ISSN: 2455-8400
International Journal of Aquaculture and Fishery Sciences
Research Article       Open Access      Peer-Reviewed

Impact of Climate Deviation on Reproductive Profile of Nile Tilapia, Oreochromis niloticus (Linnaeus, 1758) from the Tons River, India

Amitabh Chandra Dwivedi1* and N Mishra2

1Department of Zoology, Nehru Gram Bharati (Deemed to be University), Prayagraj, Uttar Pradesh, India
2Kalash Research and Welfare Society, Prayagraj-211002, Uttar Pradesh, India

*Corresponding author: Amitabh Chandra Dwivedi, Department of Zoology, Nehru Gram Bharati (Deemed to be University), Prayagraj, Uttar Pradesh, India, E-mail: [email protected]
Received: 17 October, 2024 | Accepted: 26 October, 2024 | Published: 28 October, 2024
Keywords: Nile tilapia; Oreochromis niloticus; Reproductive profile; Sex ratio; Fecundity; Tons river

Cite this as

Dwivedi AC, Mishra N. Impact of Climate Deviation on Reproductive Profile of Nile Tilapia, Oreochromis niloticus (Linnaeus, 1758) from the Tons River, India. Int J Aquac Fish Sci. 2024;10(4):031-037. Available from: 10.17352/2455-8400.000093

Copyright License

© 2024 Dwivedi AC, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Nile tilapia, Oreochromis niloticus is among the leading farmed species around the world as well as a powerful invader in many countries globally. Studies were undertaken during the period from February 2019 to January 2020 from the lower stretch of the Tons River at Prayagraj, Uttar Pradesh, India. During the sampling period, 683 fish specimens of Nile Tilapia, Oreochromis niloticus (336 males and 347 females) were collected and studied for evaluation of sex ratio and sex structure. The sex ratios of male and female fishes were very close and reported 1.0:1.03 in the stock. The male ratio was higher in the small size group of fish with 81 to 200 mm size groups and 411 to 470 mm size group. The sex structure of males and females was observed at 49.19% and 50.81%, respectively in the case of stock. The female proportion was recorded as a minimum with 37.50% in the 441-470 cm size group and highest with 54.84% in the 381-410 mm size group. However, the male proportion was reported lowest at 45.16% in the 381-410 mm size group and highest at 62.50% in the 441-470 mm size group. In the present findings, O. niloticus was found to reach maturity starting below 138 mm of total length, taking individual fish. The fishes breed in the months of March to June and September to November of the year. The number of eggs per individual ranged from 393 to 4338 in the size of fish varied from 138-452 mm. The reported fecundity and sex ratio of O. niloticus indicated that the climatic condition or environmental condition of the Tons River was most suitable. The environmental condition (especially temperature) of the Tons River at Prayagraj is slightly warm compared to the Ganga River which is very favourable for O. niloticus. The water current velocity of the Tons River is very poor. Both parameters are very helpful for the stability of O. niloticus in the Tons River at Prayagraj. The high fecundity of O. niloticus in the Tons River at Prayagraj could probably be a result of a combination of different causes such as climatic conditions, habitat structure, food abundance, water quality, and quality of food. Therefore, the present study aimed to update the information on the sex ratio, sex structure, and fecundity of O. niloticus with respect to climate from the Tons River, India.

Introduction

Nile tilapia, Oreochromis niloticus is a commercially and economically important fish species globally and plays an important function in tropical and subtropical aquatic ecosystems with respect to fish productivity [1-9]. It is found in the commercial fishery in the Ganga, Tons, Yamuna Ken, and Paisuni rivers with Cyprinus carpio [10-14]. In general, O. niloticus is well-known for its plasticity in survival (for example, tolerates a wide range of environmental conditions and ability to feed at different trophic levels, lowest dissolved oxygen need), feeding nature, fast growth, tolerance, high resistance to diseases, easily breeds and size at first maturity [15-20]. Undoubtedly, O. niloticus is one of the leading farmed species in the world and comparatively low cost of production.

In the Indian riverine system, the O. niloticus niche overlaps with Cirrhinus mrigala, Labeo calbasu, and Cyprinus carpio fishes. O. niloticus tends to quickly gain a competitive advantage because of its hardy nature and feeding plasticity due to these features. O. niloticus is the most common invader fish species globally [5,21-23] and also an invader in India and has become the dominant species (by-catch or landing) in many rivers of the Ganga river system, India [24,25].

Knowing fish reproductive biology is vital for fisheries management and conservation, and for fulfilling the knowledge gap in fundamental fisheries research [1,3,12,23]. Segmented studies on the various aspects of the reproductive biology of O. niloticus have been carried out in different parts of the world [1,3,12]. The knowledge base on the reproductive aspects of O. niloticus is lacking from the Tons River Indian Thus, the present study of sex ratio, sex structure, breeding season, and fecundity of O. niloticus from the Tons River, which is an entirely very new home for the fish. The study would help the fishery managers and planners in the management of the riverine fisheries in the Ganga basin, India. Record and assessment of the present research work is also necessary to formulate informed decisions about restoration and management of the fishery and rivers.

