Android Based Online Computer Technician Application

This study aims to analyze the role of the Android-based Online Computer Technician. This study uses a quantitative description. An online Computer Technician application is to make it easier for customer actors to seek online computer technician services to repair damaged computers and provide convenience for users. The results of the study previously showed that computer users repairing computers by approaching technicians directly to offline stores and transforming into technicians approaching computer users' homes became a good solution. Using an Online Computer Technician Application can make it easier for computer users and not waste time, so they can optimize time properly and correctly

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

The Hooghly croaker, Panna heterolepis Trewavas, 1977: Identification through morphometric and meristic characteristics

502-506As morphometric information for Hooghly croaker Panna heterolepis Trewavas, 1977 is absent in the most extensively accessed and world’s largest online database for fishes (FishBase); this study was undertaken to provide the complete informative description on morphometric relationships and meristic counts of various fin rays. A total of 200 individuals were sampled from the Bay of Bengal (Bangladesh) during July 2018 to June 2019, using several traditional fishing gears. Meristic counts were computed using a magnifying glass. Body weight (BW) and several length measurements were taken through an electronic balance and digital slide calipers for each individual. LWRs (Length-weight relationships) were calculated as: W = a×Lb. All LWRs and LLRs (length-length relationships) were found significant with r2 ≥ 0.919 (p < 0.0001) and 0.928 (p < 0.001), respectively. BW vs. TL and TL vs. SL were the best fitted models for LWRs and LLRs, respectively. Fin formula was: dorsal, D. 43–55 (VIII–X+i/34–44); pectoral, P. 15-17 (i/14–16); pelvic, Pv. 6 (I/5); anal, A. 7–10 (II/5–8); and caudal, C. 17–19 (ii/15–17). These results will a) make a vital contribution for species identification in the marine and coastal waters of Bangladesh and adjoining countries, and b) provide information for Fish Base

The Hooghly croaker, Panna heterolepis Trewavas, 1977: Identification through morphometric and meristic characteristics

As morphometric information for Hooghly croaker Panna heterolepis Trewavas, 1977 is absent in the most extensively accessed and world’s largest online database for fishes (FishBase); this study was undertaken to provide the complete informative description on morphometric relationships and meristic counts of various fin rays. A total of 200 individuals were sampled from the Bay of Bengal (Bangladesh) during July 2018 to June 2019, using several traditional fishing gears. Meristic counts were computed using a magnifying glass. Body weight (BW) and several length measurements were taken through an electronic balance and digital slide calipers for each individual. LWRs (Length-weight relationships) were calculated as: W = a×Lb. All LWRs and LLRs (length-length relationships) were found significant with r2 ≥ 0.919 (p &lt; 0.0001) and 0.928 (p &lt; 0.001), respectively. BW vs. TL and TL vs. SL were the best fitted models for LWRs and LLRs, respectively. Fin formula was: dorsal, D. 43–55 (VIII–X+i/34–44); pectoral, P. 15-17 (i/14–16); pelvic, Pv. 6 (I/5); anal, A. 7–10 (II/5–8); and caudal, C. 17–19 (ii/15–17). These results will a) make a vital contribution for species identification in the marine and coastal waters of Bangladesh and adjoining countries, and b) provide information for Fish Base

Estimation of morphometric relationships for flathead sillago, Sillaginopsis panijus (Hamilton, 1822) in the Bay of Bengal (Bangladesh) using multi-linear dimensions

253-257This study on flathead sillago, Sillaginopsis panijus (Hamilton 1822) estimates the first morphometric relationships from the marine ecosystem, Bay of Bengal, Bangladesh using multi-linear dimensions. Additionally, meristic counts for different fin-rays were done. Alltogether, 204 specimens were captured during July 2018 to June 2019 by several gears including seine net and long lines. Morphometric measurements as well as body weight (BW) were recorded for each individual. The LWRs (length-weight relationships) were assessed as: W = a × Lb. Lateral line scales and fin rays were observed by magnifying glass. The LWRs and LLRs (length-length relationships) were found significant (p r2 values being ≥ 0.913 and ≥ 0.952, respectively. Based on r2 values, LWRs by BW vs. SL and for LLRs, TL vs. FL were found as the best model. Fin formula observed for S. panijus is D1 IX; D2 I/24-28; P.17-20; Pv.1/5; A I-II/24-27; C 2/16-18. Scales on lateral line were ~82-86. This investigation should be helpful for resource management in the marine ecosystems of Bangladesh and other subtropical countries

Size at sexual maturity estimation for 36 species captured by bottom and mid-water trawls from the marine habitat of Balochistan and Sindh in the Arabian Sea, Pakistan, using maximum length (Lmax) and logistic (L50) models

