Aquaculture; Fish disease; Pond; Rajbari; Water quality The current study was conducted to determ... more Aquaculture; Fish disease; Pond; Rajbari; Water quality The current study was conducted to determine the existing fish culture systems and health management practices in the selected aquafarms of Rajbari District, Bangladesh. Data were collected from 50 fish farmers from October 2019 to February 2020 using questionnaire interview, focus group discussion and crosscheck interview. It was found that most of the aqua farmers had 11 to 15 years’ experience of fish farming and more than 30% had their own ponds. The farmers used to prepare ponds for stocking by several steps like pond drying, bottom mud removal, dyke construction, liming, fertilizer application, and finally stocking. Only 20% fish farmers stocked single fish species like pangas and tilapia, whereas other used to stock two to eight types fish species. Most of the fish farmers sell the harvested fishes either in the local or in city markets. Major fish health problems in the study area were infectious and non-infectious dise...
Identifying stock is key to sustainable fisheries management and conservation. Using traditional ... more Identifying stock is key to sustainable fisheries management and conservation. Using traditional morphometrics (TMR) and image-based truss network analysis (ITNA), we evaluated the stock structure of the endangered queen loach, Botia dario. The study was carried out in the following five stocks in Bangladesh’s northern rivers: the Atrai, Dhorala, Danu, Jamuna, and Padma. The inventory regarding stock structure was investigated using a total of nine traditional morphometrics, 11 ratios, and 23 truss measurements for each individual. To generate 23 ITNA, 12 landmarks were used. To assess variations among the stocks, a principal component analysis (PCA), factor analysis (FA), canonical variate analysis (CVA), and cluster analysis (CA) were performed. Six principal components explained 91.50% of the variation in TMR, while seven principal components explained 73.425% of the variation in ITNA. CVA, using traditional methods and ratios were correctly classified as 65.0%, 42.0%, 64.2%, 89....
The study of fisheries marketing channel and market margins is a useful tool for market managemen... more The study of fisheries marketing channel and market margins is a useful tool for market management and a crucial system for creating an effective and well-planned marketing strategy. The aim of the research is to know about the fish marketing channel, marketing margins, fish availability and difficulties related fish marketing system in three fish markets of Rajbari, Bangladesh from June to December 2019. Here, data were collected through questionnaire surveys, focus group discussions and field visits. A total of 109 species of fish and shellfish were available in the fish market. Perciformes (28.97% of total fishes) were the most dominant followed by Cypriniformes (23.37%), Siluriformes (19.63%), Clupeiformes (7.48%) and Decapoda (7.48%). A total of 19 species of processed fish were available including dried (77.77% of total processed fishes), salted (16.67%) and fermented (5.56%) that arrived from Dhaka and Chattogram. The price of fish and processed fish depends on consumer demand, availability, season, storage facilities and marketing channel. The length of marketing channel of freshwater fishes was comparatively shorter such: fisherman or farmer – auctioneer – wholesaler – retailer – consumer. Marine fishes arrived from other places like Khulna, Chattogram and Cox’s Bazar, Jashore, Barishal, Chandpur, Bhola where supplier purchased those fishes through auctioneer and supply to other cities where retailer bought fishes through wholesaler and delivery to consumer. The market channel of processed fishes was the longest. However, the market margin of marine fishes is comparatively higher than freshwater fishes. The unplanned market location (P.I = 0.80) was major constraints followed by insufficient drainage system, low supply of fish for Covid-19 pandemic, high transportation cost, and traditional fish transportation system. This research, therefore, would suggest that modern equipped fish market with high quality cold storage and ice factories could help to maintain the better quality of fish and reduce economic losses.
