Advances in Marine and Brackishwater Aquaculture 2

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Part 2 book "Advances in marine and brackishwater aquaculture" includes content: Breeding and seed production of tiger shrimp, semi intensive culture techniques for shrimp farming, review of prospects for lobster farming, mussel farming and its potential in india, present status and future prospects of sea cucumber breeding and culture in india,....and other contents.

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Nội dung Text: Advances in Marine and Brackishwater Aquaculture 2

Breeding and Seed Production of Tiger Shrimp Penaeus monodon P. Soundarapandian VetBooks.ir Introduction resources needs a low-cost technology, which should be simple enough to be used by even In the past, shrimp remained as a luxury com- semi-skilled labourer. The technology presented modity because of its high popularity and cost. here is based on a multidisciplinary research Hence, it was considered as favourite food stuff experience from experimental to commercial for the high society people. However, in recent level (Paul Raj 1999). years, due to increase of population and health consciousness, the modern world made people to consume more of shrimp and shrimp product Biology of Shrimp because of its delicious and safeness among ani- mal origin. In recent years, shrimp has become a Systematic Position more popular source of protein food, which commands high prices in the international mar- ket. This great importance increased the exploi- Phylum : Arthropoda Class : Crustacea tation of shrimp, which lead to sudden decline in Subclass : Malacostraca natural stock. Thus, it has become imperative to Order : Decapoda culture commercially important shrimp species. Suborder : Natantia The aquaculture operation of the shrimp basi- Family : Penaeidae cally requires an abundant, reliable and inexpen- Genus : Penaeus sive source of seed supply: without such source, Species : monodon the productions will not be possible. Hence, the captive shrimp seed production has received much attention. A variety of techniques for hatchery produc- Distribution tion of shrimp seed have been developed in dif- ferent parts of the world, which involved Penaeus monodon occurs in the brackishwater generally capital intensive and high technology. areas, in estuaries and in the inshore waters of A developing country such as India with limited the east and west coasts, but its availability in the world is much lesser when compared to other marine shrimps like P. indicus; P. monodon P. Soundarapandian (*) completes its life cycle in two environments, Centre of Advanced Study in Marine Biology, Faculty of namely, marine and estuarine environment. It is Marine Sciences, Annamalai University, Parangipettai 608502, Tamil Nadu, India a euryhaline species with high tolerance to e-mail: soundsuma@gmail.com ﬂuctuations of salinity. S. Perumal et al. (eds.), Advances in Marine and Brackishwater Aquaculture, 109 DOI 10.1007/978-81-322-2271-2_12, # Springer India 2015
110 P. Soundarapandian Its general distribution is along the entire east The food of the fry in the cultivating ponds is coast of Africa, Madagascar, Mauritius, Pakistan, ‘lab lab’, blue green algae and mixture of minute east and west coasts of India, Sri Lanka, plant and animals. Andaman and Nicobar Islands, Singapore, The larvae during zoeal stages feeds on algae, Malaysia, the Philippines, Southern Japan, mainly diatoms like Chaetoceros sp. Mysis stage Celebes and Nearby Islands, Taiwan and onwards feeds on minute zooplankton like Queensland and New South Wales in Australia. nauplii of Artemia sp. or phytoplankton. VetBooks.ir Postlarvae are carnivorous and prefer to feed on zooplankton. Identification (Plate 1) Alternating dark and light bands on its abdominal Growth segments and also uniform coloured internal ﬂagella This is the fast-growing and largest shrimp in the • Swimming legs fringed with bright red setae world. The female grows to a length of 363 mm • Yellow colour blotch at the base of the walk- (440 g), while the maximum size attained by ing and swimming legs males is 270 mm (180 g). In shrimp culture • Rostrum long, sigmoid with 7–8 dorsal teeth farms, they are usually harvested about and 2–3 ventral teeth 160–165 mm (30–35 g) in size. The stocked seed (15–20 mm) attain this harvest size in about 4 months in 15–25 ppt salinity. Food and Feeding Habits Crustaceans form the main food item comprising Male and Female Identification (Plate 2) the harpacticoid copepods and parts of brachyurans. Other item of food is bivalve The males are usually smaller in size and have molluscs, parts of ﬁsh, polychaete worms and external reproductive organ called petasma, vegetable matters. which is found in the ﬁrst pair of pleopods. Plate 1 Penaeus monodon
Breeding and Seed Production of Tiger Shrimp Penaeus monodon 111 VetBooks.ir Plate 2 Male and female The females are larger in size and can be broodstock on account of differential growth identiﬁed by the presence of the external repro- rate. In nature, 3 or 4 spawning may occur in ductive organ called thelycum, which is situated a year. at the base of 4th and 5th pair of walking legs. Life Cycle Maturity Though it dwells in the littoral waters, it has an The species grows to maturity, when their sizes estuarine phase in its life cycle. The adults are around 200 mm (weighing about 65 g) in mature, mate and release eggs in the deep part male and 240 mm (90 g) in female. of littoral waters. The hatched out larvae dwell in the surface waters of the ocean till they reach postlarval stage. The postlarvae will drift Fecundity towards coastal estuarine/brackishwater areas, which serve as nursery ground for them. As Fecundity ranges from 2 to 19 lakh eggs these grow to subadult stage, they start migrating depending upon the size of the female. Fecundity towards inshore sea, where they mature and is more in the wild than in pond-reared reproduce. BRACKISHWATER COASTAL/ESTUARINE (5 TO 25 PPT) OR OCEANIC WATERS (28 TO 35 PPT) POSTLARVAE MIGRATION POSTLARVAE MYSIS ZOEA JUVENILES SHRIMP LIFE CYCLE NAUPLII ADOLESCENT MIGRATION SUB ADULTS ADULTS EGGS
112 P. Soundarapandian Larval Stages (Plate 3) Zoea The larval phase of the shrimp life cycle is spent in This is the ﬁrst feeding stage. Its body is elon- inshore sea in nature, and hence they need an gated and carapace, thorax and abdomen are environment with a salinity of 28–35 ppt. Nauplii distinct. Antennae, mandibles, maxillae and subsist on yolk and mysis feed on phytoplankton maxillipeds are also distinct and are useful in (unicellular algae) and zooplankton (microscopic ﬁlter feeding and swimming (7–8 pairs of VetBooks.ir animals). Postlarvae are carnivorous and prefer to appendages). It has three substages. feed on the zooplankton. The identiﬁcation features of larval stages are given in Table 1. Mysis Nauplius Mysis has well-developed carapace and abdo- men. The ﬁve pereopods have undergone consid- Nauplii are pyriform in shape, light brown in erable enlargements. The exopods serve as colour, opaque and swim in short jerks by swimming organs (13 pairs of appendages). The means of three pairs of appendages, namely, Mysis keeps its head down and swims. It has ﬁrst antennae, second antennae and mandibles. three substages. This stage has six substages. Plate 3 Larval stages
