# Age, Growth and Reproduction of Schizothorax pseudaksaiensis of the Turks River

^{1}

^{2}

^{*}

^{†}

## Abstract

**:**

## 1. Introduction

## 2. Materials and Methods

#### 2.1. Sample Collection

#### 2.2. Otolith Characteristics

_{max}(maximum radius), and R

_{min}(minimum radius). The Shapiro—Wilk test in SPSS 18.0 was used to conduct a normality test for each index of otolith morphology.

#### 2.3. Age Determination

^{#}~1000

^{#}), and polished with polishing paper. The polishing process of the otolith was observed continuously through a microscope until the central nucleus and otolith increment were clear, and the otolith was dissolved, turned over, and polished until the central nucleus was clear [22] (Figure 3).

#### 2.4. Growth Modeling

^{b}. Analysis of covariance was used to analyze the significance [20]. Student’s t-test was used to examine the correlation between the b value and 3 and to judge whether S. pseudaksaiensis grew at a uniform rate. Fulton’s condition index was calculated by the formula K = W/L

^{3}× 100,000, and its growth characteristics, fish abundance, nutritional status, etc., were observed [24,25].

_{t}is the standard length at age t; W

_{t}is the body weight at age t; L

_{∞}is the progressive standard length; W

_{∞}is the progressive body weight; t

_{0}is the age at which the standard length and body weight are equal to zero in the theoretical state; k is the average curvature of the growth curve; and b is the allometric growth index.

^{2}L/dt

^{2}is the standard length growth acceleration; and d

^{2}W/dt

^{2}is the body weight growth acceleration.

#### 2.5. Reproductive Characteristics

_{G}/W)

_{G}is the gonadal weight, and W is the body weight.

## 3. Results

#### 3.1. Size and Age Structure

#### 3.2. Fish Growth

#### 3.2.1. Length–Weight Relationship

^{−6}L

^{3.1095}(R

^{2}= 0.9749, n = 735)

^{−5}L

^{3.0436}(R

^{2}= 0.9756, n = 346)

^{−5}L

^{2.9759}(R

^{2}= 0.9650, n = 389)

#### 3.2.2. Fulton’s Condition Index

#### 3.2.3. Otolith Morphology

^{2}(0.42–6.86 mm

^{2}), the otolith minimum radius was 1.32 ± 0.27 mm (0.62–2.35 mm), the otolith maximum radius was 1.93 ± 0.45 mm (0.83–3.92 mm), the otolith perimeter was 5.45 ± 1.25 mm (2.42–10.69 mm), the otolith length was 0.95 ± 0.07 mm (0.41–1.85 mm), and the otolith width was 0.68 ± 0.12 mm (0.31–1.20 mm).

#### 3.2.4. Relationship between the Morphology of Otoliths and Standard Length/Weight

^{2}values were all greater than 0.78 and the average was higher than 0.81, showing a high correlation, and there was no significant difference in the fitting effect (p > 0.05). The correlations between body weight and otolith morphological indexes were higher for S. pseudaksaiensis than for standard length.

#### 3.2.5. Growth Equation

#### 3.3. Reproductive Biology

^{2}= 0.9615)

^{2}= 0.9113)

## 4. Discussion

^{+}, K

^{+}, Cl

^{−}), and water chemical types are suitable for plateau fish survival [1,29,30]. In fish maturation, size, age, and growth are closely related to water temperature and food supply. Borwn et al. [31] found that in W = aL

