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The bacterial population plays a crucial role in recycling the organic matter and metabolizing the toxic nitrogenous compounds under biofloc technology (BFT). The biofloc technology has been successfully implemented for several fish species, but not for shrimp culture in Bangladesh. The major objectives of this study were to determine the effects of stocking density on the growth performance of tiger shrimp Penaeus monodon under biofloc technology (BFT) rearing system using commercial probiotics and to investigate the abundance of total heterotrophic bacteria (THB) and vibrio-like bacteria (VLB) in different biofloc treatments and their water quality parameters. The experiment was conducted with three different stocking densities in three BFT tanks (2.5 × 2.0 × 1.0 m) with triplicate and three control tanks filled in clearwater. All these tanks were built with cement and can contain 5000 L of water. Visually healthy, disease-free P. monodon postlarvae (weighted 0.18 ± 0.02 g) were collected from a local hatchery and stocked in three different stocking densities, i.e., 400 PL/m3 (CW), 400 PL/m3 (BFT1), 450 PL/m3 (BFT2) and 500 PL/m3 (BFT3). Shrimps were fed four times a day with commercial feed (Biomer, 40 % crude protein) for 127 days. Significant differences (P < 0.05) in specific growth rate, food conversion ratio, and protein efficiency ratio of shrimp were found among the treatments and the control group. The overall final biomass in BFT1 (5.88 ± 0.12 kg m3) was significantly higher (P < 0.05) than that of other BFT groups and the control (3.40 ± 0.09 kg m3). The present findings showed that the biofloc technology with lower stocking density was reducing the total ammonia nitrogen, nitrite-N, and nitrate-N in water and significantly increased THB and reduced VLB populations.

Penggunaan induk pada pembenihan udang windu pada dasarnya hanya untuk periode yang singkat dan selanjutnya induk udang windu diapkir baik betina maupun jantan. Tujuan penelitian ini untuk mengevaluasi efek injeksi hormon kombinasi salmon gonadotrophin releasing hormone analogue (sGnRH-a) dan domperidone terhadap karakteristik spermatofor induk udang windu, Penaeus monodon yang telah diapkir dari unit pembenihan tanpa ablasi tangkai mata. Dua tahap penelitian dilakukan pada udang windu jantan yang diapkir dari unit pembenihan. Tahap pertama terdiri atas dua dosis 0,1 (OV-1) dan 0,2 (OV-2) mL/kg bobot udang dan ablasi mata (AB) sebagai kontrol. Pada tahap ke-2, dosis yang diaplikasikan adalah dosis terbaik dari tahap ke-1 (OV-3) dan ablasi sebagai kontrol (AB). Induk jantan apkir ditebar masing-masing dengan kepadatan 14 ekor untuk tahap ke-1 dan 12 ekor pada tahap kedua. Injeksi dilakukan tiga kali dengan interval satu minggu untuk kedua percobaan tersebut. Seminggu setelah suntikan terakhir, induk jantan diberi kejutan listrik untuk mengeluarkan spermatofornya. Pada percobaan pertama, jumlah induk jantan yang mengeluarkan spermatofor pada maturasi dan rematurasi pertama lebih banyak ditemukan pada perlakuan OV-2 daripada OV-1 dan AB. Induk jantan pada perlakuan OV-3 pada tahap ke-2 menghasilkan lebih banyak spermatofor (58,3%) dibandingkan dengan AB (50%). Hubungan antara bobot badan dan bobot spermatofor untuk total data pada tahap ke-1 sifatnya linier dengan nilai r= 0,74 sedangkan hubungan antara bobot spermatofor dan jumlah spermatozoa sifatnya tidak linier dengan nilai r= 0.14. Induk apkiran jantan udang windu masih dapat memproduksi spermatofor melalui stimulasi injeksi hormon sGnRH-a pada dosis 0,2 mL/kg bobot udang relatif lebih banyak dibandingkan ablasi.Broodstocks in black tiger hatcheries are commonly used for only a short period of time. Both female and male broodstocks are discarded due to reduced spawning frequencies. This recent study was an effort to explore whether discarded broodstocks could be re-maturated without eyestalk ablation. For the research purpose, a two-stage experiment was conducted on discarded male tiger shrimps to evaluate the effect of sGnRH-a injection on the shrimp reproductive performances. In the first stage, the experiment consisted of injection treatment of different doses of sGnRH-a at 0.1 (OV-1) and 0.2 (OV-2) mL/kg and eyestalk ablation (AB) as a control. For the second stage, the treatment consisted of injection of sGnRH-a optimum dose obtained from the first trial (0.2 mL/kg shrimp (OV-3) and ablation as the control (AB). The treated male stocks were then randomly placed in concrete tanks with a density of 14 males/tank for the first stage and 12 males for the second stage. The injections were carried-out three times with an interval of one week for both stages. A week after the last injection, males were electrically shocked to release their spermatophores. In the first stage, the number of males releasing spermatophores at maturation and first re-maturation was higher in OV-2 treatment than that of OV-1 and AB treatments. In the second trial, the number of males in OV-3 treatment released more spermatophore (58.3%) compared to AB which was 50%. The body and spermatophore weights correlation of the discarded tiger shrimp in the first trial followed a positive linear with an r-value of 0.74. However, the spermatophore weight and the sperm cell number was not positively correlated with an r-value of 0.14. The discarded male tiger shrimps produced a relatively higher spermatophore when induced with sGnRHa at a dose of 0.2 mL/kg than those of shrimp treated with ablation.