Materials and methods

The Tons River is essentially a hilly stream water body arising in the Kaimur hills of the Vindhyan range, India. Its banks are lined by deep ravines and the bed is rocky. The Tons River lies between latitude 24o 0’ to 25o 16’ 54” North and longitude 80o 26’ 45” to 82o 04’ 57” East. It is a tributary of the Ganga River. The sample was collected from February 2019 to January 2020 from the Sirsa fish landing centre at Prayagraj, Uttar Pradesh, India. Fishes were collected using a variety of methods including gill nets, drag nets, cast nets, and hook and lines.

During the course of the present study, 683 fish specimens of O. niloticus (336 male and 347 female) in the length ranges between 82 to 463 mm were examined for the estimation of sex ratio and sex structure. The female fishes were identified by microscopic examination of the gonads as they show sexual dimorphism only in the breeding season. The numbers of fish samples were segregated on the basis of their sex (male and female) to determine the percentage composition of each sex in different size groups. This helped to understand the distribution of sexes in different size groups. Their sex ratio (M:F) was computed for each size group.

The Absolute Fecundity (AF) of individual females was determined gravimetrically [26], with the number of ripe oocytes counted from triplicates (anterior, middle, and posterior) of the 1 gm sub-sample of the ovary. Twenty-seven ripe female fishes were used for the estimation of fecundity in the present study. To obtain representative samples of the whole gonads, 3 gm eggs were taken from the posterior, middle, and anterior of both lobes of the ovary. The 3 gm ripe eggs were counted and then divided by 3 for obtaining of 1 gm egg number. The total number of ripe eggs in the ovary was estimated by multiplying by 1 gm egg number. The fecundity was estimated by following the formula-

Fecundity = Total weight of ovary ´ Number of 1 gm ripe eggs

Results and discussions

During the course of the present study, 683 fish specimens of O. niloticus (336 male and 347 female) in the length ranges between 82 to 463 mm were examined for the estimation of sex ratio and sex structure. Present sample numbers are standard for all studies because the present fish is an exotic species for the Tons River. The size composition of O. niloticus fishes varied from 82 to 463 mm (total length). The recorded largest size of O. niloticus was indicated by the well-stable fish species from the Tons River at Prayagraj, Uttar Pradesh, India. The maximum total length of O. niloticus in the catches indicated its increasing colonisation success in the river Tons. The maximum length of fish is a good indicator of the health of stock in the riverine ecosystem [27,28]. The reported sex ratio (1.0:1.03) of males and females was much closer to the naturally expected ratio (1.0:1.0). The Present sex ratio is a good indicator of a healthy and stable stock of O. niloticus from the Tons River.

Sex ratio

The sex ratio of male and female fishes of O. niloticus in stock was reported 1.0:1.03 from the Tons River. The present sex ratio of the stock is most important for healthy and heavy recruitment. Male ratio was higher in small size group fishes with 81-110, 111-140, 141-170, and 171-200, mm size groups, and also in higher size groups 441-470 and 441-470 mm (Table 1). The sex ratio was reported 1.0:0.78, 1.0:0.85, 1.0:0.88, 1.0:0.93, 1.0:0.71, and 1.0:0.06 in size groups of fishes 81-110, 111-140, 141-170, 171-200, 441-440 and 411-470 mm, respectively (Table 1). The oral incubation behaviour (female, eggs, and larvae) is responsible for the higher male proportion of O. niloticus in the Tons River in the case of small-size fishes. After spawning in the nest made by a male fish, the young fry or eggs are carried in the mouth of the mother for a period of 12 days. During the oral incubation behaviour period, female fish’s movement is limited. The female proportion was estimated higher in 201-230, 231-260, 261-290, 291-320, 321-350, 351-380 and 381-410 mm size group of fishes and sex ratio was 1.0-1.11, 1.0-1.10, 1.0-1.12, 1.0-1.05, 1.0-1.12, 1.0-1.09 and 1.0-1.21, respectively (Table 1).

The sex ratio is a fundamental parameters used in age-structured models in stock assessments of fishes. The sex ratio is helpful in understanding the recruitment pattern of fish in the population. Theoretically, the expected ratio of males to females should be 1.0:1.0 [29-31]. The sex ratio of most fish species in the wild tends to be 1:1, but deviations can occur and seasonal variations are very common [32-33]. It was also reported a slightly higher proportion of female O. niloticus in the case of stock from the Yamuna River, India [12]. The sex ratio is influenced by several factors, including mortality, longevity, and growth rate, these in turn lead to differences in the catch rate [34]. The sex ratio in the spawning population and in the various age and size groups varies with the species, reflecting the relationship of that species to its environment [35-41]. It was reported that the sex ratio was 1:1 of O. niloticus from Khashm El-Girba Reservoir and Atbara River, Eastern Sudan [42]. It was observed that of the 316 O. niloticus examined 148 (46.8%) were males and 168 (53.2%) females and overall male-to-female ratio of 1:1.14 in Geray Reservoir, Ethiopia [43].

