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This study aims to provide insights into the growth pattern and conditions of Atropus atropos in the Bay of Bengal, Bangladesh. The lack of information on this species in the region has made it crucial to carry out such research for better understanding about its growth and health in this particular habitat. A total 100 individuals were collected from fishers catch during November 2021 to October 2022 by using traditional fishing gears such as trawl and gill nets (mesh size: 2-3 cm). Data showed that TL was found to be between 15 and 21 cm and the BW remained as 46 and 136 g. All LWRs had r2 values below 0.945 and were significant (P<0.001). The estimated allometric coefficient (b) suggested the combined sexes showed isometric growth (b~3). The statistical analysis conducted in this study revealed a highly significant LLR (p<0.001) with an r2 value exceeding 0.944. The form factor (a3.0) was found as 0.0155, while the size at first sexual maturity (Lm) was determined as 12.36 cm TL. The natural mortality (Mw) was calculated as 1.57 y-1. A major connection between KR and BW for this species, indicating that KR was an exceptionally significant in revealing the health of A. atropos. Thereafter, a high condition rating (KF, KA, and KR) indicates that the species is in short and deep shape. This study found that the habitat was in a state of equilibrium and the mean WR indicated that there was no significant deviation from the expected value of 100 for A. atropos. Consequently, information gathered from the present study would be impactful for managing this fishery in the Bay of Bengal, Bangladesh, along with the surroundings. [ABSTRACT FROM AUTHOR]

Morphological characteristics, length-weight relationships (LWRs) and length-length relationships (LLRs) using multi-linear dimensions of Tenualosa ilisha (Hamilton, 1822) from the Ganges River, north-western Bangladesh, are examined. Samples (257 specimens) were occasionally collected during July 2018 – June 2019. Fin rays and scales were counted by a magnifying glass. A total of 9 morphometric lengths and total body weight (BW) were measured to the nearest 0.1 cm and 0.01 g for each specimen. Fin formula was: Dorsal, D. 15-19 (2-4/13-17); Pectoral, P. 14-16 (1/13-15); Pelvic, PV. 6-10 (1-2/5-8); Anal, A. 18-21 (1-2/16-20); and Caudal, C. 20-22 (2/18-20). Each LWRs were greatly significant (p< 0.001) with r² ≥0.963. Based on r² value, BW = 0.0215×SL3.01 was the fittest. Additionally, LLRs by TL vs. SL was the best fitted model among 8 equations depending on r² values. The provided biological information will support further studies and management of T. ilisha in the Ganges River and elsewhere using any liner-dimensions. [ABSTRACT FROM AUTHOR]

The Elongate glass-perchlet Chanda nama Hamilton, 1822 is broadly found in Bangladesh, Myanmar, India, Pakistan, and Nepal. Our study represents a detailed report on stock status such as population structure, growth parameter (asymptotic length, L∞; growth co-efficient, K; age at zero length, t0; growth performance index, Ø'), life span (tmax), mortality (total, Z; natural, M; fishing, F), recruitment pattern, exploitation rate (E) and maximum sustainable yield (MSY) of ray-finned Chanda nama for the first time from the Ganges River of north-western Bangladesh. A sum of 1260 fish was collected during January to December 2017. The total length (TL) was recorded in the range of 3.3 to 9.9 cm. The negative allometric growth pattern was assessed through the b value < 3.0. Further, the L∞ was 10.25 cm as well as K was found 0.55 year-1. The Ø' was calculated as 1.762, t0 was 0.057 years while the tmax was estimated as 2.49 years. In addition, the Z, M, and F were obtained as 3.11, 1.63, and 1.48 year-1, respectively. The trend of recruitment was continual through one peak occurrence in May-July. Length of the first capture (Lc50) observed at TL of 3.32 cm. However, the exploitation rate (E) was assessed as 0.48 whereas the maximum allowable yield (Emax) was 0.46. The maximum sustainable yield was estimated as 4.51 metric tons. Consequently, the information from this study would be beneficial for the implementation of a proper management strategy in the Ganges River and the related ecosystems. [ABSTRACT FROM AUTHOR]

The current study was conducted on the temporal variation of the growth pattern and the physiological status of Tenualosa ilisha (Hamilton, 1822) from the Meghna River, Bangladesh for the period of July 2018 to June 2019. A sum of 1433 individuals were collected, where its body weight (BW), total length (TL), standard length (SL) and fork length (FL) were measured with 0.01 g and 0.01 cm accuracy. The growth pattern was estimated through length-weight relationship by the equation: BW = a×TLb, where BW was in g and TL in cm. The parameters a and b were estimated with linear regression analyses. Physiological status was determined using equation provided as follows: ā = W/Lb. If ā was close to the a value (a, LWR parameter) then the fish was in an ideal condition, where ā > a pointed to fatty fish and ā < a to lean fish. The TL ranged from 15.3cm to 57.8 cm while the BW was from 37.17-2250 g. The overall growth pattern for T. ilisha was positive allometric (b = 3.135) in the Meghna River. The maximum fatty fish was found in the month of December (44%) while the minimum was in October. The highest percentage of lean fish was found in the monthof February (41%) and the lowest was in September (22%). The present findings would add some beneficial data for consumer preference, meanwhile further studies are recommended to achieve a sustainable management of hilsa fishery and other water bodies in the Meghna River. [ABSTRACT FROM AUTHOR]