^{b}, the power exponent b is used to judge fish growth. The total b value was 3.1095, with 3.0436 for females and 2.9759 for males, so it was determined to be an isometrically growing fish. In the Turks River, the seasonal variation in phytoplankton was obvious and consistent, and diatom biomass dominated in all seasons; the seasonal variation in zooplankton was not obvious, and spring rotifer biomass was dominant [1]. There are many organic debris types and benthic species in Turks River water, especially hookshrimp and Chironomidae [1,2], which provide effective food sources for indigenous fish and cause the growth trend of S. pseudaksaiensis to be stable and uniform. In this study, S. pseudaksaiensis preferred to live in cold water at high altitudes, and its adaptability varied with water temperature, resulting in slow growth, which was closely related to aquatic organisms in the Turks River, etc. These factors may be the major reasons for its uniform growth. The overall plumpness coefficient of S. pseudaksaiensis in the female group was slightly higher than in the male group. The plumpness of female fish was higher than that of male fish at 1–5 years of age, and the growth of female fish was faster than that of male fish before sexual maturity. The plumpness of female fish decreased at 6–10 years of age, increased again at 11–15 years of age, and then dropped to a stable level. This change may be closely related to sexual maturity age, reproductive energy consumption, water temperature, and food levels [1,7,32].

^{2}. Some scholars found that the R

^{2}values of 16 Mediterranean deep-sea fish and European bass (Perca fluviatilis) were all greater than 0.8 [34,35]. In this study, the correlation of S. pseudaksaiensis was high (R

^{2}> 0.8). Although the otolith had been growing, the growth on different axes was not uniform. Renones et al. [36] believe that with increasing fish age, the continuous deposition of otoliths to the distal surface results in unequal growth of otoliths and fish standard length. Therefore, for older fish or slow-growing fish, the accuracy of using otoliths to calculate the length of the fish body is not high.

_{∞}= 737.7, W

_{∞}= 6853.3, k = 0.05, t

_{0}= −0.59, and t

_{i}= 22.28; and the male population showed L

_{∞}= 667.0, W

_{∞}= 4447.2, k = 0.05, t

_{0}= −0.36, and t

_{i}= 19.55. At the turning point age, the male population was obviously smaller than the female population. Compared with S. oconnori [24] and S. waltoni [39], the t

_{i}of S. pseudaksaiensis in this study was higher, which was related to the difference in habitat, such as the habitat altitude of the fish species [40]. The growth coefficient k is a key parameter in the assessment of fish stock potential [41,42,43], and fish with a value of k between 0.05 and 0.10 are slow-growing fish. S. pseudaksaiensis had a low k value (0.05) and a high asymptotic standard length (L

_{∞}), indicating that it is a fish with slow growth and a long life. Comparing this with the previous study on S. pseudaksaiensis growth, it was found that the L

_{∞}obtained in this study was 654.80 mm higher than that in the previous study, and the growth coefficient k (total 0.05, female group 0.05, male group 0.05) was lower than that in the previous study on S. pseudaksaiensis (total 0.06). The reasons may lie in the different distribution of standard length or the different composition of age.

