Southeast Asian Fisheries Development Center
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Hatchery production of sea cucumbers (sandfish Holothuria scabra)
Get PDFThis manual, entitled Hatchery Production of Sea Cucumbers (Sandfish Holothuria scabra) includes the consolidated methods, practical protocols and good practices in sea cucumber breeding that were established within the past decade of research and development at the small-scale sea cucumber hatchery in the Tigbauan Main Station of SEAFDEC Aquaculture Department. Hence, this manual focuses only on demonstrating the technology, requirements and procedures in operating a small to medium-scale tropical sea cucumber hatchery.
This manual is written for potential sea cucumber hatchery operators, technicians, enthusiasts, researchers, and students with some basic experience and knowledge on aquaculture. However, even beginners may find this manual informative and useful, as it highlights the importance of sea cucumbers and their potential as an aquaculture commodity, particularly that of the tropical sea cucumber H. scabra, commonly known as the sandfish. This manual also serves as the primary reference material of the Training Course on “Sandfish (Holothuria scabra) seed production, nursery and management” offered by SEAFDEC/AQD. Hence, some specific descriptions of the actual facilities and existing equipment are detailed here.
The manual describes the various hatchery production methodologies that were specifically optimized for the sandfish H. scabra. These methods were designed to be practical and easy to implement. The materials mentioned therein are those that can be easily procured, otherwise if unavailable, can be fabricated from common materials.
The following are the main sections included in this manual: 1) Broodstock selection, collection and conditioning; 2) Natural food (microalgae) cultivation; 3) Spawning stimulation and fertilized eggs management; 4) Larval rearing and settlement; 5) Harvesting of early juveniles, packing and transpor
Growth and carrageenan quality of sporophyte and gametophyte of the commercially important red seaweed Kappaphycus alvarezii
No full textOne dilemma facing the farming of the carrageenophyte Kappaphycus is the deteriorating quality of seedstock. Rejuvenating the commercial stocks using spores from reproductive wild parents that are sexually and asexually produced could perhaps restore the traits that are useful for culture. The use of gametophyte and sporophyte (=tetrasporophyte) phases of Kappaphycus alvarezii from spores is explored as a source of seedstock. The growth and physical properties of semi-refined carrageenan extracted from the resulting sporophyte and gametophyte thalli of the same ages were determined. The growth rate of the diploid tetrasporophyte thalli was significantly higher than that of the haploid gametophyte. Gel strength and yield of semi-refined carrageenan from the two life cycle phases were not significantly different, whereas the viscosity was significantly higher in the diploid tissues. Kappaphycus sporophytes were potentially superior to gametophytes as a source of seedstock for mariculture, but problems need to be addressed – including improving the growth rate and reducing the cost of production – before its application could be realized.This study was funded by the Government of Japan Trust Fund (GoJ-TF FS09S2010T) in SEAFDEC/AQD
Edwardsiellosis
No full textEdwardsiellosis is an acute to chronic systemic disease in fish characterized by exophthalmia, ascites, hernia, and severe lesions of the internal organs. It is caused by Edwardsiella tarda, a Gram-negative intracellular pathogen implicated in enormous economic losses of cultured seawater and freshwater fish species. E. tarda has a broad host range and geographic distribution, and possesses important virulence factors that enhance its survival and pathogenesis in hosts. This chapter discusses some of the recent research on edwardsiellosis in fish including the etiologic agent's identification, pathology, diagnosis, and virulence factors, and as well as novel strategies aimed at preventing and controlling the disease
A technical and economic evaluation of supplemental feeding strategies for Nile tilapia (Oreochromis niloticus L.) reared in lake-based cages
No full textTilapia cage farming in eutrophic lakes uses low stocking densities since tilapias can thrive mainly on natural food or minimal supplementary feeding. For semi-intensive Nile tilapia cage culture, feeding strategies to improve productivity are adopted based on technical viability and cost efficiency, as assessed in the present study. Tilapia fingerlings stocked in triplicate cages per treatment were reared in Laguna de Bay, Philippines for five months, one run each during the dry and wet seasons. The treatments were: I – UNFED or no feeding; II - FED, fish fed for the entire 155 days; III - D45, fish fed from day 45 to harvest; and IV - D75, or fish fed from day 75 to harvest. Average weight gain or AWG (153.18 g and 225.85g, for dry and wet seasons, respectively) were highest in FED. Growth parameters in all fed treatments were significantly higher (p<0.05) than in UNFED for both seasons. Survival rates were higher during the wet season (66-70%) compared to the dry season (35-37%). Moreover, in the wet season, when the lake’s primary productivity is low, full feeding can be done without compromising lake water quality. Results showed that it favored high AWG, survival, reasonable market price, and profit.SMFI–BMEG and SEAFDEC/AQD are acknowledged for the support provided in the conduct of this project (study code: TV-05-F2013B and budget code: 6141-T-RD-BMEG01/6141-B-TV-F0114B)
