A comparison of the neuroprotective efficacy of newly developed oximes (K117, K127) and currently available oxime (obidoxime) in tabun-poisoned rats

The potency of newly developed bispyridinium compounds (K117, K127) to reduce tabun-induced acute neurotoxic signs and symptoms was compared with currently available oxime (obidoxime) using functional observational battery. The neuroprotective effects of atropine alone and atropine combined with one of three bispyridinium oximes (K117, K127, obidoxime) on rats poisoned with tabun at a sublethal dose (180 μg/kg i.m.; 80% of LD50 value) were studied. Tabun-induced neurotoxicity was monitored using a functional observational battery and automatic measurement of motor activity at 24 h following tabun challenge. The results indicated that all tested oximes combined with atropine enabled tabun-poisoned rats to survive 24 h following tabun challenge while one tabun-poisoned rats died within 24 h after tabun poisoning when the rats were treated with atropine alone. Newly developed oxime K127 combined with atropine was the most effective in decreasing tabun-induced neurotoxicity in the case of sublethal poisonings among all oximes tested. Nevertheless, the differences of neuroprotective efficacy between K127 and obidoxime are not sufficient to replace obidoxime by K127 for the treatment of acute tabun poisonings

Estimation of population parameters for a data deficient Salmostoma bacaila (Hamilton 1822) stock from the Mahananda river (tributary of the Ganges) in NW Bangladesh

403-409Salmostoma bacaila known as Razorbelly minnow (Hamilton in 1822) is an indigenous fish species in Bangladesh. This study emphasizes on population structure, growth pattern (length-weight and length-length relations), growth considerations (asymptotic length, L∞; weight, W∞; growth coefficient, K; age at zero length, t0), size and age at sexual maturity (Lm), growth performance index (φ), life-span (tmax), conditions factor (Allometric, KA; Fulton’s, KF and Relative, KR), prey-predator status through relative weight (WR), form factor (a3.0), total (Z), natural (M) and fishing mortality (F), exploitation rate (E) and maximum sustainable yield (MSY) of S. bacaila in the Mahananda river, northwestern Bangladesh. Total 305 specimens of S. bacaila were hardly sampled (ranging between 5.5 to 11.9 cm total length (TL), and 1.05 – 9.20 g total body weight (BW)) through regular fishing gears during August 2016 – July 2017. The regression coefficient ‘b’ of length-weight relations specified negative allometric growth. Growth parameters (GP) were figured as L∞ = 12.66 cm, K = 0.60 year-1, W∞ = 11.36 g, t0 = 0.048, tmax = 5.00 year-1 and φ’ = 1.98. The Lm was 7.34 cm in TL. Relative weight did not create any significant dissimilarity of 100 that would suggest a healthy habitat for S. bacaila. The a3.0 was 0.0052 specifying that this fish could be described as elongated. In addition, the Z was calculated to be 1.57 year-1. The M and F values obtained were 0.92 and 0.65 year-1, respectively. The E was 0.41 and MSY (Emax) was estimated as 0.35 year-1 by yield per recruitment model. Present research knowledge will be very useful in planning the sustainable and appropriate management of this species in Bangladesh and bordering countries

Morphometric and meristic characteristics of Spotted snakehead Channa punctata (Bloch, 1793) in a wetland ecosystem (NW Bangladesh) using multi-linear dimensions

1442-1446This research work affirms the morphometric characters and meristic counts of Channa punctata (Bloch, 1793) in a wetland ecosystem (Gajner Beel) from the northwestern Bangladesh. A sum of 307 specimens of C. punctata were sampled intermittently from the Gajner Beel during July 2017 to December 2018, using different established fishing gears (cast net, gill net and square lift net with mesh size ranges: 1.50-2.50 cm, 1.50-2.00 cm, & ~2.00 cm, respectively). Fin rays were counted by a magnifying glass. Seven diverse morphometric lengths were assessed and BW (body weight) was weighted for each specimen. The fin formula was: dorsal, D. 30-32; pectoral, P1. 15-17; pelvic, P2.5; anal, A. 19-21; and caudal, C. (ii -iv/12-14). Minimum and maximum sizes were 5.80 and 23.00 cm in total length (TL), whereas BWs were1.96 and 126.90 g, respectively. All length-weight relationships (LWRs) were greatly significant (p < 0.001) with r2 ≥ 0.986. Based on r2 value, BW = 0.0112*(TL)2.98 was the most appropriate model among seven equations. Besides, based on r2 values, length-length relationships (LLRs) by TL vs. SL was the finest model among six equations. These findings will help for species identification and further stock/ biomass estimation of C. punctata in the Gajner Beel or connected ecosystems

Bottom shrimp trawling impacts on species distribution and fishery dynamics; Ungwana Bay fishery Kenya before and after the 2006 trawl ban

The Malindi-Ungwana Bay fishery Kenya is one of the most important marine fisheries of the Western Indian Ocean. There are two fishing grounds: Formosa and Malindi, with a designated 5-nMno-trawl zone offshore. However, the fishery was faced with numerous resource use conflicts and a decline in catches, culminating in a trawl ban in 2006. This study analyses catches and fishery dynamics before and after the 2006 trawl ban. Results show that artisanal landings declined before the ban, but rapidly recovered within 2 years after the ban was imposed. However, shrimp landings in the artisanal fishery remain low. Commercial shrimp landings gradually declined before the ban: similar to 550 t in 2001 to 250 t in 2006, and the shrimp: fish bycatch ratio was 1:1.5 compared to early reports of 1:7 in 1999. SIMPER analyses shows that 6 and 16 families (groups) accounted for 91.0 and 90.2% of the similarity in catch within the Formosa and Malindi fishing grounds, respectively. Formosa was important for Claridae, Cichlidae and Protopteridae, while Malindi recorded Carangidae, Siganidae, Carcharhinidae and Lethrinidae as the main families. Future studies should therefore embark on analyses of the factors driving the spatio-temporal distributions of the species and assess the impacts of bottom trawling on fishery dynamics before the trawl ban can be lifted

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Not AvailableEffective fisheries management depend on having an exact assessment of biological parameters, including growth parameters, reproduction, size at sexual maturity (Lm), and stock assessment. The purpose of this research was to estimate the size at sexual maturity (Lm) for 20 fish species belongs to 14 families from a wetland (Gajner Beel) ecosystem in the north-western (NW) Bangladesh through multi-models such as length (Lmax) based empirical model, gonadosomatic index (GSI)-based model, and logistic model using commercial catches from January to December 2018. Also, we assessed the Lm in other water-bodies worldwide. Specimens’ total length (TL) was noted up to 0.1 cm using measuring board body weight (BW) and gonad weight (GW) weighed by digital electronic balance with 0.01 g accuracy. To assess the Lm, maximum body length (Lmax) based empirical model; the relation between TL (total length in cm) vs. GSI (gonadosomatic index in %); and a logistic model were considered. The minimum Lm was 4.64, 3.90, and 4.15 cm for Chanda nama Hamilton, 1822 and the maximum was 25.33, 24.50, and 24.70 cm for Channa striata (Bloch, 1793) through Lmax, GSI, and logistic-based models, respectively. From these three models, the minimum mean Lm was 4.23 cm for C. nama and the maximum was 24.84 cm for C. striata. The Lm with 50.0% species was in 8.80 cm TL. We also calculated the Lm from different bodies of water based on Lmax. This study was generated data of 17 new Lm among 20 species, which are globally absent. Therefore, the study will help develop sustainable management strategies, conservation through the implementation of mesh size based on the size at sexual maturity (Lm).Not Availabl