## 5. Conclusions

## Author Contributions

## Funding

## Institutional Review Board Statement

## Data Availability Statement

## Acknowledgments

## Conflicts of Interest

## References

- Ren, M.L.; Guo, Y.; Zhang, Q.L.; Zhang, R.M.; Li, H.; A, D.K.; Cai, L.G.; Yong, W.D.; Ren, B.; Gao, H.; et al. Fish Resources and Fishery of Ili River; Heilongjiang Science and Technology Press: Harbin, China, 1998; pp. 13–310. ISBN 7-5388-3369-2. [Google Scholar]
- Guo, Y.; Zhang, R.M.; Cai, L.G. Xinjiang of Fishery; Xinjiang Science and Technology Press: Urumqi, China, 2012; ISBN 9787546615295. [Google Scholar]
- Notice on the Release of the List of Wildlife under Key Protection in Xinjiang Uygur Autonomous Region (Revised). Available online: https://www.xinjiang.gov.cn/xinjiang/c112543/202209/aaaf1dd3516e46d99086b7e378c8243b.shtml?cnName=%C3%A6%E2%80%9D%C2%BF%C3%A5%C2%BA%C5%93%C3%A4%C2%BB%C2%A4l (accessed on 21 September 2022).
- Campana, S.E.; Smoliński, S.; Black, B.A.; Morrongiello, J.R.; Alexandroff, S.J.; Andersson, C.; Bogstad, B.; Butler, P.G.; Denechaud, C.; Frank, D.C.; et al. Growth portfolios buffer climate-linked environmental change in marine systems. Ecology
**2022**, 104, e3918. [Google Scholar] [CrossRef] [PubMed] - Zhan, B.Y. Fisheries Resource Assessment; China Agriculture Press: Beijing, China, 1995; pp. 8–14. [Google Scholar]
- Cai, L.G.; Meng, W.; Yang, T.Y.; Niu, J.G. Genetic differentiation of Ili Schizothorax (Schizothorax pseudaksaiensis) populations in Ili river basin. J. Aqua. Sci.
**2014**, 27, 25–29. [Google Scholar] [CrossRef] - Cai, L.G.; Niu, J.G.; Tu, E.X.; Guo, Y. Annuli characteristics of the different ageing materials of Schizothorax (Racoma) pseudaksaiensis (Herzenstein). J. Water Ecol.
**2011**, 3, 78–81. [Google Scholar] [CrossRef] - Cai, L.G.; Niu, J.G.; Zhang, B.P.; Tu, E.X.; Xie, C.G.; Tang, W.J.; Guo, Y. Observation on embryonic and larval development of Schizothorax pseudaksaiensis Herzenstein. Fresh. Fish.
**2011**, 41, 74–79. [Google Scholar] [CrossRef] - Wang, C.X.; Liu, F.; Chen, S.A.; Yang, H.K.; Xie, C.X.; Wei, Q. Biological characteristics of Schizothorax pseudaksaiensis. Xinjiang Agric. Sci.
**2022**, 59, 2065–2072. [Google Scholar] [CrossRef] - Li, Y.Y.; Zhang, H.L.; Zhang, F.H.; Qu, F.; Lai, X.Q. Analysis on the potentialof the available agriculture water resources in Manas river valley, Xinjiang. J. Natu. Reso.
**2007**, 22, 44–50. [Google Scholar] [CrossRef] - Wang, Z.; Yan, Y.C.; Jiang, P.A.; Yan, A. Effects of different factors on soil moisture content of farmland in Manas river basin. Xinjiang Agric. Sci.
**2013**, 50, 1879–1886. [Google Scholar] - Sui, F.G. Tectonic evolution and its relationship with hydrocarbon accumulation in the northwest margin of Junggar basin. Acta Geol. Sin.
**2015**, 89, 779–793. [Google Scholar] - Li, L.; Ma, B.; Jin, X. Quantitative assessment on priority conservation of Schizothoracinae fishes in the middle Yarlung Zangbo River, Tibet. J. Fish. Sci. China
**2019**, 26, 914–924. [Google Scholar] - Yang, H.Y.; Huang, D.M. A preliminary investigation on fish fauna and resources of the upper and middle Yarlung Zangbo River. J. Cent. China Norm. Univ. Nat. Sci. Ed.
**2011**, 45, 629–633. [Google Scholar] [CrossRef] - Campana, S.E.; Annand, C.M.; Millan, J.I. Graphical and statistical methods for determining the consistency of age determinations. Trans. Am. Fish. Soc.
**1995**, 124, 131–138. [Google Scholar] [CrossRef] - Aibibulla, T.; Abdushalih, N.; Kuerban, A. Evaluation of the status quo of animal and plants resources after reservoir construction in Turks river and protection measures. Anhui Agric. Sci.
**2011**, 39, 16688–16690. [Google Scholar] [CrossRef] - Shen, J.Y. Influence of storm decline index on storm flood calculation of mountain flood gully in middle reaches of Turks River. Jilin Water Conserv.
**2012**, 9–11+18. [Google Scholar] [CrossRef] - Zheng, Z.W. Spatial Variation of Hydraulic Conductivities of Yili-Kunes River Streambed Sediments and the Transformation Relationship between River and Groundwater. Master’s Thesis, Chang’an University, Xi’an, China, 2017. [Google Scholar]
- Wu, Y.F.; Wu, C.Z. The Fishes of the Qinghai-Xizang Plateau; Sichuan Science and Technology Press: Chengdu, China, 1991; pp. 1–599. ISBN 9787536421684. [Google Scholar]
