistance to bacteria. Henceforth, the application of bio-therapeutic agents from marine resources for controlling pathogens is most vital to be considered. Molecular docking is computer-assisted drug design tool to detect and counteract for drug-receptor interaction for known target protein of diseases. Therefore, an effort was made with the extract of the marine micro alga Skeletonema costatum against hemolysin protein of pathogenic bacteria Vibrio harveyi. The extract of S. costatum was tested against growth and virulence produced by V. harveyi during larviculture of Penaeus monodon. The extract was analyzed for phyto-constituents through GC-MS and used them as ligand molecule in docking. S. costatum extract at 200µgmL-1 was found to decrease 35.20% of cumulative percentage mortality (CPM) in postlarvae of P. monodon against V. harveyi infections. The biomolecule Docasane, an alkane from the extract of S. costatum, exposed highest binding interaction than other compounds during docking analysis. The level of significance (P < 0.05) was found in CPM, growth, and virulence factors of V. harveyi studies. Thus, the present finding predicts that extract of S. costatum containing biomolecules can be recommended for use in the shrimp culture-based grow-out and hatchery units for eliminating bioluminescent V. harveyi.

EKSTRAKSI BIJI PEPAYA (Carica papaya) SEBAGAI BAHAN AKTIF ANTIBAKTERIAL PADA LARVA UDANG WINDU (Penaeus monodon) SECARA IN VITRO DAN IN VIVO

This research was the administration of papaya seed extract to black tiger prawn which were challenged with Vibrio harveyii infection in vivo and in vitro to determine the effectiveness of papaya seed extract in inhibiting vibrio harveyii. This research was conducted in the laboratory of the Faculty of Fisheries and Marine Sciences, University of Borneo Tarakan in vitro and in vivo. The data obtained were analyzed descriptively and statistically. Based on observations and research it is known that papaya seed extract (Carica papaya) in vitro contains active antibacterial ingredients such as saponins, flavonoids which can inhibit Vibrio in breeding so that it has an impact on the weakness of Vibrio harveyii in disturbing and inhibiting the growth of tiger shrimp larvae during independent research. in vivo. The survival rate of black tiger prawn larvae from the total of each treatment which was maintained for 12 days of treatment showed that the highest value was achieved in treatment P3 of 90% and the lowest was obtained in the negative control treatment of 5%, while in treatment P1 (positive control) of 95 %, P4 was 78% and P2 treatment was 65%.

Developing a MySQL Database for the Provenance of Black Tiger Prawns (Penaeus monodon).

As the demand for seafood increases, so does the incidence of seafood fraud. Confirming provenance of seafood is important to combat fraudulent labelling but requires a database that contains the isotopic and elemental "fingerprints" of authentic seafood samples. Local isotopic and elemental databases can be scaled up or combined with other databases to increase the spatial and species coverage to create a larger database. This study showcases the use of isotopic and elemental fingerprints of the black tiger prawn (Penaeus monodon) to develop a database that can be used to securely store the data necessary for determining provenance. The utility of this database was tested through querying and building seven different datasets that were used to develop models to determine the provenance of P. monodon. The models built using the data retrieved from the database demonstrated that the provenance of P. monodon could be determined with >80% accuracy. As the database was developed using MySQL, it can be scaled up to include additional regions, species, or methodologies depending on the needs of the users. Combining the database with methods of determining provenance will provide regulatory bodies and the seafood industry with another provenance tool to combat fraudulent seafood labelling.

Facile fabrication of chitosan Schiff bases from giant tiger prawn shells (Penaeus monodon) via solvent-free mechanochemical grafting

