Small Crabs Research Articles

Load Management and Optimal Sizing of Special-Purpose Microgrids Using Two Stage PSO-Fuzzy Based Hybrid Approach

The sizing of microgrids depends on the type of load and its operational hours. The significance of understanding the load operational characteristics in special purpose islanded microgrids is much needed for economic system sizing. The load operation of special-purpose microgrids often consumes high power for a short duration and remains idle most of the time, thus reducing the load factor. The inclusion of such loads in microgrid sizing causes huge capital costs making islanded microgrids an unfeasible solution. The islanded microgrid under study is an agricultural microgrid in a village having a small Crab Processing Plant (CPP) and a Domestic Sector (DS). The CPP constitutes the major power consumption. The community has a unique load consumption trend that is dependent on the highly uncertain parameter of availability of the crabs. Interestingly, crab availability is an independent parameter and cannot be accurately scheduled. The existing system sizing of the microgrid is performed based on the conventional methods that consider the CPP for full-day operation. However, the microgrid sources, especially the storage system may be reflected as oversized if the crab processing plants do not operate for several days due to the uncertain behavior of CPP causing enormous power wastage. In this paper, an integrated fixed and operational mode strategy for uncertain heavy loads is formulated. The proposed algorithm is based on the optimal sizing methodology aided by the load scheduling control strategy. The Particle Swarm Optimization technique is used for the optimal sizing integrated with the fuzzy logic controller to manage the available load. The membership functions are available excess power and the state of the charge of storage that defines the operational conditions for CPP. Based on input membership functions, the fuzzy controller decides on power dispatch in DS or CPP, keeping considerable SoC available for night hours. The simulation result shows that the time-dependent fuzzy controller approach manages to provide power to both sectors under optimal sizing while reducing the overall cost by 24% less than the existing microgrid.

Heavy Metal Contents Of Hg, Cd, Pb, And Cu In Blue Swimming Crab (Portunus Pelagicus) In Banten Bay, Indonesia

Bojonegara coast, Banten Bay is an industrial zone in the West Serang region, which is characterized by the presence of some factories around the coast. These have potential to produce and pour the pollutants such as heavy metals into the water and accumulate into the body of aquatic organisms like blue swimming crab. This study aims to analyze the level of heavy metal accumulation in the blue swimming crab (Portunus pelagicus) of Banten Bay waters. Sampling was carried out from August to October 2020. Analysis of heavy metal content was carried out using AAS (Atomic Absorption Spectrophotometer). During the observation, the heavy metal content of Hg, Cd, Pb, and Cu were significantly different between large and small blue swimming crab (p<0,05). The accumulation of heavy metal Cu in small blue swimming crab ranged from 3,22-4,34 mg kg−1 and large blue swimming crab ranged from 6,64-9,52 mg kg−1 while the heavy metal content of Hg, Cd, and Pb in small crabs was below detection AAS. Bioaccumulation of Cu in blue swimming included moderate to high, while heavy metal Hg, Cd, and Pb it was low accumulation. The safe limit for consumption blue swimming crab is 22,0588 kg of meat/week for adults and 5,5147 kg of meat/week for children.

PENGABDIAN KEPADA MASYARAKAT PELATIHAN PEMBUATAN PETA DAERAH PENANGKAPAN RAJUNGAN (Portunus pelagicus) UNTUK MENINGKATKAN HASIL TANGKAPAN

The use of small crab in the waters of Pangkep Regency has not been maximized, as one of the things done is mapping the ideal fishing area. This study aims to map the fishing area to increase the crab catches. The purpose of this research is to increase the efficiency and effectiveness of fishermen and to increase the income and standard of living of fishermen. The study was conducted in the waters of Pangkep Regency. Materials and tools used in this study include the global position system, current meter, hand repractometer, DO meter, and pH meter. The data used include primary data and secondary data. Primary data is collected through direct measurements in the field and secondary data obtained from documents that have been produced by related agencies. Data analysis was obtained from laboratory analysis and measurement and geographic information systems. The results of the research conducted were obtained. The location of the adult swimming catch area includes coastal waters, around the island and in particular the outer boundaries of the islands. The criteria for catching area of ​​the crab that is "in accordance" with the area of ​​the waters is 89,131.37 ha, "quite suitable" with the area of ​​the waters is 109,164.87 ha. The criteria for the area of ​​catching crabs that are "not suitable" with an area of ​​water is 4,577.56 ha.

