Rearing and Breeding of Rainbow trout (Oncorhynchus mykiss)

Dr. N.N.Pandey (Sr.Scientist,Aquaculture) Directorate of Coldwater Fisheries Research (Indian Council of Agricultural Research) Bhimtal 263136, Distt. Nainital, Uttarakhand

Concise Background Coldwater and carnivorous exotic fish species. Feed on aquatic insects, small crustaceans and small fish in natural waters but in captivity it needs high protein content of quality feed. Native to the Pacific drainages of North America. Highly priced fast growing and maximum cultivable traits amongst coldwater species. Indian Production- 500 t against 508,662 t world production.

History In India introduced by European residents of the country during the later half of nineteenth and the beginning of twentieth century. (Howell, 1916, Mitchell, 1918, Molesworth and Bryant ,1921, Mackay, 1945, Jones and Sarojini, 1952, Sehgal et al. 1971 and MacCrimmon ,1971). In Peninsular India, introduced in the Nilgiris and Kodai hills in Tamil Nadu. In Himalayas, transplanted in Kashmir, Himachal Pradesh, Garhwal region of Uttarakhand, Arunachal Pradesh, Nagaland, Meghalaya and in certain waters of Nepal. The trout thrived in the hatcheries and some tributaries in the Garhwal region but could not survive in Kumaon hills, due to comparatively high summer temperature. DCFR further initiated successful culture and breeding of trout in Uttarakhand, Sikkim and Arunachal pradesh.

Why trout farming?

Easy to domesticate, Faster growth Accepts artificial feed, Highly priced Wide tolerance of temperature/DO Resistant to certain diseases Shorter incubation period, Easy to breed Demand in high class hotels and tourist. Very-Very tasty and easy to digest .

Trout farming in IndiaTwo types Full farming system - Egg to adult and vise versa Partial farming system- Fingerlings to the marketable size Purpose for producing stocking material for ranching for food Steps Brood stock maintenance, Spawning Incubation of eggs Rearing of young fry in nurseries Raising of fingerlings/ yearlings in growing ponds Raising table fish and brood stock etc.

Site selection for trout farmWater is the foremost criteria for site selection for trout culture. For Survival-0-250C For normal feeding & growth-14-180C For spawning & Hatching-9-140C

General Criteria Permanent water source Water- free from heavy metals and turbidity Water in enough quantity Water temperature- should below 200C round the year Dissolved Oxygen (DO) - more than 7mg/l. pH of water - 6.5.to 8.0 The site should be of 1-3 % slope The site should be accessible to road One litre of water per minute per age- month is needed for every 1,000 fry and fingerlings.

Rearing facility For production of table fish- land area of 1000 m2, having10 concrete rearing ponds/ raceways (30-60 m2 having 1 m depth) with individual water supply. The stocking ponds are generally graded during four stages; i) 2-5 gm size, ii) 10-20 gm size, iii) 5060 gm size and iv) more than 100 gm size.

Design of a Model Trout Farm (Parallel Type) Check-DamNatural Stream

Inlet

Inlet

WATER STORAGE TANK ( 5,00,000 liter)

Outlet

Design of a Model Trout Farm

Natural Stream

Screens

OUTLET

* Suitable dimension of pond 60 m2 subjected to alter based on availability of land

Stocking of the Pond Fish stocking density depends on quantity and quality of water. Trout can be stocked 10 kg /m3 at 1 l/second of water flow and 1520 kg/m3 fish can be produced during harvesting,

Feed for TroutSize of the Fish < 10 gm 50 gm Protein Content 40 % 35 % 35 % % of body weight 5-10 % 5- 6 % 2-3 % Times 7-8 3-4 2-3

Percentages Feed ingredients Fish Meal Soya bean meal Wheat middling Starch Brewers Yeast Linseed oil cake Dried Milk Vitamin premix Mineral Mix Coline chloride Monocalcium Phosphate Shark liver oil 50% 15% 6% 5% 4% 4% 5% 3% 2% 1% 1% 4%

Major ingredients

Fish meal

Soybean& wheat flour

Fish oil

Yeast powder

Vit. Min mixture

Rhododendron flowers at the tree

Starter feed

Fingerling feed

Grow- out feed

Grow out feed(wet)

Growth Performance Under suitable water and sufficient supply of good quality of feed trout attains 200-300 grams size after 14-15 months but same size is attained in 10 months if stocked 5-10 gm size of fingerlings. In a culture experiment conducted at the farm the fish attained maximum growth of 200 gm, 1100 gm, 2100 gm and 3000gm respectively, during 1-4 years life span (Joshi et al, 2005).