- Yin, M.C. Fish Ecology; China Agriculture Press: Beijing, China, 1995; pp. 31–219. ISBN 7-109-03143-8. [Google Scholar]
- Burnham, K.P.; Anderson, D.R. Model Selection and Multi-Model Inference: A Practical Information—Theoretical Approach; Springer: Berlin/Heidelberg, Germany, 2002. [Google Scholar]
- Liu, J.Y. Study on Biology and Population Dynamics of Schizothorax macropogon in the Yarlung Tsangpo River. Master’s Thesis, Tarim University, Alar, China, 2016. [Google Scholar]
- Liu, Y.C.; Liu, S.Y.; Liu, H.P. Values of eight structures as age determination of Ptychobarbus dipogon, Tibet Autonomous Region. Acta Hydrobiol. Sin.
**2019**, 43, 579–588. [Google Scholar] [CrossRef] - Ma, B.S. Study on the Biology and Population Dynamics of Schizothorax oconnori. Master’s Thesis, Huazhong Agricultural University, Wuhan, China, 2011. [Google Scholar] [CrossRef]
- Ren, B.; Ma, Y.W.; Tu, E.X.; Guo, Y.; Zhang, R.M.; A, B.D.; Au, Z.Z.; Liu, Y. The study on the biology of Triplophysa (Hedinichthys) yarkandensis (Day) in Akesu River. Chin. J. Fish.
**2004**, 17, 46–52. [Google Scholar] - Li, X. Histoembryology of Aquatic Animals; China Agriculture Press: Beijing, China, 2006; ISBN 7-109-09815-X. [Google Scholar]
- Chen, S.A.; Ma, C.H.; Ding, H.P.; Zhou, X.J.; Xie, C.X. The reproductive biology of Triplophysa (Hedinichthys) yarkandensis (Day) in Tarim river. Acta Hydrobiol. Sin.
**2013**, 37, 810–816. [Google Scholar] [CrossRef] - Wang, J.W. Spawning performance and development of oocytes in Gobiocypris rarus. Acta Hydrobiol. Sin.
**1999**, 23, 161–166. [Google Scholar] - Chen, F.; Yuan, Y.J.; Wei, W.S.; Yu, S.L.; Fan, Z.A.; Zhang, R.B.; Zhang, T.W.; Shang, H.M. Variation and prediction trend of precipitation series for theTekes river basin during the last 236 years. J. Mt. Sci.-Engl.
**2010**, 28, 545–551. [Google Scholar] [CrossRef] - Niu, Y.J.; Ren, D.Q.; Chen, S.A.; Cai, L.G.; Niu, J.G.; Xie, C.X. Growth characteristics of Gymnodipty chusdybowskii Kessler in three tributaries of the Ili river in Xinjiang, China. J. Hydroecol.
**2015**, 36, 59–65. [Google Scholar] [CrossRef] - Borwn, M.E. Experimental Studies on Growth in the Physiology of Fishes; Academic Press: London, UK, 1957; pp. 391–400. [Google Scholar]
- Gislason, H.; Daan, N.; Rice, J.C.; Pope, J.G. Size, growth, temperature and the natural mortality of marine fish. Fish Fish.
**2010**, 11, 149–158. [Google Scholar] [CrossRef] - Gauldie, R.W. Function, form and time-keeping properties of fish otoliths. Comp. Biochem. Physiol. A Physiol.
**1988**, 91, 395–402. [Google Scholar] [CrossRef] - Battaglia, P.; Malara, D.; Romeo, T.; Andaloro, F. Relationships between otolith size and fish size in some mesopelagic and bathypelagic species from the Mediterranean Sea (Strait of Messina, Italy). Sci. Mar.
**2010**, 74, 605–612. [Google Scholar] [CrossRef] - Souza, A.T.; Soukalová, K.; Děd, V.; Šmejkal, M.; Blabolil, P.; Říha, M.; Jůza, T.; Vašek, M.; Čech, M.; Peterka, J.; et al. Ontogenetic and interpopulation differences in otolith shape of the European perch (Perca fluviatilis). Fish. Res.
**2020**, 230, 105673. [Google Scholar] [CrossRef] - Reñones, O.; Piñeiro, C.; Mas, X.; Goñi, R. Age and growth of the dusky grouper Epinephelus marginatus (Lowe 1834) in an exploited population of the western Mediterranean Sea. J. Fish Biol.