Influence of Selenium Element on Regeneration and Fecundity of the Riverine crab Sesarma boulengeri Calman

The study of the influence of selenium on the regeneration and fecundity of the crab Sesarma boulengeri Calman has been conducted. The results demonstrated: The effect of selenium on the regeneration of walking legs of S. boulengeri Calman. Morphology of the regenerated appendage was different from control specimen. The speed of growth in the regenerated bud was lower than the control and it was depended on the size class of the crab. Regeneration index (R) was higher in the small crabs than in the large ones and in single autotomy than in double autotomy. Fecundity varied, when females exposed to selenium (0.27, 1.35, 2.7 ppm). It showed a decrease with all stages, especially in the first and second stage. The eggs in the last stage suffered more teratogens with exposure time and the concentration of selenium. 3

Effectiveness of Different Mesh Size To Release Small Blue Swimming Crab on Trap Fishing

Blue swimming crab (Portunus pelagicus) is a fishery commodity with important economic value and also become the main commodity for export needs. However, crab production dominantly comes from fishing activities using traps and gillnet. The fisher use traps without escape gaps so that small crabs have no chance of escaping from the traps. One alternative way to improve the crab trap selectivity is the use of larger mesh sizes on the wall of the trap. This study aimed to determine the effective mesh size for escaping small crabs. This study was conducted in Fisheries Laboratory, University of Sultan Ageng Tirtayasa from July to December 2020. We used different mesh sizes on the trap wall including of 2.0; 2.5; and 3 inches. For all experiments, we used 90 crabs with an average carapace width of 72 mm. The results showed that the pattern of crab when escaping through the net at each mesh size was varied. The crab crept up the netting wall before attempting to escape. The fastest time of crab escapes was found on a 3 inch mesh size with an average time of 10 seconds. Moreover, the highest percentage of crabs that can pass was obtained at the 3-inch mesh size with the value 60%. Based on these results, to increase the catch selectivity we recommend a 3-inch mesh to be used in the collapsible trap wall for blue swimming crab fishing.

Structural Changes and Mechanical Resistance of Claws and Denticles in Coconut Crabs of Different Sizes.

Simple SummaryUnderstanding the diverse mechanisms by which organisms achieve exceptionally high mechanical properties may enable the development of unique, biologically inspired materials. We assessed the microstructure, composition, and mechanical resistance of the pinching side with denticles and of the outer side without denticles in robust claws of coconut crabs with body weight (BW) of 300 g to 1650 g. Surprisingly, they were independent of BW except for low hardness near the surface of the denticles of a small crab of 300 g. Although the microstructure of the denticles was clearly different from that of the exocuticle, their mechanical resistance indicated the same maximum value. The denticle can be regarded as a bulge of the cuticle without phosphorus. The design principles found in the exoskeleton provided promising opportunities for the research and development of novel structural materials.The exoskeleton of the pinching side of claws with denticles and of the outer side without them on the coconut crab, Birgus latro, which is a rare organism, were studied using a materials science approach. The mechanical resistance of three claws of different sizes was investigated along the exoskeleton thickness from the outer surface to the inner surface, and the results were compared, including the contribution of the microstructure and chemical compositions. Mechanical properties, hardness (H) and stiffness (Er), were probed through nanoindentation tests. The results showed the H, Er, microstructures, and chemical components of the exocuticle and endocuticle layers were almost the same, in a BW range of 300 g to 1650 g. At the same time, the H and Er near the surface of the denticles of a small coconut crab of 300 g were lower than those of other large coconut crabs. The microstructure of the denticles was clearly different from that of the exocuticle, but the maximum mechanical properties near their surface indicated almost the same values, Hmax = 4 GPa and Er(max) = 70 GPa, regardless of being on the pinching side or the outer side. A denticle can be regarded as a bulge of the cuticle without phosphorus and with high magnesium. The results provided novel information that expanded our knowledge about the claw microstructure of coconut crabs with different body sizes, and may be used in further studies