Health and Hygiene Diseases in the trout may occur mainly due to unhygienic conditions in the pond, high water temperature and improper quality and quantity of feed.

Hatchery ManagementBrood care Brooders are selected well before the spawning. Generally they are selected two to three months before the breeding. The male rainbow trout attained maturity after 2nd year and female after completion of 3rd year. Dec-Jan is the breeding season

Sexual Dimorphism The mature females can be recognized by their round body appearance, bloat and soft belly, and swollen and reddened vent. The male fishes are dark and dull in appearance, large pointed snout with hooked lower jaw and oozing of milt

Spawning and Incubation Stripping is a process by which eggs from female fish and milt from male fish is obtained.

Steps of Dry stripping Weighed selected brooder Wiped with soft and dry cloth Stripped female with thumb and index finger of the right hand Fish is then immediately released in the aerated water

Stripping of male fishes over the eggs Mixed it up thoroughly with the help of feather Mixture is kept for 12 minutes for fertilization. 100 ml of saline water (0.9 % NaCl) is added to the bowl and kept it for 5 minutes

Washed thoroughly with the fresh water Transferred to the hatching tray trays are transferred in trough Fixed 6 liter of water flow per minute Dead eggs are segregated Hatched in 40-60 days at 9-14 0C

Green Eggs

Fertilized egg

Eyed ova

Developing ova

Sac fry

Eyed ova

Eyed Ova ready to hatch

Trays in Trough

Swim up fry

Fry Tank

Fingerlings

Yearlings

Efforts & achievement of DCFR The Directorate of Coldwater Fisheries Research (erstwhile NRCCWF), Bhimtal, Uttarakhand has played pivotal role in development of location specific feasible and viable Trout farming techniques, breeding protocols, feed and standardized husbandry practices at its experimental Fish Farm, Champawat (Uttarakhand), State trout farm Bairangna (Uttarakhand) and in Sikkim, Arunachal pradesh, J & K and Himachal.

Rainbow trout was successfully introduced in the year 1999 at Champawat. In a culture experiment conducted at the farm the fish attained maximum growth of 200 gm, 1100 gm, 2100 gm and 3000gm respectively, during 1-4 years life span (Joshi et al, 2005). In subsequent efforts the trout yearlings attained maximum growth of 300-350 g at the farm. Produced table size rainbow trout at the farm for the first time in Kumaon region and sold the surplus stock to the local people since 14.02.2001.

At Champawat, during 2005, the hatching of the stripped eggs completed after 61 days at water temperature 4.5 7.5 C with a survival rate of 42.6 % (Joshi, 2009). Breeding of rainbow trout conducted at Champawat during 2009 and produced 12000 eyed ova and 5000 fingerlings with 60% fertilization, 80% hatching and 61% survival of fry to fingerling (Incubation period 58 days) at water temperature 5-12C. During 2010 produced 10000 eyed ova with 71% fertilization, 72% hatching (Incubation period 54 days) at water temperature 6-14C.

During 2010, It was observed that there was not complete egg absorption in unused females of the last year and new eggs were partially developed.( Temp-624C) This situation was not observed at Bairangna farm.( Temp- 421C) First time, milt oozing was observed in yearlings also. Fry were obtained from the eggs of dead female (after 6 hrs.)

( Under out reach activity) At Bairangna farm, during 2009 produced 80,000 fry with 82% fertilization, 64% hatching and 56% survival. (Incubation period 60 days) at water temperature 4-12C. During 2010 produced 88,000 fry with 84% fertilization, 86% hatching. (Incubation period 61 days) at water temperature 4-11C. (Breeding is still continue)

DCFR further initiated the trout culture and breeding in Arunachal Pradesh and in Sikkim (Technical support and procurement of eyed ova). DCFR initiated the establishment of processing plant in Himachal to overcome the marketing problem with technical support of NFDB.

Feed development Starter feeds were formulated with 3 levels of protein (55, 50 & 45%) and 2 levels of lipids (14 and 16%) and found that feed S3 having 50% protein and 14 % lipid is best among the all 6 tested diets. Fingerling feeds were formulated with 3 levels of protein (40, 45 &50%) and 2 levels of lipids (14, 16 and 18%) and found that feed F6 having 45% protein and 16 % lipid is best among the all 9 tested diets. Grow-out feeds (Floating pellets) were formulated with 3 levels of protein (50, 45 & 40%) and 2 levels of lipids (14 and 16%). (Result is awaited) Field trial is in progress to explore the possibility to include Rhododendron extract to enhance the flesh quality of trout.