**2007**, 71, 346–362. [Google Scholar] [CrossRef] - Larid, A.K. Postnatal growth of birds and mammals. Grozeth
**1966**, 30, 349–363. [Google Scholar] - Shatunovskii, I.M.; Ruban, I.G. Ecological aspects of age-related dynamics of fish reproductive parameters. Russ. J. Ecol.
**2009**, 40, 339–347. [Google Scholar] [CrossRef] - Zhou, X.J. Study on the Biology and Population Dynamics of Schizothorax waltoni. Master’s Thesis, Huazhong Agricultural University, Wuhan, China, 2014. [Google Scholar] [CrossRef]
- Chen, S.A. Study on Population Ecology of Triplophysa yarkandensis (Day) in Tarim River. Master’s Thesis, Huazhong Agricultural University, Wuhan, China, 2012. [Google Scholar]
- Branstetter, S.A. Age and growth estimates for blacktip, Carcharhinus limbatus, and Spinner, Carcharhinus brevipinna, sharks from the northwestern Gulf of Mexico. Copeia
**1987**, 1987, 964–974. [Google Scholar] [CrossRef] - Musick, J.A. Ecology and conservation of long-lived marine animals. Am. Fish. Soc. Symp.
**1999**, 23, 1–10. [Google Scholar] - Fei, J.H.; Shao, X.Y. Studies on the growth characteristics and morphological differences of fish in plateau lakes. Oceanol. Limnol. Sin.
**2012**, 43, 789–796. [Google Scholar] [CrossRef] - Froyman, W.; Timmerman, D. Methods of assessing ovarian masses: International ovarian tumor analysis approach. Obstet. Gyn. Clin. N. Am.
**2019**, 46, 625–641. [Google Scholar] [CrossRef] - Alves, M.M.; Leme Dos Santos, H.S.; Lopes, R.A.; Petenusci, S.O.; Haiyashi, C. Rhythm of development in the oocyte of the tilapia Oreochromis niloticus L. (Pisces: Cichlidae); a morphometric and histochemical study. Gegenbaurs Morphol. Jahrb.
**1983**, 129, 575–592. [Google Scholar] [PubMed] - Li, H.J.; Liu, H.Y.; Fan, Q.X.; Xie, C.X. Individual fecundities of Glyptosternum maculatum. Chin. J. Appl. Environ. Biol.
**2008**, 14, 499–502. [Google Scholar] [CrossRef] - Tang, Z.S.; Lin, Y.; Yang, H.Z.; Zhang, Y.D.; Chen, Z.; Huang, Y.; Peng, T.; Zhang, Y. Growth model of GIFT strain tilapia (Oreochromis niloticus). Guangdong Agric. Sci.
**2011**, 38, 104–107. [Google Scholar] [CrossRef] - Shubhadeep, G.; Mohanraj, G.; Asokan, P.K.; Dhokia, H.K.; Zala, M.S.; Bhint, H.M. Trophodynamics and reproductive biology of Otolithoides biauritus (Cantor) landed by trawlers at Vanakbara, Diu along the west coast of india. Indian J. Fish.
**2009**, 56, 261–265. [Google Scholar] [CrossRef] - Yamaguchi, A.; Kume, G. Reproductive biology of the fanray, Platyrhina sinensis, (Batoidea: Platyrhinidae) in Ariake Bay, Japan. Ichthyol Res.
**2009**, 56, 133–139. [Google Scholar] [CrossRef] - Zhang, L.; Li, J.; Ding, Y.X.; Zheng, J.H. Study on Individual Fecundity of Pelteobagrus fulvidraco. Anhui Agri. Sci. Bull.
**2012**, 18, 164–167+171. [Google Scholar] [CrossRef] - Yang, Y.; Li, S.Y.; Zhou, X.N.; Duan, Y.L. Biology and culture of Schizothoracinae. Water Conserv. Fish.
**2003**, 4, 22–23. [Google Scholar] [CrossRef] - Zhou, C.P. Reproduce Biology of Schizopygopsis malacanthus baoxingensis. Master’s Thesis, Sichuan Agricultural University, Yaan, China, 2007. [Google Scholar]
- Le, P.Q. Chinese Zoology Teleoichthys Cypriniformes (Part II); Science Press: Beijing, China, 2000; pp. 277–305. ISBN 7030075757. [Google Scholar]
- Huo, B. Study on the Biology and Population Dynamics of Oxygymnocypris stewartii. Master’s Thesis, Huazhong Agricultural University, Wuhan, China, 2014. [Google Scholar] [CrossRef]
- Wootton, R.J. Ecology of Teleost Fishes; Chapman and Hall: London, UK; New York, NY, USA, 1990; pp. 1–404. ISBN 978-94-010-6859-8. [Google Scholar]
- Chen, M.K.; Tong, H.Y.; Chen, Z.X.; Gao, J. On the growth rate of some commercial fishes in the Qiantang Jiang River. Acta Ecol. Sin.
**1984**, 4, 181–187. [Google Scholar]

