Recent Submissions

  • Conference paper

    Mud crab fattening project of KAMAMANA in Del Carmen, Siargao Island 

    AE Sulima - In ET Quinitio, FD Parado-Estepa & RM Coloso (Eds.), Philippines : In the forefront of the mud crab industry development : proceedings of the 1st National Mud Crab Congress, 16-18 November 2015, Iloilo City, Philippines, 2017 - Aquaculture Department, Southeast Asian Fisheries Development Center
    The Kaanib ng mga Mangingisda at Magsasaka ng Numancia Aqua-Agrikultura (KAMAMANA), established in Del Carmen, Siargao Island in 2011 is a People's Organization active in promoting the advocacy in 1) protecting the environment and natural resources, 2) providing services for the family welfare, and 3) managing sustainable livelihood programs and community development. One of the major livelihood programs presently being implemented by KAMAMANA is the fattening of mud crab (mangrove crab), Scylla serrata, in plastic containers set up in a mangrove area. Tenurial rights to manage a 2-hectare mangrove area for 25 years was granted to KAMAMANA by the Department of Environmental and Natural Resources.

    Crabs obtained from the mangrove areas of Del Carmen and nearby municipalities are purchased and stocked in plastic containers. The crabs are fed trash fish and mollusks once every afternoon to satiation until they are fattened, usually for 1-2 weeks. The major problem encountered is mortality after molting. Four KAMAMANA members are involved in the crab fattening. When mortalities occur, the dead crabs are usually charged to members assigned in the operation. The fattened crabs are sold to local restaurants, hotels, resorts and walk-in buyers or brought to traders in Surigao City. The net income is divided into the following: members involved in the culture (50%), treasurer (10%), business manager (15%), organizational share (5%), savings (5%) and trust fund (15%).
  • Conference paper

    Polyculture of mud crab in Region 3 

    M Bonifacio - In ET Quinitio, FD Parado-Estepa & RM Coloso (Eds.), Philippines : In the forefront of the mud crab industry development : proceedings of the 1st National Mud Crab Congress, 16-18 November 2015, Iloilo City, Philippines, 2017 - Aquaculture Department, Southeast Asian Fisheries Development Center
    The polyculture of mud crab with one to three other species (milkfish (Chanos chanos), tilapia (Oreochromis spp.) and shrimp or sugpo (Penaeus monodon)) is a common practice in Region 3. Pond preparation is given importance prior to stocking of various species. Removal of sludge in the pond and application of probiotics are included in the standard pond preparation. The size and stocking densities of each species vary depending on the season. The volume of water to be replaced is based on the transparency of the water.

    The various species are fed natural food grown in the pond in addition to mollusks and low value fish given specifically for mud crab and shrimp. When pond water becomes transparent (indicating the decrease in phytoplankton density), the water is agitated using a small boat. If water continues to be transparent, fertilizers are applied to enhance growth of natural food. The pond water and animals are closely monitored to prevent diseases. Some of the early signs of occurrence of disease include the presence of bubbles on the water surface, and presence of weak shrimp on the feeding trays and along the dikes. The presence of weak shrimp and crab on the pond bottom and continuous swimming of these animals from night to dawn indicate poor pond water quality which can be remedied by circulating and flushing of the pond water every other day.
  • Conference paper

    Breeding and culture of the polychaete, Marphysa mossambica, as feed for the mud crab 