ANALISIS DAN STRATEGI PENGEMBANGAN USAHA PENANGKAPAN RAJUNGAN (Portunus pelagicus) DI DESA BONTO UJUNG KEC. TAROWANG KABUPATEN JENEPONTO

This study aims to see the feasibility of the small crab catcher and suitable indicators developed by fishermen in Bonto Ujung Village, Tarowang, Jeneponto district to maintain the availability of small crab resources in order to continue to provide benefits. This study uses a survey method by submitting a questionnaire to the respondents. The business feasibility data was analyzed using standard formulas that were generally available, while the small crab fishery business development strategy was analyzed by SWOT. The results showed that the crab fishery business using gill nets and traps that are currently available is still feasible to be used and developed. The strategy for developing small crab fishery business in Bonto Ujung Tarowang Village should take an effective catching strategy with a fishery information system, management arrangements, catching timing arrangements, increasing supervision with related parties, increasing knowledge of technology and information, increasing the marketing chain, increasing access to capital and access to information. to increase business opportunities, increase community innovation.

Spesifikasi dan Identifikasi Hasil Tangkapan Garok Rajungan di Pelabuhan Perikanan Pantai (PPP) Bondet Kabupaten Cirebon, Jawa Barat

Crayfish (Portunus pelagicus) is the leading export commodity of Indonesian fishermen. The increasing demand for exports and high selling prices have made fishermen at the Bondet Beach Fishing Port, Cirebon Regency, use garok crabs to maximize their catch. The purpose of this study was to identify tool specifications, catch yields, selectivity and productivity of garok crab fishing gear operated at the Bondet Coastal Fishery Port, Cirebon Regency, West Java. The research was carried out in April – June 2021. The method used was a case study method with quantitative descriptive analysis to determine the specifications of the tools and catches taken by interviewing fishermen. The results showed that the crab claws were included in the dredge gear category. Its components consist of body mouth, garok, frame, nets, and ropes of various sizes. The main catch of garok crab in Cirebon Regency consists of small crab (Portunus pelagicus), and by-catch in the form of shellfish, shrimp, cuttlefish, and demersal fish, with a total of 14 species. This tool is classified as non-selective because of the small size of the bag mesh construction (30 mm) so that this tool catches many species with large and small size fish caught. The average catch obtained from 5 trips was 23.8 kg, with the lowest catch on the 2nd trip, which was 19.7 kg and the highest on the 5th trip, which was 31.3 kg, while the average sweep area was 0.0040 km2 with an average productivity of 3.97 kg/hour and the highest catch rate value was obtained on the 5th trip, which was 5.21 kg/hour, while the lowest catch rate was found on the second trip, which was 3.28 kg/hour.