Sex structure

The sex structure of males and females was observed at 49.19% and 50.81%, respectively in the case of stock of O. niloticus from the Tons River, India (Table 2). The female proportion was reported as a minimum with 37.50% in the 441-470 cm size group and highest with 54.84% in the 381-410 mm size group (Table 2). However, the male proportion was recorded as a minimum with 45.16% in the 381-410 mm size group and highest with 62.50% in the 441-470 mm size group of fishes.

The sex structure is also adaptive to the food supply, which thereby influences the reproductive rate and the variability of the offspring [44-46]. It was reported that the 624 fishes of O. niloticus were caught with 272 females (43.59%) and 352 males (56.41%) and the sex ratio was 1:1.29 (females: males) in Emiliano Zapata dam Morelos, Mexico [47]. It was estimated that the O. niloticus had a sex structure of 121 females (54.8%) and 100 males (45.3%) in the upper Kabompo River, northwest of Zambia [38].

Breeding seasons

The environmental condition (especially temperature) of the Tons River at Prayagraj is slightly warm compared to the Ganga River which is very favourable for O. niloticus. The water current velocity of the Tons River is very poor. Both parameters are very helpful for the stability of O. niloticus in the Tons River at Prayagraj. The frequency of temporal variation between ripe males and females was similar. The smallest spent female fish was recorded with a 141 mm total length. The fishes breed in the months of March to June and September to November of the year. A lot of spent fishes were recorded in this period. A current study indicated that the O. niloticus breeds two times per year. The first breeding season was reported long with 4 months and the second was short with 3 months. O. niloticus was caught at various stages of gonad development and reproduction in almost all months. However, their frequency varied with the month of capture. The seasonal pattern of gonad development for both sexes was almost similar.

Generally, Tilapia species in temperate areas have very short breeding seasons and are limited to some months only, but in tropical countries, their breeding seasons are extended, and in most cases throughout the year [48,49]. It was recorded that the breeding period of O. niloticus occurred from April to July and the spawning of oocytes began at the end of July [50].

Fecundity

The portion of the ovary was removed before being stored in formalin and this had to influence the results. A total of 27 ripe female fishes were utilized for the estimation of the fecundity of O. niloticus from the Tons River, India. The total length of ripe female fishes varied from 138 to 452 mm and the weight of gonads fluctuated between 3.27 to 34.74 gm, respectively (Table 3). In the present findings, O. niloticus was found to be mature starting below 138 mm of total length, taking individual fish. The number of eggs per individual ranged from 393 to 4338 in size of fish 138-452 mm, respectively (Table 3). The high fecundity of O. niloticus in the Tons River at Prayagraj could probably be a result of a combination of different causes such as climatic conditions, habitat structure, food abundance, water quality, and quality of food. The number of ripe eggs increased with the ovarian weight and size of fishes. The number of eggs is closely related to the size of fishes compared to the weight of the gonad. Fecundity was linearly related to the weight of the gonad. Fecundity was also directly related to the total length of fishes. The water temperature varied from 17.8 to 29.6 °C and the mean value was recorded as 24.23 ± 4.73. The dissolved oxygen concentration fluctuated between 4.7 to 6.2 mg/l while the mean value was reported 5.76 ± 0.97. The average pH value was recorded at 7.92 ± 0.32 and the value fluctuated between 7.6 to 8.3. The nitrate varied from 0.42 to 1.6 mg/l and the mean value was recorded as 1.17 ± 0.68. The fecundity of O. niloticus indicated that the climatic condition of the Tons River is most suitable for O. niloticus.

The fecundity of fish is directly associated with the growth and climatic conditions. It was estimated fecundity was between 241 to 709 eggs/fish in 125-209 mm size of fishes at Coatetelco Lake, Morelos, Mexico [48]. It was reported that the relative fecundity of O. niloticus ranged from 3 to 9 oocytes per gram of body weight, with a mean of 6 oocytes/gm at Peele reservoir, Nakanbé River Basin, Burkina Faso [50]. It was observed mean fecundity for O. niloticus was 1422.24 ± 91.103, Zambia [51]. It was estimated that the relative fecundity varied from 0.29 to 6.8 (mean 2.77 ± 0.13) eggs/g of females in brackish water, in Iran [52]. It was recorded that the fecundity of O. niloticus varied from 149 to 2797, for fish weighing between 36 and 975 gm in 1995, and from 178 to 1898, for fish weighing between 78 and 501 gm in 1996 from man-made lakes of Cˆote d'Ivoire [53].