Breeding and Seed Production of Tiger Shrimp Penaeus monodon 113 Table 1 Identification of larval stages of P. monodon Stage Duration Feed Identiﬁcation features Egg 12–15 h after spawning – – N 1 5–6 h Subsists on yolk Furcal spines 1 + 1. The setae on appendages are not plumose N2 5–6 h Subsists on yolk Furcal spines 1 + 1. The setae on appendages are not plumose (well developed) VetBooks.ir N3 5–6 h Subsists on yolk Furcal spines 3 + 3 N4 5–6 h Subsists on yolk Furcal spines 4 + 4 N5 5–6 h Subsists on yolk Furcal spines 5 + 5 N6 15–20 h Subsists on yolk Furcal spines 6 + 6, 6 + 7 Z1 1½–2 days Unicellular algae No eye stalks Z2 1 day Unicellular algae Stalked eyes Z3 1½–2 days Unicellular algae A pair of biramous uropods and dorsal median spines on abdomen M1 1½–2 days Unicellular algae and minute Rudiments of pleopods. (Mysis keeps its head animals (zooplankton) down and glides) M2 1 day Unicellular algae and minute Unsegmented pleopods animals (zooplankton) M3 1½–2 days Unicellular algae and minute Segmented pleopods with terminal setae animals (zooplankton) PL 1 1 day Zooplankton Segmented pleopods with setae will over (postlarvae swim horizontally) Postlarvae gradient and surf action should be minimal for easy drawing of seawater. Fully developed postlarva resembles the adult in • The seawater salinity should be within the its shape. It has well-developed pleopods, which range of 28–35 ppt. serve as main swimming organs (19 pairs of • The seawater pH should be within the range of appendages). It swims horizontally like an 7.7–8.2. adult. The postlarvae are aged in days, after its • The seawater should have very low suspended ﬁrst appearance, calling it PL 1 on its ﬁrst day solids preferably below 20 ppm at any and PL 2 on its second day and so on. Usually in given time. hatchery, they are reared up to PL 3–5 in larval • The seawater should be free from agricultural, section and then transferred to postlarval section industrial and sewage pollution. for further rearing up to PL 20. These stages can easily be acclimatised to lower salinities. Freshwater Freshwater should be available in sufﬁcient quantity for daily hatchery operations such as salinity adjustment, cleaning and domestic use. Site Selection Ground water is preferred because of its better quality than surface water. Major Criteria for Site Selection Proper site selection is the key to a successful Climate hatchery. The major criteria for site selection are Rainfall: Total annual and monthly average rain- as follows: fall should be carefully studied, as it inﬂuences on seawater quality and hatchery operations Seawater like outdoor algal culture, drying, etc. • The hatchery site should be located close to Temperature: Atmospheric temperature the sea. The seashore should have gradual variations are also an important climatic
114 P. Soundarapandian factor to be taken into consideration as it Availability of labour: Labour should be avail- inﬂuences water temperature in the hatchery able locally for daily hatchery operations. areas. Wind: Wind direction and speed is important as it creates swells in the sea, resulting in turbidity Seawater Intake System of seawater. It should also be considered for design of structures and buildings. Seawater intake system used here to draw sea- VetBooks.ir Humidity and sunshine: These climatic factors water for hatchery operations is called sub-sand are important for various aspects of hatchery ﬁlter intake system (Plate 4). In this system, a operations like drying of tanks, rearing areas PVC pipe of 250 mm diameter having perfora- and heating of water during low-temperature tion on its surface and wound with two layers of period. plankton mesh and one layer of coconut coir rope is buried vertically under the sand bed to about Topography 3 m below the existing bed level. Topography means the ‘lag of land’. The site for The water, which enters into the ﬁlter by in hatchery should be elevated, ﬂat and easily ﬂow suction, is pumped through a 90 mm PVC drainable. The seabed should have gradient for suction pipe. A non-return ﬂap-type PVC check installation of low-cost seawater intake system. valve is ﬁtted with suction line either inside or outside the ﬁlter. Pumping can be done by using Soil 5 HP monobloc pump installed in the beach at Physical composition, i.e. sand, silt and clay con- about 100 m away from the intake point. The tent of the soil, should be checked for determin- water from the surface of the sea enters into the ing the soil type. Load-bearing capacity of the ﬁlter through different layers of sand, gets ﬁl- soil should also be determined for the design of tered and comes to the suction point. In the initial foundations for buildings. stage of pumping, all ﬁne sand present around the ﬁlter is pumped along with the inﬂow water. On continuous pumping, coarser sand, which cannot Geographical Location enter into the ﬁlter, forms a layer around the ﬁlter and prevents the entry of ﬁne sand thereafter. The Availability of broodstocks: Broodstock should water pumped through this ﬁlter is very clean and be regularly available year round for success- totally free from debris, organic matter and ful hatchery operation. The landing centre plankton and to some extend pathogen also should not be beyond 2–4 h drive; otherwise transportation loss and high transportation cost will increase the cost of production. Precautions Proximity to market: The farming areas, where the fry is expected to be marketed, should be • Pumping has to be started immediately after within 300–400 km. installation of ﬁlter; otherwise, the ﬁlter will Availability of electricity: Electricity is essential get ﬁlled with ﬁne sand particles which allow for shrimp hatchery. High-tension power sup- less or no ﬂow of water into the ﬁlter and the ply should be available close to the site. system will become nonfunctional. Accessibility: The site should be easily accessible • Pumping has to be done at least 2 h/day from by an all-weather motorable road. Accessibil- each ﬁlter, even if there is no requirement of ity is important for supply of building con- water, to avoid chocking of ﬁlter. struction materials to site, procurement of • Filter has to be removed at least once in inputs for seed production and transportation 3 months, cleaned and reinstalled to avoid of broodstock and fry. the problem of biological degradation.
