UGROŽENE VRSTE RIBA U SVIJETU: Eutropiichthys vacha (Hamilton, 1822) (Siluriformes: Schilbeidae)

River catfish Eutropiichthys vacha is one of the foods high in nutritional value in Asian countries. However, natural populations have seriously declined or are on the verge of extinction due to over-exploitation and various ecological changes in its natural habitats, leading to an alarming situation which deserves high conservation attention. This paper suggests conservation measures that should be taken into account towards the preservation of the remnant isolated population of E. vacha in Asian countries.Riječni som, Eutropiichthys vacha, služi kao komercijalno visoka, nutritivno vrijedna hrana u azijskim zemljama. Međutim, prirodne populacije ozbiljno su opale ili su na rubu izumiranja zbog prekomjernog iskorištavanja i raznih ekoloških promjena u svojim prirodnim staništima, što dovodi do alarmantne situacije te je potreban visok stupanj zaštite. U radu se predlažu mjere zaštite koje treba uzeti u obzir kako bi se očuvao ostatak izolirane populacije E. vacha u azijskim zemljama

UGROŽENE VRSTE RIBA U SVIJETU: Pethia ticto (Hamilton, 1822) (Cypriniformes: Cyprinidae)

The threatened Ticto barb Pethia ticto is a small indigenous fish species widely distributed in the natural waters of Asian countries. Previously it was known as Puntius ticto. Natural populations have been reduced seriously to the verge of extinction due to excess exploitation and ecological changes in their natural habitats. This paper suggests the actions for the conservation of the remaining isolated population of P. ticto in Asian countries.Ugrožena indijska autohtona vrsta, Pethia ticto, široko je rasprostranjena u prirodnim vodama azijskih zemalja. Ranije je bila poznata kao Puntius ticto. Prirodne su populacije ozbiljno smanjene te na rubu izumiranja zbog viška eksploatacije i ekoloških promjena u njihovim prirodnim staništima. U radu se predlažu mjere za očuvanje preostalih izoliranih populacija P. ticto u azijskim zemljama

UGROŽENE VRSTE RIBA U SVIJETU: Botia dario (Hamilton, 1822) (Cypriniformes: Cobitidae)

Bengal loach Botia dario is a valuable food fish in South Asian countries including Bangladesh, Bhutan, India and Nepal. However, the wild population is declining due to heavy harvest, habitat loss and its ecological changes. This paper suggests actions for the conservation of the lasting isolated populations of B. dario in Asian countries.Benegalski vijun, Botia dario, u južnim azijskim zemljama, uključujući Bangladeš, Butan, Indiju i Nepal, ima visoku važnost u prehrani. Međutim, divlje populacije su u opadanju zbog teškog iskorištavanja, gubitka staništa i ekoloških promjena. U ovom članku se predlažu akcije za očuvanje posljednjih izoliranih populacija B. dario u azijskim zemljama

UGROŽENE VRSTE RIBA U SVIJETU: Rhinomugil corsula (Hamilton, 1822) (Mugiliformes: Mugilidae)

Mullet Rhinomugil corsula is a threatened fish of the family Mugilidae and used as food fish in Asian countries but its natural populations have declined due to over-exploitation and various ecological changes in its natural habitats leading to an alarming condition and deserving high conservation importance. This paper recommends measures for the conservation of the remnant isolated wild populations of R. corsula in Asian countries.Cipal, Rhinomugil corsula, je ugrožena vrsta iz porodice Mugilidae i koristi se kao hrana u azijskim zemljama. Prirodne populacije opadaju zbog pretjeranog iskorištavanja i raznih ekoloških promjena u njihovim prirodnim staništima što dovodi do zabrinjavajućeg stanja i zaslužuje veliku važnost u svrhu njihovog očuvanja. U radu se preporučuju mjere zaštite ostatka izoliranih divljih populacija R. corsula u azijskim zemljama

UGROŽENE VRSTE RIBA U SVIJETU: Heteropneustes fossilis (Bloch, 1794) (Siluriformes: Heteropneustidae)