    VR Alava, JB Biñas & MAE Mandario - In ET Quinitio, FD Parado-Estepa & RM Coloso (Eds.), Philippines : In the forefront of the mud crab industry development : proceedings of the 1st National Mud Crab Congress, 16-18 November 2015, Iloilo City, Philippines, 2017 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Marine worms (Annelida: Polychaeta) are considered as important food for crustacean broodstock because they contain hormones and correct balance of essential nutrients for reproduction. Marphysa mossambica (Peters, 1854) occurs in muddy coastal areas and is abundant in fish farms where it builds burrows in nutrient-rich sediments. This species encapsulates their eggs and larvae in gelatinous masses (jelly cocoons). It is a multiple spawner, and breeders are repeatedly spawning in tanks. Culture techniques have also been developed and established in tanks. Based on dry weight, cultured M. mossambica contained 62-66% crude protein and 7-12% lipids with levels of highly unsaturated fatty acids (HUFAs) such as arachidonic (20:4n-6), eicosapentaenoic (20:5n-3) and docosahexaenoic acid (22:6n-3) at 0.2-0.5%, 0.2-0.3% and 0.3-0.5%, respectively. Stocks were monitored for the presence of white spot syndrome virus (WSSV) using polymerase chain reaction-based diagnostic methods. The WSSV-free polychaetes mass-produced in tanks were utilized as live food for mud crab S. serrata broodstock. Mud crab broodstock fed natural food (mussel, fish, and squid) with live Marphysa on daily feed rotation produced higher number of crab zoeae, larval survival, total lipids and HUFAs than those fed natural food without live Marphysa. Production of nutrient-rich WSSV-free polychaetes in captivity can play a significant role in supporting crustacean hatcheries that supply seeds to the nursery and grow-out.
  • Conference paper

    Mud crab marketing practices 

    AG Decembrana - In ET Quinitio, FD Parado-Estepa & RM Coloso (Eds.), Philippines : In the forefront of the mud crab industry development : proceedings of the 1st National Mud Crab Congress, 16-18 November 2015, Iloilo City, Philippines, 2017 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Presented in the article is the mud crab (Scylla spp.) marketing practices in the province of Capiz. It is one of the major producers of mud crab in brackishwater ponds in the country. Hence, several trading centers or buying stations are found in this province. In Pontevedra, Capiz alone, there are more than 20 buying stations. The crabs from ponds coming from Aklan, Iloilo and within Capiz are brought to the buying stations almost daily. There are 5 kinds of market in the mud crab trading business such as, households, local markets/restaurants, traders/buying, exporters, and importers. Methods in classifying and packing of crabs are also discussed.
  • Conference paper

    Overview of the mud crab industry in the Philippines 

    ET Quinitio - In ET Quinitio, FD Parado-Estepa & RM Coloso (Eds.), Philippines : In the forefront of the mud crab industry development : proceedings of the 1st National Mud Crab Congress, 16-18 November 2015, Iloilo City, Philippines, 2017 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Mud crab farming has long been established in the Philippines and the country is the second top producer in the world. Except for Scylla paramamosain, the three other species, S. serrata, S. tranquebarica and S. olivacea are commonly found in the country, but S. serrata is the preferred species for farming. Crab seeds for farming are mainly from the wild and in recent years, a small percentage from the hatchery. Due to the apparent decline of the wild crab stocks, provincial and municipal ordinances have been issued by a number of Local Government Units (LGUs) along with the Bureau of Fisheries and Aquatic Resources (BFAR) to conserve and manage the remaining resources. From the hatchery, megalopa or crab instars are grown in net cages installed in the nursery pond. Mud crab farming engages mostly in long-term grow-out culture of juvenile crabs to market size for 3-5 months, short-term fattening of lean crabs for 15-45 days, and recently, soft-shell crab production. Polyculture of juvenile crabs to market size with one to three other commodities in earthen brackishwater ponds is usually practiced. Mud crabs for soft-shell crab production are mainly from the wild, while SEAFDEC/AQD demonstrates the use of hatchery-produced juvenile mud crabs as seedstock.

    Refinement is continuously being done to improve the economic viability of producing crabs, although basic technologies have been developed for all phases of culture (hatchery, nursery, grow-out, fattening and soft shell crab production). The major issues facing the industry are the lack of seedstock, difficulty of zoea 5 to molt to megalopa stage, cannibalism particularly at the nursery phase, species identification at the juvenile stage, use of fish as aquafeed, diseases, effects of climate change and quality of crabs at postharvest. In 2012, the Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development (PCAARRD) of the Department of Science and Technology (DOST) started funding projects under the National Mud Crab Science and Technology Program (NMCSTP) to address these issues. The major aim of the Program was to improve the production, profitability and sustainability of crab farming. SEAFDEC/AQD leads in capacity building with focus on the sustainability of the mud crab industry. Various collaborations and research studies on mud crab culture enabled SEAFDEC/AQD to package mud crab technologies, conduct local and international training courses and on-site technology demonstrations, and publish extension manuals and scientific publications since the mid1990s. Research and Development activities have been translated into improved production. With the recent developments and refinements of technologies, it is expected that the Philippines will increase its production by 25-50% in the next 5 years.
  • Conference paper

