INTRODUCTION OF EXOTIC FISH SPECIES

INTRODUCTION OF EXOTIC FISH SPECIES BY SMRITI BISWAS.

1. TOPIC – INTRODUCTION OF EXOTIC FISH SPECIES. SUBMITTED TO - DEPARTMENT OF ZOOLOGY AND APPLIED AQUACULTURE, BARKATULLAH UNIVERSITY, BHOPAL, MADHYA PRADESH. SUBMITTED BY – SMRITI BISWAS M.F.Sc APPLIED AQUACULTURE 4 th semester Enrollment No – R218099020003

2. Contents INTRODUCTION. HISTORY. TRAITS OF EXOTIC SPECIES. EXOTIC SPECIES IN INDIAN AQUACULTURE. REASON FOR INTRODUCTION OF EXOTIC SPECIES. MERITS OF EXOTIC SPECIES INTRODUCTION. IMPACTS OF EXOTIC SPECIES. CONTROL AND MANAGEMENT. CONCLUSION.

3. INTRODUCTION Exotic species is any species, including its seeds, eggs , spores, or other biological material capable of propagating that species , that is not native to that habitat . Exotic species belonging by nature or origin to another part of the World or brought in from abroad. Various exotic species have been introduced in the Indian water bodies and some are now well established too with varying experiences. Accidental escapes and even purposeful releases of aquaculture species that are not native to a country create biological pollution with irreversible and unpredictable ecological impacts.

4. Sir , Francis Day , the author of the “ Classical work on the Fish fauna of Indian region”, was probably the first person who tried to introduce the brown trout,  Salmo trutta fario  in the Nilgiri waters in the year 1863, but his attempt was unsuccessful. This was followed by introduction of several exotic fish species from various parts of the world to different regions of India for augmenting fish production through aquaculture, for sport fishery, for mosquito / weed control, for ornamental purpose etc with successes and failures. The larvicidal fishes, such as,  Poecilia retiuculta   and   Gambusia affinis   were introduced in the year 1908 and 1928 respectively, to contain mosquito larvae in confined waters. There are hundreds of ornamental fish species being imported to our country since the aquarium trade is in progressive growth stage/ insecticidal value of these species is not well established. HISTORY

5. TRAITS OF EXOTIC SPECIES Many features have been attributed in invasive species and invaded ecosystem. The common invasive species traits include: Fast growth. Rapid reproduction. Phenotypic plasticity. Tolerance of a wide range environmental condition. Ability to live of a wide range of food type.

6. EXOTIC SPECIES IN INDIAN AQUACULTURE SL. NO. Common Name Scientific Name Year of Introduction Source 1. Common carp Cyprinus carpio 1980 Srilanka 2. Bighead carp A. nobilis 1959 Bangladesh 3. Golden carp C. carassius 1968, 1970 England 4. Doctor fish Tinca tinca 1974 England 5. Tilapia O. mossambica 1972 Bangkok 6. Nile Tilapia O. niloticus 1952 Thailand, Israel 7. African Catfish Clarius gariepinus 1978 Thailand 8. Brook trout Salmo fontinalis 1959 Canada 9. Pangasius sutchi Pangasius hypophthalamus 1997 Vietnam 10. White leg shrimp L. vennamei 2010 USA [Source – NBFGR, Lucknow ]

7. List of restricted, banned and not approved Exotic Freshwater Ornamental fish species. SL.NO. SCIENTIFIC NAME COMMON NAME CATEGORY 1. Astronotus ocellatus Oscar Restricted 2. Aequidens rivulatus Green terror Restricted 3. Labeo chrysophycon Black shark minnow Banned 4. Leptobarbus hoeveni Maroon shark Banned 5. Osteoglossum bicirrhosum Arowana Banned 6. Haplarchus psittacus Acara Restricted [Source – NBFGR, Lucknow ]

8. INTRODUCTION OF NEW SPECIES Artificial Introduction Superior Competition Occasional Introduction Species Based Mechanism Conditions that lead to establishment of exotic species

