1. Introduction
Euchiloglanis davidi, a Sisoridae fish species, is widely distributed in the main streams and tributaries of the Jinsha River and Min River, China, at an altitude of 1800 to 3600 m [1]. It is a cold-water fish and is endemic to the upper reaches of the Yangtze River. It is known to frequently inhabit fast-flowing tributaries of rivers and mountain streams, with boulders and cobbles in the riverbed. The fish shows creeping movement with its flattened abdomen and the ventral surface of the mouth and thorax attached to the rocks. E. davidi feeds primarily on aquatic insects and their larva and attached algae [2]. Commercially, it is one of the crucial species in Sichuan Province, because of its high content of nutritional and medicinal products. However, over-exploitation of natural resources, hydroelectric development, and indiscriminate habitat degradation have severely declined the population of E. davidi. Because of its dwindling numbers, the species has been listed as the key protected wildlife of Sichuan Province and the national secondary key protected wildlife [3].
The current research on E. davidi is largely concentrated on its taxonomy, morphology, phylogeny, and biology. The genus Euchiloglanis was first reported by Chu [4], following which Zhou et al. [5] described its two species, namely E. davidi and E. kishinouyei. Guo et al. [6] and Zou et al. [7] studied the phylogeny of the genus Euchiloglanis using morphological characteristics, 16S RNA sequencing, and mitochondrial genome analysis. Luo et al. [8] reported that the skull morphology of E. davidi was highly specialized for adaption to its special living environment with rocky substrates. Pan et al. [9] reported that Euchiloglanis is a rich source of nutritious food with a high meat content and suitable composition of amino acids and fatty acids. Similar to other Sisoridae fishes, E. davidi is a small fish, characterized by slow growth and large oocytes, which might increase its vulnerability to overfishing [2,10]. Nevertheless, efforts to develop an effective population management strategy have been hampered by a lack of basic biological information about this fish species. Age and growth constitute important components of fish biology; an accurate determination of fish age can provide a theoretical basis and support to conduct biological studies on its reproduction, feeding habits, and mortality [11,12,13]. In addition, studying reproductive biology is essential in understanding a species’ life history and provides a fundamental prerequisite for its management and conservation.
The Yalong River is a typical canyon river, whose basin is located in the south of the Qinghai-Tibet Plateau with 36,000 km2 of drainage area. It originates in the southern Bayan Har Mountains and spans a length of 1571 km [14]. It constitutes the largest tributary of the lower Jinsha River and is known for its unique plateau environment, which makes it suitable for E. davidi inhabitance. This area has a subtropical climate with an annual temperature of 7.3 °C and an annual average rainfall of 900 to 1400 mm [15]. Because of a sharp decrease in the elevation (from 4500 m to 900 m) and huge hydropower resources, the Yalong River Basin has emerged as an important hydropower development base in China [14]. However, hydropower development and excessive human interference have resulted in reduced fish resources in the middle and lower Yalong River, characterized by low age and miniaturization, reduced fish abundance and diversity, and even an increased possibility of extinction [16].
The high degree of specialization, reduced wild resources, and low fecundity of E. davidi make their recovery highly challenging after damage. Therefore, it is of utmost importance to conserve the wild resources of E. davidi. The main goals of this study were to (1) describe the annulus characteristics of vertebra and otolith and compare age estimates between the two calcified structures, (2) estimate the age and growth parameters of E. davidi using vertebrae and compare growth characteristics of the species with other Sisoridae fishes, and (3) describe the reproductive characteristics of E. davidi including the male-specific organ genital papilla and study the fecundity, relative fecundity, and the regression analysis of relationships between standard length, total weight, ovary weight, age, and fecundity.
2. Materials and Methods
2.1. Sample Collection
A total of 150 specimens were collected from the Yayi River, Jiulong River, Litang River, and Anning River, which are the tributaries of the middle and lower Yalong River (Figure 1), in May 2013 and December 2015, using trap nets (mesh size of 1.5 mm) and backpack electro-fishing gear. After sampling, fish (Figure 2) were euthanized with tricaine methanesulfonate (TMS, MS-222, Wuhan, China), followed by measuring the standard length (SL) and total length (TL) to the nearest 1 mm and the total weight (W) to the nearest 0.01 g. The sex was identified by observing the genital papilla and gonads macroscopically [17,18]. The gonads were assigned a gross maturity stage based on the macroscopic features [17].
The 2nd–7th vertebrae were removed, stored in labeled packets, and frozen until further processing. The right and left lapillus otoliths were extracted from the vestibular apparatus. The otoliths were rinsed with water, air-dried, and stored in labeled tubes. A total of 35 females with mature stages were selected, and their ovaries were weighed and fixed in 7% formalin for further calculation of fecundity.
