Morinda citrifolia fruit extract enhances the resistance of Penaeus vannamei to Vibrio parahaemolyticus infection.

Vibrio parahaemolyticus is a gram-negative facultative anaerobic bacterium implicated as the causative agent of several shrimp diseases. As part of the effort to provide biocontrol and cost-effective treatments, this research was designed to elucidate the effect of Morinda citrifolia fruit extract on the immunity of Penaeus vannamei postlarvae (PL) to V. parahaemolyticus. The methanol extract of M. citrifolia was vacuum evaporated, and the bioactive compounds were detected using gas chromatography‒mass spectrometry (GC‒MS). Thereafter, P. vannamei PL diets were supplemented with M. citrifolia at different concentrations (0, 10, 20, 30, 40, and 50 mg/g) and administered for 30 days before 24 h of exposure to the bacterium V. parahaemolyticus. A total of 45 bioactive compounds were detected in the methanol extract of M. citrifolia, with cyclononasiloxane and octadecamethyl being the most abundant. The survival of P. vannamei PLs fed the extract supplement was better than that of the control group (7.1-26.7% survival greater than that of the control group) following V. parahaemolyticus infection. Shrimp fed 50 mg/g M. citrifolia had the highest recorded survival. The activities of digestive and antioxidant enzymes as well as hepatopancreatic cells were significantly reduced, except for those of lipase and hepatopancreatic E-cells, which increased following challenge with V. parahaemolyticus. Histological assessment of the hepatopancreas cells revealed reduced cell degeneration following the administration of the plant extracts (expecially those fed 50 mg/g M. citrifolia) compared to that in the control group. Therefore, the enhanced immunity against V. parahaemolyticus infection in P. vannamei could be associated with the improved hepatopancreas health associated with M. citrifolia fruit extract supplementation.

Assessment on Water Quality Parameter and Nutrients Level of Nyatuh River in Relations with Macrobrachium Rosenbergii Prawn Populations.

In order to determine the safety level of water parameters and nutrients in the natural environment of fish and freshwater prawn in Nyatuh River, Terengganu, Malaysia, it is necessary to conduct an assessment of water quality parameters. Due to its important, a study was conducted to assess the water quality parameter and nutrients contents from Nyatuh River of Setiu Terengganu in relations to the population of freshwater prawn, Macrobrachium rosenbergii caught along the Nyatuh River basin. Total of four expeditions and five stations at different tidal condition for the water quality parameter were assessed during the study. From the results achieved, the overall temperature varied between (26.56°C-29.30°C), dissolved oxygen, DO (3.59 mg/L-6.50 mg/L), pH (4.99-7.01), salinity (0.01ppt-4.22ppt), depth (2.71 m-5.54 m) while for ammonia (0.01 mg/L-0.24 mg/L), nitrite (0.01 mg/L-0.05 mg/L) and phosphate (0.01 mg/L-0.12 mg/L). While the number of prawns caught are 176, 160, 102 and 68 for Expeditions 1, 2, 4 and 3, respectively. Possibly, the heterogeneous number of prawns caught is a result of significant differences in water level depth during high tides and low tides, as well as a fluctuation in the ammonia concentration levels in each of the stations and expeditions. For statistical analysis, the temperature showed no significant difference between the expedition, stations and tidal. That is p = 0.280, p > 0.05 and F = 1.206, respectively. While dissolved oxygen, DO, showed no significant difference as well, that is p = 0.714, p > 0.05 and F = 0.737. However, the level of water depth was significantly different between expedition, station and tidal, that is p = 0.000, p < 0.05 and F = 3.120. Ammonia, on the other hand shows no significant difference between expedition, station and tidal, that is p = 0.476, p > 0.05 and F = 0.973. The same goes for nitrite and phosphate concentration. There was no significant difference between expedition, stations and tidal, that is p = 0.569, p > 0.05 and F = 0.879 and p = 0.247, p > 0.05, F = 1.255, respectively. In Expedition 1, the good water quality parameter and very low ammonia concentration resulted in a larger prawn population as compared to other expeditions. The distribution or mixture of prawns caught is heterogeneous at different stations due to the significant differences in water depth and also to the fluctuation in water quality due to varying ammonia levels. In conclusion, the water quality in Nyatuh River fluctuated across expeditions, stations, and tides, as well as significant differences in water level depths between high and low tides. Due to the rapid growth and importance of industrial and aquaculture operations along the river, extra attention should be devoted to avoid the impact of excessive pollutant in order to protect the ecosystem.

