Soft-shell Crab Research Articles

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.

Fishing pattern and environmentally friendly analysis on mud crab (Scylla spp.) fishery in Mojo mangrove ecosystem, Pemalang Regency, Central Java, Indonesia

The high market demand of mud crabs has led to increase the capture so that their availability in the wild is threatened. The purpose of this study was to determine the fishing pattern of mud crabs and analyze the environmentally friendly of mud crab catching units in Mojo mangrove ecosystem. Data analysis used descriptive analysis to analyze the fishing pattern and analysis of the level of environmentally friendly based on nine FAO criteria. From the research it is known that the peak season of mud crabs fishing occurs during the west monsoon season and the usual season during the east monsoon season, while the famine season at the end of the east monsoon season. Observation results indicate that the majority of mud crabs caught are not in accordance with regulations (size &lt;12 cm) with 70% of the total catch of mud crabs for soft shell crab farming needs. Based on environmental analysis of fishing gear, it is known that crab traps, trammel net, crabbing with a line and scoop net are environmentally friendly fishing gear with a score of 32.37, 26.81 and 32.40. However, there are criteria that do not meet environmentally friendly scores, namely the capture of mud crabs of a prohibited size and many non-target species caught with trammel net fishing gear.

Electrochemistry as a screening method in determination of carotenoids in crustacean samples used in everyday diet

Electrochemistry of carotenoids has attracted a lot of interest because it provides an understanding of their oxidative properties. We report the application of electrochemistry in the analysis of carotenoids. Voltammetry of microdroplets immobilized on paraffin impregnated graphite electrode in 0.1 mol dm−3 HClO4 and KNO3 aqueous electrolytes using square-wave voltammetry was applied. Previous studies have shown that carotenoids undergo complex oxidation process when characterized in aqueous media. In this research, the electrooxidation of carotenoid astaxanthin was confirmed. The obtained response allowed the development of an electroanalytical method with a limit of detection of 15.77 µmol dm−3, the limit of quantification of 47.80 µmol dm−3 and acceptable relative standard deviations for current (3.69%) and potential (0.41%). Extraction using DMSO and acetone has shown to be appropriate for voltammetric analysis. Astaxanthin content was determined electrochemically in shrimp and soft-shell crab samples (20.63 and 6.59 μg g−1, respectively), yielding recoveries above 90%.

Pembinaan masyarakat desa untuk peningkatan pendapatan melalui teknologi budidaya kepiting soka di Desa Pulau Cawan Kecamatan Mandah Kabupaten Indragiri Hilir

Kepiting soka adalah kepiting bakau yang dibudidayakan dan dilakukan pemanen disaat molting sehingga cangkangnya menjadi lunak dan mudah untuk dikonsumsi. Tujuan dari pengabdian ini adalah untuk meningkatkan pendapatan masyarakat Desa Pulau Cawan, Kecamatan Mandah, Kabupaten Indragiri Hilir melalui budidaya kepiting soka dengan memperkenalkan teknik budidaya yang ramah lingkungan, namun dapat menghasilkan nilai tambah dari segi peningkatan ekonomi keluarga melalui budidaya kepiting soka. Pelatihan teknik-teknik budidaya kepiting soka dan pelatihan pembangunan konstruksi wahana budidaya (crabs box). Kegiatan pengabdian ini dilaksanakan dengan menggunakan beberapa metoda pendekatan yaitu memberikan pemahaman kepada masyarakat yang dilaksanakan dalam bentuk FGD (Focus Group Discussion). Serta melakukan diskusi dan praktek budidaya kepiting untuk menggali informasi tentang pemahaman budidaya yang ramah lingkungan, menjaga ekosistem mangrove, peningkatan pendapatan rumah tangga melalui penambahan nilai terhadap hasil tangkapan dan solusi mengenai adanya nelayan dari luar desa yang melakukan cara-cara penangkapan yang merusak, yaitu dengan memberi racun. Serangkaian kegiatan penyuluhan yang dilakukan mengenai teknik budidaya kepiting cangkang lunak (soka) dapat diterima dengan baik oleh nelayan penangkap kepiting yang ada di Desa Pulau Cawan. Peningkatan pengetahuan dan keterampilan nelayan penangkap kepiting dalam budidaya kepiting cangkang lunak yang di letakkan dalam kotak kepiting (crab box) dapat menjadi bekal agar kegiatan budidaya ini dapat terus berlanjut, dan Desa Pulau Cawan dapat menjadi desa percontohan teknik budidaya kepiting cangkang lunak (soka) untuk beberapa tahun ke depan.