Breeding and Seed Production of Tiger Shrimp Penaeus monodon 115 Plate 4 Seawater intake system VetBooks.ir • Filter has to be installed about 1 m below the The capacity of the pump required to run whole existing bed level and make sure that a water set-up is decided based on the rate of ﬂow of depth of 1 m must be available above sand bed water and total head loss due to pipes, valves, even at low tide level. sand ﬁlters and cartridge ﬁlters. The capacity of • Avoid exposing ﬁlters to direct wave action. sand ﬁlters and cartridge ﬁlters is decided based on every day water requirement for total hatchery operation and period in which the ﬁlters are to be Advantages of the System operated. • Cheapest and can be fabricated available at the site itself. Design of Pump • Supplied good quality of water, which may sometimes pass through a series of ﬁltration Total water requirement for hatchery operation is units. 370 t/day, of which, the PL rearing section • Can be installed instantly. requires about 200 t and the remaining water is • Can be removed cleaned and reinstalled. used for the other sections. Except postlarval Therefore, no wastage of material. section, all other sections required either sand- • No massive seawater intake structure is ﬁltered or cartridge-ﬁltered water. The postlarval required. section required water only when stocking or • Can be installed by trained and skilled local water exchange is done. labours. Therefore, a sand ﬁlter supplying approxi- In order to ensure good quality of seawater, mately 20–25 t of water per hour will be sufﬁ- the following steps have to be adopted. cient to meet the requirement. Seawater Treatment Plant Head Losses (Approximately) Treatment plant is a place where micro-level ﬁltration of seawater is done. Basically treatment 1. Suction pipe 1M plant has 3 major set-ups, namely, sand ﬁlters, 2. Deliver by pipe 3M cartridge ﬁlters and UV steriliser (Plates 5 and 6). 3. Valves and bend 3M (continued)
116 P. Soundarapandian 4. Due to sand ﬁlter 5M 2 numbers of cartridge ﬁlters (5 μm) 5. Due to cartridge ﬁlter 5M 2 numbers of cartridge ﬁlters (1 μm) Total 17 M Discharge required ¼ 0:0069 M2 =s Filtration in intake system: The seawater intake 1,000 Â 0:0069 Â 17 system should be designed in such way that Capacity pump required ¼ 75 Â 0:75 Â 0:75 the water passes through a ﬁlter bed before it ¼ 2:78 HP ¼ 3 HP is pumped into the reservoir. In the process, VetBooks.ir most of the particulate matter will be ﬁltered In treatment plant, two sets of ﬁltration system in the intake system itself. are to be installed to assure supply of water at any Chlorination: While pumping, seawater should time since cartridge ﬁlters require periodic be chlorinated (5–10 ppm) before it reaches cleaning and maintenance. the reservoir. In the reservoir, the chlorine should be allowed to react for a period of It Is Recommended to Buy: 1–2 h. This chlorination kills all pathogenic 2 numbers of 3 HP pump 2 numbers of sand ﬁlter Plate 5 Treatment tank Plate 6 Filtering system
Breeding and Seed Production of Tiger Shrimp Penaeus monodon 117 microbes and also chemically removes iron by Source forming a red precipitate with it. Filtration: The seawater should be recirculated Live breeders can be collected either from com- through a rapid sand ﬁlter (50 μ) till all the mercial trawler operators at ﬁshing harbours or particulate matters and other precipitates are from country boat operators at ﬁsh landing completely ﬁltered. centres. Dechlorination: The residual chlorine available VetBooks.ir in the seawater should be estimated with chlo- From Trawlers rine test kits by using O-tolidine. Adding To collect live spawners, the trawl operation sodium thiosulphate pentahydrate can chemi- should not exceed 30 min. Practically this may cally neutralise the residual chlorine. This not be possible since no trawler operator will be chemical reaction is as follows: willing to do this. What the trawler operator usually does is to collect whatever live specimen 2 Cl2 þ 2 Na2 S2 O3 5 H2 O available after the hauls in the trawl net. The ! 2 NaCl þ NaO2 S4 O6 þ 10H2 operator has to be provided with large ﬁbreglass or syntax tanks and a portable battery-operated It is observed that sodium thiosulphate (hypo) aerator. required to neutralise 1 ppm of residual chlorine gas will vary between 0.5 and 2 ppm due to the From Country Boats inﬂuence of various factors speciﬁc to site and They normally operate gill nets, which are usu- chemicals. ally set at sunset and the catch is checked at Treatment with EDTA: EDTA (ethylenediamine- midnight or at sunrise. The traditional ﬁshermen tetraacetic acid) is a chelating agent, which are adopting at bringing the spawner live by their can remove chemical pollutants like trace own ingenious methods. metals and other ﬁne debris. It is safe to add 10 ppm EDTA for ensuring clear seawater. Temporary Storage at Collection Centre Allow at least 1 h settlement time before The chances of getting live animal are totally using the seawater in order to ensure comple- unpredictable since the breeder availability tion of EDTA action. varies seasonally as well as daily. Hence, arrangements for temporary holding of live spawners have to be made at or near the site of Broodstock Collection and Transport collection. A collapsible PVC sheet tank or a ﬁbreglass tank of 1–2 t capacity will serve the Introduction purpose. A portable seawater pump and