Mud Crab Farming Research Articles

Analysis of the factors influencing the quality of farmed mud crabs in the Mekong Delta, Vietnam

Enhancing the quality of cultivated mud crabs is a crucial element for elevating productivity, quality, and economic effectiveness within the mud crab farming sector. This study investigates factors influencing the quality of farmed crabs in the Mekong Delta, Vietnam. The study employs descriptive statistical methods and synthesis approaches to analyse the current situation of crab farming in the Mekong Delta, Vietnam. Additionally, multivariate regression analysis was employed to identify factors affecting the quality of farmed crabs in the Mekong Delta, Vietnam. The survey results from 304 crab farmers in the Mekong Delta, Vietnam indicate that the total area of the Mekong Delta, Vietnam is 465 thousand hectares, with a production of 68 thousand tons. Among the provinces in the Mekong Delta, Vietnam, Kien Giang, Ca Mau, and Bac Lieu are the top three provinces with the highest area and production. Furthermore, factors influencing the quality of crab products during the farming process were analysed, and three main factors were identified: the decision to catch crabs at the fourth moult stage (Y4), the number of crab traps used, and the duration of the farming period. This research represents the first study on the quality of farmed crab in the Mekong Delta, Vietnam. Therefore, these findings provide guidelines for improving the quality of farmed crab and serve as a foundation for further research in this field

MicroRNA sequencing analysis reveals injury-induced immune responses of Scylla paramamosain against cheliped autotomy

During pond culture or intensive culture system of crabs (mainly Eriocheir sinensis, Portunus trituberculatus and Scylla paramamosain), high-density farming has typically contributed to a higher limb autotomy level in juvenile animals, especially in S. paramamosain which has a high level of cannibalism. Due to the high limb autotomy level, the survival and growth rates in S. paramamosain farming are restricted, which limit the growth of the mud crab farming industry. MicroRNAs (miRNAs) are small noncoding RNAs that regulate a series of biological processes including innate immune responses by post-transcriptional suppression of their target genes. MiRNAs are believed to be crucial for innate immune process of host wound healing. Many miRNAs have been verified to be required in host immune responses to repair wound and to defense pathogen after tissue damage. However, to our best knowledge, the miRNAs functions of crustacean innate immune reactions against injury induced by limb autotomy have not been studied yet. Here in this study, for the first time, miRNAs involved in the S. paramamosain immune reactions against injury induced by cheliped autotomy were obtained by high-throughput sequencing. A total of 575 miRNAs (518 known miRNAs and 57 novel predicted miRNAs) were obtained, of which 141 differentially expressed microRNAs (93 up-regulated microRNAs and 48 down-regulated microRNAs) were revealed to be modified against cheliped autotomy, and the qPCR results of randomly selected miRNAs confirmed the expression patterns in the miRNAs sequencing data. Numerous immune-related target genes associated with innate immune system were mediated by miRNAs to induce host humoral immune and cellular immune defense to minimize acute physical damage. Furthermore, the genes expression in hemolymph coagulation and melanization pathways, as well as Toll and Imd signaling pathways were mediated by miRNAs to activate host immune responses including melanization and antimicrobial peptides for rapid wound healing and killing invaded pathogens. These results will help to understand injury-induced immune responses in crabs and to develop an effective control strategy of autotomy rate in crabs farming.

Challenges and opportunities in achieving sustainable mud crab aquaculture in tropical coastal regions

Aquaculture plays a significant role in food security and provides livelihoods and employment for millions of people among coastal communities worldwide. However, the growing aquaculture sector has also created debates around its long-term ecological sustainability, economic viability, potential social inequalities and governance issues. We investigated the perceived challenges and opportunities to achieving sustainable mud crab aquaculture in tropical coastal regions by using the case study of coastal mud crab farms in Andhra Pradesh, India. Informed by perceptions and indicative financial data from a sample of stakeholders we investigated the potential economic outcomes under different scenarios representing varying yield levels, risk factors and project time periods. The main risks identified by the stakeholders were associated with the limited supply of mud crab seeds and the lack of access to governmental and non-governmental support schemes. There are no financial buffers, therefore major disease outbreaks or extreme weather conditions caused by climate change would lead to a loss of livelihoods. This paper also highlights the most critical factor determining the level of success of mud crab farming being the crab survival rate which is influenced by a variety of factors including increasing sea surface temperature. The results of this study show that small-scale mud crab farming has fewer risks and higher flexibility involved than large-scale mud crab farming. It could be an economically sustainable enterprise and serve as a tool for poverty alleviation in developing countries if microfinance support and training are available.