In riverine ecosystems, sex ratio and fecundity also varied from season to season and year to year with respect to water flow, photoperiod, temperature, richness of fish species, size of fishes, age of fishes, stock of exotic fishes, availability of food and fishing pressure [12,34,38,43,54-60]. Due to the low concentration of heavy metals in the riverine ecosystems, it is also helpful for successful and healthy recruitment [61-66]. More and more detailed studies on the sex ratio, sex structure, breeding season, and fecundity as well as other aspects of biology (for example age and growth, food and feeding, length-weight relationship) of different fish species should be explained for sustainable management of fish biodiversity and stock of the Tons river, Uttar Pradesh, India.

Conclusion

It may be concluded that the reported sex ratio of male and female fishes in stock is 1.0:1.03 which is very close to 1.0:1.0 (for example naturally expected sex ratio, male and female) and healthy condition and creates a chance for heavy recruitment. The fecundity and breeding frequency of O. niloticus also indicated that the climatic condition of the Tons River is most suitable and forms a favorable environmental condition for heavy recruitment. The number of eggs per individual ranged from 393 to 4338 in size of fish 138-452 mm, respectively. The fecundity of O. niloticus from the Tons River is higher compared to other places in the world. The reported maximum size of O. niloticus indicates that the present fish powerfully invaded from the Tons River, Uttar Pradesh, India.

Recommendations

A population dynamic study should be necessary for the estimation of the fishing pressure of the present fish species from the Tons River.

The food and feeding patterns of the present fish species should be studied.

Ethical xonsiderations

This research work was conducted only on dead fish that were fished by fishermen community/fishers. The fish samples were collected from the fish market (Sirsa landing centre) at Prayagraj, Uttar Pradesh, India, thus it did not need ethical approval.