**Figure 2.**Morphological measurement of S. pseudaksaiensis. Note: 1. Total length; 2. Standard length; 3. Body depth; 4. Head length; 5. Snout length; 6. Eye diameter; 7. Length of caudal peduncle; 8. Depth of caudal peduncle.

**Figure 8.**Relationship between otolith morphological index and standard length of S. pseudaksaiensis.

**Figure 12.**Ovarian development in S. pseudaksaiensis. Note: (

**a**), Ovary at stage Ⅱ (50 μm); (

**b**), Ovary at stage Ⅲ (100 μm); (

**c**), Ovary at stage Ⅳ (100 μm); (

**d**), Ovary at stage Ⅴ (50 μm); O2, Perinucleolar oocyte; O3, Cortical alveoli oocyte; O4, primary yolk oocyte; O5, Second yolk oocyte; O6, Tertiary yolk oocyte.

**Figure 13.**Testis development in S. pseudaksaiensis. Note: (

**a**), Testis at stage I (100 μm); (

**b**), Testis at stage II (100 μm); (

**c**), Testis at stage Ⅲ (50 μm); (

**d**), Testis at stage IV (100 μm); (

**e**), Testis at stage V (100 μm); (

**f**), Testis at stage VI (50 μm); sg, spermatogonia; sc, spermatocytes; st, spermatids; sz, spermatozoa.

**Figure 16.**The relationship between absolute fecundity and standard length/body weight of S. pseudaksaiensis.

Time | Site | Number | Standard Length/mm | Body Weight/g | ||
---|---|---|---|---|---|---|

Range | Mean ± S.D. | Range | Mean ± S.D. | |||

Apr. 2021 (Spring) | E 80°57′, N 42°57′—E 80°96′, N 42°95′ | 192 | 48.41~534.84 | 244.01 ± 94.04 | 1.59~2500.00 | 344.31 ± 452.61 |

Jun. 2021 (Summer) | 196 | 47.30~532.60 | 187.04 ± 112.13 | 1.83~2600.00 | 228.12 ± 412.48 | |

Oct. 2021 (Autumn) | 173 | 69.82~538.60 | 256.20 ± 110.45 | 5.00~2850.00 | 422.50 ± 515.65 | |

Jan. 2022 (Winter) | 174 | 76.05~515.01 | 247.96 ± 77.07 | 8.84~2450.00 | 324.59 ± 349.15 |