Octolasmic Octolasmis spp. parasite attack on mudcrab Scylla serrata in Tomini Bay

The present study aimed to identify the Octolasmis spp. ectoparasite’s intensity and prevalence in mud crab in Pohuwato Regency. It employed survey and site observation methods with sampling technique of mud crabs in Pohuwato Regency. The research was carried out in three different sites: site 1 (Pohuwato Timur Village), site II (Bulili Village), and site III (Mootilango Village). The results showed that the parasites infesting mud crab in the three separate locations are Octolasmis angulata and Octolasmis cor. The highest intensity rate was at site III, which was dominated by Octolasmis cor. The prevalence of the parasite in sites I, II, and III was 60%, 40%, and 60% in consecutive order. Moreover, the parasite has a 100% and 46% prevalence in female and male crabs, respectively. The water quality indicator (involving temperature, pH level, and soluble oxygen) was at the appropriate rate for mud crab farming.

Reovirus occurrence in mud crab farming systems and wild-caught brooders located in eastern coastal area of India

Reovirus occurrence in mud crab farming systems and wild-caught brooders located in eastern coastal area of India

Biochemical, metabolic, and immune responses of mud crab (Scylla paramamosain) after mud crab reovirus infection

Mud crab reovirus (MCRV) is a serious pathogen that leads to large economic losses in the mud crab farming. However, the molecular mechanism of the immune response after MCRV infection is unclear. In the present study, physiological, transcriptomic, and metabolomic responses after MCRV infection were investigated. The results showed that MCRV infection could increase lactate dehydrogenase, alanine aminotransferase, and aspartate aminotransferase activities. MCRV infection decreased antioxidant enzyme activity levels, induced oxidative stress, and caused severe histological damage. Transcriptome analysis identified 416 differentially expressed genes, including 354 up-regulated and 62 down-regulated genes. The detoxification, immune response, and metabolic processes-related genes were found. The results showed that two key pathways including phagocytosis and apoptosis played important roles in response to MCRV infection. The combination of transcriptomic and metabolomic analyses showed that related metabolic pathways, such as glycolysis, citrate cycle, lipid, and amino acid metabolism were also significantly disrupted. Moreover, the biosynthesis of unsaturated fatty acids was activated in response to MCRV infection. This study provided a novel insight into the understanding of cellular mechanisms in crustaceans against viral invasion.

Development of Polyculture Engineering Technology on Milkfish and Mud Crab Farming

The current study aimed to evaluate the role of polyculture engineering technology on milkfish and mud crab farming and observe the growth and survivability of different milkfish and mud crab combinations. The study used milkfish, which was received artificial feed containing 35 % protein content enriched with vitamin E (3%/biomass/day). The study used completely randomized design with 4 treatments (n = 3): T1 = 5 milkfish + 5 mud crab, T2 = 10 milkfish + 5 mud crab, T3 = 5 milkfish + 10 mud crab, T4 = 10 milkfish + 10 mud crab. The following parameters were measured: absolute weight growth, survival rate, feed conversion rate (FCR), and water quality. The difference in the density of milkfish and mud crabs significantly affected (p < 0.05) the growth and survivability of milkfish and mud crabs. The polyculture cultivation system exhibited a significant increase in absolute weight growth of milkfish and mud crabs, which is the highest increase found in T4 treatment (187.85 g ± 0.9 g and 60.65 g ± 0.95 g, respectively). Meanwhile, the survival rate of milkfish and mud crab was 95% ± 0.3% and 95% ± 2.3%, respectively, followed by a lower FCR at T4 (1.54 ± 0.10). The water quality remained good for fish and mud crabs to survive. Milkfish and mud crab polyculture greatly affect the abundance of phytoplankton, demonstrating good community structure.

