Journal of Fisheries (University of Rajshahi)
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Determination of fatty acid composition in relation to the growth of meagre (Argyrosomus regius) cultured in net cages
The aim of this study was to determine the composition of fatty acids of meagre (Argyrosomus regius) produced in net cages at a private company in the Aegean Sea. Regular samples were taken over the study period by random sampling for the estimation of fatty acid contents. At the end of the study, the highest mean (± SD) fatty acids in fish flesh were recorded as oleic acid (26.46 ± 0.01%), linoleic acid (20.91 ± 0.01%) and palmitic acid (15.99 ± 0.01%). Mean (± SD) total saturated (SFA), monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acid values were determined as 26.17 ± 0.03%, 32.62 ± 0.03% and 31.24 ± 0.01% respectively. The total values of omega-3, omega-6, omega-9, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were 8.73 ± 0.01 – 14.51 ± 0.04%, 18.78 ± 0.03 – 25.26 ± 0.01%, 27.12 ± 0.01 – 30.5 ± 0.01%, 1.39 ± 0.01 – 3.52 ± 0.01% and 4.24 ± 0.01 – 7.64 ± 0.01% respectively and all these values varied significantly over time (P < 0.05). Despite having a low crude fat content, the meagre could be a good source of PUFA, in terms of fatty acids
Risk assessment of persistent organic pollutants in fishes from Pakistan and its neighbouring countries
Persistent Organic Pollutants (POPs) include a wide range of compounds including dichlorodiphenyltrichloroethanes’ (DDTs), hexachlorocyclohexanes (HCHs), polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs). These pollutants are present everywhere on earth i.e. soil, water and air. Their excessive use has adversely affected all ecosystems and their components including marine and freshwater, wildlife and human health. Although the use of POPs has been banned in many countries but they are still in use in many developing countries. This paper presents the sources and distribution of different POPs with special reference to their adverse effects and possible routes of contamination. Moreover, accumulation of these persistent pollutants in different body parts of fishes from major locations in Pakistan and its neighbouring countries (India, China and Iran) has been presented which exhibits their risk assessment for these important bioindicators of aquatic environments
Effects of Beta vulgaris powder on growth and survival of common carp Cyprinus carpio
The use of plant material in a diet to increase the growth of fish may be beneficial and can reduce the production cost. This research was carried out at Behbahan University, Iran, in 2016 with a view to determining effects of Beta vulgaris powder on feeding, growth and survival of common carp (Cyprinus carpio). A total of 360 individuals (mean weight, 20 g; mean standard length, 9 cm) were randomly divided into 12 tanks for treatments. Fish were fed diets with 0% (control), 0.5% (T1), 1% (T2) and 2% (T3) of B. vulgaris powder for six weeks. The results showed that the addition of B. vulgaris to fish diets had a positive effect on survival index and feed conversion index of fish. The presence of B. vulgaris in the diet had increased specific growth rate, and hepatosomatic and viscerosomatic indices
New host and geographical record of Eudactylina pusilla Cressey, 1967 from Indian waters with DNA barcodes
The present paper reports the first record of the parasite Eudactylina pusilla Cressey, 1967 from the gills of the pelagic thresher shark, Alopias pelagicus Nakamura, 1935 collected during a multifilament longline operation at a depth of 762 m from Indian EEZ around Andaman Islands. The occurrence of this copepod gill parasite on A. pelagicus in the Indian waters constitutes new host record and extends the parasite’s known geographical distribution, thus contributing to the knowledge of biodiversity of the parasitic copepods in Indian waters. Molecular marker based taxonomical annotation using Mitochondrial 18S r DNA sequencing also confirmed the identity of the E. pusilla specimen
Seasonal variations in nutritional profile of the freshwater mud eel, Monopterus cuchia (Hamilton, 1822)
Seasonal variations of proximate compositions, amino acids, and fatty acids contents of Monopterus cuchia were studied for the first time in Bangladesh. The fat and fatty acid, protein and amino acid contents showed a significant seasonal dependency. Lipid contents showed the wider variation than the protein contents. Among the 14 recorded amino acids, the primary amino acids were lysine, glutamic acid, arginine, glycine and aspartic acid. The ratio of essential and non-essential amino acids was higher in the post-monsoon season (0.69) than pre-monsoon (0.68) and monsoon season (0.68) and did not show seasonal discrepancies. The amount of fatty acids were found in order of saturated fatty acids (SFA) > mono unsaturated fatty acids (MUFA) > polyunsaturated fatty acids (PUFA). The predominant fatty acids were palmitic and stearic acids of SFAs, oleic and palmitoleic acid of MUFAs and linoleic and α linolenic acids of PUFAs group. The combined value of EPA+DHA varied from 1.44–5.34% depending on the season, with the highest in monsoon season. However, the n-6/n-3 ratios were notably lower (0.58–2.51) throughout the season than the greatest esteem of 4. Therefore, M. cuchia may be consumed as healthy as safe food with reference to n-6/n-3 ratio, irrespective of catching seasons