Reproductive performance of female blue swimming crab (Portunus pelagicus) from some waters in South Sulawesi

The blue swimming crab (Portunus pelagicus) is one of the endangered species due to overexploitation. The development of hatchery technology is expected to be a solution in overcoming this problem. However, until now the availability of seeds is not stable due to high mortality, especially in the larval stage which is often caused by poor quality of broodstock. This study aims to assess the reproductive performance of small crab crabs from various small crab production centers in South Sulawesi to find quality broodstock sources. The sampling locations included 3 areas, namely Bone Regency, Maros Regency and Takalar Regency, South Sulawesi Province, Indonesia. The reproductive performance measured was the length and width of the carapace as well as body weight, fecundity, egg diameter and number of larvae produced by each broodstock and assessing the development of egg diameter based on embryo development. The results obtained, namely the value of fecundity, egg diameter and number of larvae were different from each region. The highest body size, fecundity, egg diameter and embryo development and number of larvae were obtained from Takalar while the lowest was from Maros (P <0.05). The aquatic environment affects reproductive performance. This can be seen from the infestation of octolasmis and barnacles found in nearly 90% of bone broodstock which is thought to have an effect on reproductive performance. From this research, it is obtained an illustration that the broodstock of Takalar is better used as the source of broodstock.

Diurnal and nocturnal scavenger communities differ at two shallow-water depths in an Irish marine lough

We report on still/video photographic studies in 2018/9 of diurnal and nocturnal benthic scavenging on carrion in shallow water (2 m and 12 m depths) within Lough Hyne (a biodiverse Irish sea lough) using natural light during replicated 6 h daytime deployments and dim red light (630 nm) during 6 h deployments at night. In 2018 at 2 m depth in the North Basin, bait was present throughout day-time deployments, showing little evidence of scavenging; scavenger species' richness and abundance were low. At night, baits disappeared or were skeletonised; they were scavenged by a significantly more abundant and species-rich scavenger guild. At 12 m depth in the same basin, baits were removed or skeletonised during day and night. This confirmed our hypothesis that scavengers avoid well-lit very shallow water during the day, probably to avoid predation. Multivariate analysis of 2018/19 still photo data (12 m depth) revealed pronounced and statistically significant separate clustering of day, night and basin abundance/species data, although overall species' richness values did not differ significantly. These analyses together reflected differences in species’ compositions associated with contrasting sediments, flow regimes and night/day. Nephrops norvegicus, Pagurus bernhardus and Crangon crangon were only found in the low flow rate North Basin; Homarus gammarus, Trigla sp., Callionymus lyra, Agonus, Tritia reticulata and Marthasterias glacialis were only found in the high flow rate South Basin. Most scavenger species foraged in both day and night (though in different proportions). However, prawns (Palaemon serratus) only appeared at night. Small mobile scavenging fish, small crabs and prawns arrived at baits within seconds to minutes, as did locally-abundant slow movers (e.g. anemones (Anthopleura ballii), whelks (T. reticulata)). These times are shorter than recorded in earlier studies in deeper water. Larger crustaceans (e.g. Cancer pagurus, H. gammarus) took tens of minutes to hours before arrival; similar times have previously been recorded in deeper water. Large crustacean scavengers (C. pagurus, Maja squinado, H. gammarus) took substantial quantities of bait during long feeding bouts, but catsharks (Scyliorhinus canicula) often took similar quantities in a few seconds. All of the dominant scavenger species are broad-spectrum omnivores; only one obligate scavenger species (Tritia reticulata) was present (only in South Basin) and consumed negligible quantities of bait.

Studies on fecundity and spawning of blue crab (Callinectes Amnicola) in Cross River Estuary

Studies on identification of species, fecundity and development stages of blue crab, (Callinectes amnicola) were investigated at the Cross River Estuary between the months of December, 2018 and May, 2019. The parameters used for the study were gonadosomatic and hepatosomatic indices, egg diameter and counts. All measurements followed standard procedures. Gonadosomatic index was at its peak in December (88.9) and April (83.3). This coincided with the peak in egg size suggesting that spawning occurred twice within the period.The low values of hepatosomatic index around December (1.20) and April (0.45) added to confirm the spawning in these months. The species spawns at a mean egg size of 17.55mm. The dimension of crabs examined were in the following range: carapace length 40.0 to 70.0mm, carapace width, 5.0 to 60mm and body weight 40.0 to 140.0g. The relationship between fecundity and weight of crab was significant (r = 0.295: p&lt;0.05), indicating positive correlation. Absolute fecundity of the species ranged between 1,375 and 225,132 eggs. The smallest crab with egg had a carapace width of 39.5mm and weight of 46.9g. Spawning at this size seems to be a strategy adopted by the species to cope with exploitation pressure. The result of this study revealed that C. amnicola had a high reproductive potentials. Hence, adequate regulation is required to enhance sustainability of the species in the Cross River Estuary.