Fabrication of chitosan Schiff bases (ChSB) from giant tiger prawn shells (Penaeus monodon) using an environmentally friendly method has been conducted successfully. Transformation of Prawn Shells (PS) as raw material into chitin then chitosan was executed under ambient temperature. Later, three Ch Schiff bases (ChSB-A, ChSB-S, and ChSB-V) were successfully synthesized for the first time via solvent-free mechanochemical grafting with 2-hydroxy benzaldehyde, 4-methoxy benzaldehyde, and 3-methoxy-4-hydroxy benzaldehyde, respectively. Synthesis was carried out with Shaker Mill-Ultimate Gravity equipped with a Teflon jar with zirconia balls; then the product was characterized. FTIR analysis proved the conversion of free amine to imine groups. The degree of substitution (DS) and crystallinity index (CrI) were determined by elemental analysis and X-ray diffraction. The DS values obtained were about 0.343, 0.795, and 0.055 for ChSB-A, ChSB-S, and ChSB-V, respectively. The CrI of ChSB-A, ChSB-S, and ChSB-V was 53.3, 51.7, and 46.9 %, respectively. The thermal gravimetric analysis showed that the mechanochemical grafting of Ch improves the thermal stability of ChSB. This developed method provides a novel potential technique to convert PS into ChSB products by solvent-free mechanochemical grafting.

Variation of Water Quality in Intensive Aquaculture Areas of the Mekong Delta, Vietnam

The Mekong Delta produces about 70 % of Vietnam's national aquaculture output, and water quality management is a key factor in maintaining high levels of production and profitability. Effective water management strategies depend on understanding the spatial and temporal variations in water quality along major waterways. Therefore, this study aimed to assess the spatial and temporal fluctuation of water quality in the waterways of five provinces with intensive aquaculture operations in the Mekong Delta. The study sites included two inland provinces (An Giang and Can Tho) where striped catfish, Pangasianodon hypophthalmus (Sauvage, 1878), is farmed, and three coastal provinces (Soc Trang, Bac Lieu, and Ca Mau) where white leg shrimp, Litopenaeus vannamei (Boone, 1931), and black tiger shrimp Penaeus monodon Fabricius, 1798, are cultured. At each sampling site, physicochemical parameters were monitored for 12 months on the main rivers which supply water to aquaculture systems. Water quality data were analysed and compared based on the coefficient of variation (CV), Pearson correlation coefficients to identify relationships among variables and principal component analysis (PCA) to identify 2–3 key parameters having the most significant influence on spatial and temporal variation in water quality in each province. BOD, COD, PO4 3-, S2-, NO2 - and NO3 - were highly variable (CV 40–120 %). Significant interrelationships ranged from -0.5 to 0.5 between many water quality parameters. Overall, water in most provinces was considered polluted. However, the water quality parameters, except for S2- and NO2 - , were within acceptable levels specified by National Technical Regulation on Surface Water Quality for Protection of Aquatic Life.

Traditional polyculture as a mangrove restoration solution in Delta Mahakam, East Kalimantan Indonesia

The Mahakam Delta is a large mangrove ecosystem in East Kalimantan with a precious ecosystem and a massive mangrove species. Because of the conversion to shrimp aquaculture, the mangrove ecosystem has been devastated. This study looks at shrimp pond management in Salo Palai, Muara Badak, Kutai Kartanegara, East Kalimantan, using the traditional polyculture concept to increase pond productivity. The current shrimp pond condition was decreased water quality, substrate infertility, and natural food availability crisis. This model focused on traditional management, with a particular emphasis on pond preparation, polyculture, and used plant extracts. For 100 days, Penaeus monodon, Chanos chanos, Litopenaeus vannamei, Lates calcarifer, Scylla spp., and Gracilaria verrucosa were grown in the same time and pond. The yield from the pond was thrived: 332.14 kg/Ha. This concept can be used to restore mangroves, preserve the mangrove ecosystem, increase shrimp pond production, and protect the sea ecosystem; thus, this method achieves sustainable aquaculture.

Multiple origins define the genetic structure of tiger shrimp Penaeus monodon in the colombian Caribbean Sea

The tiger shrimp Penaeus monodon is a native species of the Indo-Pacific Ocean that was introduced to promote its cultivation in several American countries, including Colombia. As a result of inappropriate aquaculture practices, it has established itself in the wild in almost all the Colombian Caribbean Sea. To evaluate the genetic diversity, population structure, and origin of the founder populations, samples from three sites in the Colombian Caribbean were analyzed from 10 microsatellite loci and the mitochondrial DNA Control Region. Genetic diversity similar to native populations was found to be present in three relatively discrete populations and their origin is related to natural populations from Thailand, the Philippines, Taiwan and China. We discuss how oceanographic conditions and culture systems of tiger shrimp facilitated the success of biological invasion processes in marine ecosystems of the Colombian Caribbean.

