Exotic Aquatic Organisms - International Development Research ...

More documents

Recommendations

Info

Grass carp The grass carp, Ctenopharyngodon idella, was introduced mainly for purposes of biological control of submerged aquatic vegetation in fishery waters, in particular Hydrilla, Vallisneria and smaller floating weeds like Lemna sp. However, because of its fast growth rate, it was very soon included as a component in composite fish culture. It does not usually breed naturally even after hormone injection and therefore has to be stripped. It feeds on aquatic weeds and more voraciously on soft aquatic vegetation like Hydrilla, but does not feed on Eichhornia, Pistia and Salvinia (Singh et al. 1967) and grasses and leaves of leguniinious plants. The grass carp has been widely used in the country for weed control in canals (Kulshreshthra and Sharma 1976; Singit, pers. comm.), water cooling tanks (Chaudhuri et al. 1976) and ponds (Keshavanath and Basavaraju 1980). In composite culture systems, the grass carp lends an added advantage in that it consumes vegetation more than its own body weight and voids most of it in semi-digested form, which serves as food for omnivorous fishes and also as pond fertilizer. The introduction of grass carp, therefore, has proved beneficial. Tawes The Tawes, Puntius javanicus, is known to be macrophagous, and is cultured in only some parts of the country. It breeds naturally and attains a weight of over one kg in a year. However, the species is not popular in culture practices in India. Tench The Tench (Tinca tinca) introduced into Nilgiris in 1874 is established well in the Nilgiris region and individuals weighing over 1 kg can be caught from Ooty Lake. It matures in the 2nd or 3rd year and breeds under pond conditions. However, recent reports indicate the disappearance of the tench from Nilgiris waters (Sreenivasan et al. 1988). Bighead carp Bighead carp (Aristichthys nobilis) were accidentally introduced into India (Das 1988), where they remained confined to the fish farm of Central Inland Fisheries <strong>Research</strong> Institute at Cuttack and later disappeared altogether. They have reportedly reappeared in the country in 1987, presumably through private trade from Bangladesh. Jhingran (1985) has discussed in detail the likely consequence of the introduction of bighead to Indian waters. Its feeding habits are similar to that of catla and is likely to pose a threat to catla. The suitability of bighead is yet to be assessed in terms of consumer preference, growth rates under Indian conditions and disease resistance. 49
50 Gourami The gourami Osphronemus goramy, an anabantid, has been cultured in several states for nearly four decades, but with little success. Because of its slow growth, it is no longer actively cultured anywhere in the country. However, it has established itself in waters in some parts of peninsular India. Because of its nest building habit, the rate of survival of its progeny is high. Being phytophagous, it also serves to control aquatic weeds to some extent. Tilapia The Java tilapia Oreochromis mossambicus, a cichlid, is the most controversia among the exotics in India. Apart from the official introductions, this fish has also found its way into the country through unofficial transplantation from Bangladesh by private entrepreneurs. Even though the Government of India has never advocated the commercial culture of tilapia and its introduction into natural water bodies, it has spread to several parts of the country and has even established itself in some reservoirs (Sukumaran and Tripathi 1988; Chandrasekeran and Sreenivasan 1988). A number of factors has led to overpopulation and stunted growth. Though the fish has been found to feed predominantly on phytoplankton, in the absence of :Lts preferred food it tends to be an omnivore and sometimes even a carnivore (Jhingran 1974). Tilapia was cultured with encouraging results during the initial stages, production ranging from 2000-10,000 kg/ha/yr (Chandrasekaran and Sreenivasan 1988). The catches from a few reservo:Lrs in Tamil Nadu are given in Table 4 and it is apparent that there is a general decline in tilapia catches over the years. It is quite difficult to eradicate this fish from where it has already gained a permanent foothold (Natarajan 1988; Jhingran 1988). It is reported that another species of tilapia, 0. niloticus, has already been introduced through private trade in West Bengal and is being cultured in sewage-fed farms. Table 3. Catch composition in Gobindsagar Reservoir (in tonnes; percentages are given in parentheses). Year Total (t) Common carp (Source: Kuldeep Kumar, personal communication) Catla Silver carp 1976-77 546.6 81.10 142.12 8.00 (14.80) (26.00) (1.46) 1977-78 706.8 135.03 169.01 10.00 (19.23) (29.91) (1.41) 1978-79 754.6 176.53 101.92 13.17 (23.39) (13.50) (1.74) 1979-80 715.8 222.76 40.68 43.66 (29,72) (5.68) (6.09) 1980-81 707.9 176.03 69.34 88.53 (17.59) (8.28) (14.68) 1981-82 653.4 114.99 54.11 95.89 (17.59) (8.28) (14.68) 1982-83 561.8 130.53 26.96 102.58 (23.30) (4.79) (18.25) 1983-84 425.6 119.46 25.41 107.08 (28.06) (5.97) (25.15) 1984-85 505.5 91.41 41.97 223.34 (18.08) (8.30) (44.18) 1985-86 546.5 122.81 29.81 244.34 (22.47) (5.45) (44.70) 1986-87 377.1 71.06 19.94 176.32 (18.84) (5.29) (46.76)