Medium rearing of the P. monodon Fabricius seed at the hatcheries usually used closed system and without water changes during culture period, until certain time the water quality could deterioted. The purpose of this research was to understand the effects of recirculation system on the water qualities (total suspended solids, ammonia, ammonium, nitrite and dissolved oxygen) of tiger shrimp (P. monodon Fabricius) seed medium. This research was conducted in the hatchery of Marine Science of Diponegoro University at Teluk Awur. The research used experimental method with two treatments, recirculation and non-recirculation system. Concentrations of total suspended solids (TSS), ammonia, nitrite and dissolved oxygen (DO) were descriptive analyzed. Average concentration on recirculation system of TSS was 0,570 mg/L, ammonia was 0,039 mg/L, nitrite was 0,076 mg/L and DO was 6,00 mg/L. Average concentration on without recirculation system of TSS was 0,983 mg/L, ammonia was 0,09 mg/L, nitrite was 0,2 mg/L and DO was 3,86 mg/L. The resirculation rearing system was improve water quality on tiger shrimp seed medium. Keywords : Water Quality, Recirculation System, Tiger Shrimp (P. monodon Fabricius) Budidaya benih udang windu (P. monodon Fabricius) pada bak pembenihan umumnya menggunakan sistem tertutup dan air media tidak diganti, sehingga dalam waktu tertentu dapat terjadi penurunan kualitas air. Penelitian ini bertujuan untuk mengetahui perubahan kualitas air (MPT, amonia, amonium, nitrit dan DO) pada pemeliharaan benih udang windu (P. monodon Fabricius) dengan sistem resirkulasi dan tanpa resirkulasi. Penelitian dilakukan di Marine Center, Jurusan Ilmu Kelautan, Teluk Awur, Jepara. Metode penelitian yang digunakan adalah eksperimental dengan dua perlakuan yaitu penggunaan sistem resirkulasi dan tanpa resirkulasi. Data konsentrasi material padatan tersuspensi (MPT), amonia, nitrit, oksigen terlarut (DO), pH dan suhu selama penelitian dianalisis secara deskriptif. Hasil penelitian menunjukkan bahwa pada sistem resirkulasi konsentrasi rata – rata MPT 0,570 mg/L, amonia 0,039 mg/L, nitrit 0,076 mg/L dan DO 6,00 mg/L, sedangkan pada bak tanpa sistem resirkulasi konsentrasi rata – rata MPT 0,983 mg/L, amonia 0,09 mg/L, nitrit 0,2 mg/L dan DO 3,86 mg/L. Sistem resirkulasi mampu memperbaiki kualitas air media pemeliharaan benih udang windu. Kata kunci: Kualitas Air, Sistem Resirkulasi, Udang Windu (Pennaeus monodon Fabricius).