First record of Trypauchen vagina (Bloch and Schneider 1801) (Perciformes: Gobiidae) in the Narmada River, Gujarat, India
Gobiids are a large group of fishes inhabiting freshwater, marine and brackish water habitats. Trypauchen is the Indo-Pacific genus and comprises of two species: Trypauchen pelaeos known from Myanmar, Malaysia, Thailand, Vietnam and China; and T. vagina, distributed from Kuwait, along the coasts of India, ranging eastward to the Philippines, Taiwan and China. A specimen of T. vagina (Bloch and Schneider 1801) was caught by cast net from the shallow water of the Narmada River on 11 April 2017 that has later been preserved in the museum of Department of Zoology, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara (voucher number: ZL-CH-OSH-026). This paper presents the first observation of T. vagina in the Narmada River in Gujarat
Growth performance, haematology and histopathology of African catfish (Clarias gariepinus) fed varying levels of Aloe barbadensis leaves
One hundred and twenty Clarias gariepinus fingerlings (2.33 ± 0.07 g) were fed with 40% crude protein diets containing three concentrations of Aloe barbadensis leaves-paste: ABL1, 1%; ABL2, 2%; ABL3, 3%, and control, 0% ad libitum twice daily for 12 weeks. Mean weight gain and percentage weight gain increased (P < 0.05) as concentration of A. barbadensis increased. Survival rate decreased as concentration of paste increased. Differences (P < 0.05) seen in packed cell volume (PCV), haemoglobin (Hb), and red blood cell (RBC), thus highest in ABL3: PCV (36.67 ± 0.89%), Hb (12.37 ± 0.37 g dl–1) and RBC (3.47 ± 0.08×106 L–1) and lowest in control: PCV (22.0 ± 0.58%), Hb (7.37 ± 0.20 g dl–1) and RBC (2.07 ± 0.06 ×106 L–1). Liver histology of control fish was normal, while fatty degenerations were seen in the treated fish. The histology of fish kidney was normal in all treatments. The study concluded that 1% A. barbadensis leaves-paste could effectively improve growth performance, nutrient utilization and survival of cultured C. gariepinus
African catfish Clarias gariepinus farming practices in North and South 24 Parganas districts of West Bengal, India
Clarias gariepinus is widely cultured due to its tolerance to environmental extremes, high production and good feed conversion rate. This communication describes the farming practices of C. gariepinus in North and South 24 Parganas districts of West Bengal. Clarias gariepinus is cultured in ponds of 0.1–0.75 ha, where fingerlings were stocked at a density of 860–1150 cubic.m–1. The current practices of seed transportation were stressful to fish as the majority of the farmers noticed 5–10% mortalities, despite the use of antibiotics. Acclimatization of seeds was practiced by the majority of farmers before stocking. Different feeds including slaughter-house wastes and dead poultry were supplied. Multiple stocking and harvesting were a common practice. Major problems identified were insufficient feed, disease, transport, poor seed quality and lack of financial support. The survival percentage was poor, as 88% of the farmers recorded <40–50% survival at harvest. Dropsy was the most common disease and had a significant impact on economy. Antibiotics or other aquadrugs were frequently used for treatment, although the success varied. In general, the C. gariepinus farming has helped to recycle the wastes generated in and around metropolitan Kolkata and adjacent municipalities into wealth, but it suffers from management issues and economic losses
Toxic effect of lead on the fingerlings of Cirrhinus mrigala (Hamilton, 1822)
Pollution of water bodies caused by heavy metals such as lead is a major problem affecting aquatic fauna. The effect of lead on the fingerlings of fishes has not been widely investigated. The present study was undertaken to evaluate the impact of heavy metal lead on the fingerlings of the freshwater fish, Cirrhinus mrigala. Different concentrations of lead nitrate solutions, viz., 1 ppm, 10 ppm, 40 ppm, 100 ppm, 120 ppm, 160 ppm, 200 ppm, 240 ppm, 300 ppm, 400 ppm and 500 ppm were prepared. Ten fingerlings were introduced into each concentration. The mortality rate and the time of survival of fingerlings in the lead nitrate solution during next 96 hours were recorded. The mortality rate increased to a sudden plateau from 100 ppm to 200 ppm (from 10% to 100%) and total mortality was attained at 200 ppm. LC50 for the fingerlings was found to be 160 ppm. There was almost instantaneous mortality – absolute intolerance – of the fingerlings at 500 ppm. Our study results show that the fingerlings of Cirrhinus mrigala can survive the toxic effect of lead nitrate up to 40 ppm, without physiological stress
Dynamics of bioindices in mud crab Scylla serrata (Forsskål, 1775) occurring in Hooghly-Matlah Estuary of West Bengal, India
Dynamics of some bio indices (carapace width [CW] and body weight [W] relationship, relative condition factor [Kn]) of mud crab Scylla serrata (Forsskål, 1775), collected from the Hooghly-Matlah Estuary of West Bengal, were studied for a period of one year. A total of 325 specimens were collected (CW 44 – 120 mm, W 20 – 210 g) and studied. The CW and W relationship was found as W = 0.0006 CW2.665 for male and W = 0.001 CW2.561 for female. The b value was found relatively higher in male indicating better growth rate compared to females. Moreover, the growth pattern was allometric. The monthly mean Kn was 0.968 to 1.058 for males and 0.962 to 1.054 for females that significant varied (P < 0.05) among sampling months