Journal of Bangladesh Agricultural University, 2020
Hydroponics is a plant growing procedure in water and aquaponics is an eco-friendly, water and en... more Hydroponics is a plant growing procedure in water and aquaponics is an eco-friendly, water and energy-saving bio-integrated recirculating aquaculture system that integrates fish farming and vegetable gardening in a symbiotic close loop system. This experiment was carried to observe the production potentiality of broccoli in different type hydroponics like organic hydroponics (T1), inorganic hydroponics (T2) and tilapia based aquaponics systems (T3) each with three replicates for 106 days from 19 th February to 4 th June, 2018. Three kg vermicompost as T1 was soaked in 90 L water in a drum with a net bag and after that 1 kg vermicompost was added weekly discarding the old one. In case of T2, 28.50 g mixed fertilizer composed of 5g urea, 7.50g TSP, 5g MOP, 5g dolomite, 5g DAP, 0.50 g boron and 0.50 g iron were added in 90 L water and after seven days 22.80 g was added fortnightly. In the aquaponics tank, 10 healthy tilapia fingerlings were released in the same amount of water and 30% protein containing commercial floating feed was fed twice daily at the rate of 3% body weight. Sampling were carried out fortnightly for collecting different parameters of broccoli, fish and water quality. Significantly (P≤0.01) the highest broccoli production was found in T2 (11.79±0.51 tons/ha/106 days) followed by T3 (4.77±0.85 tons/ha/106 days) and the least was in T1 (2.24±0.14 tons/ha/106 days). The analysis showed that, the leaf area, root length and weight were statistically similar in all the three treatments. Fish production was 21.55±3.36 tons/ha/106 days. Nutritional composition of broccoli was also highest in T2 except moisture and ash content. Water dissolved oxygen, electrical conductivity, ammonia, nitrate, nitrogen and phosphorus concentration were suitable for growing broccoli in T2. Whereas in T3, ammonia concentration was high for fish. Broccoli production at higher temperature (31.40 to 36.00°C) in the laboratory than the optimum temperature was possible. Further experiment is needed to carry out in larger areas with different crops and fishes before extension in the field level.
Aquaculture; Fish disease; Pond; Rajbari; Water quality The current study was conducted to determ... more Aquaculture; Fish disease; Pond; Rajbari; Water quality The current study was conducted to determine the existing fish culture systems and health management practices in the selected aquafarms of Rajbari District, Bangladesh. Data were collected from 50 fish farmers from October 2019 to February 2020 using questionnaire interview, focus group discussion and crosscheck interview. It was found that most of the aqua farmers had 11 to 15 years’ experience of fish farming and more than 30% had their own ponds. The farmers used to prepare ponds for stocking by several steps like pond drying, bottom mud removal, dyke construction, liming, fertilizer application, and finally stocking. Only 20% fish farmers stocked single fish species like pangas and tilapia, whereas other used to stock two to eight types fish species. Most of the fish farmers sell the harvested fishes either in the local or in city markets. Major fish health problems in the study area were infectious and non-infectious dise...
Lakes & Reservoirs: Science, Policy and Management for Sustainable Use, 2021
The present study provides the first wide-ranging elucidation of life-history traits, including l... more The present study provides the first wide-ranging elucidation of life-history traits, including length–frequency distribution (LFD), length–weight and length–length relationship (LWR and LLR), form factor (a3.0), best condition factor (allometric, KA; Fulton, KF; relative, KR; and relative weight, WR), length at first maturity (Lm), natural mortality (Mw) and optimum catchable length (Lopt) of Lepidocephalichthyes guntea from the Payra River in southern Bangladesh. A total of 470 fishes were randomly collected seasonally from February 2019 to January 2020, using several traditional fishing gears (cast nets; drag nets; lift nets; and gill nets). The total length (TL), standard length (SL) and total body weight (BW) of each individual fish were measured with a 0.01 cm and 0.01 g precision, respectively. The TL size classes of 6.00–6.99 cm and 7.00–7.99 cm TL were the numerically dominant groups among the total fish population. Exponential b values of LWR (TL vs. BW) indicate a positive allometric growth (b = 3.20) pattern in the Payra River. The b value of LLR also indicates the same growth pattern. The estimated a3.0 value was 0.007, indicating the fish has an elongated body profile. Among the four types of condition factors, KF is the best-suited tool for evaluating the well-being of L. guntea in the Payra River. Additionally, WR exhibited very significant divergence from 100 (p < .0001), designating an imbalanced habitat for L. guntea. The calculated Lm, Mw and Lopt values were 6.54 (~6.5 cm) in TL, 1.16/year and 7.46 cm TL for L. guntea in the Payra River, respectively. Thus, the results of the present study could be used in the future for improved management of this species in Payra River, as well as for linking ecosystems.