    Unified provincial fisheries law enforcement of ordinance of Camarines Norte focusing on mud crab 

    EA Estanislao - In ET Quinitio, FD Parado-Estepa & RM Coloso (Eds.), Philippines : In the forefront of the mud crab industry development : proceedings of the 1st National Mud Crab Congress, 16-18 November 2015, Iloilo City, Philippines, 2017 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Due to overfishing and widespread coastal habitat degradation, the Province of Camarines Norte passed a provincial fisheries law enforcement known as the Unified Provincial Fisheries Law Enforcement Ordinance of Camarines Norte (UPFLEON) (P.O. 50-10). Given emphasis in the paper is the banning in the collection and possession of less than 1.0 cm juvenile crabs.
  • Conference paper

    Growth, survival, proximate and fatty acid composition of sandworm Perinereis quatrefagesi (Grube, 1878) fed variable feed types 

    JB Biñas, VR Alava & WL Campos - In ET Quinitio, FD Parado-Estepa & RM Coloso (Eds.), Philippines : In the forefront of the mud crab industry development : proceedings of the 1st National Mud Crab Congress, 16-18 November 2015, Iloilo City, Philippines, 2017 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Sandworm Perinereis quatrefagesi has been used as feed for crustacean broodstock due to its reproductive-enhancing properties particularly protein and highly unsaturated fatty acids (HUFAs). Juvenile sandworms collected along the coast of Guimbal, Iloilo were reared in tanks and fed three nutritionally variable feed types: fish fecal waste, fish meal and rice bran. After 56 days, feeds affected (p<0.05) sandworm growth and crude fat contents but not (p<0.05) survival and crude protein levels. Survival rates were 86~c3 to 89~c5% while crude protein levels were 57.0 ~c 2.5 to 68.0 ~c 5.3 g 100 g-1 dry weight. High crude protein fish meal promoted better (p<0.05) growth (2.2~c0.4% day-1) than fish feces (1.2~c0.3% day-1) and rice bran (1.1~c0.3 % day-1). However, crude fat content of sandworm was higher (p<0.05) in rice bran (18.9~c1.6 g 100 g-1) than in fecal waste (13.6~c2.9 g 100 g-1) and fish meal (10.5~c3.1 g 100 g-1) treatments. Levels of highly unsaturated fatty acids (HUFAs) such as 20:4 n-6, 22:6 n-3 and 20:5 n-3 did not differ significantly (p>0.05) at 0.41~c0.21 to 0.89~c0.51 g 100 g-1, 0.21~c0.24 to 0.43~c0.22 g 100 g-1 and 0.57~c0.46 to 0.88~c0.31 g 100 g-1, respectively.

    The study demonstrated that P. quatrefagesi: (1) can survive well in nutritionally variable feed types although it grows better in high protein diet; (2) crude protein levels were high regardless of feed types; and (3) crude fat content was high in high fat diet but n-3 and n-6 HUFAs were not significantly different regardless of feed types.
  • Conference paper

    Evaluation of the bioremediation capacity of the polychaete, Marphysa mossambica (Peters, 1854) in pond sediments 

    MAE Mandario, VR Alava & NC Anasco - In ET Quinitio, FD Parado-Estepa & RM Coloso (Eds.), Philippines : In the forefront of the mud crab industry development : proceedings of the 1st National Mud Crab Congress, 16-18 November 2015, Iloilo City, Philippines, 2017 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Marphysa mossambica is commonly found in brackishwater ponds and is an important natural food for cultured stocks particularly mud crabs. To understand the burrowing activity of polychaete, survival and capacity to bioremediate pond sediments, tank experiments were conducted. In a completely randomized design with three replicates per treatment, small (1-month old, 28 mg) and large (3-month old, 139 mg) hatchery-bred M. mossambica were reared in two sediment types for 30 days without feeding. Aeration was supplied and water change was done every other day. Polychaete-free sediments served as control. Sediments obtained from SEAFDEC/AQD Dumangas Brackishwater Station were sun-dried, ground and passed through 1-mm sieve.

