Invasion of an exotic fish—common carp, Cyprinus carpio L. (Actinopterygii: Cypriniformes: Cyprinidae)in the Ganga River, India and its impacts

Background. The Ganga River (Ganges) is known of its rich fish diversity which is adversely affected by degrading environmental and ecological conditions. There are more than 300 exotic fish species in India.  Many of them (particularly Cyprinus carpio) escaped from confinement and are now present in the Ganga River, challenging its ecological equilibrium.  The aim of this project was to study the population characteristics of Cyprinus carpio (i.e., the abundance, size range, food and feeding, gonado-somatic index (GSI), gonad maturity stage, maturity and breeding) and the altered fishery dynamics. Materials and methods. The commercially caught fishes, including the exotic ones, were identified, examined and measured. Important indices such as: the abundance index of exotic fishes, the gonado-somatic index (IG), as well as the gonad maturity stage of the escapee C. carpio were determined. The gut content was also analyzed to identify food items and thereafter the food richness, diet breadth, and gut repletion index (GRI%) were calculated using the Simpson’s diversity index. Results. C. carpio introduced about sixty years ago for aquaculture has now been found to invade into the Ganga, the largest river of the country contributing significantly to the fishery. The abundance index of C. carpio ranged from 12.2% to 45.5 % in 250 km long river stretch of the Ganga River flowing along Kanpur to Varanasi in the state of Uttar Pradesh. The gut content analysis revealed the presence of Eichhornia (9.8%), Pistia (11.6%), Nymphaea (8.5%), annelids worms (7.8%), algae (20.2%), mud and detritus (14.8%). The calculated diet breadth ranged from 0.82% to 0.91%; food richness ranged from 12 to 16, and the gut repletion index (GRI%) was 100% at different sampling sites. Mature females represented all the six reproductive stages with varying gonado-somatic index (IG) (0.5 to 30) in different catches. Presence of spent, ripe, and mature females was recorded. Conclusion. Abundance of exotic fish primarily C. carpio and Oreochromis niloticus in the fishery of the Ganga River was observed. The gonado-somatic index (IG) and the presence of all the six gonadal stages confirmed that C. carpio established its breeding population. The dominant catch of exotic fishes negatively impacted on the important indigenous fishes particularly Indian major carps (Catla catla,Labeo rohita,and Cirrhinus mrigala). The change in dynamics of the fishery due to the presence of common carp attracted attention to conserve rich indigenous germplasm facing threats of shifting from their natural habitats

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Not AvailableOf the 200 taxa of freshwater prawns, Macrobrachium rosenbergii is the most preferred species due to its suitability for aquaculture on account of fast growth rate, omnivorous feeding habit, hardy nature, compatibility for polyculture, resistance to certain diseases, unique appearance and high price in domestic as well as in international markets. In natural system, it attains a size of 30-35 cm with 400-450 g weight thus being the largest prawn available for culture. It grows well in almost all freshwater and low-saline water bodies such as lakes, rivers, swamps, irrigation ditches, canals, ponds and small dams. While cultured in earthen ponds, the marketing size of 70-80 g is obtained over a period of 8-10 months under the tropical climate. Polyculture with compatible species of carps facilitate better utilization of pond resources and also control excessive growth of algae and zooplankton. The grass carp, silver carp, catla, rohu, milkfish and green chromids can be used for polyculture with scampi, however, the bottom feeders like mrigal, common carp and tilapia are not advisable as they compete for food and space.Not Availabl

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Not AvailableBreeding experiments were conducted in Heteropneustes fossilis employing GnRH-based inducing agents like ovaprim, ovatide and wova-FH. The catfish responded well to ovaprim (0.40-0.55 ml/kg), ovatide (0.45-0.55 mg/kg) and wova-FH (0.50-0.60 mg/kg). Ovaprim gave better results in terms of fertilization and hatching success on low dose and latency period was also less as compared to ovatide and wova-FH. The overall performance of ovaprim was better when compared with the other two drugs. Among ovatide and wova-FH, the latter appeared to be better in spawning performance. The gonadotrophs (cynophils), distributed in the proximal pars distalis (PPD) of the pituitary gland, exhibited hyperactivity and degranulation in ovaprim, ovatide and wova-FH induced-bred H. fossilis suggesting release of the hormone (gonadotropin) in response to administration of the drugs.Not Availabl