Hubungan Kondisi Rajungan (Portunus Pelagicus) dan Ekosistem Padang Lamun di Perairan Pulau Poteran Madura

C rab is one of the marine biota which has important economic value , m eanwhile, seagrass beds are one of the marine resources that have many benefits for marine life and the coastal environment. This study aims to determine the catch of small crabs and the condition of the seagrass beds in Poteran Island waters. This research uses Sentinel-2A image data downloaded from the earthexplorer.usgs.gov website; Earth Map (RBI) scale 1: 1,000,000, and field data in the form of identification of seagrass objects and water quality. The results showed that the number of female crabs that were caught was more than the male crabs. Based on the width of the carapace, the catch is categorized as unfit to catch. However, based on the weight measurement, the crabs that were caught were categorized as fit to catch. The results of the regression analysis showed that the length and weight of the crab had a fairly good relationship with a regression coefficient of 0.63. The length of the crab is more dominant than the weight. This is indicated by the negative allometric growth pattern (b&lt;3). Many crabs are distributed in areas close to seagrass beds. Two types of seagrass were found, namely Enhalus acoroides and Halodule uninervis with rich or healthy conditions. Good water quality is believed to be one of the factors that support the growth of seagrass beds in the waters around Poteran Island.

Jual Beli Kepiting Ditinjau Dari Sad Adz Dzariah Dan Peraturan Menteri Kelautan Dan Perikanan Republik Indonesia Nomor 12 Tahun 2020

In the practice of buying and selling crabs in the village of Meunasah Paya, the fishermen sell all the crabs they catch without sorting them out, whether they are small, large, laying eggs or not, and this is not in accordance with Permen KP number 12 of 2020 which only allows crabs above. 150 grams and crabs that are not in egg-laying condition. The formulation of the research problem is how the practice of buying and selling crabs in Meunasah Paya village, Manyak Payed district, Aceh Tamiang district and how is Sad Adz Dzariah's review and Regulation of the Minister of Maritime Affairs and Fisheries of the Republic of Indonesia Number 12 of 2020 on the practice of buying and selling crabs in Meunasah Paya village, Manyak Payed district, Aceh district Tamiang. The purpose of the study was to find out the practice of buying and selling crabs in Meunasah Paya village as well as a review of Sad Adz Dzariah and KP Ministerial Regulation number 12 of 2020 on the practice of buying and selling crabs in Meunasah Paya village, Manyak Payed district, Aceh Tamiang district. This research includes field research (Field Research) with qualitative descriptive analysis method. The results of the study concluded that in Meunasah Paya village, crab fishermen sell all the crabs they catch to collectors without looking at the standardization of Ministerial Regulation No. 12 of 2020 which has been determined whether large or small crabs, laying eggs or not, will still be sold to collectors. According to sad adz dzariah, the law of buying and selling crabs in Meunasah Paya village is divided into two, namely some are prohibited because they are not in accordance with the candy and this will damage the crab population in nature and some are not prohibited. Meanwhile, according to Permen KP Number 12 of 2020, the sale and purchase of crabs in the village of Meunasah Paya is also divided into two, namely, some are appropriate and some are not.

