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.

Pangasinan’s vast fishpond and mangrove areas have not been fully tapped for mud crab (Scylla serrata) production. The main reason identified for this is the limited supply of crab seedstock. At present, there is no reliable source of seedstock in Pangasinan. The total requirement of Pangasinan for crab seedstock is estimated at 8.89 million based on the total area (ha) devoted to mud crab polyculture in the province. Mud crab growers in Pangasinan procure wild juvenile crabs from Cagayan, Bicol and Visayas but the volume is limited. Thus, an adoption of a modified commercial scale mud crab hatchery and nursery systems in Alaminos City would be helpful. A model mud crab hatchery will be constructed to enable the local government unit (LGU) of Alaminos City to produce seedstock in commercial quantity to boost the production in Pangasinan and nearby provinces. The hatchery aims to produce 480,000 juvenile crabs per year to supply the nursery and grow-out ponds. Likewise, the hatchery technology will promote the mud crab hatchery and nursery technologies in the city of Pangasinan and coastal towns (Infanta, Dasol, Burgos, Agno, Bolinao, Anda, Bani, Sual, Labrador, Lingayen, Binmaley, Dagupan City and San Fabian), and nearby provinces of La Union, Ilocos Sur, Ilocos Norte and Zambales.

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.

The effects of water temperature and autotomy of chelipeds on growth, survival and molting of mud crab, Scylla serrata, juveniles were investigated under laboratory conditions in separate experiments. Hatchery-produced crabs at the intermolt stage with 2.0-2.3 cm carapace width and 1.7-2.2 g body weight were either exposed to temperature levels of 29, 32 and 35°C and ambient temperature of 24-31°C or subjected to autotomy (voluntary removal of one or two chelipeds). The crabs were allowed to molt twice prior to termination. All crabs held at 35°C had 100% mortality due to incomplete molting during the first molt. The mean survival of crabs upon termination was 58, 64 and 50% for ambient temperature, 29 and 32°C, respectively. Specific growth rate (SGR) of crabs in the ambient (2.83 ± 0.12%) and 29°C (3.02 ± 0.15%) were comparable but significantly lower than (P<0.01) those at 32°C (3.85 ± 0.28%). The molt interval of crabs was significantly shorter in treatments with constant water temperature (29°C: 32 ± 0.80 days, 32°C: 28 ± 1.11 days) compared to ambient temperature (39 ± 0.93 days). The survival of crabs with intact chelipeds (51.17 ± 3.56%) was comparable to those with one (50.55 ± 2.36%) or two (43.41 ± 1.59%) autotomized chelipeds. Juveniles with intact (5.80 ± 0.47%) or one autotomized cheliped (5.45 ± 0.30%) had a significantly higher SGR than crabs with both chelipeds autotomized (4.20 ± 0.52%) in the first molt. On the second molt, however, high SGR was observed in crabs with two chelipeds autotomized. The molt interval was significantly shorter in the autotomized crabs (one cheliped: 28 ± 1.66 days; two chelipeds: 23 ± 0.63 days) compared to those with intact chelipeds (36 ± 1.52 days). The results suggest that optimum water temperature for rearing S. serrata juveniles ranges from 29 to 32°C. Likewise, autotomy of one cheliped can promote molting without adversely affecting the growth and survival of the juveniles.

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.

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.

Determination of the population structure and connectivity of natural populations of Scylla serrata are useful tools for decision making related to conservation and management efforts of this species. They provide important considerations as recovery and sustainability of the industry relies on the availability of hardy recruits that can replenish harvested resources from the system. In the case of marine domesticated species, admixture is expected due to commodity trade and exchanges. Current population structure of five wild populations of S. serrata from Pangasinan, Bataan, Cagayan, Quezon, and Panay was determined using five microsatellite markers, cross-amplified from Scylla paramamosain in a total of 259 samples. Mitochondrial 16S rDNA sequences of 25 representative individuals from the same locations were used to provide a comparison with original evolutionary patterns. Quality check of microsatellite data revealed no null alleles in the data set, with all loci and populations exhibiting Hardy-Weinberg Equilibrium. Pairwise FST analysis reveals FST values between 0.001-0.08432 with 9 out of the 16 possible comparisons considered significant. Phylogenetic analysis was performed on the 16S rDNA sequences, supported by bootstrap values. Both sets of data suggest 2 distinct groupings: the east coast populations of Cagayan and Quezon, the west coast populations of Pangasinan and Bataan, with admixture observed in the group from Panay. Additional data from 5 microsatellite markers specifically developed for S. serrata and the D-loop region will be added to the analysis. The results from both mitochondrial and microsatellite markers, revealing an East-West separation of S. serrata populations, suggest that current and evolutionary population patterns are matching. Aquaculture practices appear to have not yet significantly affected the population structure of this domesticated species, as initially speculated.

The study was conducted to identify the mud crab species (Scylla spp.) that thrive in 12 coastal municipalities and 2 cities in Pangasinan. Ten mud crab samples were taken from each of the sampling site and classified based on Keenan et al. (1998). Likewise, the abundance and differences in size and weight of the mud crab samples were determined. The study showed that there are only three mud crab species, Scylla serrata, S. tranquebarica and S. olivacea, found in the coastal areas of Pangasinan. S. serrata was the most abundant species (54.28%), followed by S. tranquebarica (24.28%) and S. olivacea (22.14%). Crabs weighing more than 300 g (~.12 cm carapace width or CW) were obtained from the municipalities of Anda, Bolinao, Dasol, Burgos, Bani, Agno, Alaminos and Infanta. These municipalities are geographically situated in coastal areas where S. serrata are found. Crabs weighing below 300 g (~.12 cm CW) were collected from the municipalities of Sual, Labrador, San Fabian, Lingayen, Dagupan and Binmaley. These towns have mangrove areas and low saline waters where S. tranquebarica and S. olivacea thrive.

The Bureau of Agriculture and Fisheries Standards (BAFS) of the Department of Agriculture (DA), in collaboration with the relevant government and research agencies, academe and industry organization, is currently developing the Philippine National Standard (PNS) for live mangrove crabs (also known as mud crabs). This PNS defines the food safety and quality requirements for live mangrove crabs in order to ensure consumers&rsquo; health and make the product globally competitive. The process in the development of standards include review of the existing requirements of local and foreign markets and internationally recognized standards, creation of the Technical Working Group, initial drafting of the PNS, conduct of public consultations in major production areas, finalization of the draft for the PNS, notification to the World Trade Organization and approval of the DA Secretary. The PNS for live mangrove crabs specifies the scope of the standard, product description, essential composition and quality factors, hygiene, handling, labeling requirements, methods of sampling, examination and analysis, definition of defectives, and the requirements for product lot acceptance.

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.