  1. Peterson MS, Slack WT, Brown-Peterson NJ, McDonald JL. Reproduction in nonnative environments: establishment of Nile Tilapia, Oreochromis niloticus, in coastal Mississippi watersheds. Copeia. 2004;4:842–849. Available from: https://doi.org/10.1643/CE-04-134R1
  2. Dwivedi AC, Mayank P, Tiwari A. The River as transformed by human activities: the rise of the invader potential of Cyprinus carpio and Oreochromis niloticus from the Yamuna River, India. Journal of Earth Science & Climatic Change. 2016;7(7):361. Available from: http://dx.doi.org/10.4172/2157-7617.1000361
  3. Bucur C, Costache M, Daniel O, Nino M. Studies and observations on the spawning of Oreochromis niloticus species reared at SCDP Nucet-Dambovita. Animal Science and Biotechnologies. 2012;45(2):1-6. Available from: https://spasb.ro/index.php/public_html/article/view/653
  4. Kour R, Bhatia S, Sharma KK. Nile Tilapia (Oreochromis niloticus) as a successful biological invader in Jammu (J & K) and its impacts on native ecosystem. International Journal of Interdisciplinary and Multidisciplinary Studies. 2014;1(10):1-5. Available from: https://www.ijims.com/uploads/fed5a90a8798fa1151b7oc1.pdf
  5. Grammer G, Slack W, Peterson M, Dugo M. Nile tilapia Oreochromis niloticus (Linnaeus, 1758) establishment in temperate Mississippi, USA: multi-year survival confirmed by otolith ages. Aquatic Invasions. 2012;7(3):367-376. Available from: http://dx.doi.org/10.3391/ai.2012.7.3.008
  6. Mayank P, Dwivedi AC. Stock assessment and population structure of alien fish species, Oreochromis niloticus (Linnaeus) from the lower stretch of the Yamuna river, India. Journal of the Experimental Zoology, India. 2016;19(1):163-167. Available from: https://www.amrita.edu/publication/stock-assessment-and-population-structure-of-alien-fish-species-oreochromis-niloticus-linnaeus-from-the-lower-stretch-of-the-yamuna-river-india/
  7. Mayank P, Dwivedi AC. Resource use efficiency and invasive potential of non-native fish species, Oreochromis niloticus from the Paisuni River, India. Poultry Fisheries & Wildlife Sciences. 2017;5(1):1. Available from: http://dx.doi.org/10.4172/2375-446X.1000177
  8. Tripathi S, Gopesh A, Dwivedi AC. Characterization and role of non-native fishes (Cyprinus carpio, Oreochromis niloticus) from the middle stretch of the Ganga river, India: Current knowledge and research needs. Journal of the Kalash Science. 2024;12(1):27-35.
  9. Zengeya TA, Robertson MP, Booth AJ, Chimimba CT. Ecological niche modeling of the invasive potential of Nile tilapia Oreochromis niloticus in African river systems: concerns and implications for the conservation of indigenous congenerics. Biological Invasions. 2013;15(7):1507-1521. Available from: https://link.springer.com/article/10.1007/s10530-012-0386-7
  10. Mishra N, Dwivedi AC. Age and growth of commercially exploited fish species, Oreochromis niloticus (Linnaeus, 1758) from the tributary of the Ganga River, India. Poultry Fisheries & Wildlife Sciences. 2021;9:222.
  11. Mayank P, Mishra N, Dwivedi AC. Invasive potential of Nile Tilapia, Oreochromis niloticus (Linnaeus, 1758) from the tributary of the Ganga River, Central India. Journal of Earth and Environmental Sciences Research. 2021;SRC/JEESR-175. Available from: http://dx.doi.org/10.47363/JEESR/2021(3)152
  12. Alam A, Chadha NK, Joshi KD, Chakraborty SK, Sawant PB, Kumar T, Sharma AP. Maturation profile and fecundity of the exotic Oreochromis niloticus in the river Yamuna, India. Journal of Environmental Biology. 2015;36(4):927-93. Available from: https://pubmed.ncbi.nlm.nih.gov/26364471/
  13. Tiwari A, Dwivedi AC, Mayank P. Time scale changes in the water quality of the Ganga River, India and estimation of suitability for exotic and hardy fishes. Hydrology Current Research. 2016;7(3):254. Available from: https://www.hilarispublisher.com/open-access/time-scale-changes-in-the-water-quality-of-the-ganga-river-india-and-estimation-of-suitability-for-exotic-and-hardy-fishes-2157-7587-1000254.pdf
  14. Nautiyal P, Dwivedi AC. Fishery in the tributaries of Yamuna river (Ken river, Paisuni rivers) and Ganga river (Tons river). Journal of Mountain Research. 2019;14(2):19-36. Available from: http://dx.doi.org/10.51220/jmr.v19i2.3
  15. Zambrano L, Martinez-Meyer E, Menezes N, Peterson AT. Invasive potential of common carp (Cyprinus carpio) and Nile tilapia (Oreochromis niloticus) in American freshwater systems. Canadian Journal of Fisheries and Aquatic Science. 2006;63:1903-1910. Available from: http://dx.doi.org/10.1139/F06-088
  16. Offem BO, Akegbejo-Samsons Y, Omoniyi IT. Biological assessment of Oreochromis niloticus (Pisces: Cichlidae; Linne, 1958) in a tropical floodplain River. African Journal of Biotechnology. 2007;6:1966-1971. Available from: http://dx.doi.org/10.5897/AJB2007.000-2300