Very low naturally mating rate of pond-reared tiger shrimp broodstock is probably due to the slow maturation of the male stock. The aim of this study was to evaluate the salmon gonadotrophin releasing hormone analoque (sGnRHa) in stimulating the gonadal maturation of male stock of pond-reared tiger shrimp. The treatments were three dosages of sGnRHa at 0.1 (OV-1), 0.2 (OV-2), and 0.3 (OV-3) mL/kg of shrimp weight and control was eye stalk ablation (AB). The sGnRHa was administered via injection three times with one week interval. Male stocks with average initial body weight of 82.1 g were randomly distributed into four of 10 m3 concrete tanks, 26 males for each tank. Variables observed were performances of spermatophores and profiles of amino acid and fatty acid of muscle of the male stocks. After induction, number of male maturing indicated by spermatophores releasing from terminal ampullas was higher in shrimp induced with OV-1 (80.8%) compared to control which was only 46.1%. Furthermore, shrimp treated OV-2 had the highest spermatophore weight of 0.16 g compared to control (0.11 g) and other two groups. Amino acid profiles improved as the dose of sGnRHa increased up to 0.2 mL/kg from 61.23% for ablated male becoming 71.27% for OV-2. Total fatty acid also tended to improve by increasing the dose of hormone injection, however, the ablated male had higher total fatty acid content than that of OV-1. The present finding demonstrated that the dose of sGnRHa to stimulate the gonadal maturation of pond-reared male tiger shrimp could be applied at range between 0.1-0.2 mL/kg of shrimp weight.

Vibrio harveyi causes disease of tiger shrimp (Penaeus monodon) aquaculture in East Kalimantan. This research aimed to investigate the susceptibility of tiger shrimp on various molt stage and osmolarity, and determine the salinity (osmolarity) of water that can reduce the risk of V. harveyi attack. Shrimp age of 1.5 months was maintained in 4 aquariums with salinity 29.72 ‰, 26.07 ‰, 22.35 ‰ and 17.79 ‰, then challenged with V. harveyi. After 7 and 14 days, osmolarity of haemolimph was observed with automatic osmometer and Digital Roebling Osmometer. The susceptibility of tiger shrimp to V. harveyi was evaluated based on clinical symptoms, pathological anatomy of shrimp and density of V. harveyi (TPC) in the hepatopancreas. Osmolarities of shrimp haemolymph at premolt, postmolt, and intermolt stage were 575.30-812.60; 534.00-788.80, and 566.20-795.60 mOsm/l H2O, respectively. The lowest bacterial content in the premolt stage was maintained at a salinity 22.35 ‰, and the highest one was obtained in postmolt stage at 29.72 ‰. The molting and postmolt stage were the most susceptible to V. harveyi attacks. The results suggested that the shrimp maintained at 22.35 ‰ salinity was less susceptible to V. harveyi.

