Larval survival and megalopa production of Scylla sp. at different salinities
Abstract
Salinity tolerance was determined for each zoeal stage of Scylla sp. Larvae from ablated pond-grown females were abruptly transferred to salinities of 12, 16, 20, 24, 28 and 32 ppt. Spawning salinity or previous rearing salinity was 32 ppt, except for Z5 which were previously reared at 26 ppt. The mean median lethal time or LT50 values were compared between salinities. For Z1 and Z2, highest values were obtained at 20–32 ppt. Z3 had highest LT50 values at 20–24 ppt and Z4 at 24–32 ppt. For Z5, highest LT50 values were obtained at 20–32 ppt. Another batch of Z3 and Z4 were subjected to the same abrupt salinity transfers and reared to the megalopa stage. Significantly higher percentages of larvae metamorphosed to the megalopa stage at salinities of 20–28 ppt when transfer to test salinities was at Z3. When transfer was at Z4 or Z5, the highest percentage of larvae moulted to the megalopa stage at 24–28 ppt or at 28 ppt, respectively.
Citation
Parado-Estepa, F. D., & Quinitio, E. T. (1999). Larval survival and megalopa production of Scylla sp. at different salinities. In C. P. Keenan & A. Blackshaw. (Eds.). Mud Crab Aquaculture and Biology. Proceedings of an international scientific forum held in Darwin, Australia, 21–24 April 1997 (pp. 174-177). Canberra, Australia: Australian Centre for International Agricultural Research.
Publisher
Australian Centre for International Agricultural ResearchSubject
Type
Conference paperCollections
- Conference Proceedings [283]
Related items
Showing items related by title, author, creator and subject.
-
Book
Soft-shell crab production using hatchery-reared mud crab
- 2015 - Aquaculture Department, Southeast Asian Fisheries Development Center; Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development (PCAARRD)
Series: Aquaculture extension manual; No. 61"The production of soft-shell crabs is well established in other Asian countries but its sustainability is already being threatened due to the decreasing mud crab population in the wild where the seedstocks are sourced. In the Philippines, production of soft-shell crabs has only been practiced recently due to lack of seedstock and technology. Sourcing of crablets from the natural environment is not encouraged due to dwindling populations of all sizes of mud crabs. Instead, it is recommended that crablets for soft-shell crab production come from hatcheries. The project on soft-shell mud crab production at SEAFDEC/AQD started in 2012 and was later funded by the Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development of the Department of Science and Technology. The project is adopting the individual crab culture sytem of Thailand and Myanmar in pilot-scale and uses hatchery-reared crablets grown to 60-100 g in earthen ponds and stocked in trays. The pilotscale soft-shell production set-up is showcased at the Dumangas Brackishwater Station of SEAFDEC/AQD using crab boxes available in the country. Various sectors are interested to learn how soft-shell crabs are produced. Hence, the previous manual on Soft-shell Mud Crab Farming by Emilia T. Quinitio and May Myat Noe Lwin published in 2009 was revised to include the recent refinements using hatchery-reared crabs and locally available materials. This manual includes sections on the biology of mud crab, how to set-up the facility, management of soft-shell crab production and the cost and return analysis. We hope that various sectors will benefit from this revised manual" -- Foreword -
Conference paper
Soft-shell crab production using hatchery-produced mangrove crab Scylla serrata juveniles
- In ET Quinitio, FDP Estepa, YC Thampi Sam Raj & A Mandal (Eds.), Proceedings of the International Seminar-Workshop on Mud Crab Aquaculture and Fisheries Management, 10-12 April 2013, Tamil Nadu, India, 2015 - Rajiv Gandhi Centre for Aquaculture (MPEDA)Soft-shell crab production is being practiced in many Asian countries but the major source of seedstock is from the wild, which could no longer sustain the increasing demand. Commercial scale soft-shell crab production can become sustainable only if there is a continuous supply of seedstock not dependent on wild stock. Rajiv Gandhi Centre for Aquaculture (RGCA) under the Marine Products Export Development Authority (MPEDA) has established a pilot-scale mud crab hatchery at Thoduvai, Nagapattinam District, Tamilnadu in 2004 with the technical assistance from SEAFDEC/AQD. At present, RGCA has the biggest mud crab hatchery in India and a demonstration farm at Karaikal, U.T. of Puducherry, where nursery rearing, grow-out and soft-shell crab production are conducted using hatchery- produced mangrove crabs or mud crabs, Scylla serrata. This paper presents the results of the soft-shell crab production using hatcheryproduced S. serrata juveniles maintained in perforated low density polyethylene (LDPE) boxes. The duration of the molt interval, time of molt (day or night) and the increase in body weight and carapace width of each size group (40-60, 61-80, 81-100, 101-120, 121-140, 141-160, 161-180 g) after molting were determined.Results showed that the percentage increase in body weight and carapace width increased as the crabs grew bigger. Likewise, the molt interval was longer in bigger-sized groups of crabs. Sixty to seventy percent of the population molted during night time and the next molt occurred within 25 days in 80-160 g size groups. Soft-shell crabs in boxes within the water surface and juvenile crabs (2.5 cm CW initial size) for culture until market size in the pond can be a viable technology technology for mud crab growers. -
Book | Conference publication
Philippines: In the forefront of the mud crab industry: Proceedings of the 1st National Mud Crab Congress
- 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
