The new technical solutions in thee presentstudy including stocking density, feeding ration, photoperiod and optimum DHAProtein Selcon enriched concentration are firstly applied to impro
Trang 1MINISTRY OF EDUCATION AND TRAINING
NHA TRANG UNIVERSITY -oo0oo -
NGO VAN MANH
EFFECTS OF SOME TECHNICAL FACTORS ON
REPRODUCTIVE PERFORMANCES AND RESULTED SEED
PRODUCTION OF SNUBNOSE POMPANO (Trachinotus blochii
Lacepede, 1801) IN KHANH HOA
Major code: Aquaculture Code: 62620301
SUMMARY OF DOCTORAL THESIS
KHANH HOA – 2015
Trang 2Research was accomplished at Nha Trang University
Supervisors: 1 Associate Prof PhD Lai Van Hung
2 PhD Ngo Anh Tuan
Referee 1: Associate Prof PhD Do Van Khuong
Hai Phong Research Institute for Marine Fisheries
Referee 2: PhD Truong Ha Phuong
Research Institute for Aquaculture No 3
Referee 3: PhD Huynh Minh Sang
Institute of Oceanography
The thesis was defended at the committee of doctorate thesis examiners of Aquaculture Institute in Nha Trang University at …… , ………, ……… 2015
The thesis can be found at: National Library of Vietnam
The Library of Nha Trang University
Trang 3The snubnose pompano (Trachinotus blochii) is a pelagic fish and able to
tolerate a wide range of salinities It has become an important marine fish at manycountries in Asian Pacific Ocean due to high market price, available culturetechniques Many studies had been conducted on reproduction and grow-out culture ofthis species However, the current problems relating to the low maturity, low fertilizedand hatching rates as well as fluctuated survival rate and high deformity of early larvaehas not been paid adequate attentions
Many studies have indicated the influence of egg and larval quality on seedproduction This may be attributed by aspects of the broodstock nutrition The dietscontaining available n-3 HUFA, vitamin E and astaxanthin play important roles ingonadal development and quality In addition, the applications of new technicaladvances in fish reproduction including feeding regime, stocking density, nutrientsupplementation as well as photoperiod to enhance the efficiency of rearing efficiencyalso evaluated in some marine fish species such as European sea bass, barramundi
Therefore, it is important to continuously solve the current problems to improvereproductive effeciency of snubnose pompano Acording to these reasons, the thesis
“Effects of some technical factors on reproductive performances and resulted
seed production of snubnose pompano (Trachinotus blochii Lacepede, 1801) in
Khanh Hoa »was conducted
Objectives:
- General objective: Provide new techniques in reproduction of snubnose pompano
- Particular objective: Improve the fecundity, egg and larval quality as well asjuvenile rearing efficiency
The main contents:
1 Effects of different trash fish, feeding rations and vitamin E levels fed to snubnosepompano broodstocks on reproductive efficiency in terms of fecundity, egg andlarval quality
2 Effects of different hormones injected to broodstocks on fecundity, egg and larvalquality of snubnose pompano
3 Efficiency of technical solutions applied in larval and juvenile rearing of snubnosepompano
The significances:
Trang 4- Scientific significance: This research contributes to the understanding inreproduction and seed production.