battery- operated aerators and oxygen cylinders also have A large-scale hatchery has to necessarily depend to be provided. on wild caught breeders (Plate 7) in addition to its own reared stock. To programme the hatchery Packing and Transport operations and to meet the production Usually the spawners are packed and transported requirements, a thorough knowledge about the by the following methods: availability of breeders, their collection and Live animal holding tanks in trucks with pro- transportation technique is a prerequisite vision for continuous aeration/oxygenation. Dif- (Chakraborty and Sadhu 2001; Handbook on ferent types of tanks can be used for this purpose. shrimp hatchery operation and management by In doublewalled plastic bags with cool seawater the marine products export development author- (22–24 C) and oxygen which is then packed in ity; Operation manual for tiger shrimp hatchery Styrofoam boxes. The rostrum of the shrimps is by Sampath Associates 1994). covered with small rubber tube to prevent
118 P. Soundarapandian VetBooks.ir Plate 7 Brooders puncturing of plastic bags, or the spawners are 6. Salinity refractometer 1 no immobilised in separate PVC tubes. 7. Oxygen cylinder (small) 4 nos 8. Oxygen regulator with key 4 nos Quarantine 9. Syntax tank (500 L) 1 no Upon arrival in hatchery, the spawners are kept 10. Heavy duty plastic bucket 6 nos in a quarantine tank containing clear seawater 11. PVC pipe (1 ft size 63 mm dia. with holes) 100 with good aeration. The animals are then exam- nos ined for damage, disease or parasitism. Precau- 12. Mosquito net 10 m tionary treatment is given as follows, before they 13. Small rubber tube (3 mm dia.) 2 rolls 14. Thermocol-lined cardboard cartons 400 are transferred to the maturation tanks: nos 15. Polyethylene tube (for bags) 100 nos Formalin dip 25 ppm 15–20 min 16. Small polyethylene bags for ice packing 10 Malachite green dip 0.5 ppm 02–03 min nos Furazolidone 0.4 ppm 05–10 min 17. Rubber band 2 kg 18. Scissor 2 nos Materials Required for Breeder Collection 19. Plastic tape 10 and Transport rolls 20. Strapping clip 4 kg 21. Strapping machine 2 nos 1. Transport vehicle (mini truck) 1 no 22. Flexible pipe (20 mm dia.) 40 m 2. Fibreglass tank (small) to ﬁt in the truck 2 nos 3. Plastic pools/ﬁbreglass tanks for maintaining 2 nos breeders (1 t capacity) 4. Battery-operated aerator/air pump 8 nos 5. Portable pump (0.5 HP) 1 no
Breeding and Seed Production of Tiger Shrimp Penaeus monodon 119 Maturation and Spawning given in the next feed. If any balance is left, a few grams may be reduced. Siphoning should be done twice a day, Introduction once in the morning and other in the evening This is the ﬁrst major unit of any commercial shrimp hatchery, which involves in the produc- General Information About VetBooks.ir tion of the ﬁrst stage of shrimp larvae, the Maturation Unit nauplii. Operation of maturation section involves procurements of spawners, acclimatising them to Ovarian maturation stages of tiger prawn local conditions, breeding techniques and categorised in ﬁve steps: spawning. 1. Undeveloped 2. Developing 3. Early ripe Maturation Techniques 4. Ripe 5. Spent General Mating required a minimum water volume and depth. Fertilisation of eggs from initial Stocking 4–6 Nos./m2 spawnings of captive broodstock is dependent density on sperm from mating in the wild or pond envi- Sex ratio 3:1 ronment. Stocking density of P. monodon in (female/male) tanks will be 4–6 m2, depending on the water Eye stalk All females are unilaterally eyestalk quality and exchange rate. Sex ratio maintained ablation ablated at 1 male: 1 female to ensure mating success. Water 28–32 C Higher female ratio 3:1 would be more economi- temperature Salinity 28–36 ppt cal because egg and larval production per tank Filtration Sand ﬁlter water is used are maximised. Light Artiﬁcial low blue colour Stocking of disease-free quality broodstock of Feeding Fresh feeds-squids, fresh beef liver, both female and male in the maturation tanks is cattle ﬁsh, clams, oysters and mussels. preferred in the ratio of 2:1 or 3:1. Prior to 10 % of the body weight. 3 times per stocking, ablate the females with one eyestalk, day which induces the ovary development. Water exchange 30 % per day Prophylactic Chloramphenicol or prefuran or treatment erythromycin or oxytetracycline is applied at a dose of 4 ppm twice per Eyestalk Ablation month Sanitation Disinfect and wash all glasswares, PVC In selecting females to undergo ablation, avoid support columns, etc. regularly. The soft (moulted) animals or they will not survive ﬂoor of the section as well as spawning room should be disinfected twice a ablation. Determine the mean weights of the week using 100 ppm chlorine water. males and females based on ﬁve samples of Using long handled dip net, remove all each set and then calculate the total biomass of moults and any dead animals from each each tank. Before ablation, segregate the males tank and females in two separate tanks containing Siphoning Systematically siphon the entire tank bottom making sure to remove any 100 L of seawater. Transfer the males to the residual food left from previous tanks with antibiotics (20 ppm oxytetracycline feedings. Observe and record the or chloramphenicol or Erythromycin). Hold the residual food in each tank, and if none animal, exactly for half an hour, and transfer is left, a slightly higher dose may be them to the maturation tank.
