Journal of Fisheries (University of Rajshahi)
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Modelling several morphometric relationships of swordfish (Xiphias gladius), black marlin (Makaira indica) and blue marlin (Makaira nigricans) caught from Indonesian longliners in the eastern Indian Ocean
Get PDFThis paper presents several equations for converting among measures of size (length and weight) for swordfish (Xiphias gladius), black marlin (Makaira indica) and blue marlin (Makaira nigricans) caught by Indonesian longliners in the Indian Ocean. The equations use for transforming non-standard measurement i.e. eye fork length (EFL) and pectoral fork length (PFL) to standard measurement, lower jaw fork length (LJFL). The paper also discussed about the length-weight relationship, including converting from non-standard length (EFL and PFL) to round weight. The result showed that both PFL and EFL were positively related to LJFL but there were no significant differences existed between females and males among length measures for swordfish, blue marlin, and black marlin (ANCOVA, P>0.05). All regression equation models were considered to be valid (P<0.01) with coefficient of determinations (r2) ranged from 0.81-0.99. Allometric growth pattern was statistically observed for all swordfish (b=2.94, r2=0.94), black marlin (b=3.12; r2=0.90) and blue marlin (b=3.30; r2=0.91)
Messages of invasive Perccottus glenii individuals eaten by an Esox lucius from the Danube Delta
Get PDFIn the stomach of a pike from the Danube Delta we have found seven Perccottus glenii individuals. Their message indicated that in the Danube Delta P. glenii has already large population. Also, it proves that in its habitats, the pike can consume numerous individuals of this invasive species. Their gut contents prove that P. glenii hunted near the shores, ingesting numerous terrestrial preys
Prevalence and antibiotic susceptibility of Aeromonas hydrophila isolated from freshwater fishes
Get PDFAeromonas hydrophila is an opportunistic microorganism. It is a secondary biological agent that contributes to the occurrence of fish diseases and its deterioration. This research was undertaken to determine the prevalence of A. hydrophila in some freshwater fishes collected from three different fish markets of Dhaka City and to test their antibiotic susceptibility. Total bacterial count and total aeromonas on different aeromonas selective media were enumerated using serial dilution technique. Bacterial isolates were characterized to identify A. hydrophila using biochemical tests and with comparison to reference strain (ATCC 7966). The lowest Aeromonas count was detected to be 2.83±0.40×102 cfu/g in Anabas testudineus and the highest was 1.03±0.153×103 cfu/g in Oreochromis mossambicus. On market basis highest aeromonas count was found in Anando Bazar (8.10±1.09×102 cfu/g) and lowest in Hatirpool Bazar (5.63±0.90×102 cfu/g) with no significant difference. Maximum susceptibility to amikacin and gentamicin was observed whereas all of the isolates were found resistant to a commonly used antibiotic amoxycillin. The obtained results point that antimicrobial susceptibility was more or less similar regardless of the origin of the samples collected. All the fishes investigated in this study contained A. hydrophila in their different organs
Fish growth, yield and economics of conventional feed and weed based polyculture in ponds
Get PDFFish growth, yield and economics of polyculture were evaluated for six months from April to September, 2011 in ponds of Kushtia district, Bangladesh under 4 treatments of feeds and weeds as T0: rice bran, wheat bran and mustard oilcake; T1: Azolla; T2: Grass and T3: Banana leaf. Each treatment had 3 replications. Mean initial stocking weight of fishes like Hypophthalmichthyes molitrix, Catla catla, Labeo rohita, Cirrhinus mrigala, Cyprinus carpio, Ctenopharyngodon idella and Barbonymus gonionotus was 62, 64, 57, 54, 63, 65 and 25 g, respectively. Stocking density (11,115 fishes/ha), liming (250 kg/ha), basal fertilization (Cowdung, 1,500 kg/ha; urea, 60 kg/ha; and Triple Super Phosphate, TSP 60 kg/ha) and periodic fertilization (Urea, 2.5 kg/ha/day; TSP, 2.5 kg/ha/day) were same for all the treatments. Water quality parameters (water temperature, transparency, dissolved oxygen, pH, alkalinity and free carbon dioxide) were monitored fortnightly and fish growth parameters (weight gain and Specific Growth Rate, SGR) were monitored monthly. Treatments did not vary significantly for the mean water quality parameters. Treatment T0 varied more significantly for the mean final weight, weight gain, SGR, survival rate and yield for almost all the species except C. idella and B. gonionotus. Significantly highest CBR was recorded with treatment T1
Size at first maturity and maturity stages of Terapon jarbua (Forsskal, 1775) from Pondicherry Coast, India
Get PDFSize at first maturity of Terapon jarbua was studied based on 114 male (14 to 28 cm in TL) and 140 female (14 to 32 cm in TL). The Logistic curves describing the relationship between the sexes and the proportion of 50% maturity (Lm50) were estimated at 20.8 cm in male and 21.8 cm in female of Terapon jarbua. The male reached 50% first sexual maturity at smaller lengths than female in this species. The gonads were classified into five maturity stages based on the size, colour and texture. Month wise predominance of different stage of maturity deferred during different months
Present status of fish diversity in the Beel Kumari in relation to fish sanctuary and fishing gears