The threatened stinging catfish Heteropneustes fossilis is a nutritionally valuable food in Asian countries but its natural populations have declined due to over-exploitation, habitat loss and pollution, thus deserving high conservation importance for the remaining isolated, wild populations of H. fossilis in Asian countries. The results would be useful for the protection of the presence of endemic species and sustainable fisheries in the lake.Ugroženi bodljasti som, Heteropneustes fossilis, je nutritivno vrijedna namirnica u azijskim zemljama, ali njegove prirodne populacije opadaju zbog pretjeranog iskorištavanja, gubitka staništa i zagađenja zbog kojih zaslužuje visoku važnost za zaštitu preostalih izoliranih, divljih populacija H. fossilis u azijskim zemljama

UGROŽENE VRSTE RIBA U SVIJETU: Anabas testudineus (Bloch, 1792) (Perciformes: Anabantidae)

Climbing perch Anabas testudineus is commercially important fish in Asian countries, mostly in Bangladesh, China, India, Malaysia, Pakistan, Sri Lanka and Thailand. Also, it is used as valuable food fish in different countries of the world. Nevertheless, its natural populations are seriously declining due to heavy harvest, habitat destruction and other ecological changes to its habitat. This paper recommends actions for the conservation of the long-lasting isolated populations of A. testudineus in Asian countries.Grgeč penjač, Anabas testudineus, je komercijalno važna vrsta ribe u azijskim zemljama, uglavnom u Bangladešu, Kini, Indiji, Maleziji, Pakistanu, Šri Lanki i Tajlandu. Također, koristi se kao vrijedna hrana u različitim zemljama svijeta. Ipak, prirodne populacije ozbiljno opadanju zbog pretjeranog izlova, uništavanja staništa i drugih ekoloških promjena. U članku se preporučuju akcije za očuvanje dugotrajnih izoliranih populacija A. testudineus u azijskim zemljama

Relationships between body size, weight, condition and fecundity of the threatened fish puntius ticto (Hamilton, 1822) in the Ganges River, Northwestern Bangladesh

The ticto barb Puntius ticto (Hamilton 1822) is a small, indigenous fish species of Bangladesh that is widely distributed in the natural waters of Asian countries. This study describes the relationships between body size, weight, condition (Fulton’s, KF; allometric, KA, KR; and relative weight, WR) and fecundity of the threatened species P. ticto from the Ganges River, northwestern Bangladesh. A total of 24 mature female specimens were collected by the traditional fishing gears from March to August 2006. For each individual, total (TL), fork (FL), standard length (SL), and ovary length (OL) were measured by digital slide calipers, while body (BW) and ovary weight (OW) were taken by a digital balance. Total fecundity (FT) of each female was calculated as the number of eggs found in each ovary, whereas relative fecundity (FR) was the number of eggs per gram of fish weight. The results showed that TL of P. ticto varied from 9.10 to 10.80 cm, with calculated mean ± SD as 9.77±0.57 cm. Body weights extended from 14.00 to 24.00 g, with calculated mean ± SD as 17.83±3.39 g. The mean FT was 2586±700 and ranged from 1611 to 4130. BW was more significantly correlated with total fecundity (r2>0.633; p<0.001) than various other body metrics. The results also indicated significant correlation between length-weight (df=22, t-test≥8.86, p<0.001); FT -KF (rs=0.473; p=0.019), FT-KA (rs=0.502; p=0.012), and FT-WR (rs=0.483; p=0.016), but insignificant correlations were found between FT-GSI (rs=0.309; p=0.141) and FR-with various other body metrics. The knowledge of fecundity would be useful to impose adequate regulations for the conservation of this threatened species in the Ganges River and nearby areas of Bangladesh

Biometric relationships of the pool barb puntius sophore (Hamilton 1822) (Cyprinidae) from three major rivers of Bangladesh