120 P. Soundarapandian Eyestalk ablation is the common technique formalin bath and rinse in the holding bath, and which involves destroying the X-sinus gland in then place each female in an individual spawner one of the eyestalks that produce and store tank. Record the maturation tank number from gonad-inhibiting hormone (GIH), thus which each female was removed and the accelerating gonad maturation. An ablated spawning tank number into which it was trans- female spawner takes 3–7 days to mature. Eye- ferred in a data sheet. stalk ablation enables the technician to have a When the ovaries have developed to stage VetBooks.ir better control over the time of maturation for 4, the spawners are transferred to spawning proper planning of fry production. tanks. The eggs produced from early spawning Eyestalk ablation may be performed in several are usually more and of better quality than those ways. Some of the common methods are: from subsequent spawning. 1. Pinching the eyestalk and eyeball with or The fertilised eggs are spherical and hatch without prior incision on the eyeball. into ﬁrst stage, the nauplii within 12–15 h after 2. Cauterisation of the eyestalk with heated sur- spawning. These nauplii can be harvested with a gical clamps, forceps or soldering iron. help of light source, as they are phototactic in 3. Direct cutting of eyestalk with a pair of nature. Harvested nauplii can be stocked in larval scissors. rearing tanks for further rearing. 4. Lighting the base of eyestalk. The ablated females are kept in the maturation tank together with unablated males. The breeders Daily Work in Maturation Unit are fed daily with chopped fresh clams, mussels or oysters, and their quantity is depending on the consumption. Daily cleaning of maturation tanks Daily work Fresh feed distribution and water exchange depends on the water quality 07.00 A.M. Sanitary management Checking the aeration, light and water and tank condition. exchange of the tank Checking and recording temperature, salinity, pH, ammonia and nitrite in each Spawning and Production of Nauplii tank and in coming water Removal of dead animals, if any, and The maturity of females is determined by observ- uneaten feed ing the condition of the ovary, which is located Fresh feed will be cut – frozen into slices of about 0.5 Â 0.5 cm2 and then on the dorsal side of the body. It can be roughly defrosted before feeding classiﬁed according to the appearance of the 08.00 A.M. Distribution of feed in each tank ovaries into ﬁve stages. Washing the ﬂoor of the maturation tank 1. Immature or resting stage – Ovaries 09.00 A.M. Maintenance works, equipment repairs, extremely thin. etc. 2. Developing stage – Ovaries appear as a light 02.00 P.M. Distribute the feed green in colour and straight band is visible 02.30 P.M. Arranging the water exchange through the shell. Arranging the aeration, light, etc. 3. Early ripe stage – Ovaries become broader 04.00 P.M. Checking the maturity conditions in each tank and clearly visible as an olive green band. 04.30 P.M. Selecting the gravid female to spawning 4. Ripe stages – Ovaries are dark green in colour. tank 5. Spent – Complete spent ovaries are thin and 08.00 P.M. Distribution of feed appear like ﬁrst stage of ovaries. 12.00 P.M. Distribution of feed Dip the gravid spawner in 100 ppm formalin. After exactly 5 min, remove the females from
Breeding and Seed Production of Tiger Shrimp Penaeus monodon 121 Spawning Tank temperatures, shade clothes (preferably sky blue) should be arranged over the tanks to pre- vent direct sunlight on the tank, which affects the 07.00 P.M. Collection of females from maturation survival of larvae. tank 09.30 A.M. Spawning tank one by one, observation and recording about the success of Larval Rearing Tanks spawning Shrimp larvae are being reared in tanks of differ- VetBooks.ir Checking the rate of fertilisation under ent types of shapes (Plate 8) and capacities in microscope different hatcheries. The recent studies and 09.30–01.30 Cleaning the equipments with chlorine and experiences have proved that the parabolic- P.M. soap shaped tanks with set aeration line are yielding Eggs are allowed to hatch in the spawning best results owing to its ability to provide tank; enough time should be given for complete hatching uniform aeration, uniform distribution of food The next day, morning hatched nauplii materials, giving least scope for settlement of will be harvested organic detritus on the tanks surface and then minimising the growth of microbes in the tank. In these tanks, it is easy to siphon out the left overfeed, organic detritus faecal strands, etc. Larval Rearing Disinfection Tanks Introduction One FRP tub of suitable dimensions is required in the section for disinfecting the strainers, Shrimp nauplii received from maturation section screens, hoses, ﬁlter bags and plastic ware are reared in larval rearing tanks for 13–15 days after use. till they reach PL3 or PL5 stages. These pass through 6 nauplius, three zoeal and three mysis Laboratory stages before they reach postlarval stage. Larval A laboratory equipped with a microscope for stages are very critical and sensitive phases of evaluating the health of the larvae, seawater test- shrimp life cycle. They need clean and healthy ing kits and equipment for conducting environment, timely feeding, gentle and careful microbiological studies, etc. should be attached handling, etc. The technical personnel should to the larval section (Plate 9). have sound scientiﬁc knowledge of biology, ecology, behaviour and nutritional requirements Equipment of the larvae. They should be critical in observa- Strainers (Plate 10) with 100, 250, 350 and tion, quick in decisions making and dedicated in 500 nylon mesh; harvesting buckets; plastic discharging the duties. Negligence and compla- buckets and tubs, 100 L; plastic cans for transfer- cency can very easily yield poor results in larval ring larvae; glass and plastic beakers; etc. are section. essential equipment for water exchange, treatments, feeding and other management activities. Facilities Required for Larval Rearing Chemicals and Drugs Larval Rearing Room Bleaching powder for disinfection; detergents for Larval rearing room, being one of the most sen- washing; aquatic grade antibiotics like chloram- sitive areas of the hatchery, needs complete iso- phenicol, oxytetracycline, erythromycin, furazol- lation from other sections to avoid idone and perfuran; and fungicides like Treﬂan, contamination. If it is provided with natural malachite green and formalin are essential for lights in the rooﬁng for checking low larval rearing.