Age | Turks River | ||||
---|---|---|---|---|---|

Number | Standard Length/mm | Body Weight/g | |||

Range | Mean ± S.D. | Range | Mean ± S.D. | ||

1 | 23 | 47.30~70.44 | 61.03 ± 7.59 | 1.59~4.98 | 3.52 ± 1.09 |

2 | 84 | 53.82~97.57 | 79.348.16 ± 7.02 | 2.69~11.51 | 7.69 ± 1.86 |

3 | 38 | 86.30~133.12 | 110.39 ± 10.32 | 10.00~27.43 | 20.56 + 4.54 |

4 | 17 | 126.33~166.84 | 148.79 ± 10.54 | 30.10~58.11 | 46.97 ± 8.01 |

5 | 52 | 155.17~198.44 | 177.92 ± 9.11 | 59.30~150.00 | 83.61 ± 14.41 |

6 | 92 | 167.61~235.00 | 208.02 ± 13.37 | 81.82~200.00 | 131.37 ± 18.16 |

7 | 124 | 204.00~264.17 | 231.28 ± 11.55 | 137.82~250.00 | 192.99 ± 24.58 |

8 | 68 | 242.00~285.06 | 256.38 ± 10.01 | 237.47~350.00 | 270.04 ± 27.77 |

9 | 57 | 252.00~301.91 | 278.71 ± 11.07 | 211.42~501.98 | 336.63 ± 47.11 |

10 | 49 | 284.06~324.45 | 301.12 ± 11.80 | 306.54~550.00 | 423.04 ± 37.04 |

11 | 26 | 302.41~340.96 | 322.30 ± 9.14 | 450.00~650.00 | 522.03 ± 41.32 |

12 | 23 | 320.00~359.73 | 342.26 ± 10.80 | 548.42~800.00 | 652.01 ± 70.36 |

13 | 20 | 344.37~369.77 | 358.67 ± 7.30 | 449.94~848.00 | 721.74 ± 76.78 |

14 | 9 | 360.00~394.00 | 378.08 ± 11.90 | 500.00~1000.00 | 817.65 ± 142.81 |

15 | 7 | 378.00~406.82 | 497.22 ± 10.35 | 850.00~1300.00 | 1016.60 ± 141.39 |

16 | 2 | 406.00~408.00 | 407.00 ± 1.41 | 1300.00~1350.00 | 1325.00 ± 35.36 |

17 | 7 | 418.18~432.18 | 427.25 ± 5.75 | 1159.38~1700.00 | 1423.99 ± 197.10 |

18 | 7 | 436.38~451.70 | 445.11 ± 5.48 | 1224.95~1764.74 | 1552.97 ± 168.03 |

19 | 10 | 453.06~467.10 | 459.97 ± 4.88 | 1403.16~1755.68 | 1614.93 ± 113.78 |

20 | 4 | 466.50~475.00 | 472.78 ± 4.19 | 1520.36~1850.00 | 1692.59 ± 157.640 |

21 | 6 | 475.53~485.00 | 479.81 ± 4.45 | 1750.00~2300.00 | 2041.67 ± 205.95 |

22 | 4 | 503.67~515.01 | 509.58 ± 4.69 | 1850.00~2450.00 | 2112.50 ± 268.87 |

23 | 6 | 530.74~538.60 | 533.89 ± 2.73 | 2200.00~2850.00 | 2475.00 ± 238.22 |

Total | 735 | 47.30~538.60 | 232.62 ± 103.32 | 1.59~2850.00 | 327.06 ± 440.90 |

Parameter | Linear Equation | Logarithmic Equation | Power Equation | Exponential Equation |
---|---|---|---|---|

OA | −388.81959 | −326.00457 | −837.21834 | −727.98510 |

R_{min} | −988.28599 | −1010.62538 | −1188.16460 | −1100.23007 |

R_{max} | −818.08214 | −807.90184 | −1217.95391 | −1107.54899 |

OP | −164.87986 | −150.30386 | −1141.61319 | −1065.05038 |

OL | −1230.35127 | −1221.03375 | −1224.43525 | −1117.13393 |

OW | −1363.38737 | −1387.88444 | −1195.11009 | −1104.32348 |

Parameter | Linear Equation | Logarithmic Equation | Power Equation | Exponential Equation |
---|---|---|---|---|