Get PDFThe study was conducted on Beel Kumari beel (wetland) in Rajshahi, Bangladesh from October 2013 to September 2014. A total of 52 species of fish were recorded and the dominant species was Mystus tengara (Tanagra (9.75%). Exotic species like bighead carp (Aristichthys nobilis), silver carp (Hypophthalmichthys molitrix) and common carp (Cyprinus carpio) were also commonly found. Of the indigenous species, Ompok bimaculatus, Puntius sarana, Pseudeutropius atherinoides, Botia dario, Mystus aor and Chitala chitala were abundant, though these species were rare before the establishment of the fish sanctuary. Four groups of fishing gears i.e. net, trap, spear and harpoons and line fishing were found to use, among them 8 types of net, 7 types of trap, 4 types of spear and harpoon and 4 types of line fishing were recorded. Among these gill net contributed to the highest catch (32%) and push net was the lowest (6%). Most of the respondents (80%) were found to believe that their fish catch had increased considerably due to impact of fish sanctuary establishment and effective community based fisheries management approach employed in this beel
Rapid review on the use of new age induced breeding agent ‘LHRHa’ in Indian finfish seed production sector
Get PDFA focused review on the use of LHRHa in induced breeding of fishes in India was made. Use of LHRHa is mainly restricted to high value brackish water and marine fish species whose market value generally exceeds INR 300-400/kg (USD 4.5-6/kg). Published information on use of LHRHa in induced breeding of fishes in India could document only twelve species out of which nine were brackishwater or marine fish. Besides length and weight, the egg diameter of female fishes (>0.45–0.7 mm) is an important criterion for treating the fishes with LHRHa. LHRHa is either used alone or in combination with HCG (most popular), PGE, 17α-MT and Pimozide. Dosage of 20-70 µg/kg body weight for females and 10-40 µg/kg body weight for males with a latency period of 24-36 hours is most common in India. Experiments with LHRHa are being carried out mainly by ICAR-CIBA, Chennai (dominant) and ICAR-CMFRI, Kochi. Standardization and optimization of LHRHa dosage has been attained in Asian Seabass (Lates calcarifer), Cobia (Rachycentron canadum), Grey mullet (Mugil cephalus) and Spotted scat (Scatophagus argus) while in Grouper (Epinephelus tauvina), Moonfish (Monodactylus argenteus), Milk fish (Chanos chanos), Crescent Bass (Terapon jarbua) and Silver Pompano (Trachinotus blochii), it is under progress
Fishing gears and methods in the Chalan Beel, Bangladesh
Get PDFPresent study on fishing gears and methods in the Chalan Beel was conducted during the period of July 2011 to June 2014. The Chalan Beel is the large network of fluvial waters body that harbors rich ichthyofaunal diversity. Most of the fishing methods of the Chalan Beel are primitive, based on indigenous traditional knowledge and well suited to turbulent nature of the streams. In this study thirty fishing methods and gears have been documented and classified into five categories- fishing nets, traps, wounding gears, hooks and lines, and others. Many of these were harmful to fishes as well as aquatic biodiversity. Effective measurements are required to make proper use of the Chalan Beel
Fish fauna of the Brahmaputra River, Bangladesh: richness, threats and conservation needs
Get PDFThe Brahmaputra River is one of the largest rivers in the world as well as in Bangladesh. The present study was carried out for a period of one year from January to December 2013 with a view to assessing the availability of fishes in the river with species emphasis on species richness, existing threats and conservation issues. Daytime and night sampling were carried out in three sites located along the upstream to downstream course of the river on a monthly basis. Three fishing gears including cast net, seine net and drag net and one fishing trap were employed to collect fishes. A total of 67 finfish species including 63 indigenous and 4 exotic/alien species have been recorded belonging to 46 genera, 24 families and 8 orders. Cypriniformes and Cyprinidae were the most dominating order (21 species) family (15 species) of native fishes. A small portion (2%) of native fishes was globally threatened. Over one third of total species (38%) were considered threatened to extinct species in Bangladesh. Population trend of over two third of total fish species was Declining in the river. Major threats were alien/invasive species, banned fishing gears and loss of habitats
Production of organic grass carp (Ctenopharyngodon idella) and GIFT tilapia (Oreochromis niloticus) using napier grass, Pennisetum purpureum
Get PDFThis study was conducted to examine the growth and production of grass carp and tilapia cultured organically using napier grass in Bangabanbhu Sheikh Mujibur Rahman Agricultural University, Bangladesh from March-June, 2013. Three stocking ratios were tested: grass carp at 0.6 fish/m2 with GIFT tilapia at 0.3 fish/m2 (T1), grass carp at 0.6 fish/m2 with GIFT tilapia at 0.6 fish/m2 (T2), grass carp at 0.6 fish/m2 with GIFT tilapia at 0.9 fish/m2 (T3) and grass carp only at 0.6 fish/m2 as control (T4). Chopped fresh napier grass leaf was the sole nutrient input and provided twice daily. The water quality parameters were within suitable ranges for fish culture. Grass carp attained a daily growth increment ranging from 2.80-3.73 g/day and GIFT tilapia from 1.30-1.86 g/day. The combined yields was significantly higher (P<0.05) in stocking ratio of 1:1 (2.72 t/ha/90 days) compared to other stocking ratios. The result indicates on the basis of benefit-cost-ratio that the farmer’s income will be around double or more in the combined production of organic grass carp and tilapia with stocking ratio of 1:1 than the other stocking ratios. The density of grass carp should be further studied