Journal of The Bangladesh Agricultural University, 2020
Prosun Roy, Suprakash Chakma, Zubyda Mushtari Nadia, Newton Saha, Md. Arifur Rahman Department of... more Prosun Roy, Suprakash Chakma, Zubyda Mushtari Nadia, Newton Saha, Md. Arifur Rahman Department of Aquaculture, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh Department of Fisheries Technology, Patuakhali Science and Technology University, Patuakhali 8602, Bangladesh Department of Aquatic Animal Health Management, Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka 1207 Department of Fisheries Management, Patuakhali Science and Technology University, Patuakhali 8602, Bangladesh Department of Fisheries Biology and Genetics, Patuakhali Science and Technology University, Patuakhali 8602, Bangladesh
Management of fish health is one of the main considerations in aquaculture and different plant co... more Management of fish health is one of the main considerations in aquaculture and different plant compounds are being used for supporting fish health to minimize the negative impacts of synthetic aqua drugs. In the present experiment, potentiality of moringa (Moringa oleifera; Lamarck, 1785) leaf as a nutritious dietary source for tilapia (Oreochromis niloticus; Linnaeus, 1758) fish was tested and the duration was two months from 30th September to 30th November, 2020. The moringa leaves were brought, cleaned, dried, and finally crushed into powder. Three experimental diets were formulated using the processed moringa leaf powder (MLP) at the rate of 0% (MLP0%) as control, 10% (MLP10%) and 20% (MLP20%) as treatment mixing with rice bran, wheat bran, mustard oil cake, fish meal, soya oil and vitamin-mineral premix. Fifteen tilapia fingerlings having average initial length 10.88±0.11 cm and initial weight 29.06±0.50 g was stocked in each tank with 90 L water. Sixty days feeding trial was performed with three replications of each treatment. The fishes were fed with formulated feeds twice daily at 9 am and 4 pm at a rate of 3% of their body mass. Sampling of fish and water quality parameters were carried out at twelve days interval. Moreover, the blood glucose and cholesterol of tilapia were measured monthly. Final length, final weight, weight gain, percent weight gain, feed conversion ratio (FCR), specific growth rate (SGR) and production of tilapia were significantly different among the treatments. The highest FCR (3.17±0.25) and SGR (1.33±0.12 %) values were in MLP20% and MLP10%, respectively. In the experiment, the highest and the lowest tilapia production were 9.21±0.39 and 7.39±0.35 kg m-3 in MLP10% and MLP20%, respectively. The blood glucose values were significantly different among the treatments (p< 0.05) and the highest value was in MLP0% (48.00±2.00 mg dl-1). Moreover, the highest and the lowest blood cholesterol was found in MLP0% (177.67±2.52 mg dl-1) and MLP20% (148.33±1.53 mg dl-1), respectively whereas the values were highly significantly different among the treatments (p≤ 0.01). Water quality parameters were statistically similar among the treatments (p> 0.05) and the values were within acceptable range for tilapia culture.