This study demonstrates the impacts of eco-hydrological factors (Temperature, rainfall, dissolved oxygen, pH, total dissolved solids, and alkalinity) on the growth of Asian stinging catfish Heteropneustus fossilis (Bloch, 1794) in the Ganjer Beel wetland ecosystem, northwestern Bangladesh. This study was conducted in the Gajner Beel wetland ecosystem which is located at Sujanagar under Pabna District, NW Bangladesh. Eight hundred forty-five (845) fish individuals were collected from January to December 2019. Total length (TL) and body weight (BW) were measured using the measuring board and electronic balance with 0.01cm and 0.01g, precision. The length-weight relationship was calculated by this equation: W = a × Lb. TL was ranged from 6.30-24.10 cm and BW was 1.20-83.94 g. Overall growth pattern (GP) was a positive allometric of H. fossilis in this wetland. Among the eco- hydrological factors temperature, DO and pH showed significant correlation with the growth pattern of H. fossilis. Finally, these findings will be useful for further studies and to suggest a sound policy for the sustainable management of H. fossilis in wetland ecosystems. [ABSTRACT FROM AUTHOR]

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The present study designates the length-frequency distributions (LFDs), temporal variations of relative growth pattern and relative condition factor (KR) of the Glossogobius giuris, which are evidently lacking in the literature. Sampling was done in the Garai River, southwestern Bangladesh using traditional fishing gears (Doar and Cast net) from March 2016 to February 2017. Total length (TL) was measured by digital slide calipers, while individual body weight (BW) was determined using digital electronic balance. A total of 972 specimens (male = 446, female = 526) ranging from 3.4 to 28.0 cm TL and 0.3 to 212.0 g BW were analyzed in this study. The LFDs showed that the 6.99 -9.99 cm TL size group was dominant for both sexes, constituted 46% for males and 41% for females of its population, respectively. The allometric coefficient (b) values were 2.89 for males and 2.92 for females, which indicated that the relative growth pattern was negative allometric (b< 3.00) in both sexes. The LWRs were significantly different between males and females (ANCOVA, p < 0.001). Minimum value of KR was found in April and maximum value in December for male. For the female, minimum value was found in January and maximum value in December. The KR were not significantly different between males and females (ANCOVA, p=0.9745). These results will help further studies on the population assessment as well as stock assessment of the G. giuris. Furthermore, this research has established a strong base for monitoring the biological changes of this important species due to high fishing pressure, climate changes or other reasons within the Garai River ecosystem or elsewhere. [ABSTRACT FROM AUTHOR]

This research describes the first complete and inclusive information on morphometric and meristic characteristics of three Ambassid species (Chanda nama, Parambassis lala and Parambassis ranga) from the Mathabhanga River collected during August 2017 to July 2018. In our study, range of the total length was 2.0-7.2 cm for C. nama; 1.7-3.9 cm for P. lala and 1.9-6.4 cm for P. ranga. All length-weight relationships were highly significant (p < 0.001) with r² values ≥ 0.900 (except W vs. PrDL relationship in P. lala, where, r² = 0.861). Also, all length-length relationships were highly correlated with r² values being ≥ 0.900. Based on r² value, W vs. FL and TL vs. FL was best fitted model for all the three species among the 11 equations. The calculated fin formula is: dorsal, D. 21-22 (VIII/13-14); pectoral, P1. 8-10 (2/6-8); pelvic, P2. 6 (I/5); anal, A. 17-18 (III/14-15); and caudal, C. 20-22 (4/16-18) for C. nama; D. 20-21 (VIII/12-13); P1. 8-9 (1-2/7); P2. 6 (I/5); A. 16-18 (III/13-15); C. 18-20 (4-6/14) for P. lala and D. 20-21 (VIII/12-13); P1. 9-10 (2/7-8); P2. 6 (I/5); A. 18-20 (III/15-17); C. 22-24 (4-6/18) for P. ranga. These outcomes will be a functional tool for identification of Ambassid fishes up to species level in any water-bodies of Bangladesh as well as in the adjacent countries. [ABSTRACT FROM AUTHOR]

For the first time, we describe the life-history traits including growth pattern, condition factors including (relative weight WR), form factor (a3.0), size at sexual maturity (Lm), and natural mortality (Mw) of Gudusia chapra in the Mahananda River, Bangladesh. Fishing gears, including gill (fash jal) and push nets (thela jal), were used for sampling during August 2016 to July 2017. Body lengths and weight (BW) of each individual were measured. A total of 226 individuals ranging from 6.20- 15.10 cm total length (TL) and 2.44-26.10 g BW were collected. On the basis of b value, the growth pattern of G. chapra was negative allometric (b<3.0). KF was the best for assessing the overall health of this species. WR was not significantly different from 100 indicating balance population. Also, a3.0 was 0.0062, which indicates that the fish was fusiform in shape. Moreover, Lm and Mw were 9.13 cm TL and 1.14 year-1, respectively. These results should benefit shad management. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic has had a negative impact on the global economy, with Bangladesh as a developing country exhibiting greater vulnerability. This pandemic has negatively affected the livelihoods and food security of the nation. Baor (oxbow lake) fisheries communities also were significantly affected during the pandemic, in terms of incomes, food security, health conditions, etc. Fishers have had to stop harvesting, or lower the quantity, of fishes, the sale of which was the main income source of the baor fishers' community because of reduced consumer demands during the lockdown conditions. The supply chains of fishes and fish culture inputs were also disrupted because of a lack of needed transportation, thereby hindering the availability of this convenient protein source from the fish. All these factors negatively impacted the incomes of the people dependent on this important fishery. If appropriate measures are applied to overcome these various difficulties, the baor fisheries may again contribute significantly to the livelihoods and food security of the population in the southwestern part of Bangladesh., Competing Interests: The authors declare they have no conflicts of interest regarding this publication., (© 2021 John Wiley & Sons Australia, Ltd.)