122 P. Soundarapandian VetBooks.ir Plate 8 Larval rearing tanks Plate 9 Laboratory Seawater Larval Feeds The seawater should be made free from particu- The larvae during zoeal stages feed on algae. late material and turbidity, by drawing it from a Diatoms like Chaetoceros sp. and Skeletonema subsoil ﬁlter arranged below beach sands in the sp. are suitable feed for shrimp larvae. A separate intertidal zone. This water will be chlorinated facility for culturing algae under aseptic (8–10 ppm) to kill all the microﬂora and fauna. conditions is an essential component of a shrimp Then it should be dechlorinated with sodium hatchery. thiosulphate. EDTA (10 ppm) is added to remove Mysis stage onwards, a minute zooplankton the dissolved heavy metal pollutants if any. This like Artemia nauplii, is to be introduced as a feed seawater will be passed through a two μm ﬁlter along with algae. A suitable facility for hatching bags before use in larval section. the Artemia cysts is also essential for a shrimp hatchery. Aeration In addition, supplementary feed, Filtered, dust and oil-free air is supplied continu- microencapsulated diets of different particle ously, by using an air blower (Plate 11). sizes are essential to get better results as well as to use as substitutes during scarcity of live feeds.
Breeding and Seed Production of Tiger Shrimp Penaeus monodon 123 Plate 10 Equipments VetBooks.ir Plate 11 Aeration Environmental Conditions Required for 7. Nutrients Larval Rearing 8. Pollutants The natural environment in which the shrimp larvae live is marine. The characteristic environ- Seawater Salinity mental parameters of seawater which account for its quality are: This is a natural parameter, for which greater 1. Salinity importance is given during site selection, since 2. Temperature artiﬁcial manipulations to increase the salinity 3. pH are laborious and uneconomical. However, 4. Turbidity adding freshwater can bring down salinities. For 5. Dissolved oxygen content a shrimp hatchery, the recommended salinity 6. Microﬂora and fauna
124 P. Soundarapandian range is 28–35 ppt. This should be monitored the tank, it should be scrubbed with detergent and every day. rinsed with freshwater thoroughly. Then the tank is ﬁlled to 60 % of treated and ﬁltered seawater. Prophylactic treatment with fungicide (Treﬂan Seawater Temperature 0.05 ppm) and an antibiotic (Table 2) should be given to the tank water 1 h before stocking. Just The recommended range of seawater tempera- before stocking, algae (Chaetoceros sp.) should VetBooks.ir ture is 28–32 C. Temperature should be be added at a density of 100,000 cells/ml. The recorded twice a day at 7 A.M. and 3 P.M. - tank water should be sufﬁciently aerated Low-temperature problems can be overcome to throughout the culture operation. Recommended some extent by using the following methods. stocking density is 100,000 nauplii/t. If the tank • By providing natural light with translucent is newly constructed, it should be thoroughly ﬁbreglass sheet rooﬁng leached with freshwater and seawater, for • By covering the culture tanks with 2–3 days before the preparations are carried out. PVC/plastic sheets • By using thermostatically controlled insulated immersion heaters in the culture tanks Microencapsulated FRIPPAK FEEDS like CAR, feeds (optional) CD-2 or other larval feeds may be • By using room heaters fed at least 4 times a day as per the • By using solar water heating systems directions of the manufacturer • By passing the seawater through thermostati- Prophylactic drugs: Treﬂan (0.05 ppm); antibiotics: cally controlled electrical heating system antifungal chloramphenicol (4 ppm) before ﬁlling the tanks oxytetracycline (4 ppm), prefuran (1 ppm), furazolidone (1–3 ppm), High temperatures can be checked by neomycin sulphate (3–10 ppm) (1) providing shade clothes over the tanks and (2) providing proper ventilation to the culture rooms. Acclimatisation and Stocking of Nauplii The nauplii (N5/N6) received from the matura- tion section should be acclimated by adding the Seawater pH larval tank water to the acclimation buckets slowly by using a ﬂexible tube (1 cm dia.) for Seawater pH is good indicator for chemical qual- about 10–20 min. Aeration should be given dur- ity of the seawater. The seawater pH should be ing acclimation. The nauplii can be released into within the range of 8.2–8.5 for larval rearing the tanks slowly in small quantities at different operations. pH should be recorded along with points of the tank. One hour after stocking, the salinity once in a day. Seawater pH also should population should be estimated and recorded. be given due importance during site selection. Schedule of Larval Rearing Operations The larval rearing from N6 to PL-3 takes 13 days. Larval Rearing Operations The schedule of different operations like water exchange, feeding regime and drug treatment is Preparation of Larval Tanks for Stocking summarised chronologically in Table 2. The Nauplii procedures and methods followed for each oper- The tanks should be disinfected with 200 ppm ation are explained in Table 2. Under normal chlorine water for 8–10 h and then thoroughly conditions, this schedule provides clean and scrubbed with a mixed solution of 200 ppm chlo- healthy environment to the larvae. But the tech- rine and 5 % detergent by using sponge pads. nical personnel have to constantly observe the Then the tank is thoroughly rinsed with freshwa- tank conditions and animal health and modify ter and dried for at least 24 h. Just before ﬁlling the water management, feeding and treatment
