Seasonal growth, carrageenan properties, and resistance to disease and epiphytic pests between Kappaphycus alvarezii (Rhodophyta) var. tambalang (brown) tissue-cultured and farm-sourced seaweeds

Growth performance (specific growth rate [SGR] and biomass yield), carrageenan properties (yield, viscosity, and gel strength), and disease and pest incidence were compared between Kappaphycus alvarezii var. tambalang (brown) tissue-cultured (TC) plantlets and farm-sourced (FS) seedlings. Seedlings used in the trials were propagules (4‒19 g pieces) and these were deployed on lines in sea cages over three separate runs of 60 days. The highest growth rate was recorded in TC plantlets and the SGRs were significantly higher (1.5‒6.5x) in TC than FS after Day of Culture (DOC) 15 (i.e., measurements taken every 15 days in each cycle). The carrageenan properties did not differ between treatments, with the exception of viscosity at DOC 45, where TC was higher than FS. “Ice-ice” disease (IID) was observed in both FS and TC in May‒June and August‒October at DOC 45 to 60, coinciding with changes in environmental conditions (i.e., dry‒wet and wet seasons). IID in FS had a moderate to very high incidence (31.2‒86.2%), while TC IID had a lower range of incidence (12.8‒60.6%). On the other hand, epiphytic filamentous algae (EFA) were observed only in August‒October with a low incidence (≤25%). However, EFA appeared earlier in FS than in TC. Taken together, these results highlight that tissue-cultured seaweeds had higher growth performance without compromising carrageenan quality and may be more resistant to health problems than farm-sourced seedlings. Studies should now assess the long-term viability of using tissue-cultured seaweeds over farm-sourced seedlings scaling to allow testing in standard farm settings, including the size of the initial seed.The study is supported by SEAFDEC/AQD with study code DP-01-S2020I

The reestablishment of mangrove crabs (Scylla spp.) in an abandoned pond following natural mangrove recolonization

Scylla spp. are among the most economically important fisheries resources derived from the mangroves. However, the widespread mangrove destruction resulted in the loss of habitat, thus the dwindling capture production of many mangrove-associated faunas. Although studies have shown that Scylla populations have reestablished in mangrove-reforested areas, this study was the first in a mangrove-recolonized abandoned pond in the Philippines. Six fishers conducted standardized fishing every spring tide of the month using cylindrical bamboo traps. All crabs caught from July 2010 to December 2011 were recorded for species, sex, sexual maturation of females, carapace width (CW), and body weight (BW). Total landings comprised 14,262 crabs weighing 1,743 kg; 79.67% Scylla olivacea, 20.18% S. tranquebarica, and 0.15% S. serrata. CW ranged 3.1–17.1 cm and BW 10–1,250 g, with the male crabs comprising 39.23–64.65% of the monthly landings and the females distributed as 19.88–45.01% immature, 0.50–16.57% mature, 0.45–16.02% gravid, and less than 0.10% spent crabs. Monthly landings ranged 254–1,231 pcs of crabs or 32.38–160.59 kg. The monthly mean catch per unit effort (CPUE), in terms of number, was 0.101 ± 0.01–0.456 ± 0.02 crab gear−1 day−1 (max = 1.13), while in terms of biomass, 12.86 ± 0.84–54.36 ± 3.16 g gear−1 day−1 (max = 112.50). Length–weight relationships of S. olivacea and S. tranquebarica are expressed as W = 0.224967L2.9864 (r2 = 94.08%, p < 0.001; n = 11,363) and W = 0.173409L3.1074 (r2 = 92.71%, p < 0.001; n = 2,878), respectively. This study revealed that Scylla spp. could reestablish in mangrove-recolonized abandoned ponds.The Project Team greatly appreciates the Government of Japan Trust Fund (GOJ-TF) and the Aquaculture Department of the Southeast Asian Fisheries Development Center (SEAFDEC/AQD) for jointly funding the project (Study Code FS-03-C2010T

AQD Matters 2023 July - August

In this issue: 1) SEAFDEC/AQD's new facilities to boost milkfish, shrimp production; 2) Chief Baliao graces bilateral talk between PH, Papua New Guinea; 3) Executive Committee members engage in dialogue at global aquaculture conference; 4) Strengthening bonds and cultivating skills: The SEAFDEC/AQD OJT Program; 5) Week-long 50th anniversary celebration; 6) 6 Aquaculture manuals unveiled in SEAFDEC/AQD's 30th book launching; 7) Filipinos, Thais train on marine fish hatchery; 8) Fish farmers, stakeholders gather for Farmer's Forum; 9) Training in marine fish hatchery organized for MAFAR-BARMM; 10) SEAFDEC/AQD at 37th PH Chemistry Congress in Bacolod; 11) More lab services accredited to meet international standard