  17. Tripathi S, Gopesh A, Dwivedi AC. Framework and sustainable audit for the assessing of the Ganga river ecosystem health at Allahabad, India. Asian Journal of Environmental Science. 2017;12(1):37-42. Available from: http://dx.doi.org/10.15740/HAS/AJES/12.1/37-42
  18. Jere A, Jere WWL, Mtethiwa A, Kassam D. Impact of Oreochromis niloticus (Linnaeus, 1758) (Pisces: Cichlidae) invasion on the taxonomic and functional diversity of native fish species in the upper Kabompo River, northwest of Zambia. Ecology and Evolution. 2021;11:12845-12857. Available from: https://doi.org/10.1002/ece3.8031
  19. Dwivedi AC, Tiwari A, Mayank P. Environmental pollution supports to constancy and invader potential of Cyprinus carpio and Oreochromis niloticus from the Ganga river, India. International Journal of Poultry and Fisheries Sciences. 2018;2(1):1-7. Available from: http://dx.doi.org/10.15226/2578-1898/2/2/00113
  20. Beaune D, Guillard J, Cottet M, Kue K, Lae R, Chanudet V, et al. Investigating key biological parameters of Nile tilapia (Oreochromis niloticus L.) in a large Asian reservoir to better develop sustainable fisheries. Hydroécol. Appl. 2021;21:157-179. Available from: https://doi.org/10.1051/hydro/2020001
  21. Gu DE, Luo D, Xu M, Ma GM, Mu XD, Luo JR, et al. Species diversity defends against the invasion of Nile tilapia (Oreochromis niloticus). Knowl Manag Aquat Ecosyst. 2014;414:07. Available from: https://doi.org/10.1051/kmae/2014018
  22. Hu YC. The common alien aquatic species in China. Beijing, China: Science Press; 2015.
  23. Dwivedi AC. Age structure of some commercially exploited fish stocks of the Ganga river system (Banda-Mirzapur section). Thesis submitted to Department of Zoology, University of Allahabad, Prayagraj, Uttar Pradesh; 2006;138.
  24. Mayank P, Dwivedi AC, Pathak RK. Age, growth and age pyramid of exotic fish species Oreochromis niloticus (Linnaeus 1758) from the lower stretch of the Yamuna river, India. National Academy Science Letter. 2018;41(6):345-348. Available from: http://dx.doi.org/10.1007/s40009-018-0673-7
  25. Dwivedi AC, Mishra AS, Mayank P, Tiwari A. Persistence and structure of the fish assemblage from the Ganga river (Kanpur to Varanasi section), India. Journal of Geography and Natural Disasters. 2016;6:159. Available from: http://dx.doi.org/10.4172/2167-0587.1000159
  26. Bagenal T, Braum E. Eggs and early life history. In: Methods for Assessment of Fish Production in Fresh Waters, pp 165-201. T. Bagenal, editor. Oxford: Blackwell Scientific Publication; 1978. Available from: https://www.scirp.org/reference/referencespapers?referenceid=903831
  27. Kumar A, Dwivedi AC, Thakur VR. The record of the largest Fresh water Shark, Wallago attu (Bloch & Schneider, 1801) from the Sarayu river, Uttar Pradesh, India. Journal of the Kalash Science. 2023;11(2):21-23. Available from: https://www.researchgate.net/publication/377575296_The_record_of_the_largest_Fresh_water_Shark_Wallago_attu_Bloch_Schneider_1801_from_the_Sarayu_river_Uttar_Pradesh_India
  28. Kumar D, Dwivedi AC, Kumar J. Maximum size of Helicopter catfish, Wallago attu (Bloch & Schneider, 1801) from the Rapti river, Uttar Pradesh, India. Journal of Nehru Gram Bharati University. 2023;12(2):48-51.
  29. Holick J, Hensel K, Nieslanik J, Skacel J. The Eurasian Huchen, Hucho hucho largest Salmon of the World; 1988.
  30. Dwivedi AC, Nautiyal P, Joshi KD. Sex ratio and structure of certain cyprinids of Vindhyan region in Central India. Journal of the Inland Fisheries Society of India. 2011;43(1):77-82. Available from: https://doi.org/10.47780/jifsi.43.1.2011.121293
  31. Mishra N, Dwivedi AC. Reproductive properties and impacts of invasive alien species, Common carp (Cyprinus carpio Linnaeus, 1758) from the Tons river at Prayagraj, India. Journal of the Kalash Science. 2022;10(2):5-11. Available from: https://www.researchgate.net/publication/368455143_Reproductive_properties_and_impacts_of_invasive_alien_species_Common_carp_Cyprinus_carpio_Linnaeus_1758_from_the_Tons_river_at_Prayagraj_India
  32. Dwivedi AC, Nautiyal P. Population dynamics of important fishes in the Vindhyan region, India. Saarbrucken, Germany: LAP LAMBERT Academic Publishing GmbH & Co. KG; 2010. Available from: https://www.researchgate.net/publication/289674778_Population_dynamics_of_important_fishes_in_the_Vindhyan_region_India
  33. Helfman EJ, Collette BB, Facey DE, Bowen BW. The diversity of fish: biology, evolution and ecology. Oxford, England: Wiley-Blackwell; 2007.
  34. King RP, Etim L. Reproduction, growth, mortality and yield of Tilapia mariae Boulenger 1899 (Cichlidae) in a Nigerian rainforest wetland stream. Journal of Applied Ichthyology. 2004;20:502-510. Available from: https://doi.org/10.1111/j.1439-0426.2004.00545.x
  35. Anupama, Dwivedi AC, Bhawana B. Study of sex ratio and sex structure of Schizothorax plagiostomus (Heckel) from the river Alaknanda. Aquacult. 2006;7(2):327-330.