Molecular docking approaches of biomolecules extracted from red seaweed Kappaphycus alvarezii against hemolysin protein of bioluminescence disease-causing bacteria Vibrio harveyi

Shrimp culture systems are being affected by bacterial diseases particularly Vibrios. Use of therapeutic agents in shrimp culture has lead to the resistance among aquatic bacteria. Accordingly, health management becomes of major importance in aquaculture. Under this situation, developing bio-inhibitors from natural marine resources which are most appropriate, which is considered as an unmatched reservoir of several biological products. Molecular docking is suited to a major approach in structural biology and computer-assisted drug design against the proteins of disease-causative agents. In the present study, marine macroalga Kappaphycus alvarezii was used for developing inhibitors against bioluminescence disease-causing pathogenic bacteria Vibrio harveyi. K. alvarezii was collected from the Mandapam, Tamil Nadu, India. Ethyl acetate based extract of K. alvarezii was tested against the growth and virulence factors of V. harveyi during Penaeus monodon larviculture. Further K. alvarezii extract was subjected to GC–MS analysis to identify the biomolecules. The homology modelling of the virulent protein, hemolysin of V. harveyi was designed during this study. Hence, it was aimed at molecular docking against the biomolecules identified from K. alvarezii extract. During shrimp larviculture, the extract of K. alvarezii (200 μg mL−1) exhibited a reduction on Cumulative Percentage of Mortality (29.70 %) in postlarvae against the challenge of V. harveyi infection. Among the compounds docked, an inhibitory effect was observed based on docking scores and were found the highest binding affinity/inhibiting activity in Cyclotetracosane with the least energy required with a docking score of binding energy −7.66 kcal/mol, inhibition constant 0.002 mM and intermolecular efficiency −0.32 kcal/mol. Using statistical analysis, significant differences (p < 0.05) were observed between the growth and virulence factors of V. harveyi during shrimp larviculture trials. While considering these findings, it was determined that K. alvarezii extract can be replaced as an alternative bio-agents protecting against infections caused by V. harveyi and possibly other aquatic pathogenic bacteria in shrimp farming systems.

SIMULTANEOUS PATHOGEN DETECTION OF SHRIMP VIRUSES ON CULTURED TIGER SHRIMPS (Penaeus monodon) IN INDONESIA

The multiple-pathogen infection causes severe economic impact to shrimp industry in Indonesia and worldwide due to mass mortality and multiple abnormalities of the survived infected shrimps. However, multiple-pathogen detection tools in shrimp diseases have not yet widely used. The purpose in this study was to develop and applied simultaneous detection system using multiplex polymerase chain reaction (PCR) assay from natural infections caused by white spot syndrome virus (WSSV), infectious hypodermal and haematopoietic necrosis virus (IHHNV) and monodon baculovirus (MBV) in Black tiger shrimp culture. To analyze multiple-pathogen infections in the shrimp, the study designed and used three pairs of specific primers targeting DNA virus from the shrimp diseases. All amplifications used a specific master mix for multiplex PCR assay and standardized extracted nucleic acid from the samples. This mPCR assay successfully amplified the DNA of three viruses in a single tube-run by multiplex PCR for each virus. Based on the results, the study confirms that multiple-pathogen infection contributes the highest mass mortality rather than from single infection by either WSSV, IHHNV or MBV. This study also confirms that the mPCR assay is a faster, cheaper, and efficient method to detect and subsequently prevent the spreading of multi-pathogen shrimp diseases.

Adsorption capacity of chitosan hydrogel beads fabricated from Penaeus monodon shrimp shell waste for safranin o dye

In this study, we extracted chitosan from Penaeus monodon shrimp shell waste and used it as a bio-sorbent to remove safranin O (SO) dye in aqueous solutions. The chitosan adsorbent was characterised by using SEM and FTIR techniques. Batch adsorption experiments were carried out to evaluate the influence of solution pH (3–10), chitosan dosage (0.1–3 g), contact time (1–720 min), and initial SO concentration (10–200 mg·L–1) on adsorption. The results show that the adsorption of SO with chitosan reached equilibrium after 120 min, and after that, an insignificant change in SO removal efficiency was observed. The maximum adsorption capacity of SO, calculated according to the Langmuir model, was 17.86 mg·g–1 under ambient temperature (25 ± 2 °C), pH 7, chitosan dose of 0.2 g, and SO concentration of 50 mg·L–1. The adsorption kinetics followed the pseudo-second-order model with a correlation coefficient R2 of 0.95. The Langmuir and Freundlich adsorption isotherm models described the SO’s adsorption well, with R2 higher than 0.95.