Penilaian parameter kualiti air perlu dijalankan untuk menentukan tahap keselamatan parameter air dan nutrien dalam persekitaran semula jadi ikan dan udang air tawar di Sungai Nyatuh, Terengganu, Malaysia. Maka, satu kajian telah dijalankan untuk menilai parameter kualiti air dan kandungan nutrien di Sungai Nyatuh, Setiu, Terengganu dalam hubungan dengan populasi udang air tawar, Macrobrachium rosenbergii yang ditangkap di sepanjang lembangan Sungai Nyatuh. Sebanyak empat ekspedisi dan lima stesen pada keadaan pasang surut berbeza untuk parameter kualiti air telah dinilai semasa kajian dijalankan. Berdasarkan keputusan yang dicapai, suhu keseluruhan berbeza-beza antara (26.56°C­29.30°C), oksigen terlarut (3.59 mg/L­6.50 mg/L), pH (4.99­7.01), kadar kemasinan (0.01ppt­4.22ppt), kedalaman (2.71 m­5.54 m) sementara bagi ammonia (0.01 mg/L­0.24 mg/L), nitrit (0.01 mg/L­0.05 mg/L) dan fosfat (0.01 mg/L­0.12 mg/L). Manakala bilangan udang yang ditangkap adalah 176, 160, 102 and 68 ekor, masing-masing untuk Ekspedisi 1, 2, 4 dan 3. Bilangan heterogen udang yang ditangkap berkemungkinan adalah hasil daripada perbezaan ketara dalam kedalaman paras air semasa air pasang dan air surut, serta turun naik paras kepekatan ammonia di setiap stesen dan ekspedisi. Bagi analisis statistik, suhu tidak menunjukkan perbezaan yang signifikan antara ekspedisi, stesen dan pasang surut, iaitu p = 0.280, p > 0.05 dan F = 1.206, masing-masing. Oksigen terlarut juga tidak menunjukkan perbezaan yang signifikan, iaitu p = 0.714, p > 0.05 dan F = 0.737. Walau bagaimanapun, paras kedalaman air adalah berbeza secara signifikan antara ekspedisi, stesen dan pasang surut, iaitu p = 0.000, p < 0.05 dan F = 3.120. Ammonia pula tidak menunjukkan perbezaan yang signifikan antara ekspedisi, stesen dan pasang surut, iaitu p = 0.476, p > 0.05 dan F = 0.973. Begitu juga dengan kepekatan nitrit dan fosfat. Tidak terdapat perbezaan yang signifikan di antara ekspedisi, stesen dan pasang surut, iaitu masing-masing pada p = 0.569, p > 0.05 dan F = 0.879 dan p = 0.247, p > 0.05, F = 1.255. Dalam Ekspedisi 1, parameter kualiti air yang baik dan kepekatan ammonia yang sangat rendah menghasilkan populasi udang yang lebih besar berbanding ekspedisi lain. Taburan atau campuran udang yang ditangkap adalah heterogen di stesen yang berbeza disebabkan oleh perbezaan ketara dalam kedalaman air dan juga turun naik kualiti air akibat paras ammonia yang berbeza-beza. Kesimpulannya, kualiti air di Sungai Nyatuh berubah-ubah merentasi ekspedisi, stesen dan pasang surut, serta perbezaan ketara dalam kedalaman paras air antara air pasang tinggi dan rendah. Disebabkan pertumbuhan pesat dan kepentingan operasi perindustrian dan akuakultur di sepanjang sungai, perhatian tambahan harus ditumpukan untuk mengelakkan kesan pencemar yang berlebihan untuk melindungi ekosistem.

Microplastics biodegradation by biofloc-producing bacteria: An inventive biofloc technology approach.

Microplastics pollution has become a threat to aquaculture practices, as nearly all farming systems are saturated with microplastics (MPs) particles. Current research on MPs is limited considering their effects on aquatic organisms and human health. However, limited research has been conducted on potential cures and treatments. In today's world, bioremediation of needful parameters in different culture systems is being successfully practiced by introducing floc-forming bacteria. Researchers had found that some bacteria are efficacious in degrading microplastics particles including polyethylene (PE), polystyrene (PS), and polypropylene (PP). In addition, some bacteria that can form floc, are being used in fish and shellfish culture systems to treat toxic pollutants as the heterotrophic bacteria use organic compounds to grow and are effective in degrading microplastics and minimizing toxic nitrogen loads in aquaculture systems. In this review, the ability of biofloc bacteria to degrade microplastics has been summarized by collating the results of previous studies. The concept of this review may represent the efficacy of biofloc technology as an implicit tool in the fish culture system restricting the MPs contamination in water resources to safeguard ecological as well as human health.

Recent advances on microalgae cultivation for simultaneous biomass production and removal of wastewater pollutants to achieve circular economy.