The study was conducted to evaluate the impact of epsom salt, rich in magnesium and sulfur conten... more The study was conducted to evaluate the impact of epsom salt, rich in magnesium and sulfur content beneficial to plant, on beetroot production in aquaponics system. Media based aquaponics systems (nine units) were employed for beetroot and tilapia culture where three treatments T1, T2 and T0 were applied with three replications (R1, R2, and R3) each. Epsom salt was applied in T1 as foliar spray in the form of 5% solution in each replication, whereas same amount of epsom salt (5 g) was directly applied on vegetable bed in T2 as root application. But in control (T0) no epsom salt was used. Beetroot saplings were planted in retrospect at a rate of two saplings per growbed (replication). After thirty days, plants grew enough to support the water clarification in aquaponics, ten tilapia fry were stocked per tank (90 L) in each replication. Fish were fed commercial floating feed containing 30% protein. Although the fish growth parameters in three treatments were statistically similar, the...
Aquaculture; Fish disease; Pond; Rajbari; Water quality The current study was conducted to determ... more Aquaculture; Fish disease; Pond; Rajbari; Water quality The current study was conducted to determine the existing fish culture systems and health management practices in the selected aquafarms of Rajbari District, Bangladesh. Data were collected from 50 fish farmers from October 2019 to February 2020 using questionnaire interview, focus group discussion and crosscheck interview. It was found that most of the aqua farmers had 11 to 15 years’ experience of fish farming and more than 30% had their own ponds. The farmers used to prepare ponds for stocking by several steps like pond drying, bottom mud removal, dyke construction, liming, fertilizer application, and finally stocking. Only 20% fish farmers stocked single fish species like pangas and tilapia, whereas other used to stock two to eight types fish species. Most of the fish farmers sell the harvested fishes either in the local or in city markets. Major fish health problems in the study area were infectious and non-infectious dise...
Identifying stock is key to sustainable fisheries management and conservation. Using traditional ... more Identifying stock is key to sustainable fisheries management and conservation. Using traditional morphometrics (TMR) and image-based truss network analysis (ITNA), we evaluated the stock structure of the endangered queen loach, Botia dario. The study was carried out in the following five stocks in Bangladesh’s northern rivers: the Atrai, Dhorala, Danu, Jamuna, and Padma. The inventory regarding stock structure was investigated using a total of nine traditional morphometrics, 11 ratios, and 23 truss measurements for each individual. To generate 23 ITNA, 12 landmarks were used. To assess variations among the stocks, a principal component analysis (PCA), factor analysis (FA), canonical variate analysis (CVA), and cluster analysis (CA) were performed. Six principal components explained 91.50% of the variation in TMR, while seven principal components explained 73.425% of the variation in ITNA. CVA, using traditional methods and ratios were correctly classified as 65.0%, 42.0%, 64.2%, 89....
The study of fisheries marketing channel and market margins is a useful tool for market managemen... more The study of fisheries marketing channel and market margins is a useful tool for market management and a crucial system for creating an effective and well-planned marketing strategy. The aim of the research is to know about the fish marketing channel, marketing margins, fish availability and difficulties related fish marketing system in three fish markets of Rajbari, Bangladesh from June to December 2019. Here, data were collected through questionnaire surveys, focus group discussions and field visits. A total of 109 species of fish and shellfish were available in the fish market. Perciformes (28.97% of total fishes) were the most dominant followed by Cypriniformes (23.37%), Siluriformes (19.63%), Clupeiformes (7.48%) and Decapoda (7.48%). A total of 19 species of processed fish were available including dried (77.77% of total processed fishes), salted (16.67%) and fermented (5.56%) that arrived from Dhaka and Chattogram. The price of fish and processed fish depends on consumer demand, availability, season, storage facilities and marketing channel. The length of marketing channel of freshwater fishes was comparatively shorter such: fisherman or farmer – auctioneer – wholesaler – retailer – consumer. Marine fishes arrived from other places like Khulna, Chattogram and Cox’s Bazar, Jashore, Barishal, Chandpur, Bhola where supplier purchased those fishes through auctioneer and supply to other cities where retailer bought fishes through wholesaler and delivery to consumer. The market channel of processed fishes was the longest. However, the market margin of marine fishes is comparatively higher than freshwater fishes. The unplanned market location (P.I = 0.80) was major constraints followed by insufficient drainage system, low supply of fish for Covid-19 pandemic, high transportation cost, and traditional fish transportation system. This research, therefore, would suggest that modern equipped fish market with high quality cold storage and ice factories could help to maintain the better quality of fish and reduce economic losses.
