Cirrhinus reba, is a freshwater fish species which is distributed throughout the South Asian countries. The current study reports the detailed biometric indices of C. reba in the Bergobindapur oxbow lake (Baor) located in southwestern Bangladesh. The parameters assessed included length-frequency distributions (LFD), length-weight relationships (LWR), form factor (a3.0) and length at first sexual maturity (Lm) and four types of condition indices (i.e. allometric, KA; Fulton, KF; Relative, KR and Relative weight, WR).Conventional fishing equipment such as cast nets and monofilament fixed gill nets were used to collect samples from July to August 2019. Digital slide calipers were used to assess total length (TL), standard length (SL), fork length (FL), and trunk length (TrL), and body weight (BW) was quantified with an electronic balance with 0.01 g precision. Total 157 specimens with lengths ranging from 12.24 to 24.82 cm and weights ranging from 22.00 to 100.27 g were studied. The computed ‘b’ demonstrated negative allometric growth (< 3.00) in pooled sexes for the LWR. In this investigation, the mean of WR (100.36) did not differ significantly demonstrating that the environment was still in good shape. Furthermore, the size of C. reba at sexual maturity was estimated as 14.40 cm TL. The findings of this study would be worthwhile for the sustainable management of reba carp fisheries.

The study of life-history features of least-concerned fishes like Liza parsia is critical for developing long-term management and conservation methods for this species. The current study delivers the very first detailed clarification of life-history traits (LHT), containing length-frequency distribution (LFD), length-weight and length-length relationships (LWR and LLR), form factor (a3.0), condition factors, length at first sexual maturity (Lm), natural mortality (Mw) and optimum catchable length (Lopt) of L. parsia from the Passur River in southern Bangladesh. Fish samples (n =150) were randomly collected from May to August 2021, using gill nets. Each individual fish's total length (TL), fork length (FL), standard length (SL), and bodyweight (BW) were recorded. The size classes of TL were 15–17cmleadingmaximum sizes among the fish population. Length-Weight relations (LWR) from exponential b values (TL vs. BW) revealed a negative allometric growth trend (b = 2.6174). The b value based on the LLR similarly specifies the identical growth configuration. The a3.0 score was determined to be 0.01, demonstrating that the fish has extended body morphology. KF is the finest method for measuring the well-being of L. parsia in the Passur River among the four types of condition parameters. Moreover, WR also showed a significant deviation from 100 (p < 0.05) signifying an unstable habitat for L. parsia. The calculated Lm, Mw and Lopt values were 11.20 cm in TL, 0.76/year and 12.64 cm in TL respectively.  As a consequence, the findings of this research could be conducted in the future to effectively manage this species in the Passur River, and its interconnecting environments.

Belonging to the family Clupeidae, hilsa shad Tenualosa ilisha (Hamilton, 1822) is an important fish species in the South and Southeast Asia, especially in Bangladesh. Due to its unique nature, the fish has gained national and international demands for its nutritional values, taste qualities, special aroma and high delicacy, and provides livelihoods to the millions of fishers directly or indirectly along the coastal and riverine stretches in its range of natural distribution. It is considered as the national and most important commercial fish species of Bangladesh and contributes significantly to the national economy. In this study, an attempt is made in evaluating the data currently available on hilsa to determine the impact of the current management approaches and improvement strategies of this important fishery. Hilsa is found primarily in marine and estuarine environments, but it has been declining gradually over the last 30 years, reaching a low point in 1991-1992 and continuing until 2002-2003. Recognizing the declining trend of hilsa, the government took action to increase production by implementing regulations on jatka (juvenile) catch and restrictions on brood hilsa catch during the breeding season. As a result, total hilsa catch increased from 2.55 million MT (metric ton) in 2003-04 to 3.94 million MT in 2015-2016. Under the Protection and Conservation of Fish Act of 1950, Hilsa production peaked in 2016-2017, with a total of 4.96 lakh metric tons. Hilsa management techniques contribute 12.9% of all fish produced, while in Bangladesh, the rate of increase in hilsa production is 25.69%. The annual increase of total hilsa production climbed from 3.5% to 9.0% after 2015 as a result of the government's general management activities, payments for ecosystem service (PES) and the environmental management strategies, resulting in annual total hilsa production of 5.50 lakh MT in 2019–2020. A number of recommendations for effective management of the hilsa fisheries that might be implemented into the national policy are elicited in order to improve the situation because the current hilsa management plan has an impact on the conservation of this important fishery to a greater extent in commensurate with its national and international demands.