Mud Crab (Scylla spp.) Aquaculture in the South-West Sundarbans Region of Bangladesh

Mud crab (Scylla spp.) aquaculture has become an important livelihood option for the coastal fisher-folks in Bangladesh. Mud crabs harvested from wild sources are traditionally fattened in pens installed in tidal rivers, ghers, and earthen ponds in Bangladesh. The study was aimed at understanding the practice and production economics of mud crab farming in the South-West Sundarbans region of Bangladesh, and was conducted in the areas namely Bagerhat, Satkhira and Khulna districts where mud crab fattening are predominately ventured. Most of the farmers fatten both male (lean) and female (gonadally immature) crabs of 100 - 180 g. The crabs are stocked at varying rate (12 - 641 g/m2), and fed at the rate of 8-10% of body weight with trash live fishes, dried fishes, snails, mollusks, and cattle viscera. The fattening for a mean cycle of 22 ± 14.34 days has the survival rate of 55 - 90%, and has the production of 0.065 ± 0.26, 0.084 ± 1.33, and 0.17 ± 3.76 kg/m2 in Bagerhat, Satkhira, and Khulna, respectively. After harvesting (mostly partial), crabs are sold at average price rate of 4.35 ± 0.45 US$/kg. The lowest production cost (3.14 US$/kg) and the better economic return (US$ 147.77) per cycle was recorded in the district of Satkhira. The mud crab fattening has hitherto been evaluated economically feasible in and around the Sundarbans region, but the production and economic efficiency can be scaled up adopting scientifically demonstrated regime of stocking, feeding, and health management. The development of crab seed hatchery, artificial feed for crab, and strongest marketing network are addressed as crux issues for the sustainability of mud crab aquaculture in Bangladesh.

Morphology of the complete embryonic and larval development of commercially important mud crabScylla paramamosain

Mud crab, Scylla paramamosain, is an important aquaculture species. In recent decades, with the development of mud crab farming, seed production has become more and more important. Therefore, a precise understanding of embryonic and larval development is required for future study or application. In this study, we described the complete embryonic and larval development of S. paramamosain under the following conditions: temperature 28°C–31°C, salinity 26,000–30,000 mg/L, pH 7.9–8.2, and dissolved oxygen 4–5 mg/L. The embryonic development was divided into five stages: cleavage, blastula, appendage, eyespot-heartbeat, and prehatching. The entire embryonic period spanned 9–11 days. The larval development consisted of six stages: zoea I (Z1), zoea II (Z2), zoea III (Z3), zoea IV (Z4), zoea V (Z5), and the megalopal stage. The duration of the larval stage was about 22–24 days, and it took about 3 days for each stage of Z1–Z4, about 4–5 days for Z5, and about 5–6 days for the megalopal stage. In general, in this study, we presented a comprehensive description of both embryonic and larval development with massive image information, which would help diagnose different developmental stages and provide an important guidance for future study or application.

Limb loss and feeding ability in the juvenile mud crab Scylla olivacea: Implications of limb autotomy for aquaculture practice

In Scylla mud crab farming, limb autotomy is commonly used in soft-shell crab production to expedite the moulting process and temporarily achieve high stocking density during crablet transportation. However, little is known about the effect of limb loss on the feeding ability of mud crabs. Therefore, we investigated the effect of various degrees of limb autotomy on the feeding ability of S. olivacea on either live blood cockles or cockle meat, and subsequently the effect of different live cockle size and days after limb removal. The removal of all appendages except for swimming legs compromised S. olivacea’s ability to feed on live cockles but not on cockle meat. When fed with live cockles, the total eaten cockle mass was similar among treatments, but the loss of limbs resulted in lower number of crabs engaged in feeding activity and longer feeding duration. When fed with cockle meat, crabs of all treatments engaged in feeding activity, and only full autotomised crabs showed prolonged feeding duration. Limb loss, but not cockle size nor day after limb removal, affected cockle consumption. Only crabs with one cheliped removed improved their feeding duration after Day 7, whereas crabs that lost both chelipeds did not show change in feeding duration. These results suggest that limb removal affect the feeding ability in mud crabs, and this serves as essential knowledge for future optimisation of the feeding practices of mud crab juveniles right after transportation or during soft-shell crab culture.