Tiger shrimp diseases have occured in Indonesian shrimp ponds for more than two decades. In order to overcome this problem, five types of the RICA probiotic bacteria were tested in nine 250 m2 semi-intensive ponds of the Research and Development Institute for Coastal Aquaculture Marana Station. In the present study three different alternate use of the RICA probiotics were tested for tiger shrimp culture incompletely randomized design experiment. There were three treatments here namely: A) alternate use of probiotic bacteria RICA-1, RICA-2, RICA-3; B) alternate use of probiotic bacteria RICA-4, RICA-5, RICA-3, and C) control (without probiotic bacteria); each treatment were applied in three replications. The results showed that survival rate and production of tiger shrimp in treatment A (55.8% and 14.9 kg/pond) and B (52.7% and 16.7 kg/pond) were significantly better (P0.05). The average total bacteria population in the cultured water media of treatment A (4.32 x 104 cfu/mL) and B (5.18 x 104 cfu/mL) were relatively higher than control (1.46 x 104 cfu/mL). However the percentage ratio of Vibrio spp. and total bacteria population in the cultured water media of treatment A and B were relatively lower than control. The lower survival rate and production of tiger shrimp in control (C) compared to probiotic treatments (A and B) were not just affected by the increase of Vibrio spp. ratio, but also affected by the increase of total organic matter and nitrite concentrations in the control ponds that were relatively higher than treatment A and B.

The role of tiger shrimp defense against invading pathogen on molecular level such antiviral gene expression is limited to be reported. Gene expression is a process which codes information of genes that is converted to the protein as a phenotype. Distribution of PmAV antivirus gene, that has been reported as an important gene on non-specific response immune, is needed to be observed to several organs/tissues and size of tiger shrimp. The aim of this study is to determine the distribution of gene antiviral expression at several organ/tissue and size of shrimp. The organs/tissues observed in this study were: gill, hepatopancres, muscle tissue, eyes, heart, stomach, gonad, and intestine. While the size of shrimp consisted of three groups, those are: (A) 10-20 g/ind., (B) 30-40 g/ind., and (C) 60-70 g/ind. Analysis of antiviral gene expression was performed by RNA extraction, followed by the cDNA syntesis, and amplification of gene expression by semi-quantitative PCR. The result of PCR optimation showed the optimal concentration of cDNA and primer was 1 μL and 50 mol, respectively for PCR final volume of 25 μL. Antiviral gene was expressed on the hepatopancreas and stomach in percentage of 50.0% and 16.7%, respectively. While the highest percentage of individual expressing the antiviral gene was observed in the shrimp size of C (66.7%), followed by B (50.0%) and A (16.7%). The result of study implied that the hepatopancreas has importantly involed in tiger shrimp defense mechanism on viral infection.

The wide exploration of interferon (IFN)s in vertebrates for medical purposes has attracted researchers to investigate the existence of a similar role of interferon in other organisms such as invertebrates, including insects, and crustacea. A review of the literature indicates that there is no evidence of interferon existing either in insects such as D. melanogaster and A. gambiae which have had their genomes fully sequenced or in crustacea. However, a nonspecific antiviral state in crustacean, such as P. monodon can be efficiently triggered by both dsRNA and siRNA. The evidence suggests that anonymous cytokines, similar to interferon and not identical to any vertebrate IFNs, related to antiviral protection, do exist in crustacea. However, how widely spread of interferon immune response inducer or interferon-like molecules in this group is an important issue that remains to be explored.

