A Comparative Study on the Length-Weight Relationships of Two Freshwater Fish Families, Nandidae and Channidae, from Kawadighi Haor in North-eastern Bangladesh

doi:10.21203/rs.3.rs-5147499/v1

Download PDF

Research Article

A Comparative Study on the Length-Weight Relationships of Two Freshwater Fish Families, Nandidae and Channidae, from Kawadighi Haor in North-eastern Bangladesh

https://doi.org/10.21203/rs.3.rs-5147499/v1

This work is licensed under a CC BY 4.0 License

Version 1

posted

You are reading this latest preprint version

Length-weight relationships (LWRs) were determined for two fish species from the Kawadighi Haor, Moulvibazar District, Bangladesh. Fish specimens were collected across the Haor region from March to July 2024 using multi-mesh gill nets (approximately 1 cm) and conical and box-shaped traps. Additional specimens were obtained from local fish markets and small-scale fishermen in the Haor region. Statistical analysis was done by linear regression model and confidence interval using rstudio 4.3.2. The relationships between length and weight were found to fit well, with R² values of 0.931 for Nandus nandus and 0.708 for Channa punctatus. The b values of the LWR equations ranged from 2.976 for N. nandus to 3.231 for C. punctatus.

Animal Science

Growth

Nandus nandus

Channa punctatus

LWRs

Reservoir

Correlations

The core area of the Haor, called the Haor Basin or Sylhet Basin, is estimated by experts to cover an area of 4,450 to 25,000 square kilometres (Alam et al. 2018). Bangladesh has abundant fisheries resources, especially inland waters, which contribute 42% of the country's total fish production (Nahar et al. 2018; FAO 2016). The length-to-weight ratio (LWR) of fish is of utmost importance as it facilitates the assessment of important biological aspects such as fish health, onset of maturation, and onset of spawning using condition factors derived from this ratio. Moreover, LWR serves as a valuable tool to estimate discards of certain species (Lamprakis et al. 2003; Torres et al., 2012) and helps understand sex differences, growth patterns, early maturation, reproduction and gonadal production (Wanjari et al. 2019; El-Aiatt 2021). It is an essential part of fisheries management and research, allowing for the conversion of data collected in the field into meaningful indicators (Ecoutin and Albaret 2003). LWR facilitates the estimation of the average weight of fish within a given length group by establishing a mathematical relationship between length and weight (Le Cren et al. 1951; Das et al. 2013). The spotted snakehead (Channa punctata), a freshwater fish of the Chanidae family, is known as "taki" in Bangladesh, "wallfish" in India and "spotted snakehead" in Sri Lanka. The Ganges leaffish, Nandus nandus, is a freshwater and brackish benthic species belonging to the family Nandidae (Hossain et al. 2017). The fish is known as ‘meni’ and ‘beda’ in Bangladesh, ‘Nandosh’ in India and ‘Dalahai’ in Nepal. It is distributed throughout the Indian subcontinent, including Bangladesh, India, Malaysia, Myanmar, Pakistan, Thailand and Vietnam (Froese and Pauly 2015). This article investigates the length-weight relationship (LWR) of two fish species from the north-eastern region of Kawadighi Haor. The study provides essential baseline information on LWR, which can help develop freshwater fish conservation strategies in Moulvibazar District.

206 N (Number of individual) samples were collected from the freshwater reservoir in the Kawadighi Hoar coordinate (24° 24° 32.656' N, 91° 46' 11.26" E) quarterly from March 2024 to July 2024 The fishing gear used is gill net (~ 1 cm mesh size) and various traditional traps (conical and box type).Fish were mainly collected from the local market near the hoar area and from small-scale fishermen. All specimens were identified, measured using measuring scale, and weighed with an electronic balance (0.01 g). We calculated the length-weight relationship (LWR) using the equation:

BW = a×TL^b----------------------------------------- Le Cren et al. (1951)

Where BW is body weight (g) and TL is total length (cm). Linear regression analysis was performed to determine the parameters a and b. Additionally, the coefficient of determination (R²) and the 95% confidence intervals (CI) for a and b were calculated (Froese, 2006). R studio 4.3.2 software used to perform statistical analyses (R programming). The statistical difference from the isometric value (b = 3) for LWRs were determined by test. All statistical analyses were considered at 5% significance level (P < 0.05).