Use of different seaweeds as shelter in nursing mud crab, Scylla paramamosain: Effects on water quality, survival, and growth of crab

AbstractMud crabs (Scylla spp.) are considered luxury seafood and high market value; hence, mud crab farming is well known in Southeast Asia. However, the prevalence of cannibalistic behavior in crabs thus requires shelter in the culture system to reduce conspecific cannibalism and enhance the survival of crabs. This study aims to determine the suitability of various seaweed species as shelter to improve the survival and production of mud crab Scylla paramamosain crablets. The experiment consisted of seven treatments and was randomly designed in triplicate tanks. The control treatment had no shelter (i.e., without seaweed in the culture tank), and in the other six treatments, red seaweed (Gracilaria tenuistipitata) or green seaweed (Enteromorpha intestinalis) was placed in the rearing tanks at three density levels: 0.5, 1, and 2 kg/m2. Instar 2 crablets were reared at a density of 300 ind/m2, at salinity of 15 g/L, and with continuous aeration. Crablets were fed frozen Artemia biomass to satiation for 4 weeks. Results showed that the survival of crabs in all treatments sharply declined from Week 3 to Week 4 of culture, where the 1 and 2 kg Gracilaria groups showed less reduction than the other treatments. At the end of the experiment, the average survival of crabs in the control group was lowest (17.4%), while the survival of crabs was significantly improved, varying within the ranges of 53.3–70.7% and 27.8–35.9% in the Gracilaria and Enteromorpha groups, respectively. Notably, higher survival resulted in lower growth rates in the seaweed treatments, but enhanced biomass and production of crab juveniles. Moreover, concentrations of TAN, NO2−, NO3−, and PO43− in the Gracilaria treatments were much lower than in both the control and the Enteromorpha treatments that improved water quality in the rearing tanks. The present findings prove that red seaweed G. tenuistipitata could be considered a suitable shelter for the reliable production of mud crab juveniles in the nursery phase.

Boom and bust: Soft‐shell mud crab farming in south‐east coastal Bangladesh

Soft-shell mud crab (Scylla olivacea) farming was introduced to the coastal floodplains of Cox's Bazar, a south-east region of Bangladesh, in 2011. These farming practices then spread among many farmers within the region, and gradually increased in the southwest coastal floodplains of the Satkhira district. While farming in the Satkhira region has experienced relatively smooth growth, the mud crab farms in Cox's Bazar have gone through big ups and downs. Indeed, the number of these farms in the south-east was found to have gradually decreased by 80% in 4 years (2014–2017). This study looks at historical perspectives and thoroughly reviews the state of soft-shell mud crab farming practices. In addition to key stakeholder interviews, data were collected from all the existing and collapsed farms of this type in the Cox's Bazar region. It is revealed that social coherence was the main factor that enabled the ‘boom’ periods due to farmers sharing methods and technologies among their communities. In contrast, poor linkage to global value chains, lack of product diversification, shortage of seed supply due to an inadequate supply of trash fish for feeding, prolonged banning of sea fishing, the poor bargaining capacity of the stakeholders and small-scale farmers lacking direct access to export markets were the key factors for the ‘bust’ periods, even when global demand was increasing daily. A balance between local and global markets, value-added diversified product development and adoption of advanced technologies in the crab farming industry are recommended for the revival and sustenance of this emerging sector.

Machine learning with multistage classifiers for identification of of ectoparasite infected mud crab genus <i>Scylla</i>

Recently, the mud-crab farming can help the rural population economically. However, the existing parasite in the mud-crabs could interfere the long live of the mud-crabs. Unfortunately, the parasite has been identified to live in hundreds of mud-crabs, particularly it happened in Terengganu Coastal Water, Malaysia. This study investigates the initial identification of the parasite features based on their classes by using machine learning techniques. In this case, we employed five classifiers i.e logistic regression (LR), k-nearest neighbors (kNN), Gaussian Naive Bayes (GNB), support vector machine (SVM), and linear discriminant analysis (LDA). We compared these five classfiers to best performance of classification of the parasites. The classification process involving three stages. First, classify the parasites into two classes (normal and abnormal) regardless of their ventral types. Second, classified sexuality (female or male) and maturity (mature or immature). Finally, we compared the five classifiers to identify the species of the parasite. The experimental results showed that GNB and LDA are the most effective classifiers for carrying out the initial classification of the rhizocephalan parasite within the mud crab genus Scylla .

Induced mating of newly molted females of orange mud crab, Scylla olivacea (Herbst, 1796), in captivity

Mud crab aquaculture is gaining attention in tropical and sub-tropical regions for its high commercial value. Mating is the fundamental requirement for the natural seed production of mud crabs. The aim of this study was to develop an induced mating technique of orange mud crab, Scylla olivacea in captivity to support sustainable mud crab farming through increasing the supply of hatchery-produced mud crab seeds. Induced mating technique involved the mating of a mature induced soft-shelled female (newly molted) with a mature intermolt male. The mating pairs were selected randomly. This study proved that S. olivacea can copulate without pre-copulation (pairing of male-female before copulation) and post-copulatory guarding by the male. Spermatophores were found in the seminal receptacles of all the copulated females. A mating success of 83.33 ± 5.77% was obtained in captivity using this technique, and can be applied in future breeding and hybridization trials of mud crabs.