OA | −376.26244 | −376.26244 | −887.08062 | −452.85771 |

R_{min} | −758.20313 | −1060.49461 | −1233.47752 | −860.31769 |

R_{max} | −520.14663 | −869.60714 | −1274.17292 | −806.49466 |

OP | 72.37525 | −211.98641 | −1198.64829 | −806.26546 |

OL | −930.36584 | −1274.79386 | −1273.24277 | −816.98914 |

OW | −1130.29426 | −1434.92895 | −1238.52020 | −858.82629 |

Population | Female (n = 350) | Male (n = 389) |
---|---|---|

L_{t} | 737.7 [1 − e^{−0.05(t + 0.59)}] (R^{2} = 0.9924) | 667.0 [1 − e^{−0.05(t + 0.36)}] (R^{2} = 0.9829) |

W_{t} | 6853.3[1 − e^{−0.05(t + 0.59)}]^{3.0436} (R^{2} = 0.9651) | 4447.2[1 − e^{−0.05(t + 0.36)}]^{2.9759} (R^{2} = 0.9707) |

dL/dt | 35.9 e^{−0.05(t + 0.59)} | 36.7 e^{−0.05(t + 0.36)} |

dW/dt | 1015.8 e^{−0.05(t + 0.59)} [1 − e^{−0.05(t + 0.59)}]^{2.0436} | 725.3 e^{−0.05(t + 0.36)} [1 − e^{−0.05(t + 0.36)}]^{1.9759} |

dL^{2}/dt^{2} | −1.7 e^{−0.05(t + 0.59)} | −2.0 e^{−0.05(t + 0.36)} |

dW^{2}/dt^{2} | 49.5 e^{−0.05(t + 0.59)} [1 − e^{−0.05(t + 0.59)}]^{1.0436} [3.0436 e^{−0.05(t + 0.59)} − 1] | 39.7 e^{−0.05(t + 0.36)} [1 − e^{−0.05(t + 0.36)}]^{0.9759} [2.9759 e^{−0.05(t + 0.36)} − 1] |

t_{i} | 22.28 | 19.55 |

Standard length/mm corresponding to t_{i} | 520.17 | 507.26 |

Body weight/g corresponding to t_{i} | 2366.32 | 1943.33 |

**Table 6.**Relationship between absolute fecundity and standard length/body weight of S. pseudaksaiensis.

Parameter | Linear Equation | Logarithmic Equation | Power Equation | Exponential Equation |
---|---|---|---|---|

L | −63.14150848 | 340.538227 | 340.0967467 | −66.56823424 |

W | −49.30208045 | 357.2521667 | 339.9725195 | −57.66593688 |

Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content. |

© 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

## Share and Cite

**MDPI and ACS Style**

Wang, C.; Yao, N.; Xia, L.; Wang, X.; Song, Y.; Serekbol, G.; Zi, F.; Lin, X.; Yan, J.; Chen, S.
Age, Growth and Reproduction of *Schizothorax pseudaksaiensis* of the Turks River. *Water* **2023**, *15*, 4044.
https://doi.org/10.3390/w15234044

**AMA Style**

Wang C, Yao N, Xia L, Wang X, Song Y, Serekbol G, Zi F, Lin X, Yan J, Chen S.
Age, Growth and Reproduction of *Schizothorax pseudaksaiensis* of the Turks River. *Water*. 2023; 15(23):4044.
https://doi.org/10.3390/w15234044

**Chicago/Turabian Style**

Wang, Chengxin, Na Yao, Liwei Xia, Xinyue Wang, Yong Song, Gulden Serekbol, Fangze Zi, Xuyuan Lin, Jin Yan, and Shengao Chen.
2023. "Age, Growth and Reproduction of *Schizothorax pseudaksaiensis* of the Turks River" *Water* 15, no. 23: 4044.
https://doi.org/10.3390/w15234044