Infeksi white spot syndrome virus (WSSV) dapat menyebabkan kematian massal pada budidaya udang windu Penaeus monodon di Indonesia. Infeksi yang terjadi secara sistematis tersebut disebabkan oleh peran gen nucleocapsid viral protein (VP-15). Upaya pengembangan gen VP-15 WSSV untuk menginduksi respons imun dan menetralisasi terhadap infeksi WSSV pada udang windu perlu dilakukan. Penelitian ini bertujuan untuk mengisolasi dan merekombinasikan gen penyandi VP-15 WSSV sebagai vaksin dsRNA, serta menganalisis aplikasinya pada udang windu. Gen VP-15 diisolasi dari udang windu yang terinfeksi WSSV, dikloning ke dalam suatu vektor dan ditransformasikan ke sel kompeten (bakteri Escheria coli DH5a). Plasmid diisolasi untuk mengonfirmasi insert region gen VP-15 melalui sekuensing nukleotida. Pembuatan vaksin rekombinan dilakukan secara in-vitro menggunakan kit MEGAscript RNAi dan diaplikasikan ke udang windu melalui metode injeksi dengan dosis tunggal 0,2 µg dan kontrol (tanpa injeksi vaksin). Hewan uji yang digunakan berukuran panjang 14,75±3,17 g dan bobot 11,64±0,76 cm; serta dipelihara pada wadah bak fiber volume 250 L dengan kepadatan 10 ekor/bak. Hasil penelitian menunjukkan bahwa gen penyandi VP-15 telah diisolasi dari udang windu dan vaksin rekombinan telah dihasilkan secara in-vitro. Analisis sekuens nukleotida memperlihatkan bahwa sisipan gen DNA VP-15 sebesar 253 bp dan menunjukkan kemiripan yang tinggi (99%) pada GenBank. Penggunaan vaksin rekombinan dsRNA dengan dosis 0,2 µg memperlihatkan sintasan udang windu yang dapat mencapai 40,0% dibandingkan dengan kontrol hanya 3,3% (peningkatan 36,7%). Gambaran histopatologi pada jaringan hepatopankreas udang windu pada perlakuan kontrol menunjukkan adanya kerusakan inti sel, akibat infeksi WSSV. Gene VP-15 berpotensi sebagai bahan vaksin rekombinan dsRNA dalam mencegah infeksi WSSV.Infection of white spot syndrome virus (WSSV) causes bulk mortalities of tiger shrimp Penaeus monodon cultured in Indonesia. The nucleocapsid viral protein-15 (VP-15) is strongly suspected to be responsible for the systemic infection of WSSV. The development of VP-15 WSSV gene for inducing the immune response to and neutralize WSSV infection of tiger shrimp is vitally needed. The aim of this study was to isolate and clone the gene encoding VP-15 WSSV as dsRNA vaccine and assess the vaccine application to tiger shrimp. VP-15 gene was isolated from the genomic DNA of infected tiger shrimps, cloned into the vector, and transformed into competent cells (Escheria coli DH5a). The plasmid was isolated to confirm the insert region gene of VP-15 by the nucleotide sequence. Production of dsRNA vaccine was performed by in-vitro using MEGAscript RNAi kit and applied to tiger shrimp through muscular injection at a single dosage of 0.2 µg and without dsRNA as a control treatment. The average size of tiger shrimps used was 14.75±3.17 g in weight and 11.64±0.76 cm in length and stocked in 250 L fiber tank at 10 ind./tank. The results of the study showed the VP-15 gene was successfully isolated from the tiger shrimps and the recombinant vaccine was produced by in-vitro. The analysis of nucleotide sequence showed that the inserted DNA was 253 bp and showed a high similarity (99%) with VP-15 gene deposited in the GenBank. The application of dsRNA vaccine showed that the dosage of 0.2 ¼g resulted in the survival rate of 40.0% compared with without dsRNA (control) of 3.3% (36.7% increment). Hepatopancreas histology indicated obvious damages to cell nucleus in the un-vaccinated tiger shrimp caused by the virus infection. We suggest that the VP-15 gene is a very promising dsRNA recombinant vaccine against WSSV infection.