QUALITY OF Tetraselmis sp. CULTURED BY TIGER SHRIMP AQUACULTURE WASTE AS FERTILIZER

Tiger shrimp aquaculture waste still contained amount of nutrients needed by phytoplankton for its growth. Among nutrients was resulted from intensive aquaculture still can be used by phytoplankton. Phytoplankton used nitrates and phosphates for its growth and development. Phytoplankton requires nitrate concentration in 0,9-3,5 mg/ and phosphate in 0,27-5,51 mg/l. Utilization of tiger shrimp aquaculture waste for Tetraselmis sp. quality can be seen using fluorescence microscope with the cell of Tetraselmis sp. had to stained by acridine orange before observed using fluorescence microscope. The concept of this staining when cells of Tetraselmis sp. radiated green colour showed that cells was alive whereas cells radiated orange colour showed that cells was dead or damaged. This matter caused living cells could reducted acridine orange pigment enzymatically until become green radiated cells, instead damaged cells showed orange colour. Research procedures included cultivating Tetraselmis sp. in various dosages waste of tiger shrimp aquaculture as fertilizer. This various dosages are 2 g/l, 4 g/l, 6 g/l and 8 g/l. Culture media for Tetraselmis sp. was saltwater. Sterile saltwater was put into jars about 1 L and later added wastewater to jars. Reading of protein expression helped using imageJ software that showed histogram graphics accompanied by mean. Mean resulted by graphics indicated protein could be expressed. Based on expression of fluorescence protein with 2 g/l wastewater dosage showed that amount of protein could be ecpressed was higher than other wastewater dosage by mean value from ImageJ.

Identification and Characterization of Novel SPHINX/BMMF-like DNA Sequences Isolated from Non-Bovine Foods.

Sixteen novel circular rep-encoding DNA sequences with high sequence homologies to previously described SPHINX and BMMF sequences were isolated for the first time from non-bovine foods (pork, wild boar, chicken meat, Alaska pollock, pangasius, black tiger shrimp, apple, carrot, and sprouts from alfalfa, radish, and broccoli). The phylogenetic analysis of the full-length circular genomes grouped these together with previously described representatives of SPHINX/BMMF group 1 and 2 sequences (eight in each group). The characterization of genome lengths, genes present, and conserved structures confirmed their relationship to the known SPHINX/BMMF sequences. Further analysis of iteron-like tandem repeats of SPHINX/BMMF group 1-related genomes revealed a correlation with both full-length sequence tree branches as well as Rep protein sequence tree branches and was able to differentiate subtypes of SPHINX/BMMF group 1 members. For the SPHINX/BMMF group 2 members, a distinct grouping of sequences into two clades (A and B) with subgroups could be detected. A deeper investigation of potential functional regions upstream of the rep gene of the new SPHINX/BMMF group 2 sequences revealed homologies to the dso and sso regions of known plasmid groups that replicate via the rolling circle mechanism. Phylogenetic analyses were accomplished by a Rep protein sequence analysis of different ssDNA viruses, pCRESS, and plasmids with the known replication mechanism, as this yielded deeper insights into the relationship of SPHINX/BMMF group 1 and 2 Rep proteins. A clear relation of these proteins to the Rep proteins of plasmids could be confirmed. Interestingly, for SPHINX/BMMF group 2 members, the relationship to rolling circle replication plasmids could also be verified. Furthermore, a relationship of SPHINX/BMMF group 1 Rep proteins to theta-replicating plasmid Reps is discussed.

Automatic Penaeus Monodon Larvae Counting via Equal Keypoint Regression with Smartphones.