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Not Availablen order to evaluate the efficacy of ovaprim over the pituitary glands (PG) in induced breeding of Indian major carps under agroclimatic conditions of Uttar Pradesh, matured brooders of Catla catla, Labeo rohita and Cirrhinus mrigala were administered intramuscularly (i. m.) with ovaprim (single injection) at the dosage of 0.25-0.60 ml/kg. Control fishes received i. m. injections of carp PG - two split doses (3 & 8 mg / kg) for females and single dose (3-4 mg / kg) for males. Spawning response of rohu was complete both with ovaprim (0.35/kg) and PG. The mrigal responded even to 0.25 ml / kg ovaprim. Even catla, the species slightly difficult to breed in this area, also responded fairly well with the drug (0.60 ml / kg). The general conditions of the fertilized eggs during hatching also remained better with ovaprim. The breeding response of the Indian major carps to ovaprim shows the efficacy and potential application of the drug over PG in the agroclimatic conditions of Uttar Pradesh.Not Availabl

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Not AvailableSeasonal changes in abundance of nitrifiers (ammonia-oxidizing and nitrite-oxidizing bacteria) in surface and bottom water of freshwater ponds were examined with respect to temperature, DO, pH as well as concentration of ammonia and nitrite. The most probable number (MPN) of ammonia-oxidizers in different ponds varied from1297±3.6 to 1673.23±0.36 ml-l in bottom and 720.5±8.1 to 955.3±10.8 ml-l in surface water during the rainy season while the MPN ranged from 1074±1.07 to 1372.17±4.6 ml-l in bottom and 515±10.1 to 678±11.8 ml-l in surface water in winter. However, the MPN were greatly reduced in summer and ranged from 435.05±15.7 to 547.54±2.12 ml-l in bottom and 218.7±7.3 to 368.4±9.32 ml-l in surface water. Similar seasonal trends were also observed in MPN of nitrite-oxidizers. Among all the physico-chemical parameters, abundance of nitrifiers was more positively correlated with ammonia and nitrite concentration in all the seasons. The abundance of nitrifiers in surface and bottom water was highest in rainy season followed by winter and modest in summer. The potential nitrification activities and oxidation rates were shown to be linear and activity of ammonia-oxidizing and nitriteoxidizing bacteria was highest during rainy season.National Bureau of AgriculturallyImportant Micro-organisms (ICAR), Mau (India

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Not AvailableAnalysis of morphometric and meristic traits of twelve species of ariid catshes occurring along the west coast of India indicated that these species can be differentiated based on morphological characteristics. Higher F-ratio for inter-nostril length, mouth width and adipose n length signies their role in species separation either alone or in combination with other morphometric characters. Stepwise discriminant function analysis (SDFA) included all considered variables showing their taxonomic signicance with inter-nostril length, snout length and adipose n length, as the most important discriminating characters. The rst two discriminant functions accounted for the explanation of 89.44% of total variation. SDFA gives correct classication in 99.55% cases with only two misclassied cases among 447 specimens. Meristic features were found to be overlapping except in few instances and hence are less discriminating than morphometric variables.Not Availabl

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Not AvailableA DNA-based barcode identification system that is applicable to all animal species will provide a simple, universal tool for the identification of fish species. The barcode system is based on sequence diversity in subunit 1 cytochrome c oxidase (COI) gene. Identification and characterization of fish species based on morphological characters are sometimes found to be erroneous and environmentally affected. There are no studies on the genus Ompok in India at molecular level and species identification of the Ompok is usually carried out through morphological features. A total of 106 samples from three species Ompok pabda, O. pabo and O. bimaculatus were collected from eight sampling sites of seven Indian rivers. One hundred and six sequences were generated from COI region of three Ompok species and 21 haplotypes were observed. The sequence analysis of COI gene revealed three genetically distinct Ompok species and exhibited identical phylogenetic resolution among them. The partial COI gene sequence can be used as a diagnostic molecular marker for identification and resolution of taxonomic ambiguity of Ompok species.Not Availabl

