Biodiversity, a contraction of biological diversity as the term used to describe the total variety of living organism. It is essential for stabilization of ecosystem and protection of overall environmental qualities. The study of biodiversity is an important issue in today’s world (Khan and Hasan, 2011; Swanson and Luxmoore, 1997).
Ichthyo diversity refers to a variety of fish species; depending on context and scale, it could refer to the alleles or genotypes within fish population to species of life forms across aqua regimes (Shinde et al., 2009).
A fish is a back boned animal which lives in the water and cannot ever live very long anywhere else. Its ancestors have always dwelt in water, and most likely its descendents will forever follow their example (Jordan, 1996). Lagler (1962), defined the fish as the cold blooded animals with backbones, paired appendages, gills and fins and are depending on water for life.
Fish constitute more than a half of the total number of 54,711 recognized living vertebrate species. There are about 27,977 valid species of fishes (Nelson, 2006). Of the total species of fish 27,000 i.e. 95% are bony fishes, 970 (4%) fishes are cartilaginous fishes and 107(1%) species of agnathans. About 200-300 fish species are discovered every year and it is predicted that the eventual number of living fish species will be at least 32,500 (Ali and Narejo, 2009). Of this total diversity of fish 58% are marine, 41 % are freshwater inhabitants and 1% is diadromous (Ali, 1999).
Freshwater resources of Pakistan are immense. These include, beside a number of large rivers and their tributaries, a number of freshwater lakes, reservoirs, ponds, natural depressions, irrigational canals, water logged areas, quarry pools, and streams. The native freshwater teleostean fish fauna of Pakistan comprises of 160 species belonging to 69 genera, 23 families, and 11 orders. Of these, 90 species are of common occurrence while the remaining is less common or rare. Again a quite good number of these are of great commercial importance (Ali, 1999). There are more than 186 freshwater fish species described from freshwater bodies of Pakistan (Khan, et al, 2008).
The freshwater fish fauna of Pakistan is represented by a minimum of 193 fish species. These fishes belong to class actinopterygii, sub class teleostei, 3 cohorts, 6 super orders, 13 orders, 30 families and 86 species (8 exotic and 78 indigenous) have been identified as ‘’ species of special importance’’ (Rafique, and khan,2012).
A large variety of suitable species of fish are available in various parts of the world for cultivation in ponds. Hora and Pillaly (1962) listed about 70 species of cultivable fish in the indo pacific region alone. Fish culture in dams and reservoirs is also important areas for the culture of fish. But fish rising in these waters is more difficult than in ponds because this water cannot be drained, and predators cannot be removed. Also it is not possible to feed, fertilize, or poison the water, so natural nutrients must be providing enough food (Ali, 1999).
Fisheries play a key role in boosting the economy of the country and the prosperity of the area (Khan and Hasan, 2011). The commercially important fishes are a vital component of a country economy. It provides high quality protein, essential nutrients and minerals that are often difficult to obtain from other food sources (Rafique and Khan, 2012). The nutritional value of fish is very high, with protein contents of 15 – 20 %, low cholesterol content and many useful dietary supplements (Hassan, et al, 2007).
Researcher worldwide have discovered that eating fish regularly one or two servings weekly may reduces the risk of diseases ranging from childhood asthma to prostate cancer. Fish is low in fat, high in protein and an excellent source of omega 3 fatty acid. Fish rich in omega 3 fatty acids can contribute to the health of brain tissues and the retina. The omega 3 fatty acid in fish may reduce the risk of many types of cancers by 30 – 50%. Especially of the oral cavity, esophagus, colon, breast, ovary and prostate. Eating fish reduces the risk of heart diseases and stroke by reducing blood clots and inflammation, improving vessels elasticity, lowering blood fats.
District Bannu lies between 320 42’ to 330 06’ north latitudes and from 700 22’ to 700 57’ east longitudes. It is bounded on the north by the tribal area adjoining Bannu district, on the east by Karak district, on the south by Lakki Marwat district and on the west by South Waziristan agency and tribal areas adjoining Lakki Marwat and Bannu district. The total area of the district is 1,227 square kilometers. The Bannu district is a large oval valley of alluvial fill enclosed in an almost continuous rim of low mountains. The Bannu valley is 150 meters high from the sea level. A low structural basin is almost completely bounded by hills and mountains. However, the valley opens up on to the Indus plains. Although the Kurram and Tochi are the main river of the valley (Khan, 2006).