    Initial sediment A had 1.86% organic matter, 1,171 ppm available sulfur (SO42-), 194.23 ppm iron (Fe) and 7.86 pH while initial sediment B contained higher organic matter (4.1%), available sulfur (2,456.67 ppm), similar iron level (199.34 ppm) and was more acidic (4.91 pH). In sediment A, small and large polychaetes did not differ (p>0.05) with the control in reducing organic matter but both significantly reduced (p<0.05) available sulfur (77-73%) and iron (69-71%). However, only the large polychaetes increased the pH (p< 0.05, 2.67%). In sediment B, only the large polychaetes reduced (p<0.05) organic matter (27%) but both small and large polychaetes significantly reduced (p<0.05) available sulfur (64-70%) and iron (70-74%). The pH increase was similar to control (17-24%). Large polychaetes had higher survival (93%, p<0.05) than small polychaetes (60%) in sediment B but not different (p>0.05) in sediment A (97%, 87%). The study demonstrated the bioremediation capacity of M. mossambica particularly in reducing available sulfur and iron in sediments.
  • Conference paper

    Nursery and grow-out feeding management of mud crab farmers in the Philippines: Santeh experience 

    JRA Gabiota - In ET Quinitio, FD Parado-Estepa & RM Coloso (Eds.), Philippines : In the forefront of the mud crab industry development : proceedings of the 1st National Mud Crab Congress, 16-18 November 2015, Iloilo City, Philippines, 2017 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Mud crab (Scylla serrata) farming has been one of the means of livelihood of many Filipino farmers in coastal areas, specifically in Southern Luzon and Visayas. Nursery and grow-out operations in these areas vary in terms of their feeding management and techniques for a better yield. Farmers in Bicol region, specifically Sorsogon which is one of the sources of wild crablets in the country, are presently using pelleted feeds for nursing different crab sizes. On the other hand, farmers in Quezon, Bataan, Masbate, Negros and Capiz are growing crabs to marketable size for domestic and export markets.

    It was noted that there are still farmers in some areas that use low value fish for feeding crabs resulting in the deterioration of the pond bottom and water environment. On the other hand, pelleted feeds serve as an alternative feed that addresses the problem of the declining supply of trash fish, corn, mussel and snails. The price of trash fish has increased significantly due to its unavailability in several areas. In addition, pollution of the water environment and fluctuations in the water parameters for crabs due to improper pond preparation, pollution and climate change have added stress to the crabs.
  • Conference paper

    Private sectors perspectives: Problems and constraints of the mud crab grow-out industry 

    HR Hocson - In ET Quinitio, FD Parado-Estepa & RM Coloso (Eds.), Philippines : In the forefront of the mud crab industry development : proceedings of the 1st National Mud Crab Congress, 16-18 November 2015, Iloilo City, Philippines, 2017 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Mud crab aquaculture industry in the province of Capiz received much attention after production constraints due to diseases were encountered by the prawn industry. Fishpond operators sought for an alternative high value species and realized the potential of the king crab, Scylla serrata. This species is not native to Capiz and has to be sourced from other parts of the country, particularly from the Bicol region and Samar. The techniques for grow-out culture were gradually refined as farmers learned from the experiences of others. Presently, mud crab aquaculture is being done by private sectors based more on art. However, mud crab culture requires a lot of science to make the production consistent and sustainable. The practices of farmers and the problems they have encountered are presented together with the overall industry concerns.
  • Conference paper

    Effect of feed binder on water stability and digestibility of formulated feed for the mud crab Scylla serrata 

