Larviculture and seed production protocols for the silver pompano Trachinotus blochii, which is one of the promising finfish

species for brackishwater and marine aquaculture was developed based on six trials for the first time in India. The newly

hatched larvae were stocked at a density of 20 larvae l-1 in 2 t FRP tanks with 1.5 t of seawater. Green water technique was

employed during larviculture upto the weaning period. Enriched S-type rotifers were fed at a density of 10-12 nos. ml-1 until

3 day post hatch (dph) and the enriched L-type rotifers were given at a density of 6-8 nos. ml-1 from 7 dph and thereafter with

enriched Artemia at a density of 3-5 nos. ml-1. Weaning started from 15 dph and by 20-25 dph metamorphosis was completed.

The survival on completion of metamorphosis ranged from 10-15% and the specific growth rate in terms of length (mm) was

8% per day. The larval morphology and growth pattern are also described

Anbarasu, M

Balamurugan, V

Gopakumar, G

Jayakumar, R

Jayasingh, M

Kalidas, C

Nazar, A K A

Ramesh Kumar, P

Sakthivel, M

Sirajudeen, S

Tamilmani, G

CMFRI Digital Repository

83Larviculture and seed production of the silver pompano, Trachinotusblochii  (Lacepede, 1801) for the first time in IndiaA. K. ABDUL NAZAR, R. JAYAKUMAR, G. TAMILMANI, M. SAKTHIVEL,C. KALIDAS, P. RAMESH KUMAR, M. ANBARASU, S. SIRAJUDEEN,V. BALAMURUGAN, M. JAYASINGH AND G. GOPAKUMARMandapam Regional Centre of Central Marine Fisheries Research InstituteMandapam - 623 520, Tamil Nadu, Indiae-mail: drggopakumar@gmail.comABSTRACTLarviculture and seed production protocols for the silver pompano Trachinotus blochii, which is one of the promising finfishspecies for brackishwater and marine aquaculture was developed based on six trials for the first time in India. The newlyhatched larvae were stocked at a density of 20 larvae  l-1 in 2 t FRP tanks with 1.5 t of seawater. Green water technique wasemployed during larviculture upto the weaning period. Enriched S-type rotifers were fed at a density of 10-12 nos. ml-1 until3 day post hatch (dph) and the enriched L-type rotifers were given at a density of 6-8 nos. ml-1 from 7 dph and thereafter withenriched Artemia at a density of 3-5 nos. ml-1. Weaning started from 15 dph and by 20-25 dph metamorphosis was completed.The survival  on completion of metamorphosis ranged from 10-15% and the specific growth rate in terms of length (mm) was8% per day. The larval morphology and growth pattern are also described.Keywords: Artemia nauplii,  Green water technique, Larviculture, Rotifer, Silver pompano, Survival, Trachinotus blochiiIntroductionThe silver pompano, Trachinotus blochii is one of thesuitable candidate species for aquaculture due to its fastgrowth, good meat quality and high market demand.Further, silver pompano grows excellently in low salinity(as low as 8 ppt) (Gopakumar et al., 2011) and has goodadaptability to different farming environments. This specieseasily accept artificial feeds as it is omnivorous and has arapid and uniform growth rate compared to other farmedfishes (Chavez et al., 2011). It can be successfully culturedin tanks, ponds and cages. This species is caughtsporadically in commercial fishery and therefore itsavailability is rather scarce in fish markets. Though the seedproduction and farming of the Florida pompano,Trachinotus carolinus has been established much earlier(Moe et al., 1968; Hoff et al., 1972, 1978; McMaster, 1988),until recently there was no  focused research on pompanoaquaculture in India.Although silver pompano is a good candidate foraquaculture, its hatchery production is not withoutproblems. Even the availability of brooders from wild forinitiating the breeding trials is limited and the availabilityof male brooders from the wild is furthermore scarce. Dueto its potential in mariculture, major thrust was given bythe Central Marine Fisheries Research Institute (CMFRI)Indian J. Fish., 59(3) : 83-87, 20121for captive broodstock development since the year 2007and the first success in breeding and seed production ofsilver pompano was achieved at Mandapam RegionalCentre of CMFRI in 2011 (Gopakumar et al., 2012).Trials on larviculture were conducted to develop aprotocol for seed production.  