Breeding and Seed Production of Tiger Shrimp Penaeus monodon 125 Table 2 Schedule of larval rearing operations Water management Water level Water Mesh size of the screen Algal feeding Artemia Day Substage (in tons) exchange (in microns) (cells/ml) (naups/ml) 1 N6/Z 1 6 – 100 100,000 2 Z1 8 Make up to 100 100,000 – 8t VetBooks.ir 3 Z2 10 Make up to 100 100,000 – 10 t 4 Z3 10 30 % 250 100,000 – 5 Z3 10 50 % 250 100,000 – 6 M1 10 70 % 350 100,000 0.25 7 M1 10 70 % 350 100,000 0.25 8 M2 10 70 % 350 100,000 0.25 9 M3 10 70 % 350 100,000 0.50 10 M 3 10 70 % 350 100,000 0.50 11 PL 1 10 100 % 350 60,000 1 12 PL 2 10 100 % 350 60,000 1 13 PL 3 10 100 % 350 60,000 1 schedule according to the need as the situation quality. Hence, care should be taken to prevent demands. the primary stress factors and thus eliminate the chances for disease outbreaks. Larval Diseases and Treatment Disease is a major threat for any biological sys- Daily Routine of Larval Section tem and hatcheries are no exception to this. In an The daily routines of larval rearing section in aquatic system, prevention is the best remedy. If chronological order are given in Table 4. Larval a hatchery system is infected with a disease, it is section needs at least two technical personnel and better to discontinue the operation till the patho- three aides to take care of all the activities of a gen is eradicated by disinfection and drying. day. Since all the activities are time-bound, this Fighting the disease with drugs leads to many schedule has to be strictly followed for better complications like pathogens developing resis- results. tance to available drugs and permanent settle- ment of pathogens in the hatchery. Usually in Walk Through all shrimp hatcheries, preventive measures like This is a physical examination of the facility, using pathogen-free treated water, administering tank condition, aeration, condition of the tank prophylactic treatments and observing strict san- water, algal density, Artemia density, animal itary and hygienic principles are followed. A few behaviour, activity, health and feeding, etc. This common larval diseases have been listed in examination will help us to know the general Table 3. The standard treatments given in the condition of each tank and to identify the prob- table might help for some time, but subsequently, lematic tanks. One litre glass beaker may be used new drugs have to be tried, after conducting for examining the animals. But it should be sensitivity tests in the microbiological disinfected in chlorine bath before and after laboratory. examining a tank. Walk through should be done Usually the pathogens and parasites take three times a day at 7 A.M., 2 P.M. and 10 P.M. advantages of the damages caused by some pri- mary stress factors like pollution effects, under- nourishment, overcrowding and bad water
126 P. Soundarapandian Table 3 Diseases found in the developmental stages of penaeid prawn larvae and their control methods Life stages Disease Affected parts Symptoms Treatment affected Bacteria Appendages Appearing as localised necrosis or discoloration on any Furnace, Z, M, PL appendage, causing high mortality of zoea and mysis stages 1.1 ppm Bacterial affects postlarvae to lesser extent Erythromycin, necrosis 1.5 ppm VetBooks.ir Achromycin, 1.2 ppm Vibrio Haemolymph In initial stages of one form, some larvae will show yellow- Furazolidone, PL infection midgut gland vermilion and red colour permeating entire nervous system. 2.0 ppm Another form exhibits ‘white-turbid liver’ where the midgut Terramycin, gland of the larvae becomes generally white-turbid. Turbidity 45 mg/kg becomes more apparent and well deﬁned as the disease biomass progresses Furnace, 1.3 ppm Life Affected stages Disease parts Symptoms Treatment affected Filamentous Gills, Commonly found attached to the gill ﬁlaments and the Cutrine plus, PL bacteria pleopods pleopods turning blackish when bacteria mix with dirt. If 0.5 ppm severely affected, the respiratory function of the gill Malachite green, suffers damage 10 ppm Potassium permanganate, 8.5 ppm Cuprous chloride, 1.0 ppm Shell disease Exoskeleton If infected by chitinovorous bacteria, the exoskeleton will Malachite green, PL muscles display eroded, blackened areas. The edges or tips of the and 0.9 ppm exoskeleton parts are typically attacked Also bacteria can rapidly enter the body through surface Formalin breaks to cause internal damage combined, 2 2 ppm Black gill Gills In initial stages, gill colour turns dull orange-yellow or Malachite green, PL disease light brown. When advanced, the area darkens until it is 3.0 ppm ﬁnally black Methylene blue, 3–10 ppm Life stages Disease Affected parts Symptoms Treatment affected Fungi Body cavity, Only thin-cuticled prawns can be infected; thus, Treﬂan, Z appendages larval prawns are highly sensitive. The hyphae 0.1 ppm Lagenidium appear inside the body of zoea and continue into Malachite M infection mysis stage, resulting in massive muscle green, destruction and heavy mortality of zoea and mysis 0.01 ppm (continued)