River Kurram is originated in the mountains of Parachinar and enters the district at Kurram Garhi, about seven miles north-west of Bannu city and passes through the district in a southeast direction. At Kurram Garhi, a diversion weir has been constructed across the river, by which water can be withdrawn at a maximum rate of 3,200 cusecs. Of this discharge, 1,400 cusecs are conducted directly to an irrigational channel, while the surplus is diverted to feed the Baran Dam reservoir.
The idea of construction of a weir at Kurram Garhi, the remodeling and extending the existing system of irrigation was first conceived and investigated by J. C. Davis executive engineer in 1907. It had to be dropped because the vested saroba interest could not be persuaded to part with water surplus to their own requirements for the benefit of lands proposed for further development. The reservoir is connected with the KurramRiver through the Baran feeder channel and the main canal. The capacity of these two channels is 3000 cusecs. Surplus flood water from the Kurram River can be feed into the Baran reservoir when supplies are available. The right bank canal which takes 800 cusecs will be supplies from the river Kurram when water is available and during short supplies in river the supply in the canal will be supplemented through an Intake from the Baran storage reservoir (Khanzada).
Baran Dam Bannu is situated from 330 0’ 22’’ to 330 03’6’’ north latitude, and 700 28’ 17’’ to 700 30’ 35’’ east longitude (Google earth). The total area covered by Baran Dam is 11.746 square kilometers. Baran Dam is situated 8 kilometer away from Bannu city towards west. The Dam entered into its completion in 1962. Baran Dam was not designed on the main river Kurram at Kurram Garhi but on a small tributary of this river i.e. the Baran Nullah. The Dam was inaugurated by field Marshal Ayub Khan, Ex President of Pakistan.
The Baran Dam is bounded from each side with mountainous ranges, which are barren, but now efforts have been made to make plantation on the banks of the Dam. This Dam was built for irrigational purpose. This storage Dam is of maximum of 120 fetes, and is designed as an earth Dam. The only disadvantage of the scheme is its limited storage capacity which could be increased appreciably increasing its height.
Baran Dam was commissioned in 1962 and was worked flawlessly for 22 years but as invariably happens with such earthen dams, the capacity of the reservoir of too gradually reduced by siltation, approximately at the rate of 1.7 feet per year. Beside, the Dam could not achieve its feeding arrangement. The record of the Dam reveals that it attained its maximum conservation level of 1430, only twice in the last 31 years.
The total storage capacity of Baran Dam is 9800 acre feet. The sediments studies were carried out for the period of 1954 to 1957 for Baran Nullah and it was found that the average silting is about, 1290 acre feet. The reservoir was thus assumed to get completely silted up in 76.96 years. All the silt coming in Baran Nullah would be entrapped in the Baran reservoir. The physico-chemical data shows that climate and environmental conditions of Baran Dam varies in various seasons of the year. The water depth decreases from summer to winter and color of the water is blue green.
Fish forming in Baran Dam was started in 1966-67 with Cirrhinusmrigala (Mori), Labeo rohita (Rahu) and Tor putitora (Mahaseer). Among the introduce species, C. mrigala alone attained a prominent position. It gradually formed a sizeable proportion of fish production of the Baran Dam forming 50 to 80%. Mahaseer form a dominant first rank dwindled to 25%. Now a day’s three species viz Labeo rohita, Cirrhinus mrigala, and carps are cultured in Baran Dam (Shahjehanand Khan, 1998).
Parasite is an important group of pathogen causes infection and diseases of fish both in freshwater and marine environments. With the increasing interests in aquaculture parasitic infestations are becoming threats for fish health management and aquatic crop production throughout the world. It is therefore an essential area for proper attention to be given by the scientists for sustainable aquaculture production. The various fishery development programmes depends to certain extent on the successful fish parasitological research, as the improvement of fish yield can mainly be achieved from healthy fish stock. As hosts fishes play an important role for parasites. Among the animals fishes are the most important host for maintenance of mainly helminthes. Most of the fishes have parasites. They not only serve as the host of different parasites but also serve as carrier of many larval parasitic forms that mature and cause serious diseases in many vertebrates including man. The parasites of fishes cause decrease in growth rate, weight loss and emaciation, affect yield of fish products (liver oiletc), spread human and animal diseases, postpone sexual maturity of fish and mortalities of fish(K. J. CHANDRA, 2006).