Alternate day feeding as a cost-effective strategy for tank culture of the Pacific shortfin eel Anguilla bicolor pacifica

There is a growing interest in the aquaculture of tropical anguillid eels as an export commodity. However, studies on feeding strategies, and the present demand to reduce feed costs need to be addressed to ensure the economic viability of eel farming. In this study, the effects of daily (DF) and alternate day (ADF) feeding on growth, feed utilization, body composition, blood chemistry, liver and intestinal morphology, and economic viability in the Pacific shortfin eel Anguilla bicolor pacifica were examined. Each feeding group of 30 elvers (166.25 ± 16.23 g mean initial wt) were randomly stocked in triplicate 4 m3 outdoor concrete tanks. These were fed for 155 d with formulated eel powder diet (49.77% crude protein; 10.21% crude lipid) made into a paste. Growth and survival were not significantly different between the two feeding groups. However, feed efficiency was improved in the ADF group, with significantly higher protein efficiency ratio (0.63) than in the DF group (0.39). Feed conversion ratio (FCR) was lower in ADF (3.85) than in the DF group (6.44), resulting in a 40% reduction in total feed consumption. Biometric indices, body proximate composition, and blood chemistry were not significantly affected. Likewise, liver and intestinal morphology showed no apparent alterations between groups. Partial costs-and-returns analysis showed that ADF yielded higher net profit and profit index. These results suggest that feeding on alternate days promote compensatory growth, better feed utilization, and normal physiological condition of A. bicolor pacifica, and reduce feed cost in the rearing process. Therefore, alternate day feeding should be promoted as a sound feed management strategy in the tank culture of tropical anguillid eels.This study was supported by the Japan ASEAN Integration Fund (Br-02-Y2018B) and the Government of Japan-Trust Fund (8300-B-RD-FD0415 and 8300-B-RD-FD0120)

Fresh chilled and fresh frozen shrimps and prawns – Product standard

This Standard applies to fresh chilled and fresh frozen raw shrimps and prawns, which may be whole, deheaded, peeled, and peeled and deveined. This document applies to shrimps and prawns of the Penaeidae, Pandalidae, Crangonidae, Palaemonidae families but not limited to the species listed in Annex A (Commercially available shrimps and prawns species in the Philippines)

Lime application to condition soil to pH 11 controls growth of harmful vibrios and WSSV

Shrimp farming has been devastated by several diseases. Disease outbreaks can be prevented by optimising environmental conditions or by eliminating risks factors including carrier organisms. These can be achieved through proper pond preparation. One important step in pond preparation is the application of hydrated lime. This paper describes the effect of hydrated lime application to condition pond soil to pH 11 on the pond ecosystem, more specifically on soil pH and biota. The experiment was done using three 600 m2 brackish water ponds. After hydrated lime application, the wet soil pH on the 1st-8th day was significantly higher (P<0.05) compared to the pH before liming to pH 11, and flushing after flooding for 24 h. Soil pH of 11 was observed 24-48h after lime application. Moreover, unwanted species like crabs and fish were found dead. Liming to pH 11 negatively affects the counts of green vibrio colonies thereby decreasing the percentage of green vibrios (PGV). In another experiment, three 750m2 earthen ponds were used. The pond soils were previously positive for the Whitespot Syndrome Virus (WSSV), hydrated lime were applied to bring the pond soil pH to 11. After lime application, WSSV was not detected in the pond soils. Results showed that increasing the soil pH to ≥11 positively affects the pond ecosystem. Liming encourages the proliferation of yellow vibrios and the eradication of carrier species (i.e. crabs) as well as predators (i.e. fish) in the ponds. Furthermore, liming to pH 11 may also eradicate White spot virus from the pond sediment. To implement a 1-unit increase in wet pH, hydrated lime should be applied at 2T/ha.The study was funded by the Government of Japan (GoJ), under the trust fund awarded to SEAFDEC/AQD (study code: 8300-T-RD-FH0710)

SEAFDEC/AQD highlights 2021

SEAFDEC/AQD highlights 2021 is SEAFDEC/AQD's annual report updating on its accomplishments and progress for the year 2021