    MR Catacutan - In ET Quinitio, FD Parado-Estepa & RM Coloso (Eds.), Philippines : In the forefront of the mud crab industry development : proceedings of the 1st National Mud Crab Congress, 16-18 November 2015, Iloilo City, Philippines, 2017 - Aquaculture Department, Southeast Asian Fisheries Development Center
    The binding capacity of six natural and eight synthetic feed binders were tested in a basal diet formulated for the mud crab. Incorporation levels of natural binders ranged from 1 to 25% while those of synthetic binders ranged from 0.1 to 5% and these were tested for pellet stability in seawater by a) 10-min immersion, and b) at different time intervals. Pellets with synthetic binders were more water-stable than pellets with natural binders. Three synthetic binders and natural binders (glutinous rice starch and carrageenan + CMC) showed best results. The Apparent Digestibility Coefficients (ADC) of crude protein (ADCCP) and crude fat (ADCCFt) of the basal diet were determined when selected feed binders were included in the formulation. These were determined by using an inert indicator, chromic oxide. Results showed that the ADCCP and ADCCFt of the basal diet were not similar when different binders were used, and these differences ranged from 3 to 7%. Carrageenan combined with a synthetic binder improved ADCCP and CDCCFt values.
  • Conference paper

    Updates on the larviculture of mud crab at SEAFDEC/AQD 

    ET Quinitio, JJDC Huervana, JC Virgula & FD Parado-Estepa - In ET Quinitio, FD Parado-Estepa & RM Coloso (Eds.), Philippines : In the forefront of the mud crab industry development : proceedings of the 1st National Mud Crab Congress, 16-18 November 2015, Iloilo City, Philippines, 2017 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Although the mud crab (Scylla serrata) hatchery technology has been developed, issues such as high cost of production due to the need for additional facilities and labor for natural food culture, inconsistent survival rate at megalopa stage due to Molt Death Syndrome (MDS), and disease due to luminescent bacteria (Vibrio spp.), remain to be addressed. Refinements on the existing mud crab larviculture technology were done to address these problems.

    Poor nutrition, low water temperature and application of prophylaxis during the zoea l stage have been identified as possible causes of MDS. Six shrimp formulated diets (FD) were tested, and 3 of these proved to be suitable for mud crab larvicuture. Larval performance was compared using the 3 diets + natural food (NF, rotifers and Artemia) and NF alone as control. No significant difference was noted in the survival among the 4 treatments, although BP Nippai fed larvae had higher values. Lesser occurrence of MDS was observed in all the larvae fed FD+NF. Three mud crab larval diets with various attractants (squid, annelids, and squid + annelids) were also formulated and fed to the larvae. Results showed no significant difference among the 3 diets. The results of another experiment investigating the effects of the reduction of natural food showed that larvae fed 50% NF + 50% FD and 75%NF + 25% FD had higher survival compared to those fed 75% AD +25% NF and no NF at all. The results indicate that the larvae cannot survive with formulated diet alone. It has been observed that frequency of antibiotic application can be reduced to every 5 days if good quality mud crab larvae are used. Formalin stress test proved to be a reliable method to determine the quality of a batch of newly hatched zoeae. All prophylactic treatments are stopped when megalopae reach the benthic stage.

    To accelerate the dissemination of science-based mud crab hatchery technology to industry stakeholders, SEAFDEC/AQD entered into an agreement with private hatchery operators, State Universities and Colleges, and Local Government Units on giving assistance during initial hatchery operations. Technicians were given free training, followed by in-situ hatchery operations with assistance from SEAFDEC/AQD with the funding from PCAARRD-DOST. Crablets are now being produced by the collaborators. Increase in the production of hatchery-reared crablets will eventually reduce the dependence on wild-sourced mud crab seed stock for farming.
  • Conference paper

    Capacity building initiatives of Winrock International on mud crab culture in the Caraga Region 

    J Nobillos, D Gudahl & J Orprecio - In ET Quinitio, FD Parado-Estepa & RM Coloso (Eds.), Philippines : In the forefront of the mud crab industry development : proceedings of the 1st National Mud Crab Congress, 16-18 November 2015, Iloilo City, Philippines, 2017 - Aquaculture Department, Southeast Asian Fisheries Development Center
    The paper presents the output of the capacity building initiatives of Winrock International on Mud crab culture in the Caraga Region, Philippines. The capacity building seminar included lectures on the mud crab biology, pond preparation, nursery and grow-out culture, fattening, and soft-shell crab farming. Identification of the various crab body parts, actual pond preparation, nursery and grow-out culture of crab were demonstrated after the series of lectures.
  • Conference paper

    Mud crab production trials at the College of Fisheries and Marine Sciences, Aklan State University, New Washington, Aklan 