Growth performance and survival rate of Portunus pelagicus (Linnaeus, 1758) broodstock females fed varying doses of amaranth extracts

Background: Formulated diets made from food waste enriched with amaranth extract largely determine the level of softshell crab production. The study was carried out to analyze the growth performance and survival rate of blue swimming crab Portunus pelagicus (Linnaeus, 1758) broodstock females fed formulated diets with different doses of amaranth extracts. Methods: The female crab samples were collected from the coastal region of Padang, West Sumatra. The method used in this study was a completely randomized design, with four treatments and five replications of amaranth extract-enriched diets (0, 250, 500, and 750 ng/g crab). Results: The results show that the enrichment of the formulated diet with amaranth extracts significantly affected (P &lt; 0.05) the absolute weight gain (AWG), carapace length (ACL), and carapace width (ACW). Conclusions: A quadratic relationship existed between the amaranth extract dose in the formulated diet and the AWG, ACL and ACW.

Two Poems

89 REBECCA MACIJESKI Two Poems  Yeti Eats a Brunch of Soft-Shelled Crab His sandwich has legs. From between the sourdough bread and pesto emerges a tiny orange claw: the gaping jaw of some unfortunate tyrannosaur served alongside a La Brea of homefries. He dines in the front window, napkin in his lap, watching townspeople pass. Something about the sun, the way its light hits the small knuckles in his sandwich. Something about the weave of the tablecloth. Something about how the waitress pours cool water into his glass slowly, from the side, keeping the ice from leaping out, makes him remember his mother. One Sunday, when he was young, he helped her candy violets. He walked with her out into the yard where they gathered tiny blossoms into the large pockets of their aprons. At first she’d fill a whole tray with the white and purple stars. Then she’d lift him up and let him dip the flowers into the wet sugar, let him place them face up to dry in delicate rows, let him lick the sweetness that ran onto his fingers and down his arm. Something about the stillness, the lemon walls, and the restaurant’s quiet eating. Something about the way Yeti crunches, bits of shell and bread clattering onto his plate. The brightly colored debris. 90 Yeti Gazing On a clear night he’ll be up on his rooftop tending his roses, waiting for the clouds to disperse and reveal his favorite manifesto: the night sky. Through his telescope he’ll peer into a matrix of stars and record coordinates of the deep past. He wonders whether Schrödinger and Heisenberg are out there calculating uncertainties. He wonders, through his eyepiece, how far the Voyager compilation has travelled carrying Mozart and human laughter toward the universe’s grandly imagined edge. As crickets, unseen from his lawn, drone the tiny violins of their legs, he’ll step back from his lens to lift a single bloom to his nose and breathe its pink galaxy. Morning rain water spills from the soft cups of the petals, splashing him with cool, clear matter, a sense of opening. His fur matted where the sky touched him. ...

Investigating risk factors for mortality and reovirus infection in aquaculture production of soft-shell blue crabs (Callinectes sapidus)