Today, large-scale Penaeus monodon farms no longer incubate eggs but instead purchase larvae from large-scale hatcheries for rearing. The accurate counting of tens of thousands of larvae in these transactions is a challenging task due to the small size of the larvae and the highly congested scenes. To address this issue, we present the Penaeus Larvae Counting Strategy (PLCS), a simple and efficient method for counting Penaeus monodon larvae that only requires a smartphone to capture images without the need for any additional equipment. Our approach treats two different types of keypoints as equip keypoints based on keypoint regression to determine the number of shrimp larvae in the image. We constructed a high-resolution image dataset named Penaeus_1k using images captured by five smartphones. This dataset contains 1420 images of Penaeus monodon larvae and includes general annotations for three keypoints, making it suitable for density map counting, keypoint regression, and other methods. The effectiveness of the proposed method was evaluated on a real Penaeus monodon larvae dataset. The average accuracy of 720 images with seven different density groups in the test dataset was 93.79%, outperforming the classical density map algorithm and demonstrating the efficacy of the PLCS.

Effects of dietary betaine supplementation on growth performance, feed intake, intestinal histology, lipid metabolism, and immune response of black tiger shrimp (Penaeus monodon) fed diets containing two levels of raw feed attractants

Effects of dietary betaine supplementation on growth performance, feed intake, intestinal histology, lipid metabolism, and immune response of black tiger shrimp (Penaeus monodon) fed diets containing two levels of raw feed attractants

Effects of PmDOME and PmSTAT knockdown on white spot syndrome virus infection in Penaeus monodon

Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling pathway plays an important role in antiviral immunity. This research reports the full-length DOME receptor gene in Penaeus monodon (PmDOME) and examines the effects of PmDOME and PmSTAT silencing on immune-related gene expressions in shrimp hemocytes during white spot syndrome virus (WSSV) infection. PmDOME and PmSTAT were up-regulated in shrimp hemocytes upon WSSV infection. Suppression of PmDOME and PmSTAT showed significant impacts on the expression levels of ProPO2 (melanization), Vago5 (interferon-like protein) and several antimicrobial peptides, including ALFPm3, Penaeidin3, CrustinPm1 and CrustinPm7. Silencing of PmDOME and PmSTAT reduced WSSV copy numbers and delayed the cumulative mortality caused by WSSV. We postulated that suppression of the JAK/STAT signaling pathway may activate the proPO, IFN-like antiviral cytokine and AMP production, resulting in a delay of WSSV-related mortality.

Oral administration of Zingiber officinale and Aegle marmelos extracts enhances growth and immune functions of the shrimp Penaeus monodon against the white spot syndrome virus (WSSV)

Oral administration of Zingiber officinale and Aegle marmelos extracts enhances growth and immune functions of the shrimp Penaeus monodon against the white spot syndrome virus (WSSV)

Effects of vitamin C on transport of Penaeus monodon

The experiment simulated the logistical transportation of Penaeus monodon. It set four distinct gradient Vitamin C (Vc) addition levels, including 0mg/L, 111mg/L, 222mg/L, and 333mg/L, to investigate the impact of Vc on the anti-stress ability of P. monodon during transportation. And the survival rate following transportation and a 15-day interim rearing period were recorded. Moreover, the alterations in tissue structure and activity of the enzymes alkaline phosphatase (ACP), alkaline phosphatase (AKP), total superoxide dismutase (T-SOD), and total superoxide dismutase (T-AOC) were checked. The results showed that with the increase of Vc supplemental level, the survival rate of P. monodon after transportation and after 15 days of temporary rearing increased to varying degrees. ACP and AKP in the hepatopancreas increased first and then decreased. T-SOD activity in the 0mg/L group was the lowest and then decreased gradually. The activity of total antioxidant capacity (T-AOC) in the 0mg/L group was the lowest and then stabilized. The branchial tissue structure also changed. The branchial tissue blood cell disorder decreased, the diaphragm gradually narrowed, the cornered cortex gradually recovered, and the swelling decreased. In conclusion, Vc positively affects the survival rate of P. monodon after transportation and temporary cultivation and alleviates the stress of P. monodon. The amount of Vc added at about 333mg/Lin, the transportation of P. monodon could play a positive role. The experimental results provide primary data for the transportation of P. monodon.

