Mud crab hatchery and grow-out status in the Philippines
Abstract
Interest in mud crab aquaculture is increasing throughout the Philippines because of its demand both in local and export markets. Mud crab culture started as low-density polyculture with fish or shrimp using wild crab juveniles and developed to monoculture in ponds and cages. Recently, an integrated mangrove-crab culture system has been practiced. Mud crab species commonly cultured are Scylla serrata, S. tranquebarica, and S. olivacea.
The yearly increase in production from 1996 to 2000 (Table 1) may indicate a corresponding increase in the seed collection activity due to greater demand of seeds for stocking. According to many gatherers in the country, there has been a declining volume of all size-classes, from juveniles to adult crabs, gathered from the wild over the last decade. Hence, the development of a commercially viable hatchery technology can play an important role in promoting sustainable crab aquaculture and fisheries management.
Citation
Quinitio, E. T. (2004). Mud crab hatchery and grow-out status in the Philippines. In G. Allan & D. Fielder (Eds.), Mud crab aquaculture in Australia and Southeast Asia. Proceedings of the ACIAR Crab Aquaculture Scoping Study and Workshop 28–29 April 2003, Joondooburri Conference Centre, Bribie Island (pp. 53-56). Canberra, Australia: Australian Centre for International Agricultural Research.
Publisher
Australian Centre for International Agricultural ResearchSeries
ACIAR Working Paper;No. 54Subject
Type
Conference paperISBN
1863203990Collections
- Conference Proceedings [283]
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Article
Larval rearing of mud crab (Scylla): What lies ahead
-Aquaculture , 2018 - ElsevierThe increasing global demand for mud crabs (genus Scylla) and threats to the wild populations highlight the urgency of fully rearing them in captivity. Despite considerable progress in mud crab production, most crab farms still rely heavily on wild-caught crablets and juveniles while the low and inconsistent success rates of larviculture remain as the main bottleneck impeding the development of mud crab aquaculture. Over the years, numerous studies have been conducted to determine the optimum larval rearing parameters, the ontogenic changes in digestive function and feeding behaviour, and the diets for different larval stages. These data, however, are dispersed and not summarised to inform culture practices. This review provides an update on the current progresses and to pinpoint the gaps in knowledge regarding mud crab larval rearing. We include all four mud crab species under the genus Scylla, i.e. Scylla serrata, Scylla olivacea, Scylla tranquebarica and Scylla paramamosain. Knowledge compiled in this review serves as an important guideline for prospective mud crab larviculture. Future research should gear towards filling in the gaps in our knowledge to advance mud crab larval rearing, thus fully incorporating mud crab into the aquaculture sector. -
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- 2011 - Aquaculture Department, Southeast Asian Fisheries Development CenterResearched and conceptualized by Emilia T. Quinitio. -
Conference paper
Updates on the seed production of mud crab
- In MRR Romana-Eguia, FD Parado-Estepa, ND Salayo & MJH Lebata-Ramos (Eds.), Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia: Challenges in Responsible Production … International Workshop on Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia 2014 (RESA), 2015 - Aquaculture Department, Southeast Asian Fisheries Development CenterWidespread interest in mud crab species is increasing because these are highly prized both in domestic and export markets. Among the three mud crab species commonly found in the Philippines, Scylla serrata, S. olivacea, and S. tranquebarica, S. serrata is preferred by farmers because it is larger and less aggressive than the other species. Likewise, S. serrata is the most widely distributed species in the Indo-west Pacific region. Hatchery-produced seedstock are presently used by some crab farmers in their grow-out operations. In the hatchery phase, feeding mud crab larvae with shrimp formulated diets and natural food was found to reduce the occurrence of molt death syndrome, one of the major problems in seed production. Larvae given 25% formulated diet (FD) + 75% natural food (NF; rotifers and Artemia) and 50% FD + 50% NF showed better performance than those larvae fed 100% FD, 100% NF and 75% FD + 25% NF indicating that usage of natural food, especially the expensive Artemia, can be reduced. Since the early crab instar (C) produced in the hatchery need to be grown further before stocking in grow-out ponds, two phases of nursery culture have been developed. C1-2 are grown to 1.5-2.0 cm carapace width (CW) size in the first phase and further grown to 3.0-4.0 cm CW in the second phase. Nursery rearing is done in net cages installed in ponds for easy retrieval. A combination of mussel or trash fish and formulated diet is used as feed. Domestication of the mud crab S. serrata as a prerequisite to selective breeding has been done at SEAFDEC/AQD. Likewise, defining criteria for the determination of quality of newly hatched zoeae for stocking in the hatchery was initiated. Newly hatched zoeae were subjected to starvation and stress test using formalin. Starvation failed to elicit responses that were significantly different between the good and poor quality larvae hence it is not suitable for larval quality evaluation. Based on three-year data, the formalin stress test gave mean cumulative mortalities of 2.38±0.32, 8.24±0.88, 20±1.58 in good quality larvae, and 43.74±2.39 while 22.93±4.19, 63.68±7.17, 84.29±3.88 and 97.65±1.06 for poor quality larvae at 0 (control), 20, 30 and 40 ppm formalin, respectively. As formalin level increased, cumulative larval mortality also increased regardless of the quality of the larvae. Formalin stress test proved to be a reliable method to determine whether a batch of newly hatched zoeae was of good or poor quality.