Crustacean aquaculture is prone to mortality from the combined effects of disease agents and the stresses associated with crowded, closed conditions. The culture practice of producing soft-shell blue crabs is no exception, suffering from mortality of about 25%. The virus, Callinectes sapidus reovirus 1 (CsRV1), has been reported at high viral loads in crabs dying in soft-shell shedding facilities. We investigated the relationship between crab mortality and CsRV1 prevalence and load in soft-shell crab production and whether death and virus infection correlated with identifiable aquaculture practices, environmental stresses, crab characteristics, or geographic regions. The patterns of CsRV1 prevalence, infection intensity, and mortality in blue crab aquaculture were studied in the Chesapeake Bay and Gulf of Mexico, USA. Using a genome-targeted assay, we compared virus loads in live and dead aquaculture crabs by individual sex and injury state from recirculating and flow-through systems of variable salinity, temperature, and crabs per aquaculture tank. Mortality was two-fold higher in flow-through aquaculture systems (33%) than in recirculating aquaculture systems (16%). Flow-through aquaculture systems had higher daily water temperature variability than recirculating aquaculture, and hypoxic events were observed only in flow-through systems during this study. High CsRV1 intensity was found in 62% of all pre-molt mortalities in production compared with 7% of successfully molted soft-shell crabs. The CsRV1 virus load in dead crabs was elevated in higher salinity conditions. In a mixed-effect model analysis, the random effects of location and time were more significant than salinity in predicting CsRV1 load in all crabs and dead crabs. Our results support previous research showing that recirculating aquaculture has lower mortality in soft-shell production, and confirms the association of high viral loads of CsRV1 with crab mortality in these production systems. Moreover, the findings indicate that although CsRV1 is ubiquitous in these systems, management of culture conditions such as salinity and temperature may limit virus-associated mortality.

Prevalence of the pathogenic crustacean virus Callinectes sapidus reovirus 1 near flow-through blue crab aquaculture in Chesapeake Bay, USA

Understanding the ecology of diseases is important to understanding variability in abundance, and therefore management, of marine animals exploited commercially. The blue crab Callinectes sapidus fills a crucial benthic-pelagic niche in Atlantic estuarine ecosystems and supports large commercial fisheries in both North and South America. In the USA, pre-molt blue crabs are typically held in short-term shedding (ecdysis) facilities to produce soft-shell crabs of increased value. However, mortality rates in these facilities are high and commonly associated with the pathogenic C. sapidus reovirus 1 (CsRV1). To assess whether crab mortalities in these facilities might increase CsRV1 prevalence in wild crab populations, tissue sampled from crabs collected over 2 summers either near to or far from shedding facilities using flow-through water systems were tested by reverse transcription quantitative PCR (RT-qPCR) for the presence of CsRV1 RNA. In support of our hypothesis, PCR data identified the probability of detecting CsRV1 in wild crabs sampled close to shedding facilities to be 78% higher than in crabs sampled from far sites. PCR detections were also 61-72% more probable in male crabs and 21% more likely in male and female crabs over the minimum landing size. As the prevalence at which CsRV1 was detected varied within seasons, among locations and between years, blue crab migration and/or population fluctuations appear to also be involved.

ESTABLISHING THE HYDROLYSIS PROCEDURE OF SOFT-SHELL CRAB (Scylla sp.) IN VIET NAM

The mud crab (Scylla sp.) belonging to Portunidae family has been aquacultured and used to provide a lot of nutrient foods and materials for supplementary food. Recent researches showed nutrient content of soft-shell crabs is higher than that of harden crabs. In this study, the content of total lipid and protein of Scylla sp. are found to be 1.2% and 30.5%, respectively. Additionally, trace elements contents (calcium and zink) were obtained of high level with 1.76% and 203.53 mg/kg, respectively. This is a potential source of materials for application in medicine and pharmaceutical industry in Vietnam. A enzymatic hydrolysis procedure was established as well in order to keep the high nutritional value of soft-shell crab materials. Based on these results, this procedure will be optimized as prospective in next step to obtain the maximized hydrolysate yield.

Budidaya Kepiting Soka dengan Metoda Sangkar Massal

Mangrove forest stores enormous economic potential. Economic activity in the mangrove forest village Dabong was catching mangrove clams, fish, shrimp and mud crab. Cultivation of soft-shelled crabs can be done with simple methods such as single cage and mass cage combained moulting pool to facilitate moulting monitor the change of the crab skin. Advantages of moulting pool are ease moulting time monitoring and crab moulting secure against attack other animals.Cultivation of soft-shelled crabs need to be developed extensively for broad economic benefits for the sailor. The results indicate that the development of aquaculture activities shelled crabs using mass cage and moulting pool provide greater benefits. Labor productivity with the same can be increased up to 4- fold compared to a single cage aquaculture way. Excellence moulting pool caused by intensive monitoring for skin exchange both day and night.