Factors affecting individual foraging behavior in a threatened seabird: Olrog’s Gull (Larus atlanticus) as a case study

The analysis of feeding strategies in animals is one of the most important topics in foraging ecology. The individual’s foraging behavior depends on both the individual’s own actions and the behavior of other foragers. Here we analyse the effect of the sex and group size on the foraging behavior of immature Olrog’s Gull (Larus atlanticus Olrog, 1958), endemic to the Atlantic coast of southern South America and regionally listed a threatened species. Birds were captured, banded, sexed, and aged during the non-breeding season in Mar Chiquita coastal lagoon, Argentina. The foraging behavior was quantified by observations made on individuals of known identity, recording the size of foraging groups, as well as prey size and type. Foraging parameters estimated were foraging effort, capture rate, and foraging efficiency. Males spent more time in agonistic behavior and captured larger prey. With an increase in group size, the capture rate, the capture of small crabs by males, and the foraging effort were higher. The agonistic behaviors, size of consumed prey, and foraging effort were affected by individual identity. Our study pinpoints factors underlying variation in the foraging behavior of Olrog’s Gulls and illustrates the importance of modelling individual variation when analyzing foraging behavior.

The ecological impacts of multiple environmental stressors on coastal biofilm bacteria.

Ecological communities are increasingly exposed to multiple interacting stressors. For example, warming directly affects the physiology of organisms, eutrophication stimulates the base of the food web, and harvesting larger organisms for human consumption dampens top-down control. These stressors often combine in the natural environment with unpredictable results. Bacterial communities in coastal ecosystems underpin marine food webs and provide many important ecosystem services (e.g. nutrient cycling and carbon fixation). Yet, how microbial communities will respond to a changing climate remains uncertain. Thus, we used marine mesocosms to examine the impacts of warming, nutrient enrichment, and altered top-predator population size structure (common shore crab) on coastal microbial biofilm communities in a crossed experimental design. Warming increased bacterial α-diversity (18% increase in species richness and 67% increase in evenness), but this was countered by a decrease in α-diversity with nutrient enrichment (14% and 21% decrease for species richness and evenness, respectively). Thus, we show some effects of these stressors could cancel each other out under climate change scenarios. Warming and top-predator population size structure both affected bacterial biofilm community composition, with warming increasing the abundance of bacteria capable of increased mineralization of dissolved and particulate organic matter, such as Flavobacteriia, Sphingobacteriia, and Cytophagia. However, the community shifts observed with warming depended on top-predator population size structure, with Sphingobacteriia increasing with smaller crabs and Cytophagia increasing with larger crabs. These changes could alter the balance between mineralization and carbon sequestration in coastal ecosystems, leading to a positive feedback loop between warming and CO2 production. Our results highlight the potential for warming to disrupt microbial communities and biogeochemical cycling in coastal ecosystems, and the importance of studying these effects in combination with other environmental stressors.

Perbedaan Pendapatan dan Kelayakan Usaha Penangkapan Rajungan dengan Alat Tangkap Bubu dan Jaring Insang

This study aims to determine the differences in the income of small crabs fishing between those using traps and gill nets, and to determine the feasibility of catching small crabs. The study was conducted in March 2020 in Bajo Indah Village, Soropia Subdistrict, Konawe Regency. The population in this study, for trap fishermen as many as 25 people and gill net fishermen as many as 25 people. The sampling method was cluster random sampling. The number of samples for trap fishermen is 10 people and gill nets are 10 people. The data collected is the number of inputs, outputs, costs, revenues, and incomes. Data collection was carried out by means of interviews and documentation. Data analysis used the t-test with a confidence level of 95 percent or α = 0.05. The results of the study show that the income of small crab fishing between those using traps and gill nets is significantly different. The business of catching small crabs using gill net fishing gear is more feasible to operate than traps.Keywords: crab; traps and gill nets; income; different tests; feasibility

Isolation and characterization chitosan from varied crab shell

Crab shells chitosan processing consists of 3 steps, the process is deproteinization,demineralization, and deacetylation. This study aims to produce chitosan with a high yield asan alternative to natural adsorbents and coagulants. This research was conducted using threedifferent raw materials for crab shells, namely mangrove crab shells (K1), small crab shells(K2), and kappa crab shells (K3). In this study, a demineralization process was carried out ondried crab shells using strong acids. Furthermore, deproteination is carried out using a strongbase to obtain chitin and deacetylation with a strong base to produce chitosan. The results ofresearch carried out observations including moisture content, ash content, solubility, and yield.The results of the isolation of the crab shell chitosan obtained the chitosan yields of 31%,32.2%, and 24.5%, respectively.

