Bacteria Associated with Wild Mud Crab (Scylla serrata) from Setiu Wetland, Malaysia with Emphasis on Antibiotic Resistances

Market demand for mud crab (Scylla serrata) is increasing so that its catch in nature is high in the long term. The growth of mud crabs (Scylla serrata) occurs through molting (molting) mechanisms. Softshell crab has a higher economic value than hard shell crab. The purpose of this study was to assess the molting rate of mud crab (Scylla serrata) with different salinity treatments in controlled containers. The study used a completely randomized design (CRD) with three treatments of 20 ppt, 25 ppt, and 30 ppt salinity with three replications. The crabs used are mud crabs (Scylla serrata) measuring 80-175 grams with the carapace still hard. The test parameters include the weight gain and absolute length of the individual, daily growth rate, molting percentage, and survival and mortality rates. Besides, the chemical-chemical parameters of the culture media water and the effectiveness of using controlled containers were also observed. The research data were analyzed descriptively quantitatively. The difference in treatment and the use of controlled containers had a significant effect on the 95% significance level (α = 0.05) on all parameters of the response to treatment. Absolute individual weight values 40.6 – 47.41 grams, absolute individual length 2.6 – 3.2 cm, molting percentage 75 – 100%, daily growth rate 1.3 – 1.6 grams, 75 – 100% survival and mortality of mud crab (Scylla serrata) 25-16.7%. Optimal salinity level at 20 ppt. Water quality parameters during the study were still feasible for mangrove crab (Scylla serrata) cultivation. Controlled containers using a water rotation system are quite effective for the cultivation of mud crab (Scylla serrata).

This study aims to know various types, prevalence, and intensity of ectoparasite on mud crab (Scylla serrata) in Mangrove Forest Wonorejo, Surabaya. This study used survey method with random sampling to collect the data. This study was conducted in November 2020. Ectoparasite in this study collected by smear method. In-situ water quality measurement were applied in this study. Mud crab (Scylla serrata) in this study was obtained from local fisherman that consist of 30 crabs. There are 3 types of ectoparasite was infected mud crab there are Octolasmis sp. (208 ind), Zoothamnium sp. (93 ind), dan Epistylis sp. (116 ind). Those ectoparasite was found in mud crabs gills. The highest prevalence was Octolasmis sp. (70%), Epistylis sp. (30%), Zoothamnium sp. (23%). The highest intensity was Zoothamnium sp (13,29 ind/crab), Epistylis sp. (12,89 ind/crab), dan Octolasmis sp. (9,90 ind/crab). Based on Ministerial Decree of Ministry Environment and Forestry No. 1 of 2004 water quality in Wonorejo Mangrove Forest was still optimal for life cycle of mud crab with average of temperature is 31,20°C, Dissolved Oxygen 5,53 mg/l, salinity 11 ppt, and pH 7,40.

Abstract. Hastuti YP, Rusmana I, Nirmala K, Affandi R, Tridesianti S. 2019. Identification and characterization of nitrifying bacteria in mud crab (Scylla serrata) recirculation aquaculture system by 16S rRNA sequencing. Biodiversitas 20: 1339-1343. Recirculation is one of the systems used for increasing aquaculture production, for example, is mud crab Scylla serrata culture. Aquaculture activities will produce organic nitrogen waste and can be affected to inorganic condition (nitrification bacteria). Nitrifying bacteria are capable of changing aerobically from NH4+ to NO2-(nitrite) and from NO2-to NO3-(nitrate). This current work aimed to identify and characterize nitrifying bacteria in mud crab (S. serrata) culture with a recirculated system. Nitrifying bacteria were isolated using serial dilution (10-1 until 10-5) of open filter FB water sample previously cultured in a specific medium. Bacterial identification was performed using a procedure of PrestoTM Mini gDNA Kit (Geneid) for DNA extraction and Polymerase Chain Reaction (PCR) primer 63F and 1387R for 16S rRNA gene amplification. Molecular identification using 16S rRNA sequences, the nitrifying bacteria isolated from mud crab recirculation aquaculture system were 99% identified as a group Pantoea calida, Pseudomonas stutzerii dan Halomonas sp. Morphological characterization of the colony morphology showed that a mucoid appearance and appeared cream in color and large size. Furthermore, their cells were recognized as basil and Gram-negative.