ANALISIS DAMPAK PERMEN KP RI NOMOR 1/PERMEN-KP/2015 TERHADAP PERDAGANGAN DOMESTIK ANTAR PROVINSI KOMODITI LOBSTER (Panulirus spp), KEPITING (Scylla serrata) DAN RAJUNGAN (Portunus pelagicus) DI KALIMANTAN SELATAN

This study aims to (1) analyze the impact of Permen KP RI No. 1/PERMEN-KP/2015 against the decrease/increase of the amount of volume, frequency and value of interprovincial domestic trade of lobster ( Panulirus spp), crab ( Scylla serrata ) and small crab ( Portunus pelagicus ) commodities; (2) to analyze the causes of the offense of smuggling attempts by large inter-provincial traders of lobster ( Panulirus spp), crab ( Scylla serrata ) and small crab ( Portunus pelagicus ) commodities; and (3) to analyze the impact of Permen KP RI No.1/PERMEN-KP/2015 against the marketing channels of trade of lobster ( Panulirus spp), crab ( Scylla serrata ) and small crab ( Portunus pelagicus ) commodities and trade organizations involved in domestic trade of the three commodities. This thesis study activities were carried out in the province of South Kalimantan. The data collected were data sourced directly from the observation in the study site, and other supporting data relating to the object of study. The results of this study: (1) Impact of Permen KP RI No. 1/PERMEN-KP/2015 are as follows: (a) it has an effect of significantly reducing the volume, frequency and value of inter-provincial domestic trade of live crab ( Scylla serrata ) and small fresh crab ( Portunus pelagicus ) commodities, (b) it has an effect of significantly reducing the volume and value of trade and has no significant effect on the frequency of inter-provincial domestic trade of soft-shelled crab commodity ( Scylla serrata ); (c) it has no impact on inter-provincial domestic trade of fresh/frozen lobster commodities ( Panulirus spp); (d) it has no significant effect on the volume, frequency and value of inter-provincial domestic trade of crab meat ( Scylla serrata ), small crab meat ( Portunus pelagicus ), fresh/boiled crab ( Scylla serrata ) and live lobsters ( Panulirus spp) commodities. (2) The occurrence of repeated violations in the form of an attempt smuggling by entrepreneurs (wholesalers) of inter-provincial domestic sender of crab ( Scylla serrata ) and small crab ( Portunus pelagicus ) in South Kalimantan caused by less strict actions and sanctions in accordance with applicable laws and regulations as well as the background of route system purchase (overall purchase) in the marketing chain. (3) Permen KP RI No. 1/PERMEN-KP/2015 affects on the forming of a new pattern of marketing chart and new institution in commodities trading of live crab ( Scylla serrata ), soft-shelled crabs ( Scylla serrata ) and small fresh crab ( Portunus pelagicus ) after the application of these rules.

Global status of production and commercialization of soft-shell crabs

Commercial exploration of swimming crab is rapidly increasing worldwide. In 2015, total production of crabs (fisheries plus aquaculture) reached almost 1300 thousand tons. One of the most valuable marketing forms is called “soft-shell crab”. The internet is one of the most important marketing channels for soft-shell crab, with prices starting at US$3.5 a unit, but going up to US$8.00–10.00, depending on the size and presentation form of the product (live, cooled, frozen, or processed). In luxury restaurants, a dish containing one large animal may cost well over US$75.00. Increasingly, this market requires exporting companies to present some kind of quality certification of the product or process (mainly certifications related to food safety). Almost all soft-shell crab production is based on crabs caught in the wild, by either trawling or trapping. Crab populations are suffering from environmental impacts associated with human activity, so much that obtaining the raw material (crabs in pre-molt stage) has become the biggest challenge for companies that market soft-shell swimming crab nowadays. Even recognizing the aquaculture as an alternate form to acquire crabs, it is necessary to understand that technology for commercial crab cultivation is still incipient and restricted to some species of few genera, such as Scylla, Portunus, and Callinectes. The present article reviews and discusses the problems and challenges related to the productive chain of soft-shell swimming crab, and presents an overview of the worldwide market, identifying the main exporting and importing centers, and their respective trading methods.

