Study of Ectoparasite Prevalence and Intensity on Mud Crab (Scylla serrata) in Mangrove Area of Wonorejo Surabaya

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%.

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.

Mangrove crab (Scylla serrata) is a fishery commodity that has high economic value. The supply of mangrove crabs in Indonesia is still dominated by wild catches. One of the places to catch mangrove crabs is in the Mangrove Area of ​​Deah Raya Village, Syiah Kuala District, Banda Aceh, Indonesia. Mud crabs are very susceptible to infestation by pathogens in their environment. Pathogens that are often found infesting mud crabs are parasites. Ectoparasite attacks are very dangerous for mud crabs because they can damage the body organs of mud crabs. Therefore, this research was conducted to determine the level of intensity and prevalence of ectoparasites in mud crabs (Scylla serrata) caught by fishermen in Deah Raya Village. This research uses a survey method with a purposive sampling method. Ectoparasite examination is carried out using the smear method. This research was conducted at the Hatchery Laboratory of the Faculty of Maritime Affairs and Fisheries in May 2024. Thirty crabs (Scylla serrata) were randomly sampled from the mangrove area in ​​Deah Raya Village, Syiah Kuala District, and observed for the presence of ectoparasites. The observations revealed that the crabs were infested by ectoparasites from the protozoa phylum (such as Zoothamnium sp., Epistylis sp., and Vorticella sp.) and from the arthropod phylum (Octolasmis sp.). Infestation by Zoothamnium sp. was found as the most prevalent (n=15, 50%), followed by Epistylis sp. (n=6, 20%), Vorticella sp (n=3, 10%), and Octolasmis sp (n=3, 10%). The infestation intensity for Zoothamnium was 7.5 individuals per crab, Epistylis sp. 5.0 individuals per crab, Vorticella sp. 2 individuals per crab, and Octolasmis sp. 1 individual per crab. Considering the high prevalence and intensity of Zoothamnium sp. in the mangrove crabs, the mitigating efforts can be focused on this ectoparasite.

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 experiment was designed to study the optimum dose of thyroxine supplementation in accelerating ovarian maturity in broodstock mud crab (Scylla serrata). The production of mud crab is very low since the production system relies on the natural harvesting that has not applied aquaculture technology optimally. The low productivity in natural culture is thought to be related to the low magnitude of biological process and metabolism that support optimum reproduction system such as the slow and low rate of vitellogenesis. The ovarian maturity is started by the synthesis and the release of vitellogenin into the hemolymph and then transported to the ovum to be used as a precursor of egg yolks synthesis. The thyroxine hormone is found in the follicle and assists the process of yolk absorption. This study used 4 levels of thyroxine supplementation i.e., 0 μg/g BW (control), 0.05 μg/g BW, 0.10 μg/g BW and 0.15 μg/g BW. In general, the supplementation of thyroxine significantly improved the rate of ovarian maturity (P<0.05). Supplementation of thyroxine at the dose of 0.10 μg/g BW gave the highest rate of ovarian maturity. Supplementation of thyroxine increased yolk absorption during ovarian maturity. It was also found that thyroxine supplementation increased concentrations of protein and RNA/DNA during ovarian maturity.

Avicennia marina leaf extract is known to suppress the activity of Vibrio spp. using solvent klorform and methanol. Therefore, the authors conducted a further study using different solvents. This research interest determine the ability of extracts of A. marina in suppressing the activity of Vibrio spp. isolated from mud crab (Scylla serrata). A. Marina leaf take in Pantai Amal Lama, The process of extraction, isolation and testing of clear zone performed at the Laboratory of the Faculty of Fisheries and Marine Sciences, University of Borneo Tarakan. Stages of research are: manufacture A. marina leaf extract, isolation, culture of Vibrio spp., and data analysis. The study consisted of 6 treatments, blank control, negative control, positive control, A. marina leaf extract concentration of 15%, 25% and 35%, A. marina leaf extract in each treatment were significantly different (P <0.05). Diameter of clear zone produced at a concentration of 15% obtained an average value of 12.25 ± 5.37 mm, at a concentration of 25% 24.4 ± 1.41 mm, at a concentration of 35% 30.37 ± 0.95 mm. While the positive control 42.5 ± 0:00 mm. But the blank control and negative controls do not form clear zones. Based on these results it can be concluded that there are indications A. marina leaf extract in suppressing the activity of Vibrio spp. were tested in vitro. Keywords : Lea f of A. marina, Vibrio spp., Mangrove crab s (Scylla serrata), in Vitro

Scylla serrata is a portunid crab which can attain a weight of over 2 kg and a carapace width exceeding 250 mm. It is distributed throughout the Indo-West Pacific extending down the east coast of Africa, and both the east and west coasts of Australia. In Australia it is commonly known as the mud crab because it occurs within muddy, mangrove-lined bays and estuaries. Mud crabs are generalist predators eating most small, slow moving animals which they can catch, but they are also vigorous scavengers. Being scavengers, they are readily caught in baited traps set by commercial and recreational fishers, and are the stock for these popular fisheries. Female crabs spawn offshore and larvae spend a period in the plankton where they develop into postlarvae or megalopae...

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.

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.