    YH Primavera-Tirol, R de la Cruz & EB Pastrana - In ET Quinitio, FD Parado-Estepa & RM Coloso (Eds.), Philippines : In the forefront of the mud crab industry development : proceedings of the 1st National Mud Crab Congress, 16-18 November 2015, Iloilo City, Philippines, 2017 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Two hatchery and nursery trials have been conducted at the College of Fisheries and Marine Sciences, Aklan State University (ASU) for the Multi-species Hatchery and Fishfarm Project from August to September 2014 and April to May 2015, in collaboration with the Aquaculture Department (AQD), Southeast Asian Fisheries Development Center (SEAFDEC) under the National Mud Crab Science and Technology Program of the PCAARRD-DOST.

    Two ASU staff underwent training on Mud Crab Hatchery, Nursery and Grow-out Operations at SEAFDEC/AQD from September to October 2013. This was followed by SEAFDEC/AQD&rsquo;s provision of technical assistance during the actual hatchery and nursery operations using Scylla serrata at ASU. Survival rates of 3% and of 66-76% were recorded in the hatchery and nursery phases, respectively. The natural food consisting of rotifer and Artemia, and commercial formulated diet were fed to S. serrata larvae (zoea to megalopa). Juvenile crabs were fed formulated feeds and molluscs. Water temperature ranged from 27 to 30°C and salinity from 29 to 33 ppt in the hatchery. Initial results and insights are discussed and evaluated as guide for future hatchery and nursery protocols.
  • Conference paper

    Mud crab Scylla serrata hatchery operation 

    M Santos & F Santos - In ET Quinitio, FD Parado-Estepa & RM Coloso (Eds.), Philippines : In the forefront of the mud crab industry development : proceedings of the 1st National Mud Crab Congress, 16-18 November 2015, Iloilo City, Philippines, 2017 - Aquaculture Department, Southeast Asian Fisheries Development Center
    The initial exposure of the Santos family in aquaculture was the culture of milkfish (Chanos chanos) and mud crab (Scylla serrata) in brackishwater pond in Quezon. The milkfish fry were obtained from our own milkfish hatchery, in which several broodstock are maintained as source of eggs. The juvenile crabs for stocking were wild-caught obtained from Quezon, Camarines or Bicol Region traders. In the late 2012, SEAFDEC/AQD collaborated with the Mari-al Hatchery for the seed production of mud crab under the National Mud Crab S and T Program of the Department of Science and Technology. This collaboration was timely since the source of juvenile crabs was no longer reliable. Furthermore, excess crabs that would be produced from the hatchery can also be sold to other farmers. Training at SEAFDEC/AQD and technical assistance on site were provided by SEAFDEC/AQD prior to the operation of the mud crab hatchery. Part of the existing milkfish hatchery facilities were utilized for the crab larval rearing. The protocol of SEAFDEC/AQD was followed with some modifications based on the existing facilities and source of water supply. After the successful runs, a separate hatchery facility dedicated for mud crab larval rearing was constructed in 2013. Four runs were conducted with 1-2% survival rate from zoea 1 to crab instar. Problems encountered during the runs include: insufficient rotifers since the culture had to be shared with milkfish larvae, poor water quality due to typhoon and presence of a wharf nearby, low water temperature, human error, resignation of trained staff, lack of good quality broodstock source nearby, and MDS. The problems were addressed one by one. Although the technology has been developed, this has to be modified accordingly.
  • Conference paper

    High throughput RNA sequencing reveals temperature tolerance mechanisms in Scylla serrata 