- Practical significance: The results of the research provide suitable techniques insnubnose pompano reproduction The application of these protocols can improvesurvival rate and growth performance of snubnose pompano in hatcheries.Consequently, it also introduces new species for marine finfish aquaculture inVietnam
Findings
- This is the first publication in nutritial requirement for broodstocks of snubnosepompano in Vietnam The study has determined the suitable diets, optimumfeeding ration and vitamin E for broodstocks of snubnose pompano The suitablehormones and dose also have been determined to optimize the reproductiveperformances of snubnose pompano The new technical solutions in thee presentstudy including stocking density, feeding ration, photoperiod and optimum DHAProtein Selcon enriched concentration are firstly applied to improve the survival,growth performances of snubnose pompano in Vietnam
Trang 5CHAPTER 1 – LITERATURE REVIEW 1.1 Overview of marine fish culture in the world and Vietnam
In 2010, the total production marine fish culture in both marine and brackishwater was 4,429,000 tons, accounting for 19,3% of total production of aquaculture.The average annual growth rate for brackishwater fish and marine fish aquacultureproduction from 1990 to 2010 was 9,3% The major cultured species were Atlanticsalmon, snapper, European seabass, red drum, milkfish, grouper, barramundi, redseabream, mullet, turbot, cobia, cod and tuna, in which salmon aquaculture productionwas 1.9 00.000 tons The main producers were China, Norway, Chile, Japan, Greece,Turkey, Taiwan-China, Philippine, Indonesia and Vietnam
The marine fish aquaculture in Vietnam started in 1990s in small-scales systemsincluding cages and earthern ponds in coastal provinces such as Quang Ninh, HaiPhong, Nghe An and Khanh Hoa, in which grouper, barramundi and cobia and redsnapper were the major cultured species Although, the successful reproductions ofsome marine finfish have been developed, the limitation of seed supply still has not metthe seed demand for marine aquaculture
The reproduction of snubnose pompano was first developed in Taiwan in 1989,and then China, Indonesia and Vietnam also achieved the success in reproduction ofthis species
1.2 Biology of snubnose pompano
Snubnose pompano (Trachinotus blochii Lacepede, 1801) is belong to
Carangidae family, the order Perciformes It mainly distributes in Pacific Ocean,Atlantic Ocean and Indian Ocean
Snubnose pompano is omnivores, but mostly feed aquatic animals with activefeeding Snubnose pompano has fast growth rate Juvenile (19 – 26 g) can grow to 608
– 610 g after 5 months
The breeding season of snubnose pompano was from March to October, andindependent with the fullmoon The fecundity of this species ranges from 38.000 –122.000 eggs/kg female
1.3 The maturity and spawning of teleost fish.
The reproductive biology varied in fish species to adapt to the environmentalconditions For example, the Pacific salmon only spawn once before death, whilemany other species can spawn many times during their life Many species usuallybuild nests for spawning and egg protection, while the changes in reproductive
Trang 6characteristics including increase in fecundity, reproduce several times per year areobserved in unprotected egg species.
The available foods and environmental conditions play important roles in fishreproduction Fish can perceive and utilize seasonal variations in environmentalfactors such as photoperiod, temperature, moon phase, water flowing and waterpressure to ensure reproductive success during suitable periods of the year
The breeding cycle is controlled by hormones produced from pituitary glandand gonad, in which gonadotropic hormone (GTH), follicle- stimulating hormone(FSH) and luteinizing hormone (LH) play important roles
1.4 The overview on nutrional requirements of broodstock and young juvniles
The broodstock nutrition management plays important role in improvement thequality of eggs and larvae, determining the success of marine fish reproduction
The available foods with good quality play crucial roles in survival anddevelopment of larvae Thus, the understanding in nutritional requirement, digestivedevelopment and suitable feeding regimes is particularly important in the development
of early larvae
1.5 The effects of induced hormone on reproductive performance of fish