Journal of Bangladesh Agricultural University, 2020
Hydroponics is a plant growing procedure in water and aquaponics is an eco-friendly, water and en... more Hydroponics is a plant growing procedure in water and aquaponics is an eco-friendly, water and energy-saving bio-integrated recirculating aquaculture system that integrates fish farming and vegetable gardening in a symbiotic close loop system. This experiment was carried to observe the production potentiality of broccoli in different type hydroponics like organic hydroponics (T1), inorganic hydroponics (T2) and tilapia based aquaponics systems (T3) each with three replicates for 106 days from 19 th February to 4 th June, 2018. Three kg vermicompost as T1 was soaked in 90 L water in a drum with a net bag and after that 1 kg vermicompost was added weekly discarding the old one. In case of T2, 28.50 g mixed fertilizer composed of 5g urea, 7.50g TSP, 5g MOP, 5g dolomite, 5g DAP, 0.50 g boron and 0.50 g iron were added in 90 L water and after seven days 22.80 g was added fortnightly. In the aquaponics tank, 10 healthy tilapia fingerlings were released in the same amount of water and 30% protein containing commercial floating feed was fed twice daily at the rate of 3% body weight. Sampling were carried out fortnightly for collecting different parameters of broccoli, fish and water quality. Significantly (P≤0.01) the highest broccoli production was found in T2 (11.79±0.51 tons/ha/106 days) followed by T3 (4.77±0.85 tons/ha/106 days) and the least was in T1 (2.24±0.14 tons/ha/106 days). The analysis showed that, the leaf area, root length and weight were statistically similar in all the three treatments. Fish production was 21.55±3.36 tons/ha/106 days. Nutritional composition of broccoli was also highest in T2 except moisture and ash content. Water dissolved oxygen, electrical conductivity, ammonia, nitrate, nitrogen and phosphorus concentration were suitable for growing broccoli in T2. Whereas in T3, ammonia concentration was high for fish. Broccoli production at higher temperature (31.40 to 36.00°C) in the laboratory than the optimum temperature was possible. Further experiment is needed to carry out in larger areas with different crops and fishes before extension in the field level.
Aquaculture; Fish disease; Pond; Rajbari; Water quality The current study was conducted to determ... more Aquaculture; Fish disease; Pond; Rajbari; Water quality The current study was conducted to determine the existing fish culture systems and health management practices in the selected aquafarms of Rajbari District, Bangladesh. Data were collected from 50 fish farmers from October 2019 to February 2020 using questionnaire interview, focus group discussion and crosscheck interview. It was found that most of the aqua farmers had 11 to 15 years’ experience of fish farming and more than 30% had their own ponds. The farmers used to prepare ponds for stocking by several steps like pond drying, bottom mud removal, dyke construction, liming, fertilizer application, and finally stocking. Only 20% fish farmers stocked single fish species like pangas and tilapia, whereas other used to stock two to eight types fish species. Most of the fish farmers sell the harvested fishes either in the local or in city markets. Major fish health problems in the study area were infectious and non-infectious dise...