Microalgae are known for containing high value compounds and its significant role in sequestering carbon dioxide. This review mainly focuses on the emerging microalgae cultivation technologies such as nanomaterials technology that can improve light distribution during microalgae cultivation, attached cultivation and co-cultivation approaches that can improve growth and proliferation of algal cells, biomass yield and lipid accumulation in microalgal. This review includes a comprehensive discussion on the use of microbubbles technology to enhance aerated bubble capacity in photobioreactor to improve microalgal growth. This is followed by discussion on the role of microalgae as phycoremediation agent in removal of contaminants from wastewater, leading to better water quality and high productivity of shellfish. The review also includes techno-economic assessment of microalgae biorefinery technology, which is useful for scaling up the microalgal biofuel production system or integrated microalgae-shellfish cultivation system to support circular economy.

Gonad Quality of Banana Shrimp Male Broodstock Penaeus merguiensis (De Man, 1888) Fed Different Natural Diets.

A study was carried out to determine the maturation period, quality and quantity of sperms production in Banana shrimp male broodstock, Penaeus merguiensis fed different natural diets. The three different natural diets namely; squid, fish and shrimp flesh used in this study were obtained from known sources and fed to the tested shrimp in triplicate groups. Based on the results obtained, squid seem to be the most effective natural diet as it enhances the sperms maturation within 20 days. Feeding fish and shrimp flesh as diets for the Banana shrimp broodstock resulted in the observation of maturation in 22 and 24 days, respectively. Similarly, squid diet also recorded the highest (p = 0.002; p < 0.05) sperms count (58.6 to 74.5) as compared to fish diet (44.0 to 61.3) or shrimp diet (28.0 to 42.8). Also, feeding squid diet resulted in a higher percentage of live sperms with ranged between 97.75% to 98.80%. On the other hand, broodstocks fed fish and squid flesh was observed with ranges of between 96% to 97.86% and 92.54% to 96.06%, respectively. It was therefore concluded that squid diet was most effective to improve sperm quality, quantity and maturation period in male broodstock of P. merguiensis. Further study should be carried on the reproductive performance of broodstock fed with squid as diets and it effect on the performances of post larvae obtained.

Histology and External Morphological Assessment on Ovarian Maturation Stages of Wild Female Banana Shrimp, Penaeus merguiensis (de Man, 1888) for Broodstock Selection Purpose.

Study on ovarian maturation stages were carried out using external morphological assessment of ovarian colourations and histological assessment of Oocyte structure for broodstock selection purpose. Stage 1 to Stage 4 of female shrimps broodstock were sampled from Kuala Muda, Kedah, Malaysia. Four obvious colourations of ovary stages were identified which are: yellow (Stage 1), green yellowish (Stage 2), light greenish (Stage 3) and dark green (Stage 4) through the morphological assessment. The Gonadosomatic Index (GSI) showed significant increment as the gonad reach advance stages. Histological assessment of Stage 1 ovary identified perinucleolar oocyte (PO) with small size oocytes. Stage 2 ovary was identified with yolkless oocyte (YO), Stage 3 ovary was identified with late stage of yolky globules and Stage 4 ovary was identified with fully yolky globules. From the results achieved, it can be concluded that the ovarian colourations and GSI can be applied to identify the ovarian maturation stages, meanwhile, the histology assessment is the most precise method to determine the ovarian maturation stages in more details and accurate for each of the ovarian maturation stages.

Kajian mengenai peringkat kematangan ovari telah dijalankan menggunakan penilaian morfologi luaran pewarnaan ovari dan penilaian histologi struktur oosit untuk tujuan pemilihan induk. Peringkat 1 hingga Peringkat 4 induk udang betina telah diambil sampel dari Kuala Muda, Kedah, Malaysia. Empat warna jelas peringkat ovari telah dikenal pasti iaitu: kuning (Peringkat 1), hijau kekuningan (Peringkat 2), hijau muda (Peringkat 3) dan hijau gelap (Peringkat 4) melalui penilaian morfologi. Indeks Gonadosomatic (GSI) menunjukkan peningkatan yang ketara apabila gonad mencapai peringkat lebih tinggi. Penilaian histologi ovari Peringkat 1 mengenal pasti perinucleolar oocyte (PO) dengan oosit saiz kecil. Ovari Peringkat 2 telah dikenal pasti dengan yolkless oocyte (YO), ovari Peringkat 3 telah dikenal pasti dengan peringkat akhir globul kuning dan ovari Peringkat 4 telah dikenal pasti dengan globul kuning sepenuhnya. Dari keputusan yang dicapai, dapat disimpulkan bahawa pewarnaan ovari dan GSI boleh digunakan untuk mengenal pasti peringkat kematangan ovari, sementara itu, penilaian histologi merupakan kaedah yang paling tepat untuk menentukan peringkat kematangan ovari dengan lebih terperinci dan tepat untuk setiap peringkat.

Inhibitory effect of thiourea derivatives on the growth of blue-green algae.