  36. Dwivedi AC, Mishra AS, Khan S, Singh KR, Mayank P, Mishra P. Studies on the sex ratio, sex structure and exploitation pattern of Labeo calbasu (Hamilton) in the Ghaghara river. Journal of Natural Resource and Development. 2006;1(2):124-128. Available from: https://www.researchgate.net/profile/Asheesh-Mishra-2/publication/285917514_STUDIES_ON_THE_SEX_RATIO_SEX_STRUCTURE_AND_EXPLOITATION_PATTERN_OF_LABEO_CALBASU_HAMILTON_IN_THE_GHAGHARA_RIVER/links/5f8bd063458515b7cf881b64/STUDIES-ON-THE-SEX-RATIO-SEX-STRUCTURE-AND-EXPLOITATION-PATTERN-OF-LABEO-CALBASU-HAMILTON-IN-THE-GHAGHARA-RIVER.pdf
  37. Khan S, Dwivedi AC, Mishra P. Sex ratio and exploitation structure of Labeo calbasu (Hamilton) in the tributary of the Ganga river system (Ghaghara river). Bioved. 2007;18(1, 2):7-12. Available from: https://biovedjournal.org/bv18(1,2)/2.pdf
  38. Jere A, Jere WWL, Mtethiwa A, Kassam D. Breeding pattern of Oreochromis niloticus (Linnaeus, 1758) versus native congeneric species, Oreochromis macrochir (Boulinger, 1912), in the upper Kabompo River, northwest of Zambia. Ecology and Evolution. 2021;11:17447–17457. Available from: https://doi.org/10.1002/ece3.8377
  39. Srivastava S, Dwivedi AC, Mayank P. Sex structure and sex ratio of Labeo calbasu (Hamilton) from the tributary of the Ganga river system. Life Science Bulletin. 2009;6(1):67-70.
  40. Mayank P, Dwivedi AC, Tiwari A. Reproductive profile of Cirrhinus mrigala (Hamilton, 1822) and suggestion for restoration from the Yamuna river, India. Bioved. 2016;27(1):115-120. Available from: https://biovedjournal.org/bv27(1)/16%20abs.pdf
  41. Dwivedi AC, Mayank P, Imran S. Reproductive structure of invading fish, Oreochromis niloticus (Linnaeus, 1757) in respect of climate from the Yamuna river, India. Journal of Climatology and Weather Forecasting. 2016;4(2):164. Available from: http://dx.doi.org/10.4172/2332-2594.1000164
  42. Abdalla MYM, El Khair Shuaib AEIAE, Hamid AM, Sati NA, Elhassan MM, El-Bedawi Adam A. A study of age, sex ratio, gonado-somatic index, fecundity, and breeding season, of Nile Tilapia (Oreochromis niloticus Linnaeus, 1758) from Khashm El-Girba Reservoir and Atbara River, Eastern Sudan. Asian Journal of Research in Zoology. 2024;7(3):28-46. Available from: https://doi.org/10.9734/ajriz/2024/v7i3154
  43. Wagaw S, Sisay A, Bazezew A, Enawgaw Y, Wosnie A. Biological aspects of Oreochromis niloticus (Linnaeus, 1758) in Geray Reservoir (Ethiopia) for effective sustainable fisheries. Fisheries and Aquatic Science. 2024;27(2):100-110. Available from: https://doi.org/10.47853/FAS.2024.e11
  44. Pathak RK, Gopesh A, Dwivedi AC, Joshi KD. Sex structure of commercially exploited fish species, Cyprinus carpio var. communis from the Ganga and Yamuna rivers at Allahabad, Uttar Pradesh. Journal of the Kalash Science. 2014;2(1):43-46. Available from: https://krishi.icar.gov.in/jspui/handle/123456789/16347
  45. Pathak RK, Gopesh A, Dwivedi AC. Invasion potential and biology of Cyprinus carpio (Common carp). Saarbrucken, Germany: LAP LAMBERT Academic Publishing GmbH & Co. KG; 2015. Available from: https://www.researchgate.net/publication/289674923_Invasion_potential_and_biology_of_Cyprinus_carpio_Common_carp
  46. Mayank P, Dwivedi AC. Biology of Cirrhinus mrigala and Oreochromis niloticus. Saarbrucken, Germany: LAP LAMBERT Academic Publishing GmbH & Co. KG; 2015. Available from: https://www.researchgate.net/publication/290920185_Biology_of_Cirrhinus_mrigala_and_Oreochromis_niloticus
  47. Pena-Mendoza B, Gomez-Marquez JL, Salgado-Ugarte IH, Mamirez Noguera D. Reproductive biology of Oreochromis niloticus (Perciformes: Cichlidae) at Emiliano Zapata dam, Morelos, Mexico. Revista De Biologia Tropical. 2005;53:515-522. Available from: https://www.scielo.sa.cr/scielo.php?script=sci_arttext&pid=S0034-77442005000200019
  48. Gómez-Márquez JL, Peña-Mendoza B, Salgado-Ugarte IH, Guzmán Arroyo M. Reproductive aspects of Oreochromis niloticus (Perciformes: Cichlidae) at Coatetelco lake, Morelos, Mexico. Revista De Biologia Tropical. 2003;51:221-228. Available from: https://www.scielo.sa.cr/scielo.php?script=sci_arttext&pid=S0034-77442003000100020
  49. Dwivedi AC. Population dynamics, age, growth and sex ratio of Labeo bata (Hamilton) from the middle stretch of the Ganga river, India. Flora and Fauna. 2013;19(1):133-137. Available from: https://www.researchgate.net/profile/Amitabh-Dwivedi/publication/320700729_Population_dynamics_age_growth_and_sex_ratio_of_Labeo_bata_Hamilton_from_the_middle_stretch_of_the_Ganga_river_India/links/59fd5bee0f7e9b9968c0d48f/Population-dynamics-age-growth-and-sex-ratio-of-Labeo-bata-Hamilton-from-the-middle-stretch-of-the-Ganga-river-India.pdf
  50. Parfait GS, Adama O, Awa N, Awa G, Wendengoudi G, Papa N, Gustave KB. Some reproductive aspects of Oreochromis niloticus (LINNAEUS, 1758) at Peele reservoir, Nakanbé River Basin, Burkina Faso. International Journal of Fisheries and Aquatic Studies. 2018;6(4):124-130. Available from: https://www.fisheriesjournal.com/archives/2018/vol6issue4/PartB/6-3-24-831.pdf