Utilizing reflex impairment to assess the role of discard mortality in “Size, Sex, and Season” management for Oregon Dungeness crab (Cancer magister) fisheries

We found that crab discarded from Oregon (USA) commercial and recreational fisheries for Dungeness crab (Cancer magister) have lower postrelease mortality than previously estimated. This aligns with the goals of the “3-S” management strategy currently employed for these fisheries, to protect discarded sublegal male (Size), female (Sex), and soft-shell (Season) crab. We found that for the commercial ocean Dungeness fishery, overall discard mortality rates (5 days after release) were 0.080 (95% confidence interval: 0.061–0.100) for females; 0.012 (95% confidence interval: 0.002–0.022) for hard-shell males; and 0.092 (95% confidence interval: 0.026–0.157) for soft-shell males. The overall discard mortality rate for the recreational bay fishery (from a boat) was estimated to be 0.009 (95% confidence interval: 0–0.018). A reflex action mortality predictor relationship, which relates reflex impairment to mortality probability, was created and utilized to estimate mortality rates. Our study highlights the importance of looking not only at discard and mortality rates to evaluate 3-S fishery management, but also the mortality- and bycatch-per-retained ratios and temporal trends relative to changes in effort, animal condition, and catch composition.

An Automated Feeding System for Soft Shell Crab

&lt;p&gt;Soft shell crab farming has been practiced in south-east Asian countries such as Indonesia. Soft shell crabs are harvested when they have just molted to prevent their shells from being hardened. An issue arises when feeding the crabs. Farmers need to feed the crabs 5% food of their body weight. However, farmers sometimes provide incorrect amounts of food to the crabs. If farmers feed the crab exceeding the required amounts of food, it causes food wastage and dirty water in the crabs’ cage. On the other hand, less amounts of food causes slow growth and molting of the crabs. In this study, we developed an automated feeding system for properly feeding of soft-shell crabs. The automated feeding system schedules the feeding time and controls the portion of food using a microcontroller. We also developed a web-based monitoring system to monitor and generate alert message to farmers to make sure that feeding process runs properly.&lt;/p&gt;

A Simulation Study to Evaluate Survey Designs and Assessment Models for Estimation of Dungeness Crab (Cancer magister) Softshell Periods

Softshell Dungeness Crabs have inferior meat quality and are vulnerable to handling by harvesters; therefore, knowing when softshell periods occur is important for managing Dungeness Crab fisheries. A computer simulation was used to study the effectiveness of several survey designs and statistical models for estimating softshell periods which normally would be construed from crab shell condition data obtained from trap surveys. Survey designs varied in the number of years of data collection (1, 3, 5 or 10 years) and by the number and arrangement of sampling events per year. Three statistical models, including standardized catch-per-unit-effort (SCPUE), hierarchical, and generalized additive, were tested using catch-per-unit-effort data (CPUEs) or CPUE- transformed data. CPUEs were standardised by dividing CPUE estimates by the maximum CPUE obtained in the sample year, and then transformed using the complementary log-log function. In the hierarchical model, CPUEs were modelled using a lognormal distribution, assuming the expected logarithms of CPUEs are a quadratic function of days plus a random normal error. CPUE-transformed data were modelled using a normal distribution, assuming expected values are a quadratic function of days in the SCPUE model or a spline smooth function of days in the generalized additive model. Results suggest the best survey design requires a relatively high number (6 or 11) of sampling events during several key consecutive months which contain the softshell period, and fewer sampling events during those months when softshell crab abundance is low. A minimum 3 years of data collection is required to produce reliable outputs. The hierarchical model performs best, slightly better than the SCPUE model. Use of the generalized additive model is not recommended.

Moulting synchrony in green crabs (Carcinus maenas) from Prince Edward Island, Canada