Table 1

The estimated length-weight relationships for two freshwater fish species collected in Haor, March-July 2024.
Species	N	L (cm)			W (g)			a		b		R²
Species	N	Max	Min	Mean ± SD	Max	Min	Mean ± SD	value	95% CI	value	95% CI	R²
Nandus nandus (Hamilton, 1822)	84	11.1	8.2	9.66 ± 1.13	26.85	9.54	17.533 ± 5.24	0.02	−0.749, 0.789	2.9768	2.196, 3.75	0.9313
Channa punctatus (Bloch, 1793)	122	14.7	9.9	12.41 ± 1.11	71.23	14.6	44.05 ± 13.45	0.012	-2.308, 2.332	3.2319	0.89, 5.58	0.7083

In this study, 206 specimens of two fish species were sampled from the Nandidae and channidae. Nandus nandus growth parameters "a" and "b" were 0.02 (95% CI: -0.749, 0.789) and 2.9768 (95% CI: 2.196, 3.757), respectively, with an R² value of 0.9313. For Channa punctatus, the mean length was 12.41 ± 1.11 cm, the maximum length was 14.7 cm, and the minimum length was 9.9 cm. The mean weight was 44.05 ± 13.45 g, varying between a maximum of 71.23 g and a minimum of 14.6 g. The growth parameters ‘a’ and ‘b’ of C. punctatus are 0.012 (95% CI: -2.308, 2.332) and 3.2319 (95% CI: 0.89, 5.58), respectively, with an R² value of 0.7083 (Table 1).

According to our results, the growth parameters "a" and "b" of C. punctatus were 0.012 (95% CI: -2.308, 2.332) and 3.2319 (95% CI: 0.89, 5.58), respectively, with an R² value of 0.7083. It can be seen that there is a moderate correlation between body length and weight (Table 1). In their study, Hossain et al. (2016) examined 307 individuals of C. punctatus with total lengths ranging from 5.80 cm to 23.00 cm. However, the maximum total length recorded in our study was 14.7 cm. On the other hand, reported a maximum recorded size of 20 cm total length (Talwar and Jhingran 1991). According to Hossain et al. (2006), these findings a maximum total length of 14.20 cm in their study (Hossain et al. 2006). The results showed that N. nandus the growth parameters "a" and "b" were 0.02 (95% CI: -0.749, 0.789) and 2.9768 (95% CI: 2.196, 3.757), respectively, with an R² value of 0.9313, indicating a strong correlation between length and weight (Table 1). The calculated b-value of N. nandus is between 3.04 and 3.22 (Hossain et al. 2017).

The present study provides valuable insights into the length-weight relationships (LWRs) of two freshwater fish species, Nandus nandus and Channa punctatus, from the Kawadighi Haor in north-eastern Bangladesh. The results are consistent with previous studies on these species and provide a reference for future fisheries management in the region. This study contributes to a more comprehensive understanding of freshwater fish growth dynamics and aids in the development of conservation strategies to protect fish diversity in northeast region.

Data availability

The author confirms that supports and findings of this study are available. All necessary data are incorporated and supplementary data can be accessed through the corresponding author.

Conflict of Interest

There have any no conflict of interest for particular manuscript.

Acknowledgements

We express our gratitude to the Aquaculture Departments for providing access to laboratory facilities and to the second author for receiving the National Science and Technology (NST) fellowship, which supported this work. We declare no conflicts of interest. There is no conflict of interest.