Effects of Vibrio parahaemolyticus infection on physiological response, histopathology and transcriptome changes in the mud crab (Scylla paramamosain)

Mud crab (Scylla paramamosain) is an important economic species in China. Vibrio parahaemolyticus infection have caused a great economic loss in mud crab farming. The mechanism involved in the immune responses of mud crab to V. parahaemolyticus is unclear. In this study, the physiological and immune response to V. parahaemolyticus infection were investigated in S. paramamosain. The results showed that V. parahaemolyticus infection decreased total hemocyte counts, led to cytological damage, and caused high mortality. Transcriptome analysis showed that 1327 differentially expressed genes (DEGs), including 809 up-regulated and 518 down-regulated ones, were obtained after V. parahaemolyticus challenge. These DEGs were mainly involved in the immune response and infectious disease. Additionally, transcriptome analysis revealed that Toll, immune deficiency (IMD), and prophenoloxidase signalling pathways played essential roles in antibacterial immunity against V. parahaemolyticus infection in mud crab.

Evaluation of limb autotomy as a promising strategy to improve production performances of mud crab ( Scylla olivacea ) in the soft‐shell farming system

Soft-shell crab, a newly moulted crab having non-calcified and hydrated soft exoskeleton, farming has been increasing tremendously in recent years throughout the world due to its high market price and consumer preferences. However, high aggressiveness and cannibalistic behaviour of mud crab limit its culture to an individual chamber system which ultimately makes the soft-shell mud crab farming space and labour-intensive. Therefore, the aim of this study was to improve the efficiency of soft-shell crab production by autotomy of the claw and/or walking legs to reduce the moulting duration and intensify the culture system through double stocking in the existing individual chamber culture system. To achieve our objectives, a series of experiment were conducted at both indoor and on-farm levels by removing the claw and/or walking legs of Scylla olivacea for two consecutive moulting cycles. Results showed that both claw ablation significantly (p < .01) shortened the moulting duration and increased the carapace width, weight gain, specific growth rate, feeding efficiency and yield parameter compared to the non-ablated crabs more prominently at 1st moulting than the 2nd moulting in both indoor and on-farm trials. Ablation of all walking legs while keeping the claw intact did not significantly influence (p > .05) the moulting duration and carapace width, but significantly (p < .01) improved the specific growth rate, weight gain, feeding efficiency and yield parameters at 1st moulting compared to the non-ablation and unilateral three walking leg ablation groups. However, ablation of all appendages (both claw and walking legs) showed significant (p < .01) improvements of carapace width, weight gain, specific growth rate, feeding efficiency and yield parameters, and shortened the moulting duration up to 23 days from 34 days during 1st moulting and up to 27 days from 40 days at 2nd moulting. The survivals of different autotomized mud crabs were statistically non-significant (p > .05) to the non-autotomized crabs in various indoor and on-farm trials. Besides improving the production performances, ablation of bilateral claw and all appendages allowed to double the stocking density in the existing individual chamber-based soft-shell crab farming that enhanced the production about threefold higher than the existing individual chamber-based culture system. Finally, our results suggest that autotomy could be a promising technology for the commercial farming of soft-shell mud crab in near future.

The application of the sustainable livelihood approach to small scale-fisheries: The case of mud crab Scylla serrata in South west India