    MC Ablan-Lagman & E Meyer - In ET Quinitio, FD Parado-Estepa & RM Coloso (Eds.), Philippines : In the forefront of the mud crab industry development : proceedings of the 1st National Mud Crab Congress, 16-18 November 2015, Iloilo City, Philippines, 2017 - Aquaculture Department, Southeast Asian Fisheries Development Center
    The effects of increasing temperature from global climate change threaten the sustainability and production of mud crabs from farms and wild populations in mangroves. Adaptation of mud crab populations to temperature stress is difficult to evaluate until now, with the emergence of RNA-Seq, a method which evaluates total mRNA expression under different conditions. In this study, 10 individuals each of S. serrata from Buguey, Cagayan were exposed to 26~&rsquo;C and 32~&rsquo;C for two weeks and the mRNA profiles were compared based on 186 million high quality pair-end reads which were aligned to a S. serrata reference transcriptome assembled de novo from 24,350 contigs with an average N50 of 1564 bp. Temperature related differences in gene expression were not significantly detected between the control and treatment groups and this was mostly due to the highly expressed genes such as the low and high molecular weight heat shock proteins. However, variations were greater among genes involved in the process of cell cycle regulation, the dissimilation processes such as oxidative phosphorylation, reproduction and transport across membranes. Greater differences were observed between immature or mature males and females.
  • Conference paper

    Implication of mud crab culture technology transfer on rural coastal communities: The case in northern Samar, Philippines 

    DB Baticados, RF Agbayani & ET Quinitio - In ET Quinitio, FD Parado-Estepa & RM Coloso (Eds.), Philippines : In the forefront of the mud crab industry development : proceedings of the 1st National Mud Crab Congress, 16-18 November 2015, Iloilo City, Philippines, 2017 - Aquaculture Department, Southeast Asian Fisheries Development Center
    The socio-economic implications of technology transfer of mud crab culture on small-scale growers in Northern Samar and the mechanism of nursery technology transfer were investigated. The study covered four Peoples Organizations (POs), each operating in villages of the four municipalities of Northern Samar namely, Lavezares, Rosario, Laoang, and Pambujan. These were sites of the Philippine-Australian Community Assistance Program - assisted mud crab (Scylla) culture livelihood projects. Interviews from 60 beneficiaries revealed that most (76%) were relatively new to mud crab culture, particularly fattening or growout, but 65% were gleaners of mud crabs for more than 5 years. The average age of respondents was 45 years old and were predominantly male. Most (93%) were married with an average household size of six. A cost and return analysis of mud crab fattening in pens using only two compartments showed that the net income (P4,832/month for a 30-day culture period) is not sufficient if shared among 40 PO members participating in only one economic activity. Consequently, most (63 %) respondents whose livelihood projects were cooperative undertaking were no longer keen with the cooperative-run project. Interestingly, those (83 %) who operated their own farm wanted to continue and expand (26 %), particularly those in Rosario. The motivation factors that influenced growers to continue mud crab culture and adopt the nursery technology being disseminated were primarily economic with extra income and source of cash as main reasons for adoption. Majority also claimed that the nursery technology that was being transferred by SEAFDEC/AQD was simple.

    The mud crab pond nursery technology transfer involved community training and participation of beneficiaries, beginning with the linking of technologists and socio-economists with on-the-ground partners. Thereafter, season-long training and farm demonstration followed comprising lecture series and hands-on demonstration. Nursery pond operations were conducted in an open pond (Rosario) and in a pond within a mangrove area (Pambujan). Survival in the pond within a mangrove area was higher (68 %) than in an open pond (50 %) for phase 1, suggesting that the mangrove played a role on mud crab endurance. However, survival in phase 2 (72 %, Pambujan; 83 %, Rosario) showed a reversed trend, suggesting that bigger crablets can withstand/endure harsh pond conditions.

    Results of the demonstration indicated that the nursery technology is a viable enterprise, showing an ROI of 93.50% in Rosario and 198.04% in Pambujan. Most (83%) of the growers were interested in the nursery technology, although only few PO members participated in the season-long training. Ownership of area, market, and farm distance from household were the more important considerations that influenced small-scale growers in adopting the technology.
  • Conference paper

    Enhancing mud crab population through mangrove restoration 

    MJH Lebata-Ramos, EF Doyola-Solis, RC Sibonga, JB Biñas, M Walton & L Le Vay - In ET Quinitio, FD Parado-Estepa & RM Coloso (Eds.), Philippines : In the forefront of the mud crab industry development : proceedings of the 1st National Mud Crab Congress, 16-18 November 2015, Iloilo City, Philippines, 2017 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Mangroves are known as important nurseries for different species of fish and shellfish. In the Philippines, mud crabs Scylla spp. are among the most valuable crustaceans harvested from the mangroves and are considered a delicacy. However, varying levels of overfishing have been reported in different parts of the country. The decrease in production may be due to increasing demand for the resource and the loss of mangrove habitat. This problem may be addressed through regulation of fishing effort, rehabilitation of habitats, mangrove-friendly aquaculture and enhancement of wild crab stocks. This study shows the effect of mangrove rehabilitation on mud crab population.

