An estimation of optimum dietary concentration of soy bean meal for carps (Catla catla, Labeo rohita and Cirhinus mrigala)

Soybean meal is an inexpensive plant origin protein which has been used in practical diets as a replacement of animal protein such as fish meal or chicken meal, due to the uneconomical price of animal protein diets. Consequently, a research study was conducted on some commercial species of Indian major carps i.e. Catla (Cattla cattla), Rohu (Labeo rohita) and Mrigala (Cirhinus mrigala) (Hamilton, 1822) to estimate optimum dietary protein requirement of soy bean meal in diet in an intensive polyculture. Three different diets (SBM I, SBM II and SBM III) were formulated by 80%, 50% and 20% replacement of fish meal with soybean meal from a 45% fish meal diet (control).Highest monthly mean weight gain was obtained by SBM II (with 35% CP and about 50% substitution of fish meal), while SBM III (45% Crude Protein and about 20% substitution of fish meal) was stood second. All tested diets respond enormously by producing high yield as compare to control diet, though SBM II generated highest yield among all. On the bases of the following research, it was revealed that the SBM can surrogate even50% fish meal without any augmentation of other amino acids in the diet of Indian major carps.

Fatty acid profile variations after exposure to textile industry effluents in Indian Major Carps

Indian major carps are the widely consumed fish species of Pakistan, being a cheap source of proteins and unsaturated fatty acids, they are good for cardiovascular health. Water pollution due to discharge of untreated industrial waste water into water bodies contaminates this precious source of nutrients. The present study therefore, was aimed to assess deterioration of fatty acid profile of three Indian major carp species due to different concentrations of industrial wastes. The water samples were collected from the river Chenab at the site where it receives industrial wastewater via Chakbandi drain. After exposure to 1.5%, 3.0%, and 4.5% dilutions of collected water in different aquaria it was observed that proportion of unsaturated fatty acids in selected fish species were decreased significantly as the intensity of the dose increased (P < 0.05). Conversely the level of saturated fatty acids increased with the increasing dose of treatment (P < 0.05). These findings suggest that untreated wastewater not only deteriorate the fatty acid profile of aquatic animals but also these toxic substances can reach human body through fish meat and pose further health hazards. Therefore, it is highly recommended that industrial effluents should be treated before they are dumped into water bodies.

ANTIBIOTIC-RE¬¬SISTANT MOTILE AEROMONADS ASSOCIATED WITH CULTURED INDIAN MAJOR CARPS, POND WATER AND POND SEDIMENT

The uproar in antimicrobial resistance (AMR) among the aquacultured environment has led to the isolation of multiple antibiotic-resistant (MAR) Aeromonas strains. The current study aimed at the enumeration of antibiotic-resistant Aeromonas in carps of aquacultured environment and market samples. Isolation of Aeromonas was also done in Rimler-Shotts agar supplemented with novobiocin followed by antibiotic-sensitivity assay against 12 broad-spectrum antibiotics. Five oxytetracycline-resistant strains were examined for the presence of three tetracycline-resistant genes (tetA, tetC and tetE). The presumptive Aeromonas counts on starch-ampicillin agar were determined as log 3.00-log 6.45/g in carps, log 3.00l-log 5.06/ml in pond water and log 3.30–log 5.14/g in pond sediment. Higher proportions of motile aeromonads from market carps were resistant to chloramphenicol, cefalexin, gentamycin, oxytetracycline and trimethoprim than the farmed carps. Aeromonas strains depicted 57 resistant profiles. About 88.43% of the Aeromonas strains were of the MAR group among which 12.15% and 4.67% were resistant to ≥6 and ≥7 antibiotic groups, respectively. Selected oxytetracycline-resistant strains were negative for targeted genes. The current study implied the high prevalence of AMR bacteria in cultured carps in West Bengal, India. Furthermore, the study indicated that motile aeromonads comprise an effective marker for monitoring AMR in freshwater aquatic environments.

Single Genetic Stock Revealed by Microsatellite Markers Among Wild Populations of Cirrhinus mrigala from Peninsular India

Cirrhinus mrigala (mrigal) is one of the Indian major carps widely cultured in the whole Indian subcontinent. Population genetic structure of this species from Peninsular Rivers of India is lacking. Among DNA markers, microsatellites are excellent tools to evaluate genetic variation of populations. In this study, genetic variation of six peninsular riverine mrigal populations was evaluated using seventeen microsatellite loci. In analyzing 288 samples, the number of alleles ranged from 4 to 27; observed heterozygosity from 0.595 to 1.00, expected heterozygosity from 0.586 to 0.959 and inbreeding coefficient (FIS) ranged from -0.034 to 0.02. Exact test for Hardy Weinberg disequilibrium revealed that one locus was not in equilibrium across the rivers except one. The AMOVA analysis revealed the main source of genetic variation to be within the population (94.54%) than among the populations (5.46%). The Nei’s genetic distance and structure analysis depict river Narmada and Mahi populations are different from the four east coast rivers. The overall Fst (0.05462) data showed moderate differentiation among the six populations. The results of this study provide essential information to resource recovery and help in delineating populations for fishery management. Besides, the data will provide a valuable baseline for further investigations on the geographic distribution of this commercially important fish species.