High nutrient loading in aquatic environment has become the main causative of harmful algae blooms (HABs) in water resources particularly pond, lake and river. HABs are mostly dominated by microalgae derived from the group of blue-green algae which are capable of releasing harmful toxins. Therefore, this study aims to investigate the inhibitory effects of thiourea derivatives on the growth of such blue-green algae. Thiourea derivatives have been proven to exhibit antifungal and antibacterial effects. However, there is still limited study had been conducted on the effect of thiourea derivatives toward blue-green algae species in recent years. In this research, a species of blue-green algae from Kenyir Lake, Terengganu, Malaysia was successfully isolated using morphological characters and molecularly identified as Synechoccus elongatus. Four new thiourea derivative compounds were also successfully synthesised. The compounds were designed with variation on different R-substitution group and characterised using Nuclear Magnetic Resonance (NMR) to confirm their molecular structure. Those compounds were characterised as 1-Benzyl-3-(3,5-dimethoxy-benzoyl)-thiourea (C1), 1-(3-Chloro-benzyl)-3-(3,5-dimethoxy-benzoyl)-thiourea (C2), 1-(3,5-Dimethoxy-benzoyl)-3-(3-methyl-benzyl)-thiourea (C3) and 1-(3,5-Dimethoxy-benzoyl)-3-(3-trifluoromethyl-benzyl)-thiourea (C4). For the inhibition assessment,S. elongatus were treated with C1-C4 for 5 day at concentration of 2, 5, 10 and 20 µg/ml, respectively. C3 compound showed the highest inhibition percentage with 98% of inhibition after 5 days treatment. By using Bradford method, protein extraction of S. elongatus was conducted at the highest inhibition percentage. Protein concentration of treated species was observed with 3.28 µg/ml as compared to protein concentration of control with 6.48 µg/ml. This result indicated the reduction of protein content after the treatment. Protein band pattern was identified intensed after the treatment SDS PAGE was carried out. The thiourea derivatives compound proved to have successfully inhibited the growth of blue-green algae. Hence, further study should be carried out to ensure the compound can be practically utilized in the pond and in natural environment.

Effects of Biofloc Application on Survival Rate, Growth Performance and Specific Growth Rate of Pacific Whiteleg Shrimp, Penaeus vannamei Culture in Closed Hatchery System.

BACKGROUND AND OBJECTIVE: Biofloc application has been introduced in aquaculture in order to reduce the nutrients level and sustain good water quality. Due to its importance, a study was conducted to identify the effect of biofloc application on shrimp growth performance, specific growth rate and survival rate in a closed hatchery system. MATERIALS AND METHODS: Molasses as carbon sources were applied in ratio 10:1 for biofloc formulation and no addition of molasses in non-biofloc (clear water) treatment. One way ANOVA was applied to analyze the differences between biofloc treatments and clear water. RESULTS: The survival rate of the shrimp was ranged between 23.69 and 98.77% for biofloc treatment, whereas 98.15-99.23% for non-biofloc treatment. The lowest survival rate (23.69%) was due to vibriosis infection in one of the biofloc treatment tanks. Growth performance was identified expedite in biofloc especially in (dark green) colour biofloc as compared to non-biofloc. The Specific Growth Rate (SGR) for Body Weight (BW) was identified expedite around (3.25-4.06) g day-1 for biofloc treatment compared to non-biofloc around (2.74-3.93) g day-1. The SGR for (TL) also identified expedite around (2.12-2.45) cm day-1 for biofloc, compared to non-biofloc (clear water) around (1.71-2.13) cm day-1. CONCLUSION: It can be concluded that the biofloc application successfully improved the shrimp performance and at the same time become the additional natural diet to the shrimp respectively. However, further study needs to be conducted to improve the survival rate and prevent vibriosis infection by using the biofloc system in the future.

Dataset on reproductive status of ovary mud crab at different salinity levels.

This article investigated how crabs responded to different culture salinities through ovarian maturation stages using combination of external morphology (ovarian coloration and gonadosomatic index), and histological assessment (oocyte structures and diameter sizes). A total of sixty immature crabs were sampled from coastal water of Setiu Wetlands, Kuala Nerus, Terengganu, Peninsular Malaysia, and were introduced to limb autotomy technique in order to induce molt. Crabs were reared until successfully molted, and leaves prior to hardened shell, before proceed with salinities acclimatization prior to salinity treatments (10, 20 and 30 ppt). Five crabs were randomly selected every 15 days throughout 60-day of culture (Day 15, 30, 45 and 60) for the assessment. The different between each ovarian maturation stages was recorded based on the color appearances, and Kruskal-Wallis analysis were done between gonadosomatic index and oocyte diameter sizes with different salinity treatments. Part of the data is associated with the recent articles [1], [2] and provided here as raw data of Supplementary materials.