Potential Toxic elements in shellfish from three rivers in Niger Delta, Nigeria: bioaccumulation, dietary intake, and human health risk assessment

Human health risks associated with the consumption of three shellfish (&lt;i&gt;Penaeus monodon, Crassostrea rhizophorae&lt;/i&gt;, and &lt;i&gt;Tympanostomus fuscatus&lt;/i&gt;) harvested from the Buguma, Krakrama, and Bonny Rivers in the Niger Delta region were evaluated in this study. The bioaccumulation of potential toxic elements (PTEs) [Arsenic (As), Cadmium (Cd), Chromium (Cr), Lead (Pb), and Nickel (Ni)] was analyzed using atomic absorption spectrophotometry (AAS). The pollution index (PPI), estimated daily intake (EDI), target hazard quotient (THQ), total hazard index (HI), target cancer risk (CR), and total cancer risk (TCR) were evaluated for potential human health risks. The bioaccumulation levels of PTEs in shellfish samples followed the order: Ni &gt; Cr &gt; Pb &gt; Cd &gt; As and were above standard recommended limits except for inorganic As levels observed in &lt;i&gt;T. fuscatus&lt;/i&gt; and &lt;i&gt;P. monodon&lt;/i&gt; samples from Krakrama and Bonny and &lt;i&gt;C. rhizophorae&lt;/i&gt; from Bonny river. The EDI values for iAs, Cr, and Ni were lower than the tolerable daily intake (TDI), however, the EDI of Cd for children in &lt;i&gt;P. monodon&lt;/i&gt; (4.6E-03 mg kg&lt;sup&gt;-1&lt;/sup&gt;day&lt;sup&gt;-1&lt;/sup&gt;), &lt;i&gt;T. fuscatus&lt;/i&gt; (1.7E-03 mg kg-&lt;sup&gt;-1&lt;/sup&gt;day&lt;sup&gt;-1&lt;/sup&gt;) and C. rhizophorae (1.4E-03 mg kg&lt;sup&gt;-1&lt;/sup&gt;day&lt;sup&gt;-1&lt;/sup&gt;) from Buguma were higher than the TDI value (8.00E-04 mg kg&lt;sup&gt;-1&lt;/sup&gt;day&lt;sup&gt;-1&lt;/sup&gt;). The HI values were above 1. The total cancer risk (TCR) values of all analyzed PTEs for all the shellfish species from the rivers for children and adults ranged from 8.69E-04 to 2.47E-03 and 1.86E-03 to 5.30E-03 respectively and these were higher than the priority risk level (1E-04), hence, the need to monitor shellfish consumption in the study area.

Pokkali Rice Cultivation: A Review on the Indigenous Rice Cultivation Method in Kerala

Kerala state's rice consumption is predicted to be between 3.5 and 4 million tons per year, but production is just a sixth of this. In order to boost the state's rice production, attention must be paid to traditional rice growing techniques. Thus, there is a need to understand the Pokkali rice cultivation method used in Kerala. The Pokkali style of rice farming in Kerala's acidic, saline soil is a distinctive way of rice cultivation. A native historic salt-tolerant type of rice called Pokkali, with a 120-day growing season, can withstand flooding by growing up to a height of 1.5 meters. Chettivirippu, Vyttila 1, Vyttila 2, Vyttila 3, Vyttila 4 and Vyttila 5 are the other rice varieties cultivated using the Pokkali rice cultivation method. With this technique, a single rice crop is harvested on mounds during the low salinity part of the production cycle (June to mid-October), with prawn aquaculture taking place during the high salinity phase (November to April). Pokkali cultivation only produce 2000 kg of rice per hectare, making it slightly unprofitable. The rice plant residue after harvesting is left to rot in the water which subsequently acts as prawn feed. Prawn farming takes place from November to April. Sluice gates help in prawn culture filtering by maximizing the amount of saline water that enters the field and preventing the prawns from escaping. The two main cultivated prawns species are Penaeus monodon (Tiger prawn) and Penaeus indicus (White prawn). Prawns are typically collected in mid-April, especially two to three days before new full moon days, as tidal activity affects their movement. Prawn excreta serve as a natural fertilizer for rice cultivation; prawns feeding on rice cultivation stubbles help to minimize the occurrence of illness in rice to a minimum. It is an organic rice production approach with less cost than commercial rice farming because chemical fertilizers and pesticides are not used.