A total of 320 bacteria isolated from marketable size and diseased mud crab (Scylla serrata) at a commercial farm. The isolated bacteria were Aeromonas spp. n = 70, Edwardsiella tarda n = 50, Vibrio alginolyticus n = 40, Vibrio parahaemolyticus n = 20, Salmonella spp. n = 70 and Klebsiella spp. n = 70. All the bacterial isolates were tested for antibiotic susceptibility against 16 types of antibiotics by using disk diffusion method. The antibiotics tested in this study were nalidixic acid (30 ?g/disk), oxolinic acid (2 ?g/disk), compound sulphonamides (300 ?g/disk), doxycycline (30 ?g/disk), tetracycline (30 ?g/disk), novobiocin (30 ?g/disk), chloramphenicol (30 ?g/disk), kanamycin (30 ?g/disk), sulphamethoxazole (25 ?g/disk), flumequine (30 ?g/disk), erythromycin (15 ?g/disk), ampicillin (10 ?g/disk), spiramycin (100 ?g/disk), oxytetracycline (30 ?g/disk), amoxycillin (25 ?g/disk) and fosfomycin (50 ?g/disk). Heavy metal resistance pattern of the present bacterial isolates was also characterized against mercury (Hg2+), chromium (Cr6+), copper (Cu2+), and Zinc (Zn2+) by using two fold agar dilution method. The percentage of antibiotic sensitivity of the present bacterial isolates was ranged from 12.5 % to 100 % in which most of the present bacteria isolates were not sensitive to ampicillin whereas all the bacteria isolates were sensitive to nalidixic acid, flumequine and oxytetracycline. Overall, the total of antibiotic sensitive case was reported as 72.7% whereas antibiotic resistance and intermediate sensitive case was recorded as 19.7% and 7.4 %, respectively. The Multiple Antibiotic Resistance (MAR) values were range of 0.03 to 0.29 in which Aeromonas spp (0.29) showed the highest value of MAR. This was followed by Salmonella spp. (0.21) and Klebsiella spp. (0.21), Edwardsiella tarda (0.20), Vibrio alginolyticus (0.09) and Vibrio parahaemolyticus (0.03). The MAR value indicated that the commercial S. serrata were not contaminated to the test antibiotics. Furthermore, low resistance activity of the present bacterial isolates to the tested heavy metals (Cr6+: 20.7 % to 30.8 %, Zn2+: 0 % to 40 %, Cu2+: 18.8 % to 25 % and Hg2+: 30 % to 33.3 %) was observed.

Mud crab (Scylla serrata) have potency commercial market in this country and the other country. That thing because mud crab (Scylla serrata) flesh has a delicious taste and high nutrition. People haven’t knowed about cholesterol content in both male or female mud crab (Scylla serrata), whereas the knowledge about cholesterol content is important to consider nutrition intake to keep in good health. This research aim to determine cholesterol content in Scylla serrata by observing male and female crab in Pemalang and Demak. This research used descriptive method and sampling used purposive random sampling method. Determination of sampling position used purposive sampling method. This research has done in October 30th – November 25th 2011. This research used 30 male and 30 female with mean body weigh 60 - 100 g. Analysis of cholesterol content used method by Lieberman–Burchad. Result from this research indicates that S. serrata from Pemalang has cholesterol content more large than S. serrata from Demak, while the male crab from both place has higher cholesterol content than female crab (66,67 mg/100g and 61,67 mg/100g in male crab, and 64,67 mg/100g and 58,33 mg/100g in female crab).

One of the fishery commodities in the mangrove forest area that has the potential to be cultivated in the mangrove crab (Scylla serrata). The local and international market demand for soft shell mud crab from year to year tends to increase. Most of the efforts to meet the needs of softshell crab still rely on catches from nature where availability is uncertain. The purpose of this study was to identify the effect of the long molting time of mud crab (Scylla serrata) fed trash feed and feed fed with spinach extract using natural methods and popeye. This research is experimental using a completely randomized design. The treatments consisted of the natural method with trash feed, the natural method with spinach extract feed, the popeye method with trash feed, and the popeye method with spinach extract feed. The crabs used are mud crabs with the hard carapace. The test parameter is the length of time for mud crab molting, which is calculated starting from the hard-shelled crab to molting. The data obtained in the form of differences in the length of time for mud crab molting using various treatments were analyzed descriptively quantitatively. The results of this study indicate that the popeye method with spinach extract feed is the treatment that produces the best molting time, which is 14-21 days compared to other treatments.