Page 1 and 2:
Exotic Aquatic Organisms in Asia /
Page 3 and 4:
Exotic Aquatic Organisms in Asia Pr
Page 5 and 6:
The Introduction of Exotic Aquatic
Page 7 and 8:
Introduction This special publicati
Page 9 and 10: help to promote national awareness
Page 11 and 12: Conditions in Europe and North Amer
Page 13 and 14: 2 taken as the basis for the introd
Page 15 and 16: 4 with respect to other introductio
Page 17 and 18: 6 Costa-Pierce, B. 1988. Study miss
Page 19 and 20: 8 extinction of the endemic rainbow
Page 21 and 22: 10 bottom substrates by European ca
Page 23 and 24: 12 Arthington 1988; Lloyd 1987); G.
Page 25 and 26: 14 Apparent Extinction of the Lake
Page 27 and 28: 16 successful and more often than n
Page 29 and 30: 18 Reznick, D. 1981. 'Grandfather E
Page 31 and 32: 20 -24° 4' 4 - I- .300 Cl) '1 S 36
Page 33 and 34: 22 The terminology associated with
Page 35 and 36: 24 Table 2. Translocations of indig
Page 37 and 38: 26 MELANOTAENIIDAE Melanotaenia spl
Page 39 and 40: 28 ELEOTRIDAE - GUDGEONS Hypseleotr
Page 41 and 42: 30 POECILIIDAE - LIVEBEARERS Gambus
Page 43 and 44: 32 References Allen, G.R. 1982. A F
Page 45 and 46: 34 Robinson, S.E. 1982. The ecology
Page 47 and 48: 36 1973. It has been cultured in so
Page 49 and 50: 38 northern Japan, settled off Dali
Page 51 and 52: 40 Table 1. The exotic aquatic food
Page 53 and 54: 42 Table 2. The preliminary list of
Page 56 and 57: Impact of Exotic Aquatic Species in
Page 58 and 59: Table 1. Salinonids introduced into
Page 62 and 63: Table 4. Total catch and tilapia yi
Page 64 and 65: Salvinia molesta, a floating fern o
Page 66: Joy, PJ., K.R. Sathesan and D. Jose
Page 69 and 70: 58 Table 1. Introduced aquatic spec
Page 71 and 72: 60 The 1940s The Inland Fisheries D
Page 73 and 74: 62 Indonesia includes three differe
Page 75 and 76: 64 information on the status of fau
Page 77 and 78: 66 Table 1. List of exotic aquatic
Page 79 and 80: 68 Table 1. Continued Taxonomic Sta
Page 81 and 82: 70 From this historical review, it
Page 83 and 84: 72 what they perceived as economica
Page 85 and 86: 74 Table 1. Fate of the introduced
Page 87 and 88: 76 While it is likely that at the o
Page 89 and 90: 78 Pearl Spot The pearl spot, Etrop
Page 91 and 92: 80 Trengganu Enactment No. 8 of 196
Page 93 and 94: 82 References Annual Fisheries Stat
Page 95 and 96: 84 long time ago as shown by the fa
Page 97 and 98: 86 Discussion and Recommendations E
Page 99 and 100: Table 1. Exotic aquatic species int
Page 101 and 102: Table 1. Continued Diseases/Parasit
Page 103 and 104: 92 Fisheries (Piranhas) Rules 1971,
Page 105 and 106: 94 (Caranx ignobilis) golden treval
Page 107 and 108: 96 Table 1. Main species of aquariu
Page 110 and 111:
Status of Introduced Species in Sri
Page 112 and 113:
Exotic Aquatic Species in Taiwan I-
Page 114 and 115:
appreciated in the context of the w
Page 116 and 117:
However, A. anguilla cannot tolerat
Page 118 and 119:
Today, most of these carps are poly
Page 120 and 121:
Caiman latirostris and Alligator mi
Page 122 and 123:
Conclusions The case of the tilapia
Page 124 and 125:
Table 1. Continued Culture Status P
Page 126 and 127:
Table 2. Record of tilapia introduc
Page 128 and 129:
Annex I. Continued Dascyllus melamu
Page 130 and 131:
Exotic Aquatic Species in Thailand
Page 132 and 133:
Present Status of the Exotic Specie
Page 134 and 135:
Table 1 a. Exotic fishes introduced
Page 136 and 137:
Australian Government Position: Int
Page 138 and 139:
There are presently eight State or
Page 140 and 141:
egulate any activity likely to have
Page 142 and 143:
Appendix II. Continued Name State o
Page 144 and 145:
Recommendations of the Workshop 1.0
Page 146 and 147:
(two more to be co-opted) was appoi
Page 148 and 149:
Mr. J. Maclean, do ICLARM, MC P0 Bo
Page 150 and 151:
Appendix I Definitions of Exotics T
Page 152 and 153:
Appendix II Assessment of the Impac
Page 154 and 155:
Table All.3. Assessment of the stat
Page 156 and 157:
Table All.6. Assessment table of th
Page 158 and 159:
Table All.8. Assessment table of th
Page 160 and 161:
Table All.10. Continued Family/Spec
Page 162 and 163:
Table Affi. Indigenous species whic
Page 164 and 165:
Appendix V Existing Legislation or
Page 166:
TITLES IN THE ASIAN FISHERIES SOCIE
show all

Exotic Aquatic Organisms - International Development Research ...

Create successful ePaper yourself

Delete template?

Save as template?