Motile aeromonads recovered from tilapia (Oreochromis niloticus) cultured in earthen ponds in the Philippines: Assessment of antibiotic susceptibility and multidrug resistance to selected antibiotics
No full textA total of 177 motile Aeromonas spp., comprised of A. hydrophila (n=162) and A. sobria (n=15), isolated from the water, sediment, gills and intestines of tilapia collected from the grow-out culture earthen ponds in the Philippines were investigated for their antimicrobial susceptibility to 10 antibiotics commonly used in fish aquaculture. All motile Aeromonas spp. tested generally exhibited a very high percentage of resistance to amoxicillin (A. hydrophila: 95%; A. sobria: 100%), erythromycin (99%;100%), neomycin (83%;100%), and oxytetracycline (92%;100%), respectively. On the contrary, they showed substantial susceptibility to chloramphenicol, nitrofurantoin, doxycycline, enrofloxacin and norfloxacin. Results of the antimicrobial susceptibility testing demonstrated that 94.4% and 100% of A. hydrophila and A. sobria isolates tested were resistant to antibiotics belonging to at least 3 or more categories and therefore considered as multiple drug resistant strains. The multiple antibiotic resistance (MAR) indexing of A. hydrophila and A. sobria strains showed that they originated from high-risk sources.This study was funded by the Department of Science and Technology-National Research Council of the Philippines (DOST-NRCP) (NRCP Project No. E-225) and partly by SEAFDEC/AQD (study code: FH02-F2013-T)
AQD Matters 2022 March - April
No full textIn this issue: 1) DA Usec Caballero at Igang Marine Station; 2) Aklan LGU staff complete marine fish hatchery course; 3) Tri-party collaborators ink agreement for 'ulang' livelihood project; 4) Research making headway at SEAFDEC/ AQD; 5) More aquaculture facilities underway; 6) Employees, dependents register for national ID; 7) Eel research up at SEAFDEC/AQ
Viral encephalopathy and retinopathy
No full textViral nervous necrosis (VNN), also referred to as viral encephalopathy and retinopathy (VER), has been reported in at least 120 cultured or wild marine and freshwater fish species and has caused serious economic losses among farmed marine fish species in the past decades. Since the first description of this disease at the end of the 1980s, substantial amounts of researches have been instrumental in understanding the mechanisms involved in fish infection, development of reliable diagnostic methods, and disease prevention and control. This chapter presents some important aspects of the disease with particular emphasis on etiologic agent, clinical signs and gross pathology of the disease, histopathology, disease risk factors, virus propagation and identification, molecular diagnostics, and concomitant prevention and control methods
An innovative biofloc technology for the nursery production of Pacific whiteleg shrimp, Penaeus vannamei in tanks
No full textNursery production of shrimp is usually done in small ponds; however, the use of small and circular tanks with plastic liners is gaining popularity. From an industry standpoint, there is still a need to assess how nursery systems can be of benefit to the shrimp production cycle. Hence, the use of small circular tanks coupled with the incorporation of biofloc technology was assessed in terms of its viability during the nursery production of the Pacific whiteleg shrimp, Penaeus vannamei. A 450m2 plastic lined circular tank was installed and prepared for the stocking of P. vannamei postlarvae (PLs) at a density of 500 PLs per m2. Biofloc was produced and maintained throughout the nursery phase using brown sugar as carbon source at a carbon to nitrogen (C:N) ratio of 10. Water quality was monitored daily, while presumptive Vibrios were enumerated weekly. Sampling for growth was done at the 14th day post-stocking and weekly until harvest on the 30th day. The different water quality parameters were within optimum levels required for shrimp growth. Presumptive Vibrios were dominated by the yellow colonies. At the end of the nursery phase, there was 100% survival and the shrimp attained an average body weight of 1.26 g and a feed conversion ratio (FCR) of 0.43. Our results indicate that the use of small circular tanks with biofloc during the nursery production phase of whiteleg shrimp is feasible and can be incorporated in the grow-out culture of this shrimp species.This research study is part of the project, “Bioflocbased Nursery Tank Production of Shrimp for Quality and Sustainable Supply of Aquaculture Products in the New Normal” funded by the Department of Science and Technology (DOST) through the Science for Change Program (S4CP) – Collaborative Research and Development to Leverage Philippine Economy (CRADLE) and monitored by DOST – Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development (PCAARRD) with Project Number 8444 awarded to CMA Caipang. The support provided by our respective institutional affiliations and Marmi Agricultural Corporation is gratefully acknowledged
Establishment of a community-based sandfish sea ranch in Barangay Polopiña, Concepcion, Iloilo (Western Visayas node case study)
No full textThis study was primarily funded by ACIAR through the project ‘Expansion and Diversification of Production and Management Systems for Sea Cucumbers in the Philippines, Vietnam and Northern Australia’ (FIS/2010/042) with counterpart funding support by SEAFDEC/AQD through study codes FS-10-Y2010T and FS-03-Y2014T