Abstract. Karniati R, Sulistiyono N, Amelia R, Slamet B, Bimantara Y, Basyuni M. 2021. Mangrove ecosystem in North Sumatran (Indonesia) forests serves as a suitable habitat for mud crabs (Scylla serrata and S. olivacea). Biodiversitas 22: 1489-1496. Mud crabs (Scylla serrata and Scylla olivacea) are often found in muddy substrates associated with mangrove vegetation. The habitat of these crabs ranges from tropical estuaries to sheltered subtropical areas, riverbanks, lower river traits, and intertidal areas. These crabs have an important economic value, and it increases the income of the communities living around the mangrove area. This study aims to obtain more information on the environmental factors of habitat for mud crabs (S. serrata and S. olivacea): insights on the effects of abiotic and biotic factors and potential economic value, in the village of Lubuk Kertang, Langkat, North Sumatra, Indonesia. Data were collected by measuring abiotic factors (temperature, pH, salinity, dissolved oxygen, mud depth, distance from the river) and biotic factors (mangrove stand density through canopy cover). The dataset was analyzed using a binary logistic regression analysis with a stepwise method. Results showed that the abiotic factors that contributed to the presence of the mud crab were dissolved oxygen and a mud depth of 68.7%. Meanwhile, the remaining 31.3% that contributed to the presence of mud crabs were abiotic factors (temperature, pH, salinity, distance from rivers) and biotic factors (stand density through canopy cover). The present study suggests that dissolved oxygen and mud depth have an important function in predicting the presence of mud crabs.

Report cards are increasingly popular tools communicating the condition of coastal and riverine environments to environmental managers, stakeholders and the public, and synthesising complex data drawn from a range of indicators. Mud crabs have not previously been included in ecosystem health report cards in Australia or elsewhere but have been suggested as environmental indicators for tropical coastal marine environments in Australia. Mud crabs support commercial, recreational and Indigenous fisheries and their biology is relatively well known. For these reasons and due to their local relevance, mud crabs (Scylla serrata) were selected for long-term monitoring and inclusion in a report card for Gladstone Harbour, Australia. Three mud crab measures were identified to reflect the variety of pressures across Gladstone Harbour: abundance, prevalence of rust lesions and sex ratio. A standardised field monitoring program was developed to allow for ongoing scoring and reporting of the multi-metric indicator. An indicator scoring (distance from benchmark) and grading methodology was applied to the indicator and refined over the two years of monitoring. This article provides a novel framework for monitoring and scoring mud crabs for management purposes or for use in report cards, and outlines the process of developing an indicator for an iconic crustacean species.

The mangrove pens were modified to produce mud crab (Scylla serrata) and milkfish (Chanos chanos) in a polyculture system. The modification of mangrove pens was done by adding excavations inside the pen. The water quality parameters (dissolved oxygen (DO), pH, salinity, and temperature) were monitored, and the recovery and production rates in each pen were evaluated. The experiment was conducted for a rearing period of 143 days in nine mangrove pens, each having an area of 32 m2 and an average net enclosure height of 3 m from the soil surface. The three different pens constructed (existing design: canal only, 43% excavation by area, and 54% excavation by area) were designated as T1, T2, and T3, respectively. The water quality parameters recorded in the pens were favorable for the growth and recovery of the mud crab and milkfish, except for DO. For mud crab, the highest mean recovery was recorded in T2, followed by T3, and the lowest in T1. The production rate followed the same pattern as the recovery, with T2 having the highest, followed by T3, and T1 having the lowest. The statistical analysis revealed that the variations in mud crab recovery were not significant, while in terms of production rate, modified mangrove pens were found to be more effective than the existing design. Due to the total mortality of the cultured milkfish, the current set-up of modified mangrove pens was found to be unsuitable for the polyculture system of milkfish and mud crab production.

This study aimsed to determine the type of ectoparasites on crab (Scylla serrata) in the water of Alue Naga Banda Aceh. The samples of this study were 10 heads of mud crabs were taken from the Alue Naga waters Banda Aceh and taken to the Laboratory of Parasitology. Veterinary Medicine Faculty of Syiah Kuala University Banda Aceh to identify the take ectoparasites on mud crab (Scylla serrata) by observing the outer body of the organism, then noted bleeding, wounds or swelling and pay attention to the type of organism that is attached to the body of mud crab, then dredge the outer parts of the body like the carapace, foot path, foot pool and gills were take it and then tweezers and then putting the object glass that has been provided and observed with a microscope with 100 times magnification and see what kind of ectoparasites that have been found and then compare with the identification key. From the results of this study concluded that ectoparasites which infects mud crab (Scylla serrata) in the waters of Alue Naga Banda Aceh come from genus Chilodonella sp. Whichare predilections in the gills with a prevalence rate of 10%.