Munculnya serangan White Spot Syndrome Virus (WSSV) pada udang yang dibudidayakan kemungkinan sebagai akibat menurunnya kualitas lingkungan tambak. Data diperoleh dari penelitian budi daya udang windu yang dilakukan Balai Riset Perikanan Budidaya Air Payau, Maros menggunakan 8 unit tambak ukuran 500 m2. Tokolan udang windu PL-25 dengan padat tebar 10 dan 20 ekor/m2 ditebar dalam petak tambak tersebut serta penambahan probiotik setiap minggu sebanyak 1 mg/L berlangsung selama pemeliharaan udang dan tanpa pemberian probiotik sebagai kontrol merupakan perlakuan yang diuji. Masing-masing perlakuan dengan dua ulangan. Setelah penebaran, beberapa petak terserang WSSV dan menyebabkan kematian total yaitu pada hari ke-27, 30, 41, dan 47. Serangan WSSV terus berlanjut selama pemeliharaan udang di tambak berlangsung. Pada petak menggunakan probiotik mempunyai kecenderungan terserang WSSV lebih lambat daripada yang tidak menggunakan probiotik. Semakin tinggi padat tebar udang windu di tambak, maka semakin rentan terhadap serangan WSSV. Padat tebar 10 ekor/m2 menggunakan probiotik produksinya cenderung lebih baik daripada padat tebar 20 ekor/m2. Peningkatan populasi Vibrio sp., peningkatan konsentrasi nitrit dan tingginya populasi awal Vibrio sp. di air melebihi 103 cfu/mL dan di sedimen 104 cfu/g diduga erat kaitan dengan munculnya serangan WSSV pada udang yang dipelihara di tambak pada penelitian ini.The outbreak of WSSV infection on tiger shrimp culture was thought to be an impact of its pond environmental depletion. The data was obtained from the study of tiger shrimp culture conducted in ponds Research Station of RICA Maros using 8 unit of brackishwater ponds compartment of 500 m2 each size. The PL-25 were stocked in the ponds at the density of 10 pieces and 20 pieces/m2 and on the otherhand, ponds also were treated with 1 mg/L commercial probiotics applicated in every week during culture period and no probiotics application as control. Each treatment in two replications. WSSV was infected to the shrimp in the different ponds compartment beginning at 27, 30, 41, and 47 days after stocking and affected total mortality of the shrimp. The WSSV infection was continue distributed to the other ponds compartments consecutively. The shrimp in ponds were applied with probiotics tend to delay infected, in contrary more early infected to the shrimp in pond without probiotics application. The shrimp with higher stocking density likely was easier infected by WSSV. The shrimp production tends to be higher in the shrimp stocking density of 10 pieces/m2 with probiotics application as compared to 20 pieces/m2 without probiotics applications. Increase Vibrio sp. population, enhance nitrite concentration and commenced with high Vibrio sp. population in the water and sediment pond excessive of 103 cfu/mL and 104 cfu/g respectively were presumed as the stimulate of WSSV outbreak in tiger shrimp culture in this research.

White spot syndrome virus (WSSV) has caused mass mortality on tiger shrimp (Penaeus monodon) culture and adversely affects prawn industry worldwide including Indonesia. It is well known that the protein structure of WSSV plays an important role in the virus infection and morphogenesis process. A viral protein structure called VP-15 is located in the nucleocapsid of virion virus. The protein structure involves in the life cycle of WSSV in host cells. A gene encoding VP-15 could be involved in constructing the RNA interference (RNAi), so it is needed to isolate and characterize for RNAi technology purpose. The study was aimed to isolate and characterize the VP-15 from the infected WSSV tiger shrimp. The characterization of VP-15 was undertaken through assessment of nucleotide sequence, amino acid deduction, alignment nucleotide/protein searches using Genetyx and BLAST program, and dendrogram construction analysis. The results showed that VP-15 was successfully isolated in form of ORFDNA with a fragment size of 243 bp. The phylogenetic tree analysis revealed three clusters corresponding to the time (year) of isolates collection. The VP-15 consisted of 80 amino acids, two start codons (ATG), one stop codon (TAA), and one Kozak context (AAAATGG). Hydrophilic amino acid was the highest composition (44.2%), followed by neutral (31.2%) and hydrophobic (24.6%) amino acid groups. The VP-15 was rich in amino acid of lysine (21.3%), arginine (22.9%) and serine (24.6%). The successful isolation of VP-15 is a very important step in providing a basic yet suitable material in constructing the dsRNA vaccine to control shrimp diseases in aquaculture.