AQD Matters 2023 March - April

In this issue: 1) SEAFDEC/AQD kicks off 50th anniversary celebration; 2) Oil spill-affected fisher folks learn freshwater aquaculture; 3) 4 fisheries grad join SEAFDEC's pool of skilled aquaculturists; 4) SEAFDEC/AQD stocks up on kawakawa, galunggong anew; 5) Neg Occ seeks assistance from SEAFDEC to establish multi-species hatchery; 6) Community-based hatchery to boost production of giant 'ulang

Reproduction, early development, and larval rearing of the climbing perch Anabas testudineus (Teleostei: Anabantidae) in captivity

Induced spawning, early development, and larval rearing of the climbing perch Anabas testudineus were examined under captive conditions. Five female climbing perch [125.33 ± 3.27 mm standard length (SL); 70.67 ± 5.59 g body weight (BW)] were each paired with apparently mature males (108.50 ± 3.97 mm SL; 39.27 ± 4.70 g BW) and induced to spawn with 5,000 IU human chorionic gonadotropin (hCG) + 0.5 mL Ovaprim/kg BW. All hCG + Ovaprim-injected fish spawned 9 – 11 h after hormone administration but saline-injected fish (control group) failed to spawn. Mean egg production per female, fertilization and hatching rates, and larval production per female were 7,667 ± 1,313, 98.11 ± 1.63%, 61.01 ± 19.92%, and 4,435 ± 1,041, respectively. Fertilized eggs (1.52 – 1.96 mm in diameter) were almost spherical, non-adhesive, transparent, and buoyant due to a large, single oil globule (515 ± 33 µm in diameter). First cleavage appeared 30 min post-fertilization (MPF) and egg development lasted for 20 – 24 h post-fertilization (HPF) (29°C). Newly hatched climbing perch larvae [1.73 ± 0.08 mm in total length (TL)] with yolk volume (YV) and oil globule volume (OGV) of 0.545 ± 0.104 mm3 and 0.072 ± 0.013 mm3, respectively had no pigmented eyes or functional mouth parts and digestive tract, and immobile with the yolk sac pointed upward. Eyes became pigmented and both mouth and anus opened in 1 d old larvae (2.09 ± 0.04 mm TL) in preparation for exogenous feeding. Except for body depth (BD) and pre-anal length (PAL), a general increase in TL (1.73 – 3.72 mm), eye diameter (ED) (0.164 – 0.378 mm), head length (HL) (0.205 – 0.923 mm), and mouth gape (MG) size (0.308 – 0.552 mm) was observed, coinciding with yolk resorption in 7 d post-hatched larvae. Climbing perch larvae were reared at four stocking densities (25, 50, 75, 100 larvae L-1) and fed solely on live food (Brachionus rotundiformis from days 2 to 12 and Artemia nauplii from days 13 to 40) or co-fed live food and microparticulate diet (MPD) (Artemia nauplii from days 2 to 15 and Artemia + MPD from days 16 to 40). Mean survival rates at lower densities (25 – 50 larvae L-1) were significantly higher than those reared at 75 and 100 larvae L-1 (P < 0.05). Furthermore, climbing perch larvae co-fed Artemia nauplii and MPD showed better survival (28.67 – 81.00%) than those fed solely on live food (24.88 – 64.00%). However, at the end of the 40 d trial period, growth parameters did not vary significantly among densities (P > 0.05), except for the condition factor in larvae co-fed Artemia nauplii and MPD. Taken together, results demonstrate the effectiveness of hCG + Ovaprim for captive breeding and observations on the early development of climbing perch, and the feasibility of rearing the larvae at 25 – 50 L-1 on a combination of Artemia nauplii and MPD under laboratory conditions.This study was supported by the SEAFDEC/AQD (Nr-02-F2013B and Br-02-F2015B)

Black tiger shrimp (Penaeus monodon) hatchery operations using enhanced biosecurity measures

This manual, titled “Black Tiger Shrimp (Penaeus monodon) Hatchery Operations Using Enhanced Biosecurity Measures,” includes modifications on shrimp hatchery operations done by the Aquaculture Department of the Southeast Asian Fisheries Development Center to provide high- quality postlarvae for shrimp farming. Discussed also in this manual are the necessary protocols and biosecurity measures that shrimp hatchery operators can use as their guide. Main sections included in this manual: 1. Site Selection, 2. Biology, 3. Hatchery Layout, 4. Facilities and Equipment, 5. Biosecurity Standard Operating Procedures, 6. Hatchery Operations, 7. Diseases of Shrimps, and 8. Economic Analysis