The sustainable livelihood approach is an analytical framework that helps identifying the assets that local communities rely on, the risks they are subjected to, organisations and institutions influence their daily lives and the strategies they undertake. This is a valuable approach in small-scale fisheries management as artisanal fisheries are exposed to uncertainty in terms of supply and demand, and fishing activities usually are influenced by social and institutional factors. However, in spite of its usefulness and the fact that this approach has been previously used in projects targeting small-scale fisher communities, it is still not widely applied to small-scale fisheries. In this study we applied the sustainable livelihood approach as an analytical tool to assess the potential of the mud crab Scylla serrata as a sustainable livelihood resource for the southwest Indian states such as Karnataka. As fishers worldwide face continuous pressure from industrial fishing fleets and decreased fish stocks and their productivity, we also identified what could be the potential barriers to small-scale mud crab farming for communities that are already are involved in mud crab fishing. Data were collected and analysed from a semi-structured questionnaire, two focus group discussions and key informant interviews conducted in Uttara Kannada district, Karnataka. The results indicated that though mud crab is perceived as a good source of income in this area, at present it is not recognised as a steady source of income due to the unpredictable fishery catches. Respondents were aware of mud crab farming yet stated the lack of land and financial resources as the main barriers and only the minority expressed any interest in undertaking such activity. The sustainable livelihood approach proved to be a valuable research tool for identifying matters of concern for local communities regarding their source of livelihoods and barriers to small-scale aquaculture.

Social and economic implications of small-scale mud crab (Scylla serrata) aquaculture: the case of organised community groups

Small-scale mud crab aquaculture was introduced in East Africa in late 1990s as a mangrove friendly aquaculture to improve the livelihood of coastal communities through organised community groups (OCGs). The OCGs approach was a strategy aimed at ensuring benefits to the village and regulating access to the open access resource (land in mangrove forests). A social and economic assessment was conducted at Majaoni, Makongeni, Ihaleni and Dabaso along the Kenyan coast. The paper looks at the social and economic characteristics of the groups, their management systems, contribution of mud crab aquaculture to the livelihoods of local communities and policy issues related to the interventions. There is wider involvement of the mijikenda community in mud crab farming; however, the level of women participation is low. A strong market link exists between the groups and the different market outlets, where hotels and exporters offer the highest prices. Regional price variations existed and may need networking between the groups. The paper concludes that national policies may need to be redirected to support small-scale aquaculture development and ensuring capacity building for women, operation and management of groups, provision of extension services, data management and provision of user rights for communities working in the mangrove environment.

Mud Crab (Scylla spp.) Aquaculture in the South-West Sundarbans Region of Bangladesh

Mud crab ( Scylla spp.) aquaculture has become an important livelihood option for the coastal fisher-folks in B angladesh. Mud crabs harvested from wild sources are traditionally fatte ned in pens installed in tidal rivers, ghers , and earthen ponds in Bangladesh. The study was ai med at understanding the practice and production economics of mud crab farming in the South-West Sundarbans region of Bangladesh, and was conducted in the areas namely Bagerhat, Satkhira an d Khulna districts where mud crab fattening are predominately ventured. Most of the farmers fatten both male (lean) and female (gonadally immat ure) crabs of 100 - 180 g. The crabs are stocked at varying rate (12 - 641 g/m 2 ), and fed at the rate of 8-10% of body weight with trash live fishes, dri ed fishes, snails, mollusks, and cattle viscera. The fattening for a mean cycle of 22 ± 14.34 days has the survival rate of 55 - 90%, and has the production of 0.065 ± 0.26, 0.084 ± 1.33, and 0.17 ± 3.76 kg/m 2 in Bagerhat, Satkhira, and Khulna, respectively. After harvesting (mostly part ial), crabs are sold at average price rate of 4.35 ± 0.45 US$/kg. The lowes t production cost (3.14 US$/kg) and the better economic return (US$ 147.77) per cycle was recorded in the district of Satkhira. The mud crab fattening has hitherto

Bioeconomics of mud crab, Scylla paramamosain, culture in Vietnam

AbstractThe results of bioeconomic analysis informed by a survey of 80 small‐scale mud crab farmers in Vietnam are presented in this paper. Mud crab farming in Vietnam is profitable, with net revenue being approximately 135 and 41 million VND/year (USD 7000–USD 2100 per year) in the central and southern regions, respectively. Profitability was significantly higher in the centre compared with the north, as almost three times the biomass is harvested in the centre compared with the south (in turn, due to higher aquaculture area and survival rates). The benefit–cost ratio (the ratio between total revenue and total costs) is 3.55 in the centre and 1.97 in the south. The crabs are fed almost exclusively on low‐value finfish in the centre and the south. Feeding rates were found to be low, with 95% of biomass gain coming from natural feed in the environment rather than supplementary feeding by the farmer. If pellets are to be adopted widely by mud crab farmers, negative perceptions regarding the poor adaptability of mud crab to pellets (northern farmers only), relatively slow growth rates compared with low‐value finfish and lack of availability of pellets need to be overcome.