9. ARTIFICIAL INTRODUCTION - The introduction of new species to specific habitats or reintroduction of species to the place where it was once common, in order to restore natural balance to gain commercial profit. OCCASIONAL INTRODUCTION - Many times species are introduced unconsciously or by accident. The occasional introduction has severe impact on local community structure and balance of ecosystem. CONDITIONS THAT LEAD TO ESTABLISHMENT OF EXOTIC SPECIES – These mechanism generally fall into two categories. One mechanism focus on the exotic species and other one focus on the invaded ecosystem. SPECIES-BASED MECHANISM - Species based characteristics focus on competition among different fish species. All fishes are able to compete in some manner in order to survive and persist, invasive species have specific trait or combinations of specific traits that make them especially good competitors. SUPERIOR COMPETITON - Invasive species can coexist with native species for an extended time and only gradually does the superior competitive ability of an invasive species become apparent, as population grow larger and denser, and slowly increases the risk of extinction to other species.

10. MERITS OF EXOTIC SPECIES INTRODUCTION Improve production and economic benefits from fisheries and aquaculture. Use of exotic species for fisheries and aquaculture diversification deal with rising demand for food and nutritional security. The development of aquaculture Worldwide.

11. IMPACTS OF EXOTIC SPECIES Economic Impacts Ecological Impacts Genetic Dilution Transmission of Diseases Impacts on Biodiversity

12. ECOLOGICAL IMPACTS Competition of exotic species with the native species for living space with same niche preference. For food with fishes of similar types of feeding habits, or of omnivorous feeding habits or predation on native fishes by these, spreading parasites and pathogens.

13. IMPACTS ON BIODIVERSITY Habitat destruction. Invasive species cause loss of biodiversity including species extinction and changes in hydrology and ecosystem function. The impact on global biodiversity of human introduction of non-native species that have subsequently become invasive is subjective.

14. TRANSMISSION OF DISEASES Particular concern to exotic species is that the level of uncertainty will be higher with new introduction on what pathogens may be present and may cause problems in the new environment. The diseases which comes from other country to India is – Epizootic ulcerative syndrome. Epizootic haemorhagic necrosis. Taura syndrome. Yellow head disease.

15. GENETIC DILUTION The genetic impact of introduction of exotic fishes on native fishes can be classified into two categories: Reduction of effective population size by the ecological, biological and genetic effect of introduction. Alteration/extinction of gene pools of the species /stocks by cross breeding or hybridization and backcrossing.

16. ECONOMICAL IMPACT The economical impacts can be seen at two levels – Capture fisheries and Aquaculture. Economic costs due to invasive species can be separated into direct costs due to production loss and management costs of invasive species. Since the exotic fish species never fetch higher price than the native varieties and also the decline of native fish production is observed in the presence of exotic species in natural waters, the total economic returns declined for the stakeholders of the capture fisheries. In aquaculture however it provided immediate gain, in most cases without consideration of the long term ecological consequences.

17. STRATEGIES FOR INTRODUCING EXOTIC FISH SPECIES Introduction of fishes should be avoided and attempt should be made to enhance the production of native species by biomanipulation or biotechnological means. If the introduction is essential, highest precautions should be taken before introduction and should not be allowed in the natural water before proper study of long term impact on the ecosystem. A nodal agency or panel should be made responsible to study the impacts and risks or benefits of the proposed introduction. The import and cultivation of broods or seeds of certain species which have proved as harmful to the native fauna and ecosystem as a whole should not be permitted at all. Stringent quarantine measures should be followed for the imported live specimen consignments in ornamental fish trade. It should be ensured that they don’t escape into natural waters, even accidentally. Banned or unofficial / illegal introduction or trade of fishes should be penalised by law. A comprehensive legislation needs to be introduced.

18. CONCLUSION Introduction of exotic fish species would be a threat to the existing species diversity. The introduction of species have greater adverse impact on aquatic ecosystem and also on culture practices. Species introduction result in competition for limited food, space, ecological niche and may results in genetic erosion , predation and pathogen entry. Introduction of exotic species can be used for broadening species diversity in aquaculture systems of a particular country and also for economic benefits. The recent action by the government of India to introduce only SPF L. vennamei and controlled culture of P. hypophthalamus are the new steps in this direction.

19. References Handbook of fisheries and aquaculture, ICAR. Mishra et al. ( 2013) Introductions of exotic fish species into Indian waters: an overview of benefits, impacts, issues and management. Sambid (2017) Exotic Fish Species Introduction in India and Its Impacts.