The development of industry and residential areas around the waters of Banten Bay can increase the input of heavy metal waste and cause accumulation in aquatic biota, especially in mud crab (Scylla serrata). This study aims to determine the level of accumulation of heavy metals (Hg, Cd, Pb, and Cu) contained in mud crab meat in Bojonegara Coastal Waters, Banten Bay. Sampling of the mud crabs was carried out monthly for three months, from August to October 2020 in the waters. The research method consists of the calculation of Bioconcentration Factor (BCF), Maximum Weekly Intake (MWI), and Maximum Tolerable Intake (MTI). According to the analysis, content of heavy metals Hg, Cd, and Pb in mud crab was under the AAS sensitivity value used, which was <0.001 mg/kg, <0.005 mg/kg, <0.030 mg/kg, respectively, while for heavy metal Cu ranged from 4.44 to 13.52 mg/kg. The bioconcentration factor of the heavy metals Hg, Cd, and Pb in the water was classified as low accumulation, while heavy metal Cu in water was classified as medium to high accumulation. The safe limit for consumption of the mud crab meat taken in the waters was 12.94 kg meat/week (adults) and 3.88 kg meat/week (children).

Persistent organochlorines and metals in estuarine mud crabs of the Great Barrier Reef

&lt;p&gt;Mud crab is one of the 12 aquaculture commodities of Ministry of Maritime Affairs and Fisheries. Control of reproduction to increase seed production through feed improvement, is one of the challenges and strategies in the mud crab aquaculture. Due to lack of knowledge about broodstock nutrition lead to producing rate of seeds still relatively low. This study aimed to obtain information on the kind of feed that has specific nutrient and plays a role in increasing the success of spawning and zoea survival. Mud crab of Scylla serrata with initial weight of 500.7±103.4 g, preferably under developed gonads were maintained in a fiber tank measuring length of 2.48 m, width 1.26 m, and a height of 60 cm which is partition sealed into 30×40×60 cm3 to put one crab. Tank was equipped with sand as a substrate as high as 15 cm and seawater system with flow rate of 1 L per six minutes and 25 cm high water. Treatments were consisted of: 1. PI (fresh meat fish of Decapterus sp. with dose of 5%), 2. PSC (fresh meat mixture of Decapterus sp. 1.8%, 3% of squid, and shrimp 1.2%), 3. PB (artificial feed dose of 10%) of BW, each treatment was repeated three times. Parameters measured were the duration of ovarian to mature, egg diameter, hatching rate, fecundity, and zoea production. Data were analyzed using ANOVA. The quality of larval measured by survival and larval fat and protein content. The results showed that crabs treated by PI and PSC showed faster to get mature compared to PB treatment (p&amp;lt;0.05). Hatching rate of larvae in PSC treatment was higher compared to PI and PB treatments (p&amp;lt;0.05). Furthermore, all treatments did not affect egg diameter, fecundity, and the number of zoea (p&amp;gt;0.05). In conclusion, crab which fed fresh meat (PI and PSC) could get mature earlier, and have high percentage of the larval hatching than those of fed by PB. In fact that larvae from broodstock feed of PI has survival as well as protein and fat content were higher than those of fed by PB.&lt;/p&gt;&lt;p&gt;Keywords: spawning perform, broodstock feed, mud crab (Scylla serrata)&lt;/p&gt;

Heavy metal accumulation and transfer from sediments to edible mud crab organs (Scylla serrata) pose major ecological and health risks to consumers. The bioaccumulation of these metals are detrimental if they are extremely toxic. The objectives of this study were to analyze heavy metal concentrations in sediments and crab organs and determine the transfer of heavy metals in Scylla serrata from sediments in Mida Creek, Kilifi. The crab samples were collected by simple random sampling whereas sediment samples were collected by purposive sampling. The transfer factor of heavy metals from sediments to the organs of edible mud crabs (Scylla serrata) was evaluated in both the wet and dry seasons. The measurements and examinations of heavy metals, samples of crab organs, and sediments were obtained from three sampled sites. The concentration of metals in the samples was determined using an X-ray fluorescence (XRF) spectrometer. The results showed that the majority of the components are accumulated by the crabs from sediments. The order in which the metal transfer factor to crabs from station 1 sediments increased was Fe &gt; Zn &gt; Ni &gt; Cu &gt; Cd &gt; Hg. In station 2, the transfer factor increased in the following order: Fe &gt; Zn&gt; Cu&gt;Ni&gt;Cd&gt; Hg, while in station 3, it increased in the following order: Fe &gt; Ni&gt; Zn&gt;Hg&gt;Cd&gt;Cu. The study concluded that mud crabs in Mida Creek actively absorb most of the elements from the sediments. The study recommends a routine monitoring of heavy-metal levels in other crustacean marine biota, and fish is necessary.

Nutritional properties of wild and fattening mud crab (Scylla serrata) in the south-eastern district of Bangladesh