Published reports on thelarviculture of silver pompano are very scarce except theone reported by Juniyanto et al. (2008). The results oflarviculture and seed production conducted at MandapamRegional Centre of CMFRI are described in the presentpaper.Materials and methodsThe fertilized eggs  obtained from captive broodstockdeveloped as reported in our earlier publication(Gopakumar et al., 2012) were counted and incubated in2 t capacity circular fibre reinforced plastic (FRP) tankswith mild aeration. The eggs hatched between 34 to 36 hof incubation. The newly hatched larvae were stocked inrectangular FRP tanks  of 2 t capacity. Each FRP tank wasfilled to a volume of 1.5 t of dechlorinated seawater. Thelarvae were stocked at a density of 20 nos. l-1. The numberof tanks employed varied with the number of newly hatchedlarvae obtained in each spawning. The aeration in the tankswas increased slightly during larviculture. Larviculturetanks were provided with green water, feeding was initiated84with enriched rotifers, followed by enriched Artemia naupliiand subsqquently switched to larval inert feeds. The detailsof water exchange in the larviculture tanks are given inTable 1.Green water technique employing the microalgaNannochloropsis oculata was followed during thelarviculture up to the weaning period. Both S-type(Brachionus rotundiformis) and L-type rotifers (Brachionusplicatilis) cultured using S.parkle (INVE, Thailand)supplemented with Nannochloropsis oculata at a densityof 3 x 107 cells ml-1 and Artemia nauplii were used as livefeeds. The weaning to NRD formulated larval diet (INVE,Thailand) of appropriate particle size was started from15 day post-hatch (dph). The rotifers were enriched for12 h while Artemia nauplii were enriched  for 22 h prior touse. The enrichment medium used was Selco S. presso(INVE, Thailand).Natural photoperiod was used for the larviculture tankswith illumination curtailed up to 70% using translucent FRPsheets in the hatchery roof. Salinity (by portablerefractometer), dissolved oxygen, DO (by Winkler’s method)and temperature (using mercury thermometer) were recordedin each tank daily. Dead larvae were collected usingappropriate strainers during the period of water exchangeand were counted for estimating the mortality. The larvalsurvival was quantified by taking samples at differentlocations of the tanks, using a PVC pipe of 1.5 inch dia and150 cm length. The  lengths of at least 20 larvae weremeasured daily to the nearest mm. They were placed onglass  slides and photographed  using Zeiss stemi-2000Cstereo-microscope and Canon Powershot-G10 camera.Specific growth rate (SGR) in mm was calculated as follows,to estimate the percentage length increase per day.ln final length (mm) – ln Initial length (mm)SGR  =  –––––––––––––––––––––––––––––––––  X 100Duration of the experiment (days)Six  larviculture trials were conducted during July toDecember 2011.Results and discussionLarval feeding protocolThe larval feeding protocol developed for successfulseed production is summarised in Table 1. Green water wasused till the weaning period at a density of 3 x 107 cells ml-1.Enriched S- type rotifers were given at a density of10-12 nos.  ml-1 from 3 dph onwards while the enrichedL- type rotifers were provided from 7 dph at a density of6-8 nos. ml-1 two times daily. The lorica length of theS- type rotifers was 120.8 ± 16.21 µ and that of L-typerotifers was  222.9 ± 23.10 µ. The enriched Artemia naupliiwere provided at a density of 3-5 nos. ml-1. Along withArtemia, co-feeding with decreasing quantities of rotiferswas  continued for 3 days due to the presence of differentsize groups of larvae. From 15 dph onwards, weaning ofthe larvae from Artemia to commercially available NRDlarval feed was started. Generally, water exchange was notcarried out during the first 4 days. The water exchange toan extent of 20% was provided initially to remove the algalsettlement and dead larvae. Water exchange was increasedafter weaning to artificial feed.While weaning to inert larval feeds, very smallquantities were fed initially to make the larvae graduallyaccept the feed and also to reduce the accumulation ofuneaten feed at the bottom of the tank. The transition fromArtemia nauplii to NRD inert feed was found to be smoothand quick. The size of the weaning feed used first was300-500 µ. From 20 dph onwards, only formulated feedwas provided. The inert feed of size range of 600-800 µwas provided on 19 dph along with the feed of size300-500 µ to cater to the different size groups of larvaepresent in the larviculture tanks. From 23 dph onwards,NRD feeds of 0.8 to 1.2 mm were used. The length of theA. K . Abdul Nazar  et al.Table. 