Description of a new species of emGlassella/em Campos amp; Wicksten, 1997 from a coastal lagoon, SE Gulf of California (Crustacea, Decapoda, Pinnotheridae).

A new a species of pinnotherid crab in the eastern Pacific coasts is presented. Twenty males and 21 females of small crabs were collected from burrows, presumably from ghost shrimp (Neotrypaea spp.), in sand-mud substrata from the Santa María-La Reforma coastal lagoon, SE Gulf of California. The new species was assigned to the genus Glassella because its morphological characteristics clearly match the amended diagnosis of the genus Glassella by Palacios Theil and Felder (2020) and Felder Palacios Theil (2020), including the presence of a gonopodal plate (GP) inserted in the internal part of the male pleon, similar to that described for most of the species currently grouped into the genus Glassella. The new species is similar to G. miamiensis (McDermott, 2014) from western Atlantic, but it can be distinguished from this and the rest of the species of Glassella by differences in carapace margins and ridges, male pleon outline, and the shape of the GP.

Changes in benthic macrofauna in oyster parks during an OsHV-1 μVar oyster spat mortality outbreak

In intertidal areas, oyster farming creates a crosshatching pattern between oyster tables and aisles. Tables provide a refuge from the current and solar irradiance and the oysters facilitate the accumulation of OM, thereby structuring the spatial organization of the associated macrozoobenthic community at mesoscale. The aim of this study was to describe the quality of the oyster table environment at small scale and the response of the macrozoobenthic community to OsHV-1 μvar oyster mortality. The species assemblage was dominated by Golfingia vulgaris, Tubificoides benedii, Capitella capitata and Scoloplos armiger. The table habitat appeared to be in a bad ecological state throughout the 2-month survey (May and June 2017), whereas in the aisle, eutrophication occurred lately and was clearly related to be due to the massive stranding of dead seaweed at the end of the survey (in early July). So, this disturbance of the species assemblage seemed to occur in two phases: 1) after oyster spat mortality and 2) after seaweed stranding resulted in a bad ecological status, as revealed by macrofaunal indicators. Large quantities of OsHV-1 DNA were also found in some species, including small crabs and amphipods, one week after the mortality crisis, but there is no apparent virus reservoir found in the benthic species.

Internet of things for aquaculture in smart crab farming

Internet of Things (IoT) has been introduced and applied in many applications and become an emerging technology in digital era. The major economic in southern part of Thailand is aquaculture such as fishery, shrimp, pearl, mud crab and so on. The concept of IoT which is about connecting the sensors and gathering all necessary data to cloud platform allowing us to compute, control measure, and manage farm efficiently. Soft shell crab is most important ingredient in Chinese, Japanese, and co-fusion menu requiring in many premium restaurants. Unfortunately, the productivity of soft-shell crab industry is very small due to a low survival rate in raising process and lacking of small crab. In tradition al soft-shell crab farm, each small crab has been grown separately of a small box in the old shrimp pond. Farmer has to feed them individually and monitor them every 4 hours in order to avoid soft-shell crab turns to hard shell. In this work, thus, we propose to apply IoT and intelligent system to improve the productivity in the traditional soft-shell crab farm. Water quality sensors, motion sensors, and feeding system are designed and developed to enhance the survival capability of soft-shell crab farm. Meanwhile, with the same concept, our system can be applied in another aquaculture to be smarter farm and be precision aquaculture in the southern path of Thailand.