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Not AvailableT: A 84-day feeding trial was conducted to evaluate the utilization impact of dietary omega-3 HUFA as a dietary energy source by fingerlings of striped murrel, Channa striatus on the growth study and tissue composition. There were seven treatments (L3HUF, H3HUF, MUSOL, LINOL, MIXOL, SATOL and NATFO), each having two replicates, stocked with 100 fingerlings in circular plastic pools (3001 capacity). The six feeds were formulated with basic ingredients (Soybean meal, 41%; soluble starch, 25%; Casein, 20%; carboxy-methyl-cellulose, 2%; papain, 0.5%; vitamin and mineral mix, 3.5%) with iso-energetic (19.3 kJ/g, F1-F6 ) diets and results were compared with natural food fed fishes. The isocaloric diets were formulated from semi-purified ingredients with six different types of oil supplement which were fed to replicate groups of fishes ad libitum. Based on the protein efficiency ratio (PER), specific growth rate (SGR), average per day increment (P1) and food conversion ratio (FCR), and, it was observed that C. striatus fingerlings utilized dietary lipid. The LINOL showing best growth performance followed by H3HUF, MUSOL on the basis of SGR and PER were significantly (P<0.05) influenced in striped murrel, Channa striatus. But lower SGR levels were obtained with diets containing L3HUF, MIXOL, SATOL and NATFO. This study suggests that the lipid from unsaturated origins could be effectively utilized by striped murrel fry with a better resultant growth.Not Availabl

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Not AvailablePresent study consist the instances of anomalies in two species of genus Setipinna i.e. accessory pectoral filament in s phasa, (Hamilton, 1822) and absence of pelvic fin in the s. taty (Valenciennes. 1848). collected from east coasts of India. Comparison of twenty seven morphometric measurements and twelve meristic characters of the abnormal with normal specimens confirmed abnormality. Furthermore. genetic divergence value of mitochondrial COI and 16S rRNA confirmed that both normal and abnormal specimens belong to the respective species. These abnormalities might have occurred in early stages of development, Abnormalities have affected only morphological aspects and not growth of the fish.Not Availabl

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Not AvailableVitamin D3 (0.0 IU.100 g body weight (BW)-l.day-l, 100 IU.100 g BW-l.day-l, 500 IU.100 g BW-l.day-l and 1000 IU.100 g BW-l.day-l) was administered intra-peritoneally (ip) to the freshwater threatened Bronze Featherback, Notopterus notopterus kept in freshwater for 9 days. Analyses of serum calcium levels were performed at 0, 6 hr. and 1, 2, 3, 5 and 9 days (four grow-out Notopterus notopterus from each group of ip doses at each interval). Administration of vitamin D3 elevated the maximum serum calcium elevation occurred at day 2 freshwater in 500 IU.100 g BW-l.day-l (11.2±0.92 mg.dL-l) and in 1000 IU.100 g BW-l.day-l (12.0±0.46 mg.dL-l) of the fish maintained in the fresh water. There was gradual decrease in calcium levels from day 3 and became normocalcemia on day 9. Out of the three concentrations of ip Vitamin D3 (100 IU.100 g BW-l.day-l, 500 IU.100 g BW-l.day-l and 1000 IU.100 g BW-l.day-l) the sharp elevation of serum calcium recorded in both 500 IU.100 g BW-l.day-l and 1000 IU.100 g BW-l.day-l. The control (0.0 IU.100 g BW-l.day-l) fish serum calcium behaves like normocalcemia (8.25±0.21 mg.dL-l) in every sampling up to day 2. Results demonstrated that ip Vitamin D3 exerted a dose-dependent and pronounced hypercalcemic effect in freshwater threatened Bronze Featherback, Notopterus notopterus.Not Availabl