Lakes & Reservoirs: Science, Policy and Management for Sustainable Use, 2021
The present study provides the first wide-ranging elucidation of life-history traits, including l... more The present study provides the first wide-ranging elucidation of life-history traits, including length–frequency distribution (LFD), length–weight and length–length relationship (LWR and LLR), form factor (a3.0), best condition factor (allometric, KA; Fulton, KF; relative, KR; and relative weight, WR), length at first maturity (Lm), natural mortality (Mw) and optimum catchable length (Lopt) of Lepidocephalichthyes guntea from the Payra River in southern Bangladesh. A total of 470 fishes were randomly collected seasonally from February 2019 to January 2020, using several traditional fishing gears (cast nets; drag nets; lift nets; and gill nets). The total length (TL), standard length (SL) and total body weight (BW) of each individual fish were measured with a 0.01 cm and 0.01 g precision, respectively. The TL size classes of 6.00–6.99 cm and 7.00–7.99 cm TL were the numerically dominant groups among the total fish population. Exponential b values of LWR (TL vs. BW) indicate a positive allometric growth (b = 3.20) pattern in the Payra River. The b value of LLR also indicates the same growth pattern. The estimated a3.0 value was 0.007, indicating the fish has an elongated body profile. Among the four types of condition factors, KF is the best-suited tool for evaluating the well-being of L. guntea in the Payra River. Additionally, WR exhibited very significant divergence from 100 (p < .0001), designating an imbalanced habitat for L. guntea. The calculated Lm, Mw and Lopt values were 6.54 (~6.5 cm) in TL, 1.16/year and 7.46 cm TL for L. guntea in the Payra River, respectively. Thus, the results of the present study could be used in the future for improved management of this species in Payra River, as well as for linking ecosystems.
Journal of The Bangladesh Agricultural University, 2020
Prosun Roy, Suprakash Chakma, Zubyda Mushtari Nadia, Newton Saha, Md. Arifur Rahman Department of... more Prosun Roy, Suprakash Chakma, Zubyda Mushtari Nadia, Newton Saha, Md. Arifur Rahman Department of Aquaculture, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh Department of Fisheries Technology, Patuakhali Science and Technology University, Patuakhali 8602, Bangladesh Department of Aquatic Animal Health Management, Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka 1207 Department of Fisheries Management, Patuakhali Science and Technology University, Patuakhali 8602, Bangladesh Department of Fisheries Biology and Genetics, Patuakhali Science and Technology University, Patuakhali 8602, Bangladesh
Management of fish health is one of the main considerations in aquaculture and different plant co... more Management of fish health is one of the main considerations in aquaculture and different plant compounds are being used for supporting fish health to minimize the negative impacts of synthetic aqua drugs. In the present experiment, potentiality of moringa (Moringa oleifera; Lamarck, 1785) leaf as a nutritious dietary source for tilapia (Oreochromis niloticus; Linnaeus, 1758) fish was tested and the duration was two months from 30th September to 30th November, 2020. The moringa leaves were brought, cleaned, dried, and finally crushed into powder. Three experimental diets were formulated using the processed moringa leaf powder (MLP) at the rate of 0% (MLP0%) as control, 10% (MLP10%) and 20% (MLP20%) as treatment mixing with rice bran, wheat bran, mustard oil cake, fish meal, soya oil and vitamin-mineral premix. Fifteen tilapia fingerlings having average initial length 10.88±0.11 cm and initial weight 29.06±0.50 g was stocked in each tank with 90 L water. Sixty days feeding trial was performed with three replications of each treatment. The fishes were fed with formulated feeds twice daily at 9 am and 4 pm at a rate of 3% of their body mass. Sampling of fish and water quality parameters were carried out at twelve days interval. Moreover, the blood glucose and cholesterol of tilapia were measured monthly. Final length, final weight, weight gain, percent weight gain, feed conversion ratio (FCR), specific growth rate (SGR) and production of tilapia were significantly different among the treatments. The highest FCR (3.17±0.25) and SGR (1.33±0.12 %) values were in MLP20% and MLP10%, respectively. In the experiment, the highest and the lowest tilapia production were 9.21±0.39 and 7.39±0.35 kg m-3 in MLP10% and MLP20%, respectively. The blood glucose values were significantly different among the treatments (p< 0.05) and the highest value was in MLP0% (48.00±2.00 mg dl-1). Moreover, the highest and the lowest blood cholesterol was found in MLP0% (177.67±2.52 mg dl-1) and MLP20% (148.33±1.53 mg dl-1), respectively whereas the values were highly significantly different among the treatments (p≤ 0.01). Water quality parameters were statistically similar among the treatments (p> 0.05) and the values were within acceptable range for tilapia culture.