The determination of hormone injections or adjusting the ecological factorschanges in each fish, depending on the reproductive biology, maturity Currently, thereare several types of hormones including LHRHa, ovaprim, pituitary gland, HCG, PMSused in fish reproduction with different advantages and disadvantages effects
Many studies has evaluated the effects of hormones on the fecundity, time tospawn of broodstocks, while the knowledge on the reproductive cycles, the quality ofegg and larvae affected by hormones is still unknown
1.6 The effects of stocking density, diets and photoperiod on growth performances
of young juveniles
In juvenile stage, the high stocking density may leads in the competition forfood and living space, resulting in low survival and high coefficient variation Besides,other factors such as diet, water- flow, color tanks, light and diseases also affect thegrowth, survival and feeding behavior of juveniles
Trang 7CHAPTER 2 MATERIALS AND METHODS
2.1 Species, time and location of research
- Species: Snubnose pompano (Trachinotus blochii Lacepede, 1801)
- Duration: June 2009 – June 2013
- Location: All experiments for broodstocks were conducted in Marine fishaquaculture station, located in Nha Trang bay, Khanh Hoa, whereas the trials forlarvae and juvenile were carried out in Duong De marine seed production hatchery
in Nha Trang, Khanh Hoa
2 2 Contents
Figure 2.1: Diagram of the research
Evaluating the effects of technical solutions on eggs, larvae quality and juvenile rearing efficiency
of snubnose pompano in Khanh Hoa province
Effects of different trash
fish, feeding rations and
vitamin E levels fed to
From larvae to fry
- Effects of the stocking density
- Effects of live feed with DHA Protein Selco enrichment
- Effects of weaning time to micro diets
- Effects of the photoperiod Evaluated parameters:
- Reproductive performance (maturity,
to broodstocks on fecundity, egg and larval quality of snubnose pompano.
From fry to juvenile
- Effects of the stocking density
- Effects of the feeding rations
- Effects of the photoperiod and feeding frequency.
Trang 82.3 Materials and methods
The second trial: Effects of feeding ration fed for broodstocks on reproductive performances of snubnose pompano.
Based on the results in the first trial, the broodstocks in this experiment werefed diet containing at 4 feeding ratios: 5% (NT1); 7% (NT2); 9% (NT3) and 11%(NT4) The broodstock, cages, stocking density were similar as descriptions in the firsttrial The fecundity, egg diameter, floated egg rate, fatty acid profile in egg, fertilizedrate, hatching rate, larval size, deformity and survival rate of larvae three day afterhatching were evaluated to determine the suitable feeding ration for broodstocks
The third trial: Effects of vitamin E supplementation in diet fed for broodstocks
on reproductive performances of snubnose pompano.
In this trial, all broodstocks were fed with 5 levels of vitamin E supplementing:
0 mg/kg (NT1); 250 mg/kg (NT2); 500 mg/kg (NT3); 750 mg/kg (NT4) and 1.000mg/kg (NT5) The feeding ration was 9 % body weight based on results of the secondtrial The broodstock, cages, stocking density were similar as descriptions in the firsttrial The fecundity, egg diameter, floated egg rate, fatty acid profile in egg, fertilizedrate, hatching rate, larval size, deformity and survival rate of larvae three day afterhatching were evaluated to determine the optimum dietary vitamin E for broodstocks
Trang 9The fourth trial: Effects of induced hormones on reproductive performances of snubnose pompano
Broodstocks were fed diet containing 70% fish: 15% squid and 15% shrimpwith 750 mg/kg vitamin E supplementing at feeding ration of 9% body weight.Broodstocks were injected different hormones including 50 µg LRHa + 5 mg DOM/kg(NT1); 1200 IU HCG/kg (NT2); 500 IU HCG + 40 µg LRHa/kg (NT3); Common carppituitary of 10 mg/kg (NT4) and saline water at 0,5 mL/kg (NT5) The fecundity, eggdiameter, floated egg rate, fertilized rate, hatching rate, larval size, deformity andsurvival rate of larvae three day after hatching were evaluated to determine the suitablehormone for reproduction The broodstock, cages, stocking density were similar asdescriptions in the first trial
2.3.3 Methods used in 3rd content.
2.3.3.1 Larvae
Fertilized eggs were obtained from reproduction in Vung Ngan station, and thentranferred to Duong De marine seed production hatchery for incubation Newlyhatching larvae were selected and used for experiments
The fifth trial: Effects of stocking densisty on growth, survival and deformity of snubnose pompano larvae.