Breeding and Seed Production of Tiger Shrimp Penaeus monodon 127 Table 3 (continued) Life stages Disease Affected parts Symptoms Treatment affected Ectocommensal Gills, eyes, Heavy infestation by Zoothamnium sp. of gills Malachite Z protozoa exoskeleton and eyes of larval prawn results in high mortality. green, 1.0 ppm Ciliate infection Epistylis sp. seems to prefer exoskeleton as and Formalin M (Zoothamnium sp., attachment site and is less harmful. When combined, VetBooks.ir Epistylis sp.) abundant on gill surface, both can cause hypoxia 25 ppm and death. Additionally, their abundant presence Quinacrine PL on general body surface of larvae may interfere hydrochloride, with locomotion, feeding moulting, etc. Parasite 0.8 ppm burden increases until ecdysis provides relief Chloramine-T, 0.5 ppm Methylene blue, 8. 0 ppm Saponin, 10 %, 5.0 ppm Viruses Hepatopancreas, Penaeid baculoviruses infect epithelial cells of the PL Penaeid anterior midgut hepatopancreas and, less commonly, anterior baculoviruses midgut, causing high mortality in the postlarval (PB MBV, BMN) stage Life stages Disease Affected parts Symptoms Treatment affected Infectious hypodermal Hypodermis Prawns dying from acute IHHN show massive PL and haematopoietic haematopoietic destruction of cuticular hypodermis and often of necrosis (IHHN) organs the haematopoietic organs, of glial cells in the nerve cord and of loose connective tissues such as the subcutis and gut serosa. Only prawns within a size range of 0.05–1.0 g have been observed to have these epizootics, resulting in massive mortalities (often 80–90 % within 2 weeks of onset) Miscellaneous diseases Appendages Occur as a result of poor quality of spawner N Abnormal nauplii Amoebiasis of larvae subcutis, Invasion of muscles and subcuticular tissues ZZ muscles located in the abdomen. Cephalothorax, antenna and eyestalks, by unclassiﬁed amoeba Larval encrustation Exoskeleton Brown to black encrusted deposits which contain ZPL iron salts affect larval penaeids N nauplius, Z zoea, M mysis, PL postlarva Recording Physical Parameters per litre is estimated, from which total population Physical parameters like salinity, temperature in the tank can be computed by using the formula and pH are to be monitored twice a day, before ﬁlling the tanks. Total population in the tank ¼ No: of larvae per litre Â tank volume: Population Estimation Four to eight samples of known volume (250 ml) should be collected at random from different places of the tank, and number of animals present
128 P. Soundarapandian Table 4 Daily routines of larval section in chronological order Time Technical Non-technical 06.00–07.00 – Treﬂan treatment, feeding encapsulated diets, preparing tanks for stocking Nauplii 07.00–08.00 Walk through, population estimation Recording physical parameters, draining the tanks 08.00–9.00 Microscopic examination, algal and Artemia feed Acclimation and stocking nauplii calculations VetBooks.ir 09.00–10.00 Feeding Artemia Feeding with algae and Artemia, reﬁlling the tanks 10.00–11.00 Estimating the population of postlarval transfers Harvesting and transferring, postlarvae 11.00–12.00 Data maintenance Treatment with drugs 12.00–13.00 Data maintenance Disinfecting tanks, screens, ﬁlter bags and washing the ﬂoor 13.00–14.00 – Treﬂan treatments, feeding with encapsulated diets 14.00–15.00 Walk through Cleaning 15.00–17.00 Algal and Artemia counts and feed calculations. Temperature readings, feeding algae and Microscopic observations and data maintenance Artemia Washing screens, ﬁlter bags and plastic ware; feeding with encapsulated diets 21.00–22.00 Walk through, Artemia counts and feed calculations Feeding with Artemia and encapsulated diet. Treﬂan treatment Microscopic Observation care. The water exchange schedule for each state is given in Table 2. A strainer suitable for the A sample of ﬁve to ten larvae from each tank larval stage present in the tank is selected and should be observed ﬁrst under the stereo-zoom checked thoroughly for any possible damage and dissecting microscope and then under compound leakage. Then it is disinfected in 200 ppm chlo- microscope. The observation on: rine bath and then thoroughly rinsed in freshwa- • Swimming activity ter till chlorine smell is removed. Then it is ﬁxed • Feeding to the ﬂexible hose of the inner standpipe; it is • Developmental stages lowered to the bottom of the tank. Then outer • Morphological characters standpipe is lowered to drain water from tank • Symptoms of stress into a harvesting bucket of suitable mesh size to • Presence of ectoparasite protozoans prevent the escape of animals, if any, but the • Presence of speciﬁc disease like necrosis, lar- water ﬂows off. While draining is going on, val mycosis, etc. should be recorded on the seawater should be splashed on the strainer daily sheet. once in every 10 min to wash the adhering larvae The suitable prophylactic (Table 2) or thera- into the tank. The ﬂow rate should be adjusted in peutic treatment (Table 3) should be given to the such a way that the animals are not forced in to tank, if necessary, based on the microscopic the strainer. When the draining is completed, the observations. exposed walls of the tank should be wiped with clean sponge pad to remove the adhering debris and dirt. Then algae and Artemia in calculated Water Exchange quantities should be given before reﬁlling the tanks. As water exchange plays a vital role in the suc- cess of larval rearing operation, it needs intensive