1. Larval feeding protocol for T. blochiiGreen water / Feed Days post-hatch Density Frequency of Water(DPH) feeding exchangeGreen water (N. occulata) 0 - 2 3 x 107 cells ml-1 Nil 0 %Green water +Enriched S-type rotifer 3 - 6 10-12 nos. ml-1 2 times per day 20%Green water +Enriched L-type rotifer 7 - 14 6-8 nos. ml-1 2 times per day 20 %Green water +Enriched Artemia nauplii 12 - 19 3-5 nos. ml-1 2 times per day 70 %Formulated feed (300-500 µ particle size) – 15 - 18 Weaning started 2 times per day  70 %provided 1 h before the supply of live feed on 15th dayFormulated feed (300-500 µ  to 19 - 22 Provided ad libitum 3 times per day 100 %600-800 µ particle size) –provided before the supply of live feedFormulated diet (0.8-1.2 mm) 23 - 25 Provided 3 times per day 100 – 200%dph onwards ad libitum85larvae measured on 0 dph and 25 dph were 2.1 and15.5 mm respectively. The final survival (on completionof metamorphosis) recorded during the larviculture trialsranged from 10-15% (Fig. 1). The specific growth raterecorded was 8 % per day. Salinity and temperature rangedfrom 33-35 ppt and 28-30 °C respectively throughout theculture period. The DO recorded ranged from 4.5 to6 mg l-1.onwards at MML whereas in the present study with thesilver pompano, the same was initiated from 12 dphonwards. In another study on T. carolinus by Riley et al.(2009), INVE NRD Micro Pellet of 400-800 µ was providedto 10 dph larvae.The stocking density followed in the present studywas 20 nos. l-1 where as MML reported a stocking densityof  25 nos. l-1. In another study with T. carolinus, a stockingdensity of 50 nos. l-1 was followed (Cavalin and Weirich, 2009).Larval growth, morphology and behaviourVarious stages of larval development of silverpompano are  presented in Fig. 2(a-h) . The newly hatchedlarvae lack mouth opening (Fig. 2a). They have large andelongated yolk sac extending beyond the head and alongthe ventral region of the head and alimentary canal. Theyolk reserves generally last for two to three days dependingon water temperature and it coincides with eyepigmentation, mouth formation and first feeding. The mouthgape of larvae was around 200 µ at first feeding stage.Around 6 nos. of opercular spines started appearing from12 dph (Fig. 2e) which became prominent on 15 dph.Among the spines, one was longer. These spines graduallydisappeared  as the fish grew beyond 30 dph. Thedifferentiation of the dorsal, caudal, anal and pelvic beginson 9 dph. The fin rays started appearing on 10 dph andbecame prominent on 12 dph. The different fin types arewell demarcated on 12 dph (Fig. 2f).Melanin pigmentation gradually started on the headand dorsal surface of the body from 3 dph onwards whichspread all over the body and became intense as the larvaegrew. Thereafter, the larvae looked darker in colour till themetamorphosis on 20 to 25 dph when it turned into silverywhite in colour (Fig. 2h). During this time, the fishesdeveloped entire compliments of all fins and scales. Thelarval growth pattern recorded during the larviculture isprovided in Fig. 1.The larvae do not swim actively till first feeding andthey start swimming faster and feed voraciously on 12 dph.When overfed, the larvae were found swimming lazily andvertically with the head in upside position. It is always betterto avoid over feeding in order to keep the larvae healthy.Though we experimented with a stocking density of20 larvae l-1,  it appears  better to stock the larvae initiallyat lesser densities  and pooled in higher numbers  againwhen they become hardy at around 12-15 dph.Nevertheless,  further investigation is required in thisdirection. It is  interesting to note that there was no siblingcannibalism noticed in the silver pompano larviculture,except a case or two when a weak larva died or settled atthe bottom. In our experience, any cannibalism in pompanolarviculture should only be due to shortcomings in theLarviculture of silver pompanoFig. 1. Survival and growth of silver pompano  (T. blochii) larvaeDuring the larviculture of pompano, two critical stageswith varying mortalities were recorded: 1) during 5-6 dphwhen the larvae completely changed from endo- toexogenous feeding. Heavy mortality was noticed at thisstage, and 2) during 15-19 dph when the larvae wereweaned to formulated feed.Juniyanto et al. (2008) reported the use of 5-15 nos.of rotifers  per ml three times a day during the larvicultureof T. blochii from day 3 to day 14. Artificial pellets of size250-300 µ were provided from day 10 onwards, in additionto rotifers. Artemia nauplii were given from day 14 onwardsat 0.25 individual per ml. The use of rotifers was stoppedon day 15 while the quantity of artificial feed was graduallyincreased every 1-2 h. At day 18, the quantity of Artemiawas also increased to 0.5 individual per ml which wasstopped at day 22. The survival rate reported was 20-25 %.In a larviculture study of Florida pompano,Trachinotus carolinus conducted by the Mote Marinelaboratory (MML) in collaboration with Florida