ABSTRACTThe growth and spread of non-indigenous green crabs (Carcinus maenas) in Atlantic Canada is of concern to the sustainability of shellfish resources, particularly in areas recently invaded. Commercial green crab fishing has been initiated on Prince Edward Island to help control this species and provide a new resource for inshore fishermen. Developing a soft-shell crab product modelled after the Venetian ‘Moleche’ would provide an economic incentive beyond the existing hard-shell crab bait market. However, answers to questions such as the timing and characteristics of green crab moulting are required. A pilot study conducted in 2014–2015 collected seven groups of crabs and held them in individual compartments for 2–4 weeks to record moulting rates and physical characteristics. We found that a synchronized ‘moulting window’ occurs during July for male crabs. Field experiments in 2015 had an average moulting rate of 34%, with group-specific rates as high as 60%. The same cohort of crabs held in the laboratory had an average moulting rate of 48%, with group-specific rates as high as 75%. We observed a gradual increase in moulting rates from early to mid-July, after which all crabs caught had recently moulted, with evidence of new carapaces on all crabs. In 2015, the moulting window followed a 5°C increase in water temperature. Regarding morphology, the presence of a ‘halo’ on the episternites of the carapace was an indicator that a crab would soon moult. These promising results represent the first step in assessing the feasibility of a soft-shell, green crab industry.

IMPROVING PRODUCTION OF SOFT-SHELLED SWIMMING CRABS: MACROSCOPIC SIGNS OF MOLTING AS A TOOL FOR SELECTION AND MANAGEMENT OF Callinectes danae AND Callinectes exasperatus (PORTUNIDAE, DECAPODA, CRUSTACEA)

In order to improve the efficiency of soft-shell crab production, we investigated whether it is technically viable to increase harvesting rates of soft-shelled crabs of the species Callinectes danae and C. exasperatus by selecting animals based on macroscopic molt signs and maintaining them in specific facilities. The study was conducted in three stages. In the first stage, macroscopic anatomic changes possibly related to the molting cycle identified under laboratory conditions. In the second stage we used the macroscopic clues observed in the first assay to select premolt animals harvested from their natural environments. Yet in this stage of the work, the relationship between the macroscopic changes and the microscopic signs of molting was evaluated. Lastly, an assay verified the technical feasibility of increasing the fraction of soft-shells in the total catch by selecting and maintaining premolt swimming crabs of species C. danae and C. exasperatus in specific facilities until the molt. Our results indicated that we can macroscopically identify, and therefore select, individuals in premolt phases II, III and IV that will soon molt, but further investigations are necessary to identify the requisite conditions for successful molting of individuals in premolt phase I.

SURVIVAL AND RESPONSE MOLTING OF MUD CRAB (Scylla olivacea) INJECTED WITH MURBEY (Morus spp.) LEAVE EXTRACT

The soft shell crab productivity has been hampered due to the long rearing time and unsimultaneous molting of the crab. This study aimed to determine the effect of murbey (Morus spp.) leave extract as molting stimulant on Scylla olivacea and its best extract dosage to be applied in soft shell crabs production technology. Application of murbey extract was conducted by using injection method with 5 treatments such as (a) 0 ppm (as control); (b) 100 ppm; (c) 125 ppm; and (d) 150 ppm for 12 individual per treatment. The results showed that the highest molting percentage (50%) was obtained at the concentration of 100 ppm. Meanwhile, the control (0 ppm), 125 ppm, and 150 ppm treatments displayed the same molting response (33.3%). The fastest latent molting time (29 days) was found at the treatment of 125 ppm and the slowest one of 44 days at 100 and 150 ppm treatments. The best growth of crabs injected with murbey leaves extract was at the concentration of 100 ppm with the carapace width of 6.0 mm and the body weight of 32.98 g, while the lowest was obtained at the concentration of 150 ppm with the carapace width of 3.8 mm and the body weight of 25.43 g. Crabs treated with murbey extract at the concentrations of 100, 125, and 150 ppm exhibited survival rate of 91.7 % vs. the control of 83.3%. Murbey leaves extract have been proven to be effective in stimulating molting mud crab (Scylla olivacea). The 100 ppm exhibited the best response for growth and molting percentage, while the 125 ppm showed the best performance for latent period molting of the crab. Keywords: molting response, survival rate, Scylla olivacea, murbei leaves, Morus spp.

