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.
The present study describes the length-frequency distribution, length-weight (LWR) and length-length relationships (LLR), and condition- and form-factors of Puntius sophore wild population from the Chalan beel, north-central Bangladesh. Sampling was done using traditional fishing gears including jhaki jal (cast net), tar jal (square lift net), and dughair (conical trap) during 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. A total of 185 specimens ranging from 3.62-9.02 cm TL and 0.70-13.20 g BW were analyzed in this study. The length-frequency distribution showed that the 6-7 cm TL size group was numerically dominant and constituted 43% of the total population. The coefficient b of the LWRs indicated positive allometric growth (b>3.00) for P. sophore in the Chalan beel. The results also indicated that the LWRs were highly correlated (r2 > 0.945). The calculated Fulton’s condition factor (K) values ranged from 0.69-2.35, with a mean value 1.64±0.30. The relative weight (Wr) was not significantly different from 100 for (p=0.074), indicating the balance habitat with food availability relative to the presence of predators for P. sophore. The estimated values of form factor (a
3.0) were as 0.0138, 0.0345 and 0.0435 for TL, FL and SL of P. sophore, respectively. 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.
The critically endangered catfish eutropiichthys vacha (Hamilton 1822) is one of the commercially high nutritional valuable food fish in Asian countries, but the natural populations are seriously decreasing due to high fishing pressure, leading to an alarming condition and deserving of high conservation importance. Our study describes some biological parameters, including sex ratio, length-frequency distribution (LFD), 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 e. vacha in the Jamuna (Brahmaputra River distributary) River, northern Bangladesh. A total of 350 specimens ranging from 8.01-16.95 cm TL (total length) and 1.70-30.38 g BW (body weight) were analyzed in this study. Sampling was done using traditional fishing gears during March 2010 to February 2011. The overall sex ratio showed no significant differences from the expected value of 1:1 (χ2=2.57, p>0.05), and there was no significant difference in the LFD between the sexes (p=0.38). The allometric coefficient b for the LWR indicated isometric growth (~3.00) in males and combined sexes, but negative allometric growth (<3.00) in females. The results further indicated that the LLRs were highly correlated (r2>0.997; p<0.001). KR showed significant variations (F=65.11; p<0.01) between male and female; whereas, KF was not significantly different between the sexes (p=0.64). 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 e. vacha. The estimated values of a3.0 were as 0.0060, 0.005 and 0.0054 for males, females and combined sexes of e. vacha. This study reported the first complete and comprehensive description of life-history traits for e. vacha from Bangladeshi waters. These results should be useful for the sustainable conservation of this critically endangered fishery in Bangladesh and neighboring countries.
The small indigenous species namely ailiichthys punctata (Day 1871), Botia lohachata (Chaudhuri 1912), Chanda nama (Hamilton 1822), Laubuca laubuca (Hamilton 1822) and Mystus cavasius (Hamilton 1822) comprise an important component of riverine fisheries of Bangladesh. But the natural populations are decreasing fast due to high fishing pressure as well as environmental degradation. Therefore, data and information is needed to avert the alarming decline and initiate conservation measures for these important fishes of the Jamuna River. This study describes the condition- (Fulton’s and Relative weight) and form-factor (a3.0) of the five threatened fishes from the Jamuna River, a distributary of the Brahmaputra River in northern Bangladesh. A total of 919 specimens from five species in five families used for this study were caught by traditional fishing gear during March 2010 through February 2011. For each individual, the total (TL), fork (FL) and standard (SL) length were measured by digital slide calipers while individual body weight (BW) was measured using a digital balance. The Fulton’s condition factor (KF) showed significant variations (p<0.01) among species, with best performance by B. lohachata (1.49±0.20) followed by C. nama (1.41±0.19), M. cavasius (0.79±0.14), L. laubuca (0.78±0.09) and a. punctata (0.71±0.12). The calculated minimum and maximum relative weight (WR) was 53.14 for C. nama and 167.88 for a. punctata, respectively. However, the estimated relative weight (WR) was close to 100 for
all populations (p>0.05) indicating a balanced habitat with food availability relative to the presence of predators. The calculated minimum and maximum form factor (a3.0) was 0.0062 for a. punctata and 0.0158 for B. lohachata, respectively. To the best of our knowledge, this study presents the first reference on KF, WR and a3.0 factors for these threatened species in Bangladesh. The results would be useful for sustainable management and conservation of the limited stocks in the Brahmaputra River ecosystem.