The parasites are hazardous to majority of fishes of fresh water and marine water. The ratio of infection is higher in wild fish species as compared to those species found in the farmed or captive places. Mostly these parasites are not dangerous to human beings but some products which are obtained from fish species are not suitable for human utilization, either due to the reason of decline in its quality or due to the cause that humans are used as a final host by the parasites. In many countries the common zoonotic potentials which are being reported to have a cause of severe disease conditions on human health are due its raw use, salted, smoked fishes or its improper cooking.
The parasitic activity and closeness to habitat of the fishes leads to easy parasitic movement and fulfillment of their life cycle among fishes (Dogiel, 2010). Parasitic infection not only affects the normal growth of fish (Mdegela,2010), butalso reduce fish population by increasing mortalities(Piasecki,2004). Parasites can cause physical, physiological and reproductive damage to fish. Therefore it is necessary to have sufficient knowledge of various parasites particularly crustacean (copepods) and their communities within a given fish population.
Lernaeid or anchor worms are common parasites in freshwater aquaculture of cyprinids and polymorpha) in some culturable fish species cultured in some nurseries and hatcheries of Punjab, Pakistan (Al-Jahdali & Hassanine, 2010, Iwanowicz, 2011).
Parasites on freshwater fishes are primarily protozoans, myxozoans, helminthes and crustacean. Monogeneans are typically parasites of the gills and skin of the fishes and are generally host specific (Woo, 2006). Dactylogyrids are gill parasites while gyrodactylids live on skin and fins. Dactylogyrusextensus is commonly found on goldfish, while Gyrodactylus katherineri is more often observed in koi, Cyprinus carpio. Gyrodactylus turnbulli and G.bullatarudis are parasites of guppy and areassociated with stress for fish in the aquarium (Woo, 2006; Roberts, 2010).
Most species of Monogenean are found externally on the gill filaments of fish host. Some are ectoparasitic on fins, on the body surface, in the nostrils, and in the buccal cavity, other are endoparasitic in the oesophagus, cloaca, urinary tract, and the heart. Monogeneanat the posterior end of their body have a haptor, which have hooks, used for attachment to their host body. Most Monogenean are highly host specific (Hargis, W. J.Jr, 1957b)
The major parasitic groups found in freshwater fishesaretrematodes, cestodes, acanthocephalans and nematodes that complete theirlife cycles through intermediate hosts like piscivorous birds. All of the worms are associated with social cultural and behavioral factors which enhance infection, especially the habit of eating raw fish. Fish all over the world suffer from varieties of parasitic diseases that cause mortality in fish either directly or indirectly (Shakiret al., 2006).
There are more than 30000 helminth species parasitizing marine and freshwater fish(Williams, H. and Jones, A, 1994) However, Monogenean attain their greatest diversity on the bony fishes (Teleosts) and particularly freshwater cyprinid fishes. The volatile radiation of the cyprinid is coordinated by two genera of freshwater Monogenean that rely on hooks for attachment, namely Dactylogyrus on the gills with more than 900 species worldwide.(Tinsley, R.C, 1990)and Gyrodactylus on the skin and gills with 402 described species(Tinsley, R.C, 2013). Dactylogyrus species are highly diverse, much of the diversity linked with the copulatory apparatus. In distinction, the morphology of Gyrodactylus is astonishingly conformist (Gibson, D.I., Timoffeva, T.A. and Gerasev, P.I, 1996). Ectoparasites not only harm the fish directly but also render the fish for grown, reduce host population and induce mortalities (Piaseckiet al., 2004).
Ecto-parasites attacks to gills and skin resulting in localized hyperplasia, disturb osmoregulation and ultimately kill the host (Piasecki,2004). The incidence and intensity of parasite also varied with season (Bichi,2010).Young fishes are more prone to infection than old ones(Ozturk,2005). Common carp (Cyprinus carpio) is apparently the most widely geographically distributed fish species (Baruš,2002). InPakistan, common carp is the first cultured fish and due to confined water bodies in Pakistan, the ecto-parasites are aserious problem for this species (Tasawar,2007a). Owing to its adaptation to a wide range of climatic and geographical conditions, a substantial number of almost all major taxa of parasites have been found in wild and domestic carp(Farman etal., 2015).
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