The present study describes population structure (length-frequency distribution-LFD) and biometric relationships including length-weight relationship (LWR), length-length relationship (LLR), Fulton’s condition factor (K), relative weight (Wr) and form factor (a3.0) of Puntius sophore wild populations from three major rivers of different geographical locations of Bangladesh. A total of 784 specimens were caught by traditional fishing gear from March 2010 to February 2011. For each individual, the total length (TL), fork length (FL) and standard length (SL) were measured by digital slide calipers. Individual body weight (BW) was also taken by a digital balance. The results showed significant differences in TL-frequency distributions among populations (p0.921). Fulton’s condition factor (K) showed significant variations (p<0.001) among the populations, with best performance by the Padma River, followed by the Jamuna and Rupsha River; whereas, relative weight (Wr) was close to 100 for all the populations, indicating the balance habitat with food availability relative to the presence of predators. The estimated values of a3.0 were as 0.0158, 0.0142 and 0.0152 for P. sophore in the Jamuna, Padma and Rupsha River. These results will be useful for fishery biologists and conservationists to suggest adequate regulations for sustainable fishery management and conservation its numerous stocks in the region

Square diaphragm CMUT capacitance calculation using a new deflection shape function

This article was published in the Journal of Sensors [© 2011 Md Mosaddequr Rahman and Sazzadur Chowdhury.] and the definite version is available at: http://doi.org/10.1155/2011/581910 The Article's website is at: https://www.hindawi.com/journals/js/2011/581910/A new highly accurate closed-form capacitance calculation model has been developed to calculate the capacitance of capacitive micromachined ultrasonic transducers (CMUTs) built with square diaphragms. The model has been developed by using a two-dimensional polynomial function that more accurately predicts the deflection curve of a square diaphragm deformed under the influence of a uniform external pressure and also takes account of the fringing field capacitances. The model has been verified by comparing the model-predicted deflection profiles and capacitance values with experimental results published elsewhere and finite element analysis (FEA) carried out by the authors for different material properties, geometric specifications, and loading conditions. New model-calculated capacitance values are found to be in excellent agreement with published experimental results with a maximum deviation of 1.7, and a maximum deviation of 1.5 has been observed when compared with FEA results. The model can help in improving the accuracy of the design methodology of CMUT devices and other MEMS-based capacitive type sensors built with square diaphragms.Publishe

Life-history traits of the freshwater garfish xenentodon cancila (Hamilton 1822) (Belonidae) in the Ganges River, Northwestern Bangladesh

The freshwater garfish, Xenentodon cancila (Hamilton 1822), is one of the commercially important, nutritionally valuable food fish in Asian countries, but the natural populations are seriously decreasing due to high fishing pressure and other factors. This study describes the life history traits, including sex ratio (SR), length-frequency distributions (LFDs), length-weight relationships (LWRs), length-length relationships (LLRs), condition factors (Allometric, KA; Fulton’s, KF; relative condition, KR; relative weight, WR) and form factor (a3.0) of X. cancila in the Ganges (Padma) River, northwestern Bangladesh. A total of 175 specimens ranging from 10.50-21.00 cm TL (total length) and 1.44-20.67 g BW (body weight) were investigated in this study. Sampling was done using traditional fishing gears from April 2011 to March 2012. The overall sex ratio showed no significant differences from the expected value of 1:1 (df = 1, χ2 = 0.28, p<0.05), whereas significant difference was found in the LFD (TL) between the sexes (Two tailed, p<0.001). The allometric coefficient b for the LWR indicated positive allometric growth in males, females and combined sexes. The results further indicated that the LLRs were highly correlated. Both KR and KF showed significant variations (Two tailed, p<0.001) between male and female. Also, WR was significantly different from 100 for both sexes (p<0.01), indicating the imbalance habitat with food availability relative to the presence of predators for X. cancila. The calculated values of a3.0 were as 0.0304, 0.0268 and 0.0252 for males, females and combined sexes of X. cancila. This study reports the first complete and comprehensive description of life-history traits for X. cancila from Bangladeshi waters. The data should be useful for the sustainable conservation of this critically endangered fishery in Bangladesh and neighboring countries