The study was conducted to evaluate the impact of epsom salt, rich in magnesium and sulfur conten... more The study was conducted to evaluate the impact of epsom salt, rich in magnesium and sulfur content beneficial to plant, on beetroot production in aquaponics system. Media based aquaponics systems (nine units) were employed for beetroot and tilapia culture where three treatments T1, T2 and T0 were applied with three replications (R1, R2, and R3) each. Epsom salt was applied in T1 as foliar spray in the form of 5% solution in each replication, whereas same amount of epsom salt (5 g) was directly applied on vegetable bed in T2 as root application. But in control (T0) no epsom salt was used. Beetroot saplings were planted in retrospect at a rate of two saplings per growbed (replication). After thirty days, plants grew enough to support the water clarification in aquaponics, ten tilapia fry were stocked per tank (90 L) in each replication. Fish were fed commercial floating feed containing 30% protein. Although the fish growth parameters in three treatments were statistically similar, the...
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relationship (LWR and LLR), form factor (a3.0), best condition factor (allometric, KA; Fulton, KF; relative, KR; and relative weight, WR), length at first maturity (Lm), natural mortality (Mw) and optimum catchable length (Lopt) of Lepidocephalichthyes guntea from the Payra River in southern Bangladesh. A total of 470 fishes were randomly collected seasonally from February 2019 to January 2020, using several traditional fishing gears (cast nets; drag nets; lift nets; and gill nets). The total length (TL), standard length (SL) and total body weight (BW) of each individual fish were measured with a 0.01 cm and 0.01 g precision, respectively. The TL size classes of 6.00–6.99
cm and 7.00–7.99 cm TL were the numerically dominant groups among the total fish population. Exponential b values of LWR (TL vs. BW) indicate a positive allometric growth (b = 3.20) pattern in the Payra River. The b value of LLR also indicates the same growth pattern. The estimated a3.0 value was 0.007, indicating the fish has an elongated body profile. Among the four types of condition factors, KF is the best-suited tool for evaluating the well-being of L. guntea in the Payra River. Additionally, WR exhibited very significant divergence from 100 (p < .0001), designating an imbalanced habitat for L. guntea. The calculated Lm, Mw and Lopt values were 6.54 (~6.5 cm) in TL, 1.16/year and 7.46 cm TL for L. guntea in the Payra River, respectively. Thus, the results of the present study could be used in the future for improved management of this species in Payra River, as well as for linking ecosystems.
relationship (LWR and LLR), form factor (a3.0), best condition factor (allometric, KA; Fulton, KF; relative, KR; and relative weight, WR), length at first maturity (Lm), natural mortality (Mw) and optimum catchable length (Lopt) of Lepidocephalichthyes guntea from the Payra River in southern Bangladesh. A total of 470 fishes were randomly collected seasonally from February 2019 to January 2020, using several traditional fishing gears (cast nets; drag nets; lift nets; and gill nets). The total length (TL), standard length (SL) and total body weight (BW) of each individual fish were measured with a 0.01 cm and 0.01 g precision, respectively. The TL size classes of 6.00–6.99
cm and 7.00–7.99 cm TL were the numerically dominant groups among the total fish population. Exponential b values of LWR (TL vs. BW) indicate a positive allometric growth (b = 3.20) pattern in the Payra River. The b value of LLR also indicates the same growth pattern. The estimated a3.0 value was 0.007, indicating the fish has an elongated body profile. Among the four types of condition factors, KF is the best-suited tool for evaluating the well-being of L. guntea in the Payra River. Additionally, WR exhibited very significant divergence from 100 (p < .0001), designating an imbalanced habitat for L. guntea. The calculated Lm, Mw and Lopt values were 6.54 (~6.5 cm) in TL, 1.16/year and 7.46 cm TL for L. guntea in the Payra River, respectively. Thus, the results of the present study could be used in the future for improved management of this species in Payra River, as well as for linking ecosystems.