In this study on decapod crustaceans, we examined the Ca2+- and Sr2+-activation properties of skeletal muscle fibres from an identified proprioceptor, the thoracic coxal muscle receptor organ (TCMRO) and its extrafusal promotor muscle fibres. Proprioceptors and extrafusal muscles were isolated from a walking leg from the crayfish (Cherax destructor) and the rear swimming leg of the mud crab (Scylla serrata). The crayfish and mud crab TCMROs had very low Hill coefficient (nCa) values (1.86 +/- 0.08 and 1.64 +/- 0.03, respectively). In comparison to other skeletal muscle fibre types these low Hill coefficients would enable the length of the receptor muscles to be finely controlled over a wide range of [Ca2+]. Maximum force was found to be significantly lower in the TCMROs (crayfish: 5.76 +/- 0.98; crab: 4.80 +/- 0.56 Ncm(-2)), compared to their associated extrafusal promotor muscle fibres (crayfish: 10.69 +/- 1.63; crab: 20.07 +/- 1.98 Ncm(-2)), which is consistent with their sensory role. The muscle fibres of the crayfish TCMRO had faster contractile properties than the mud crab TCMRO, we discuss how these contractile properties relate to the type of locomotion undergone by each leg. The mud crab 'red' promotor and all crayfish promotor fibres were characterised as slow with low Hill coefficients (nCa: crayfish: 3.22 +/- 0.29; crab: 3.34 +/- 0.29) and a contractile apparatus with a high sensitivity to Ca2+ (pCa50: crayfish: 6.42 +/- 0.03; crab: 6.18 +/- 0.03). In contrast the 'white' mud crab promotor fibres from the swimming leg had contractile properties that were characteristic of fast fibres with a high mean Hill coefficient (nCa: 5.27 +/- 0.76) and a lower Ca2+ sensitivity (pCa50: 6.03 +/- 0.03). The sensitivity of the contractile apparatus to Sr2+ was very low (range of mean pSr50: 4.23 +/- 0.03-3.48 +/- 0.06) and low force levels were produced in comparison to that produced with Ca2+. The results of this study show that the muscle fibres of the sensory receptor, produce less force and have been adapted to enable the length of the receptor to be finely set in relation to the length of the extrafusal muscle. We discuss how the striated fibres of the receptor have been adapted to perform a sensory role and how this is related to the type of locomotion undergone by the legs. We also discuss how the fibre types of the extrafusal muscle have adapted to the mode of locomotion.

Mangrove forest is tropical coastal vegetation that grow on muddy and sandy soils which affected by sea tides. One of important commercial species that live in mangrove ecosystem is the mud crab (Scylla serrata). Feed and water quality have been considered as critical components for supporting the growth both of weight and carapace length of this species. This study was conducted from January to February 2017 in the area of ??Ecotourism Kampung Kepiting, Bali. The influence of different natural feed such as Jerbung shrimp (Penaeus merguiensis), Mollusca, lemuru fish (Sardinella lemuru) and sea worms (Nereis sp.) on the growth performance of the mud crab were investigated. Water quality parameter data such as pH, DO, temperature, salinity and ammonium were also collected. The obtained data were analyzed by using variance analysis of Statistical Product and Service Solutions (SPSS) version 21. The result showed that the use of different types of feed have no effect on the length of carapace, but it has significantly influence on the specific growth rate of mud crab. Finally, different types of the given feeding were still resulted in the save range of water quality parameters for mud crab culture.

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).

The giant mud crab (Scylla serrata) is an important fisheries species throughout southeast Asia and the South Pacific. In Australia, marine protected areas (MPAs) and fish habitats have been declared specifically to protect the local populations of S. serrata. The cannibalistic behaviour of S. serrata coupled with the potential attraction of increased predators may counteract the effect of excluding fishing from these areas as a means of increasing the local crab population. The population dynamics of S. serrata could also be confounded by the spatio-temporal variability in environmental conditions (e.g. run-off and temperature). Here, we used a spatially explicit individual-based model (IBM) to explore the population dynamics of S. serrata in an MPA located in southern Moreton Bay, Queensland, Australia. This IBM simulated the life cycle dynamics of individual S. serrata and integrated the key processes affecting its population dynamics. These processes include physical transport of the planktonic life stages, movement, growth, metamorphosis, setting, reproduction, spawning, harvesting, and predation. Individual variability was built into the model to account for demographic variation. The modelled scenarios indicated that the effect of the different harvest strategies trialled on the population dynamics after 30 months and the MPA influenced the number of individuals in the creek system resulting in a partial 35% population increase. Further development and application of this model has implications for MPAs and catch limits under multiple stressors including climate change.

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.

Abstract. Khotimah A, Rokhmani, Edy Riwidiharso. 2018. Prevalence and abundance of Vorticella sp. on mangrove crab (Scylla serrata) landed at Sleko Fish Auction Place, Cilacap District, Central Java. Pros Sem Nas Masy Biodiv Indon 4: 87-91. Vorticella sp. are ectoparasites that attack aquatic organisms, such as fish, shrimp, and crabs. Vorticella sp. causing decreased appetite, movement disorders, larval molting process, stress and even death on the host. Deaths from Vorticella sp. can cause the decline of mangrove crab population in water. One of the potential marine waters in Indonesia is Cilacap waters area. Cilacap waters area there are mangrove ecosystems Segara Anakan which is a shelter and source of feed for aquatic organisms, including mangrove crabs. Mud crab (Scylla serrata) has high economic value, both in domestic market and international market. Mangrove crab is one of fishery commodities that live in coastal waters, especially in mangrove forests (mangroves). This study aims to determine the prevalence of crabs infected with Vorticella sp. as well as the abundance of Vorticella sp. on mangrove crabs, landed on the Sleko Fish Auction Place (TPI). The research method used is a survey method with purposive sampling technique. Samples were taken as much as 10% of the number of mangrove crabs that are landing on the TPI Sleko.Results of research conducted on carapace, gill, foot, foot, and claws. The prevalence of mangrove crabs is categorized frequently, while the abundance of Vorticella sp. including in very rare categories.