Alam, M. M., Hossain, M. K. (2018) Policy options on sustainable resource utilization and food security in Haor areas of Bangladesh: A theoretical approach. International Journal of Social, Political and Economic Research5(1):11-28. https://www.researchgate.net/publication/375599796
Ecoutin, J. M., Albaret, J. J. (2003) Length-weight relationship of 52 fish species from West African estuaries and lagoons. Cybium27(1):3-9. https://www.researchgate.net/publication/294493366
El-Aiatt, A. O. (2021) Length-weight relationship and condition factor of white grouper Epinephelus aeneus (Geoffroy saint Hilaire, 1817) in the mediterranean coast of sinai, egypt. Egyptian Journal of Aquatic Biology and Fisheries25(4): 573-586. https://www.researchgate.net/publication/377219870
Froese, R. (2006) Cube law, condition factor and weight–length relationships: history, meta‐analysis and recommendations. Journal of applied ichthyology22(4): 241-253. https://doi.org/10.1111/j.1439-0426.2006.00805.x
Froese, R., Winker, H., Coro, G., Demirel, N., Tsikliras, A. C., Dimarchopoulou, D., Pauly, D. (2019) A new approach for estimating stock status from length frequency data”. ICES Journal of Marine Science76(2): 461-465. https://www.researchgate.net/publication/330546779
Hossain, M. Y., Ahmed, Z. F., Leunda, P. M., Roksanul Islam, A. K. M., Jasmine, S., Oscoz, J., (2006) Length–weight and length–length relationships of some small indigenous fish species from the Mathabhanga River, southwestern Bangladesh. Journal of Applied Ichthyology22(4):301-303. https://doi.org/10.1111/j.1439-0426.2006.00801.x
Hossain, M. Y., Hossen, M. A., Khatun, D., Nawer, F., Parvin, M. F., Rahman, O., Hossain, M. A. (2017) Growth, condition, maturity and mortality of the Gangetic leaf fish Nandus nandus (Hamilton, 1822) in the Ganges River (Northwestern Bangladesh). Jordan J Biol Sci10: 57-62. https://www.researchgate.net/publication/316635633
Lamprakis, M. K., Kallianiotis, A. A., Montopoulos, D. K. (2003) Weight-length relationships of fishes discarded by trawlers in the North Aegean Sea. Acta Ichthyologica et Piscatoria33:145-152. https://www.researchgate.net/publication/235732587
Le Cren, E. D. (1951) The length-weight relationship and seasonal cycle in gonad weight and condition in the perch (Perca fluviatilis). The Journal of Animal Ecology :201-219.https://doi.org/10.2307/1540
Nahar, A., Hanif, M. A., Siddik, M. A. B., Chaklader, M. R., Islam, M. A. (2018) Length–weight and length‐length relationships of four endemic fish species caught from Payra River, Southern Bangladesh. Journal of applied ichthyology34(3): 785-787. https://doi.org/10.1111/jai.13601
Talwar, P. K., Jhingran, A. G. (1991) Inland fishes of India and adjacent countries (Vol. 2). CRC press.https://books.google.com/books?hl=en&lr=&id=UG90mc4yD50C&oi=fnd&pg=PA512&dq=11.
Torres, M. A., Ramos, F., Sobrino, I. (2012) Length–weight relationships of 76 fish species from the Gulf of Cadiz (SW Spain). Fisheries Research127: 171-175. https://doi.org/10.1016/j.fishres.2012.02.001
Wanjari, R. N., Ramteke, K. K., Dhanalakshmi, M., Nayak, B. B., Deshmukhe, G. (2019) Length-Weight Relationship of Yellow Shrimp, Metapenaeus Brevicornis (Milne-Edwards, 1837), Along the Mumbai, Central Eastern Arabian Sea. Journal of Indian Fisheries Association 46 (2). https://www.researchgate.net/publication/356717946

The authors declare no competing interests.

Download PDF

Version 1

posted

You are reading this latest preprint version

A Comparative Study on the Length-Weight Relationships of Two Freshwater Fish Families, Nandidae and Channidae, from Kawadighi Haor in North-eastern Bangladesh

Status:

Version 1

Abstract

Introduction

Materials and methods

Results

Discussion

Conclusion

Declarations

References

Additional Declarations

Status:

Version 1