Abstract The aim of this study was to estimate the size at first sexual maturity (Lm) for 36 species belonging to 24 families from the marine habitat of Balochistan and Sindh in Arabian Sea, Pakistan through maximum length based an empirical and logistic model using commercial catch during June 2020 to May 2021. Individual total length (TL) was noted up to 0.1 cm using measuring broad. The Lm was calculated using two formulae; (i) log (Lm) = - 0.1246 + 0.9924 * log (Lmax) for Elasmobranchs and (ii) log (Lm) = -0.1189 + 0.9157* log (Lmax) for ray-finned fishes. The minimum Lm was recorded as 10.27 cm TL for Caranx malabaricus and 108.38 cm TL for Isurus oxyrinchus, respectively. Around Lm with 58.33% species were ranges from 19.00 cm to 25.00 cm TL. This study was estimated 16 newly Lm which is globally absent and rest 20 Lm are absent in the Arabian Sea (Pakistan coastal habitats). Therefore, the results will be helpful for the sustainable management and conservation of these marine fishes through the establishment of mesh size of trawl nets based on the size at sexual maturity (Lm)

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, &amp; ~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 &lt; 0.001) with r2 &ge; 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

Temporal variation of condition and prey-predator status for a schilbid catfish Eutropiichthys vacha (Hamilton, 1822) in the Ganges River, northwestern Bangladesh through multi-model inferences

1229-1237The current study provide the baseline information on the temporal (monthly) variations of condition through multiple functions (allometric, KA; Fulton’s, KF; relative, KR) and prey-predator status through relative weight (WR) for Eutropiichthys vacha (Hamilton, 1822) from the Ganges River, northwestern Bangladesh over one year. The smallest individuals were 6.5 and 6.2 cm in TL, whereas the largest were 19.9 and 20.6 cm in TL for males and females, respectively. No significant differences were observed in the length frequency distribution, LFDs (p = 0.8152) for both sexes. KF was significantly correlated with TL for both sexes (p KF was treated as the best condition factor therefore, well-being of E. vachaa. There was no significant correlation among TL vs KA, TL vs KR and TL vs WR for males and females, respectively. But BW showed highly significant correlations with all condition factors, i.e., BW vs KA; BW vs KF; BW vs KR, and BW vs WR (p WR revealed no significant dissimilarities from 100 for males (p = 0.432) unlike females (p = 0.023), based on Wilcoxon signed-rank tests, suggesting that habitat was more suitable for males than females for food availability relative to predator presence. Moreover, this study assessed for the first time the effect of temperature and rainfall on monthly KF for E. vacha in the Ganges River. The Pearson correlation test found no significant relation between temperature and KF (r = 0.2226, p = 0.4868 for males; r = 0.2172, p = 0.4977 for females), but significant correlations were found between rainfall and KF (r = 0.6357, p = 0.0263 for males and r = 0.6983, p = 0.0115 for females)

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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

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Not AvailableDocumenting and updating life history traits of wild fish are prerequisite for undertaking any conservation and enhancement programme from inland waters. The spotted snakehead Channa punctata (Bloch, 1793) is an important small indigenous food fish in Asian countries which has high nutritional and commercial value. This is the first work on describing life-history traits including growth pattern, condition factors (Fulton's, K F ; Allometric, K A ; Relative condition, K R ; Relative weight, W R), form factor (a 3.0), size at first sexual maturity (L m) and natural mortality (M w) in the Gajner Beel, northwestern Bangladesh during July 2018 to December 2019. Traditional fishing gears were used for sampling. Different lengths (i.e., total length, TL; standard length, SL) and body weight (BW) of each individual were taken using digital slide calipers and an electronic balance to the nearest 0.01 cm and 0.01 g, respectively. In total, 583 individuals ranging from 5.8-22.8 cm TL and 1.96-115.08 g BW were collected in this study. On the basis of b value, the growth pattern of C. punctata was isometric (b=3.0) in all the LWRs. Also, all LWRs were highly significant with r 2 values ≥0.979. The LLR was highly significant (p<0.001) with r 2 =0.992. Among the four types of condition factor, K F showed highly significant relationship with TL and BW (p<0.001). Therefore, K F considered the best for assessing the overall health of this species in the Gajner Beel, NW Bangladesh. Wilcoxon Signed rank test showed that, W R was not significantly different from 100 (p=37235). Also, the calculated a 3.0 was 0.0111, which indicates the fish was fusiform in shape. Moreover, the L m and M w were 12.67 cm TL and 0.96 year-1 , respectively. Therefore, the findings of this study would serve as baseline for stock assessment of floodplain wetland population and sustainable management of wild C. punctata in Gajner Beel and adjoining watershed.Not Availabl