Southeast Asian Fisheries Development Center
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Genetic assessment of philippine milkfish (Chanos chanos) stocks based on novel microsatellites for markeraided broodstock management
No full textAbstract only.Reports on genetic diversity within/among milkfish populations using DNA markers are sparse. Earlier work dealt with evolutionary relationships among wild populations to define management units in the Indo-Pacific region where milkfish naturally abound. However, application of milkfish genetic markers in broodstock development and management remains to be investigated. Here, nine novel microsatellites developed by NGS were utilized to (a) describe the genetic structure of Philippine wild and hatchery-bred milkfish; (b) monitor the impact of domestication selection and inbreeding; and (c) formulate marker-aided broodstock management methods, a prerequisite to genetic improvement. Milkfish samples from three wild populations: Claveria (CLA), Currimao (CUR), Camiguin (CAM); eleven local hatchery stocks: SEAFDEC Integrated Hatchery (SIH), SEAFDEC Big Hatchery-Igang batches 1 and 2 (SBH-I1 and SBH-I2), SEAFDEC Big Hatchery-Dumangas (SBH-D), Hautea Hatchery (HH), Sual Pangasinan Hatchery (SPH), BFAR Dagupan Hatchery (BDH), BFAR Bohol Hatchery (BoH), BFAR Palawan Hatchery (PAL), Zambales Hatchery-P0 (ZH-P0), Zambales Hatchery-F1 (ZH-F1); and a hatchery stock from West Java in Indonesia (WJH), were examined. An Indonesian stock was included since in the Philippines, Indonesian milkfish fingerlings are imported and farmed for having purportedly better production traits. Genetic diversity indices such as expected heterozygosity (He) and allele frequency (A) ranged from 0.655 to 0.697 and 9.2 to 11.1, respectively. AMOVA showed significant but low genetic differentiation among the milkfish populations (FST = 0.013; P=0.000,) since much of the variation is attributed to intrapopulation differences (98.6%). The oldest hatchery stock SIH (30-35 years) had relatively moderate genetic variability (He = 0.66, A = 10.6), which is lower than that of 5-year old SBH-I1 (He= 0.687, A= 11.5) considering that both stocks originally came from the same source in the wild. A reduction in genetic diversity was seen when a local hatchery stock (ZH-P0;He = 0.66 and A= 10.8) was monitored after one generation (ZH-F1; He = 0.65, A=9.3). Finally, the Indonesian stock WJH had genetic variability levels (He= 0.66; A= 10.5) comparable with local stocks. Results of genetic analyses are herein discussed in the context of promoting effective milkfish broodstock management practices for the production of good quality seed stock
Use of agar-bound microparticulate diet as alternative food for tropical abalone, Haliotis asinina (Linnaeus 1758) post-larvae in large-scale cultures
No full textThe efficacy of using agar-bound microparticulate diet (A-MPD) as alternative food for abalone Haliotis asinina Linne post-larvae in large-scale culture was investigated. Larvae sourced from the hatchery-bred (HB) and wild-sourced (WS) broodstock were fed with either diatoms (TMT1-NF), agar-bound microparticulate diet (TMT2-A-MPD), or a combination of both feeds (TMT3-NF + A-MPD) in six 2-m3 tanks replicated over time. Three hundred thousand veliger larvae were stocked/tank containing 80 corrugated plates with mucus trails hanging on bamboo poles. Feeds were given at 0900 h starting at day 3 with seawater flow through introduced every 1400 h starting day 5. Two-way analysis of variance determined significant differences (p < 0.05) in survival and shell length between larval sources and feed types. Tukey’s post hoc test established differences among treatment means. At day 30, survival for HB- and WS-sourced larvae was significantly higher (42%) in TMT3 compared with TMT2 having 35% for HB and 38% for WS (p < 0.05). Larvae fed with TMT1 had significantly lowest survival among the three treatments. Survival at 60 and 90 days did not show significant difference for TMT2 and TMT3 regardless of broodstock source. Post-larval shell growth (90 days), from both sources fed with TMT2 and TMT3, was significantly higher than TMT1 (p < 0.05). Larval performance did not show any significant interactions between HB and WS broodstock. The use of A-MPD alone or in combination may elicit improvement in survival and shell length growth in abalone larvae regardless of larval sources. A-MPD may be used as full or partial replacements to diatoms as alternative food for abalone post-larvae in large-scale culture.The authors would like to thank SEAFDEC/AQD (study code 5309-TTV-MO-312T) through its chief Dr. Felix Ayson and DOST for the funds provided; the SEAFDEC/AQD Abalone hatchery staff: Mr. Rafael Barrido, Mr. Ramil Piloton, and Mr. Nestor Bayona for their valuable suggestions in carrying out post-larval rearing work; Ms. Rena Santizo and Ms. Analyn Asutilla for their significant help and contribution in the study; and Mr. Richard Tantiado for the technical assistance in the conduct of experiment
Pilot scale production of pellets suitable for mud crab Scylla serrata