    From July 2010 to December 2011, a total of 2.166 tons of mud crabs (n=17,558) have been collected from a 66.5 ha abandoned pond that has been recolonized by mangroves. The catch was dominated by S. olivacea (79.96%), then S. tranquebarica (19.92%) and S. serrata (0.12%). Male to female ratio was at 1.09:1. Individual daily yield ranged from 0.06 to 8.4 kg while catch per unit effort in terms of quantity and biomass ranged 0.02-1.46 crab gear-1 day-1 and 1.1-213.54 g gear-1 day-1, respectively. The results showed that mud crab population in this study site was much higher than the population in the reforested (Walton et al., 2006, 2007) and natural mangroves (Lebata et al., 2007) with almost the same area. For 18 months of sampling (April 2002-September 2003), only 3,924 crabs were sampled in the natural mangroves while 10,504 in the reforested mangroves. Mud crab production in the present study site resulted in a yield of 21 kg ha-1 yr-1, 5 and 3 times higher than the yield reported in the natural and reforested mangrove areas, respectively. These results imply that habitat restoration can be very effective in restoring natural populations of mud crab.
  • Conference paper

    Development of aquasilviculture at BFAR-NBFTC, Pagbilao, Quezon 

    RE Dieta & FC Dieta - In ET Quinitio, FD Parado-Estepa & RM Coloso (Eds.), Philippines : In the forefront of the mud crab industry development : proceedings of the 1st National Mud Crab Congress, 16-18 November 2015, Iloilo City, Philippines, 2017 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Aquasilviculture technology verification project was conducted at the National Brackishwater Fisheries Technology Center (NBFTC) of the Bureau of Fisheries and Aquatic Resources (BFAR) in 1996-2000. Results indicated that given the proper technology, management and favourable market, and polyculture of high-value species (grouper (Epinephelus) and mud crab (Scylla)) will provide better return on investment. Dissemination of the technology through training started in 2001. In 2002, a 4-hectare undeveloped fishpond of NBFTC was converted into an aquasilviculture project to showcase the technical and economic feasibility of the technology with emphasis on the polyculture of mud crab, grouper and saline tilapia (Oreochromis) that would serve as a model livelihood project for coastal fisherfolk. In 2011, the BFAR launched the Philippine National Aquasilviculture Program to help restore mangroves that serve as breeding and nursery grounds of fish, and to provide livelihood projects through aquasilviculture to coastal fisherfolk. With increasing cost of development and management for aquasilviculture, integration of mangrove crab fattening and/or soft-shelled crab production have shown to improve profit under the present economic condition.
  • Conference paper

    Management strategies for grow-out culture of mud crab 

    JG Genodepa - In ET Quinitio, FD Parado-Estepa & RM Coloso (Eds.), Philippines : In the forefront of the mud crab industry development : proceedings of the 1st National Mud Crab Congress, 16-18 November 2015, Iloilo City, Philippines, 2017 - Aquaculture Department, Southeast Asian Fisheries Development Center
    There is an increasing interest in mud crab farming because of the growing demand for mud crab in domestic and international markets. Different methods for rearing crabs in ponds, pens and cages have evolved through several years of research and experiences of farmers. Mud crabs are cultured in brackishwater earthen ponds and pens in mangroves. Fattening of lean crabs is also integrated with the grow-out culture system. Cannibalism is one of the major factors affecting the survival of crabs in growout ponds and pens. Hence, various strategies are recommended to reduce cannibalism such as stocking density of less than 2,000 crabs ha-1, provision of suitable shelters, sufficient quantity of natural food and formulated feeds that are evenly distributed in the pond or pen. Feeding rate used in the pen is adjusted to avoid excess feeds that can attract rats and other land animals that can damage the enclosures. Selective harvesting is normally practiced since mud crabs do not grow or get fattened at the same time even if they belong to the same batch.

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