Generation of Added Value through the Process of Soft Shell Crab: A Sustainable Development Option in the Coastal Region of Sonora

Nowadays there are fishery resources that have suffered the consequences of overexploitation, pollution or climate change, therefore, the population of marine organisms of commercial importance has diminished noticeably. One of the alternatives to mitigate this reduction, is the diversification of the fishery and aquaculture activity, through value creation.To do this, there is a great number of species to cultivate and that have not been seized due to the lack of interest or knowledge, in addition that the fishery communities have not been provided with the sufficient technology to allow its correct exploitation and leave their comfort zone. In that manner, this article has as a general objective to develop an added value proposal for the commercialization of crabs, through a Soft Shell Crab closed system technical production, for the coastal region of the State of Sonora, in such a way to be taken as a viable option of economic and social growingfor the community, by a sustainable development, the establishment of communication mechanisms and a permanent concentration among the different actors and factors that will constitute the soft crab technical process, acceding the establishment of strategic alliances and commercial agreements for the integration of productive chains with the participation in state and national production programs, with the purpose of product commercialization.

Panfish: Spot On

There's something about him when he's fried. You leave that skin on, cut him, and just eat him from the inside out. Spot is good, buddy, can tell you that. --overheard at the Bayford Oyster House, Virginia, November 21, 2011 I fry mine hard and eat the bones, the tail, and all ... always cook that head because like crunching on it. love crunching on it! leave the tail head and tail, leave on. --Katie White, Painter vie., Virginia, August 6, 2014 [ILLUSTRATION OMITTED] Late summer the phone rings in the Bayford Oyster House on the Eastern Shore of Virginia. Bayford, H. M. Arnold answers. Yes ma'am, he says a few seconds into the conversation, I don't have any spot today. They don't seem to be running. Nobody know has them. have some hardheads though, if you want to drive down and get them. Thank you. H. M. shakes his head and sits down in his plastic chair by the stainless steel counter where he shucks oysters for the winter trade from Thanksgiving to New Years. afternoon steams August hot, a bit of breeze ruffles the water on Nassawadox Creek outside the door. tide is rising and soon enough will seep under the sills and into the dock end of the venerable shucking house, sheeting over the old concrete floors, compelling H. M. and his visitors first to walk on boards and then to slosh their way past the soft-shell crab shedding tanks now all but closed down for the season. Tank, the monumental Chesapeake Bay retriever who lives up the hill, stands in the boat launch with a chunk of pine branch clenched in his jaws, waiting for someone--anyone will do--to seize the wood and pitch it into the water. Strangers shy away from the massive dog; regulars ignore him. Tank perseveres. And so do the callers seeking spot, a panfish deeply savored in this corner of the world. phone rings. Bayford, H. M. answers. Spot, it seems, have diminished in their numbers since 1890, when a fish census noted: Large numbers of young spot from 3 to 4 inches in length were seined in the bay at Cape Charles City. They were present in abundance, numerous schools being seen ... As a pan fish, the spot is the most highly prized of all fishes sold in the Norfolk market.' Writing from North Carolina, Hugh M. Smith reported in 1907, The spot, which gets its name from the round mark on its shoulder, inhabits the east coast of the United States from Massachusetts to Texas, and is one of the most abundant and best known of our food Smith concludes, The spot ranks high as a food and is by many persons regarded as the best of the pan fishes. There is a good demand for North Carolina spots in Baltimore, Washington, and other markets of the Chesapeake region, and the fish is also rated high as a salt fish for local consumption. (2) Spot, another observer reported, the smallest members of the croaker family that are sold with any regularity. Most specimens weigh only about 1/4 pound. Spots are easy to recognize by their spot right behind the gill opening. (3) spot's distinguishing markings, Pooh Johnson, oysterman and cook in Onancock, Virginia, asserts are the marks of Christ's fingertips imprinted when He divided the loaves and fishes for the multitude in Mark 6:41. (4) Communion of a different variety causes H. M.'s phone to ring. Uncommonly common in the lower Chesapeake and in North Carolina's sounds, the spot (also known regionally as Jimmy, chub, roach, Goddy, and Lafayette) lives inshore from late spring through autumn and winters in deeper offshore waters during the cold months: The waters of the Chesapeake Bay off Norfolk, Virginia, are such prime spot fishing grounds that out-of-town menus often list this small, sweet fish as 'Norfolk Spot' ... Prior to spawning season in the fall, the spot takes on a golden color much like its cousin the croaker. At that time the fish are often referred to as 'Ocean View Yellow Bellies' because they congregate to feed off Ocean View, a Norfolk neighborhood on the Chesapeake Bay. …