Satge 1: From newly hatched larvae to 23rd days old
The larvae were randomly distributed to twelve 100-L fiber-glass tanks with 4stocking densities including 15, 30, 45 and 60 larvae/L Each experimental density wasassigned to three randomly positioned tanks The survival rate, growth rate, deformity
of larvae were evaluatetd after 23 days of experimental period
Stage 2: From fry to juvenile
The fry ( average length 19,22 ± 1,63 mm and weight 0,42 ± 0,03g) wereselected from previous trials and randomly distributed to twenty four 70-L fiber-glasstanks with 8 stocking densities including: 1,0; 1,5; 2,0; 2,5; 3,0; 3,5; 4,0 and 4,5inds/L Each experimental density was assigned to three randomly positioned tanks.The survival rate, growth rate, deformity and feed conversion ratio were evaluatetdafter 28 days of experimental period
Trang 10The sixth trial: Effects of DHA Protein Selco levels in live feed on growth performances and shock resistance of snubnose pompano larvae.
The larvae were randomly distributed to thirty two 100-L fiber-glass tanks atthe stocking density of 40 larvae per tank Fish was fed live feed contained DHAProtein Selco enrichment with 8 concentrations: 0, 50, 100, 150, 200, 250, 300 and
350 ppm The survival rate, growth rate, deformity and shock resistance to temperatureand salinity shocks were evaluatetd after 33 days of the feding period Whereas theresistance to mechanical shock was evaluated after 23 and 33 days of the feedingperiod
The seventh trial: Effects of weaning time to commercial diet on growth performances and survival of snubnose pompano fry.
The newly hatching larvae were cultured in 4 m3 tanks for 12 days and then fish(average length 4,45 ± 0,81 mm and weight 2,71 ± 0,29 mg) were randomlydistributed to twenty-one 70-L fiber-glass tanks at the stocking density of 5 ind/L Fishwas fed a commercial diet (NRD, INVE, Thailand) at 7 different weaning timesincluding 13, 15, 17, 19, 21, 23, 25 days after hatching Each treatment was assigned
to three tanks and lasted for 20 days
The eighth trial: Effects of feeding rations on growth performances and survival of juvenile snubnose pompano.
Juveniles (35 days after hatching) had average length 19,76 ± 1,23 mm andweight 0,35 ± 0,04 g were randomly distributed to fifteen 70-L fiber-glass tanks at thestocking density of 2 inds/L Fish was fed commercial diet (NRD, INVE, Thailand)with 5 feeding rations including 3, 6, 9, 12 and 15 % wet body weight Each treatmentwas assigned to three tanks The survival rate, growth rate, deformity and feedconversion ratio were evaluatetd after 28 days of experimental period
The nineth trial: Effects of photoperiods on growth performances and survival of snubnose pompano larvae.
The larvae were randomly distributed to twelve 100-L fiber-glass tanks atstocking density of 40 inds/L The tank was controled with 4 photoperiod regimesincluding natural photoperiod 8 hours/day – 8L:16D (NT1); 12L:12D (NT2); 18L:6D
Trang 11(NT3) and 24L:0D (NT4) Each treatment was assigned to three tanks The survivalrate, growth rate, deformity were evaluatetd after 25 days of experimental period.
The tenth trial: Effects of photoperiod and feeding frequency on growth performances and survival of juvenile snubnose pompano.
Juveniles (average length 12,15 ± 1,14 mm and weight 0,12 ± 0,01 g) wererandomly distributed to twenty-four 70-L fiber-glass tanks Fish was fed 4 feedingrations (2, 4, 6, 8 times/day) with 2 photoperiod regimes (12 and 18 hours) Eachtreatment was assigned to three tanks The survival rate, growth rate, deformity andfeed conversion ratio were evaluatetd after 28 days of experimental period
of different factors and interaction in two factor experiments The statisticalsignificance was evaluated at P < 0.05 All charts were drawed using Microsoft Excel