StateUniversity (Main et al., 2005) to determine suitable livefeeds, it was reported that a maximum survival of 3% wasachieved if 100% rotifers were used as live feed while amaximum of 23% survival was reported while using 75%Acartia tonsa and 25% L-type rotifers. Based on the pooleddata collected from the six trials, it was reported that thelive feed comprising 75% Acartia tonsa and 25% L-typerotifers were the best as live feeds for larviculture of Floridapompano (Main et al., 2005). With regard to the use ofArtemia nauplii as live feed, it was started from 13 dph86A. K . Abdul Nazar  et al.Fig. 2. Stages of larval development of silver pompano (T. blochii)a. Newly hatched larva;  b. larva on 2 dph; c. larva on 3 dph; d. larva on 8 dph; e. larva on 12 dph showing opercular spines;f. larva on 12 dph showing fin demarcation; g. larva on 20 dph; h. Just metamorphosed larva on 25 dphA BC DE FG Hfeeding strategies. It is felt that enhancing the survival rateat metamorphosis could be achieved by standardisation offeeding protocols, initial larval density and the intensity oflight in the larval tanks. The larviculture of this species iscomparatively less difficult, which is a positive aspect formass scale production. However, the number of eggsreleased per spawning is limited and hence, more pairs ofbrooders are needed for commercial level seed production.If the required seed availability can be met, lucrativepompano farming practices both in coastal ponds and seacages can be developed in India in the near future.AcknowledgementsThe authors gratefully acknowledge Dr. G. Syda Rao,Director, CMFRI for his keen interest and constantencouragement for carrying out the present study.87ReferencesCavalin, F. G. and Weirich, C. R. 2009. Larval performance ofaquacultured Florida pompano (Trachinotus carolinus) fedrotifers (Brachionus plicatilis) enriched with selectedcommercial diets. Aquaculture, 292: 67-73.Chavez, H. M., Fang, A. L. and Carandang, A. A. 2011. Effect ofstocking density on growth performance, survival andproduction of silver pompano, Trachinotus blochii,(Lacepede, 1801) in marine floating cages. Asian Fish. Sci.,24: 321-330.Gopakumar, G., Abdul Nazar, A. K., Jayakumar, R., Tamilmani, G.,Kalidas, C., Sakthivel, M., Rameshkumar, P., Hanumantarao,G., Premjothi, R., Balamurugan, V., Ramkumar, B.,Jayasingh, M. and Syda Rao, G. 2012. Broodstockdevelopment through regulation of photoperiod andcontrolled breeding of silver pompano, Trachinotus blochii(Lacepede, 1801) in India. Indian J. Fish., 59(1): 53-57.Gopakumar, G., Syda Rao, G., Abdul Nazar, A. K., Jayakumar, R.,Tamilmani, G., Kalidas, C., Sakthivel, M., Rameshkumar,P., Hanumantha, R., Murugan, A., Premjothi, R.,Balamurugan, V., Ramkumar, B. and Jayasingh, M. 2011.Silver pompano: A potential species for mariculture in India– breeding and seed production of silver pompano(Trachinotus blochii). Fishing Chimes, 31(6): 58-60.Larviculture of silver pompanoHoff, F. H., Pulver, T. and Mountain, J. 1978. Conditioning Floridapompano Trachinotus carolinus for continuous spawning.Proc. World Maricult. Soc., 9: 299-320.Hoff, F. H., Rowell, C. and Pulver, T. 1972. Artificially inducedspawning of the Florida pompano under controlledconditions. Proc. World Maricult. Soc., 3: 53-64.Juniyanto, N. M., Akbar, S. and Zakimin 2008. Breeding and seedproduction of silver pompano (Trachinotus blochii,Lacepede) at the mariculture development center of Batam.Aquacult. Asia Mag., 13(2): 46-48.Main, K. L., Marcus, N. and Brown, C. 2005. Developing marinefish hatchery and nursery culture to expand Florida’saquaculture industry, Year 2. 4th Quarterly progress report,Mote Technical Report # 1028.  https://dspace.mote.org/dspace/bitstream/2075 /160/4/MTR%201028.pdfMcMaster, M. F. 1988. Pompano culture: past success and presentopportunities. Aquacult. Mag., 14(3): 28-34.Moe, M. A., Lewis, Jr. R. H. and Ingle, R. M. 1968. Pompanomariculture: preliminary data and basic considerations. Stateof Florida Board of Conservation Technical Series, No. 55.Florida Board of Conservation, Tallahassee, FL, 65 pp.Riley, K. L., Weirich, C.R. and Cerino, D. 2009. Developmentand growth of hatchery-reared larval Florida pompano. Fish.Bull., 107: 318-328.Date of Receipt : 07.06.2012Date of Acceptance : 01.08.2012

Larviculture and seed production of the silver pompano, Trachinotus

blochii (Lacepede, 1801) for the first time in India

http://eprints.cmfri.org.in/9110/1/AKA_Nasser_83-87.pdf

Larviculture and seed production of the silver pompano, Trachinotus blochii (Lacepede, 1801) for the first time in India

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