  51. Mbewea I, Khondoweb P, Mudendac HG. Size at maturity and fecundity of Oreochromis niloticus and mouth brooding Tilapiines indigenous to Kafue Flood Plain Fishery, Zambia. American Academic Scientific Research Journal for Engineering, Technology, and Sciences. 2023;94(1):42-57. Available from: https://asrjetsjournal.org/index.php/American_Scientific_Journal/article/view/9040
  52. Mashaii N, Rajabipoura F, Mohammadia M, Sarsangia H, Bitarafa A, Hossein-Zadehb H, Sharif-Rohanib M. Reproduction of Nile tilapia, Oreochromis niloticus in brackish water. Journal of Applied Aquaculture. 2016;27(4):1–8. Available from: http://dx.doi.org/10.1080/10454438.2015.1104943
  53. Duponchelle F, Cecchi P, Corbin D, Nunez J, Marc Legendre. Variations in fecundity and egg size of female Nile tilapia, Oreochromis niloticus, from man-made lakes of Côte d'Ivoire. Environmental Biology of Fishes. 2000;57:155–170. Available from: http://dx.doi.org/10.1023/A:1007575624937
  54. Dwivedi AC, Mayank P. Reproductive profile of Indian Major Carp, Cirrhinus mrigala (Hamilton, 1822) with restoration from the Ganga River, India. Journal of Fisheries & Livestock Production. 2017;5(1):1-5. Available from: http://dx.doi.org/10.4172/2332-2608.1000212
  55. Dwivedi AC, Mayank P, Tripathi S. Size composition, exploitation structure and sex ratio of catfish, Rita rita (Hamilton) in the lower stretch of the Yamuna river at Allahabad. Flora and Fauna. 2011;17(2):295-300.
  56. Dwivedi AC, Mayank P, Mishra AS. Feeding structure of two exotic fish species Cyprinus carpio and Oreochromis niloticus from the Ganga river. Journal of the Kalash Science. 2018;6(2):37-39. Available from: https://www.researchgate.net/publication/335174599_Feeding_structure_of_two_exotic_fish_species_Cyprinus_carpio_and_Oreochromis_niloticus_from_the_Ganga_River_India
  57. Gopesh A, Tripathi S, Joshi KD, Dwivedi AC. Size composition, exploitation structure and sex ratio of Clupisoma garua (Hamilton) from the middle stretch of the Ganga River at Allahabad, India. National Academy Science Letter. 2021;44(4):309-311. Available from: http://dx.doi.org/10.1007/s40009-020-01011-0
  58. Mishra N, Dwivedi AC, Mayank P. Invasion potential, impact and population structure of non-native fish species, Cyprinus carpio (Linnaeus, 1758) from the tributary of the Ganga River, Central India. Aquaculture and Fisheries Studies. 2021;3(3):1-4. Available from: http://dx.doi.org/10.31038/AFS.202132
  59. Wagaw S, Mengistou S, Getahun A. Aspects of the growth and reproductive biology of Oreochromis niloticus (Linnaeus, 1758) in a tropical Soda Lake, Lake Shala, Ethiopia. Fisheries and Aquatic Science. 2022;25:380-389. Available from: https://doi.org/10.47853/FAS.2022.e34
  60. Khan AS, Sherzada S, Ahmad QA, Hussain A, Hussain N, Nowosad J. Captive breeding and early developmental dynamics of Cirrhinus mrigala: implications for sustainable seed production. Animals. 2024;14(19):2799. Available from: https://doi.org/10.3390/ani14192799
  61. Dwivedi AC, Tiwari A, Mayank P. Seasonal determination of heavy metals in muscle, gill and liver tissues of Nile tilapia, Oreochromis niloticus (Linnaeus, 1758) from the tributary of the Ganga River, India. Zoology and Ecology. 2015;25(2):166-171. Available from: https://doi.org/10.1080/21658005.2015.1020012
  62. Tiwari A, Dwivedi AC. Distribution of heavy metals in tissues of the Common carp, Cyprinus carpio Linnaeus, 1758 from the Ganga river, India. International Journal of Environmental Science. 2015;6(1):881-891. Available from: http://dx.doi.org/10.6088/ijes.xxxxxxxxx
  63. Tiwari A, Dwivedi AC, Shukla DN. Accumulation of heavy metals in liver, muscle and gill of Cyprinus carpio from the Gomti river at Jaunpur, Uttar Pradesh. Journal of the Kalash Science. 2013;1(2):127-132.
  64. Tiwari A, Dwivedi AC, Rahman MA. Assessment of heavy metal accumulation in vital tissues of commercially exploited fish, Cyprinus carpio (common carp) from the river Ganga, India. Journal of Emerging Technologies and Innovative Research. 2020;7(6):959-972. Available from: https://www.researchgate.net/publication/342170202_Assessment_of_heavy_metal_accumulation_in_vital_tissues_of_commercially_exploited_fish_Cyprinus_carpio_common_carp_from_the_river_Ganga_India
  65. Tiwari A, Dwivedi AC. Assessment of heavy metals bioaccumulation in alien fish species Cyprinus carpio from the Gomti river, India. European Journal of Experimental Biology. 2014;4(6):112-117. Available from: https://french.primescholars.com/abstract/assessment-of-heavy-metals-bioaccumulation-in-alien-fish-species-cyprinus-carpio-from-the-gomti-river-india-91410.html
  66. Nautiyal P, Dwivedi AC, Mishra AS. Age structure of carp and catfish catch as a tool to assess ecological health of fished stocks from the Ganga river system with special reference to Mahseer, Tor tor (Hamilton, 1822). Journal of Threatened Texa. 2024; (In press).
 

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