Produksi tokolan udang windu PL 54 menggunakan hapa pada unit keramba jaring apung (KJA) di laut telah dilakukan di Teluk Labuange, Kabupaten Barru dari bulan Mei—Juli 2002. Penelitian ini bertujuan mendapatkan padat penebaran terbaik untuk pendederan benur udang windu dalam KJA di laut. Perlakuan yang dicobakan adalah padat penebaran benur PL 12 sebanyak padat tebar 2.000 ekor/m2 (A), 3.000 ekor/m2 (B), dan 4.000 ekor/m2 (C) masing-masing 3 kali ulangan. Hasil penelitian menunjukkan bahwa pertumbuhan tokolan pada perlakuan 2.000 dan 3.000 ekor/m2 tidak berbeda nyata (0,57—0,65 g/ekor) (P>0,05), tetapi berbeda nyata pada padat penebaran 4.000 ekor/m2 (0,39 g/ekor) (P0.05), but significantly different with stocking density of 4,000 pcs/m2 (P

Vibriosis is one of main diseases of the black tiger shrimp Penaeus monodon infected by pathogenic bioluminous bacterium Vibrio harveyi that can cause mass mortalities in shrimp culture. The bacteria can also trigger the disease white spot syndrome virus (WSSV). An effort to produce shrimp disease-resistant strains has been done through transgenesis technology with antiviral gene transfection. By this technology, it is expected an increase in the immune response of shrimp in a variety of diseasecausing pathogens. This study aimed to determine the immune responses (total haemocytes, haemocyte differentiation, and phenoloxydase activity) of transgenic tiger shrimp against pathogenic bacterium V. harveyi. Research using completely randomized design, which consists of two treatments and three replications. Test animals being used were transgenic and non-transgenic shrimp with size, weight 3.93±1.25 g and a total length of 7.59±0.87 cm. Treatments being tested were the injection of bacterium V. harveyi (density of 5x106 cfu/mL) of 0.1 mL/individual on transgenic (A) and non-transgenic shrimp (B). Immune response parameters such as total haemocytes, haemocyte differentiation, and phenoloxydase activity were observed on day 1, 3, and 6 days after challenging. Data were analyzed using t-test by SPSS software. The results showed that the total haemocyte of transgenic shrimp was not significantly different (P>0.05) from non-transgenic shrimp, but haemocyte differentiation and phenoloxydase activity were significantly different (P

An experiment was conducted to evaluate the effectiveness of producing juvenile shrimp in a reservoir pond constructed in acid sulphate soils (ASS). Many ponds constructed in ASS pose a significant economic risk due to high mortality and poor growth. In Indonesia, abandonment of ponds in ASS is widespread and alternative farming practices, such as production of juvenile shrimp, offer farms opportunities to lower their production risks. The experiment involved rearing juvenile shrimp at a high stocking density (3,000 individuals/m2) using hapas in a formerly unproductive pond located in Luwu Regency, South Sulawesi, Indonesia. The treatments tested included rearing periods of three and six weeks with four replications. A survival of 83.62% was achieved after rearing for three weeks compared to 45.44% after six weeks. Although there was a sixfold increase in the mean weight of shrimp from three to six weeks of culture, size variation after six weeks was large due to the high density of shrimp. The experiment showed that old acid sulphate soil-affected ponds, in which the bottom soil has not been excavated any further, can be used for production of juvenile shrimp in hapas. Rearing over three weeks is recommended to obtain high survival and reduce size variation.

The shrimp one of the most important crustecearis in the Persian Gulf waters is examined to identify ways of its multiplication and culturing in vitro This study, which started In middle of May, 1986 and lasted throughout September, 1986, was carried out in the Aquaculture Drvision of the Fishery Research Center of Bushehr. The results obtained in this research indicate the passibility of multiplication and culture of the Persian Gull tigershrimp in fishery facilities of Iran......