Get PDFAbstract only.Studies were conducted towards the pilot scale production of stable and nutritionally adequate pellets suitable for mud crab Scylla serrata to help in efforts to increase mud crab production in the Philippines. Preliminary studies showed that mud crabs preferred pellets which were spherical or cylindrical and contained marine based attractants. Two practical diets were formulated and prepared in the Pilot Feed Mill of SEAFDEC/AQD. The extruded diets, along with a commercial mud crab grow-out diet, were subjected to proximate and Ca/P analyses as well as cholesterol analysis and water stability tests. The diets were fed to crabs in a controlled laboratory experiment using fiberglass tanks with flow-through, aerated seawater, and monitored from initial molt (M0) up to the second molt (M2). Tests revealed that the crabs fed Diet 1 (CP 48.28 %, CF 7.74 %, Ca 5.23%, P 12.93 %, cholesterol 0.173 %) showed the highest growth and better survival than those fed Diet 2 or commercial diet. Crabs fed Diet 1 took a shorter time to attain two molt cycles from M0. Survival was 70% after M2. Diet 1 was water stable within two hours. Abnormalities were observed including absent swimming legs or chelae, exposed gills, sores on exoskeleton, incomplete molting, or soft exoskeleton, but none that could be directly attributed to a specific treatment. Incomplete molting and slow hardening of the exoskeleton in crabs that accounted for the mortalities could be due to the low cholesterol levels in the diets especially in the commercial diet which had the lowest cholesterol level. Cholesterol supplementation of the artificial diet would be needed to improve molting success and survival of mud crabs in grow-out culture. The results of these experiments will be used to formulate a cost-effective grow-out diet for mud crab (supported by DOST-PCAARRD Grant in Aid)
Mud crab fattening project of KAMAMANA in Del Carmen, Siargao Island
No full textThe 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%)
SEAFDEC/AQD highlights 2016
Get PDFSEAFDEC/AQD highlights 2016 is SEAFDEC/AQD’s annual report updating on its accomplishments and progress for the year 2016
Effects of elevated temperature on the different life stages of tropical mollusk, donkey's ear abalone (Haliotis asinina)
No full textThe increase in sea surface temperature associated with climate change can cause tremendous impact on the different life stages of aquatic organisms, particularly on the tropical species. The present study investigates the effect of elevated temperature on hatching rate, growth and survival of larvae and breeders of tropical mollusk, donkey’s ear abalone (Haliotis asinina). Different life stages of abalone were exposed to the following temperature treatments: ambient (29°C), +2°C (31°C), and +4°C (33°C). Hatching rate was significantly reduced when the fertilized eggs were incubated at temperature 4°C above ambient. Increase in temperature at 2°C above ambient can significantly influence the survival of larvae. Significant decline in the survival was observed when the larvae were exposed at temperatures 31°C and 33°C, however bigger larvae were observed in groups reared at 31°C, while those larvae that were reared in 33°C were significantly smaller. Furthermore, reduced growth, feeding rate and survival were also observed in breeders reared at elevated temperature. The result of the study suggests that early developmental stages and reproducing adult abalone were vulnerable to the impact of climate change.The study was funded by Southeast Asian Fisheries and Development Center - Aquaculture Department (Nr03-C2012T). The author wish to express her gratitude to Germin L. Moquera and the staff of abalone hatchery of SEAFDEC-AQD
Micro-propagation of Kappaphycus and Eucheuma: Trends and prospects
No full textAmong the red algae, Kappaphycus and Eucheuma are the two most commercially important carrageenophytes farmed extensively in Southeast Asian countries; they rank top in production in terms of volume of raw material produced. The farming of carrageenophytes has emerged as a successful enterprise and provides a promising, alternative livelihood option for low-income, coastal communities in a number of countries. In 2014, carrageenophyte production worldwide, surpassed other red seaweeds and was placed at the top of the production rankings with 10.99 million MT wet weight (77% of total production of farmed red seaweed) and Indonesia being a major producer. However, over time, the productivity of the crop (carrageenophytes) has declined in some regions due to sourcing of seedlings from single, selected genetic stocks considered to have higher yield potential which resulted in strain fatigue, or loss of vigour. The incidences of disease and epiphytic infestations are on rise in recent times which have severely affected biomass production, as well as the yield and product quality (carrageenan). In order to circumvent the crop productivity issues arising from clonal propagation, the raising of planting materials from spores, derived through the red algal sexual reproductive cycle, has been initiated to support the sustainability of selected, farmed carrageenophytes. Alternatively, in vitro tissue culture techniques have also been explored to not only rejuvenate the vigour of seedlings (i.e. the out-planting material) but also to seek seedlings resilient to stress, disease and epiphytes to act as an invigorated mother stock. These efforts have succeeded to a great extent in the development of appropriate techniques for explant culture, callus induction, callus sub-culture and regeneration to micro-propagules with improved traits. The present chapter briefly summarizes the developments and success achieved in micro-propagation of Kappaphycus and Eucheuma and also provides pointers to both gaps and priority areas for future research required for the advancement of sustainable farming of these carrageenophytes