Trout Disease April 2009, mass mortality in swim-up fry in rainbow trout was experienced at in Uttrakhand due to unidentified causative agent. The diseased larvae showed an axial swimming behavior or crock screw swimming motion, darkening of caudal peduncle region with upward twisting of the tail portion. With our limited cell culture facilities we have been able to observe cytopathic effect in BF-2 cells from infected material.

The pathogenic fungi was isolated from tissue and water samples of trout and identified as Saprolegnia parasitica and Saprolegnia diclina with cotton like appearance, elongated zoosporangia and pear shaped primary sporangium. High temperature increases the chances of infection. The dead eggs were more susceptible to the fungal attack during incubation. 2% Solution of the bark of Kaphal (Myrica esculenta) tree and 3% solution of the marigold leaves (Calendula officinalis) were tested ( bath treatment of 15 min. for 3 alternate days) in the infected eggs& fry of rainbow trout and found more effective than the malachite treatment. Extract of Harad ( Myrobolus indicus) was used for infected eggs of trout( 20% sol.). This extract performed a biofilm on the eggs to protect the attack of fungal spores.

Developing Mycelium /Oogonia of Saprolegnia

Seasonal variation in Proximate Composition of O. mykissS.No. Elements (%) Feb-May Pond 1 2 3 4 Moisture Protein Fat Ash 72.39 17.33 2.69 1.02 June-Sep Pond 77.03 17.44 4.39 1.57 Oct-Jan Pond 78.52 17.10 3.58 1.19

Fatty Acid AnalysisComponent C8 (Octanoic) C10 (Decanoic) C11 Dodecanoic C13 Tetra decanoic C14:1 C15 C15:1 Hexa decanoic 9-hexadecanoic C17 C17:1 Octadecanoic 9-octadecanoic Octadecadienoic C18:2n6 Octadecatrienoic C18:3n-3 Eicosanoic C20:1 C20:2 C20:3n-6 Eicosatetraenoic C20:3n-3&C21 Eicosapentaenoic Docosanoic C21:1 13,docosenoic C22:2 Docosahexaenoic C24 C24:1 Tor putitora Conc (%) 0.004 0.004 0.196 0.045 0.006 1.013 0.021 0.144 0.085 8.792 1.410 0.221 0.045 0.105 4.663 0.040 14.251 0.287 2.611 0.211 1.626 0.552 0.653 3.662 0.151 3.074 0.078 2.980 0.084 0.563 11.659 0.046 0.241 Area % 0.0006 0.000006 0.002 0.0006 0.000007 0.012 0.0002 0.0016 0.0009 0.093 0.015 0.001 0.0004 0.001 0.046 0.0003 0.1304 0.002 0.021 0.001 0.014 0.004 0.005 0.022 0.001 0.0204 0.0006 0.025 0.0006 0.504 0.063 0.0004 0.002 Oncorynchus mykiss Comp Conc (%) Area %

C11 C12 C13 C14 C14:1 C15 C16 C16:1 C17 C17:1 C18 C18:1n-9 C18:2n-6 C18:2n6 C18:3n-6 C18:3n-3 C20 C20:1 C20:2 C20:3n-6 C20:4 C20:3n C20:5n-3 C22 C21:1 C22:2 C22:6n-3 C24:1

0.022 0.090 0.020 0.593 0.034 0.064 4.200 1.567 0.137 0.047 1.592 5.053 0.011 3.109 0.119 1.224 0.054 0.250 0.185 0.193 0.790 0.092 0.734 0.024 0.199 0.139 2.424 0.045

0.154 0.592 0.121 3.429 0.192 0.348 21.894 8.188 0.528 0.231 7.525 24.346 0.050 13.774 0.488 4.879 0.246 1.103 0.778 0.743 2.395 0.369 2.376 0.105 0.842 0.608 6.420 0.187

Amino acids of Golden MahseerAmino acidsAspartic acid Threonine Serine Glutamic acid Proline Glycine Alanine Cystine Valine Methionine Isoleucine Leucine Tyrosine Phenylalanine Histidine Lysine Arginine Tryptophan

gmAA/16gmN)7.400 3.679 4.219 7.040 6.555 7.300 4.953 Nil 3.980 3.612 3.241 7.610 5.587 5.612 0.542 8.86 3.228 6.22

Total

89.638

Amino acids of Rainbow TroutAmino acidsAspartic acid Threonine Serine Glutamic acid Proline Glycine Alanine Cystine Valine Methionine Isoleucine Leucine Tyrosine Phenylalanine Histidine Lysine Arginine Tryptophan

(gmAA/16gmN)8.447 5.801 6.514 4.777 9.542 6.864 6.048 Nil 4.841 3.082 6.388 5,614 8.290 2.925 0.916 3.41 6.427 6.12

Total

96.006