2.2. Age Determination
The vertebrae and lapilli were used to estimate the age of E. davidi. The vertebrae were boiled in water for 1 to 2 min, following which the attached muscles and connective tissue were removed with a tweezer and brush. Next, they were immersed in 1% hydrogen peroxide for 24 h. The vertebrae were placed on concave slides and soaked in xylene at an adjusted angle for observation under a dissecting microscope (Zeiss Stemi 508, Oberkochen, Germany) [19].
Each lapillus was fixed on a slide with nail polish, ground manually with wet sandpaper (2000–2500#), and polished with alumina paste (3 µm) until the core and all annuli were visible under a compound microscope (Olympus CX23, Tokyo, Japan) [20].
Blinded to the sample size, sex, and collection date, the age of each vertebra and lapillus was identified by the same reader after an interval of 3 weeks. For a better comparison between two calcified structures, two counts should be consistent. If the two counts were different, then the structures were re-counted and the final count was accepted as the agreed age. The annulus clarity of the calcified structures was scored for readability on a 5-point scale as 1. excellent, 2. good, 3. acceptable, 4. poor, and 5. unreadable [21] (Table 1). In addition, the success rate of age estimation from vertebra and otolith was summed by the percentage of scale 1–4.
2.3. Length–Weight Relationship
The relationship between the length and weight of fish was calculated as W = a Lb, where W is the total weight (W, g), L is the standard length (SL, mm), a is the intercept, and b is the allometric growth coefficient. The allometric index value (b) obtained was compared to the expected value “3” using a t-test for allometry [22].
2.4. Growth Parameters
The growth parameters were calculated using the von Bertalanffy growth equation [23], , , where t is the age of the fish, Lt and Wt are the standard length (mm) and weight (g), respectively, L∞ and W∞ are the theoretical maximum length (mm) and weight (g), respectively, k is the growth coefficient, and t0 is the hypothetical age at length 0. The growth inflection point was calculated by the equation t = lnb/k + t0. The growth performance index was calculated using the equation of Munro and Pauly [24] as Ø = log10 k + 2 log10 L∞; Ø was used to compare the growth parameters obtained in this study with those reported by other Sisoridae fishes.
2.5. Fecundity and Oocyte Diameter
Thirty-five females at mature stage were used to study fecundity. To determine fecundity, all oocytes that had begun vitellogenesis were counted as potentially ripe eggs. The relative fecundity (F) was calculated by the formula FL = F/L or FW = F/W, where L is the standard length and W is the total weight. The correlations between absolute fecundity and standard length, weight, ovary weight, and age of E. davidi were assessed using the regression analysis.
Two females were randomly selected and their oocytes were imaged using a dissecting microscope (Zeiss Stemi 508). The diameters of oocytes were measured to the nearest 0.01 mm (Image Pro Plus 6.0).
2.6. Statistical Analyses
Data were processed in Microsoft Excel 2016. Statistical analyses were performed and graphs were generated using SPSS 22.0 and OriginPro 2016 at a significance level of α = 0.05.
3. Results
3.1. Comparison of Calcified Structures
A microscopic view of the vertebrae revealed that translucent bands were separated by distinct opaque bands through the focus to the margin. The vertebrae were characterized by a typical pattern of teleost fishes, with translucent zones alternating with opaque zones that were attributed to fast and slow growth periods. Annuli appeared as a series of concentric zones and parallel to the edge of the centrum. The annulus was clear and could be used to identify the age of the fish in most cases (Figure 3). However, the first and the marginal annuli were highly indistinguishable in several large centrums.
The lapillus otolith core was unclear, and the rings were not evident. The core of the otolith was thick in the middle and thin at the edges, making it difficult to polish. After grinding, the annuli were fuzzy, making it challenging to determine the age.
The annuli on the vertebrae were clearer and were rated as “excellent” and “good” in 47.00% and 27.35% of specimens, respectively (Table 2). The success rate of the identification of age using vertebrae annuli was 94%, whereas the success rate of age identification using lapillus otoliths was only about 30%. Therefore, the vertebrae were selected to determine the age of E. davidi.
3.2. Length–Frequency Distribution and SL–W Relationship
The standard length of all individuals ranged from 67 to 190 mm (mean length: 107.3 ± 35.6 mm), mainly distributed in the range of 70–100 mm and accounting for 55.33%, followed by 140–170 mm, accounting for 27.33%. The standard length of 65 males ranged from 68 to 190 mm (mean: 95.8 ± 31.3 mm), concentrated at 70–100 mm, accounting for 69.23%. The standard length of 85 females ranged from 67 to 184 mm (mean: 116.1 ± 36.3 mm), largely distributed at 70–100 mm and 140–170 mm, accounting for 44.71% and 42.35%, respectively (Figure 4).
The relationship between the standard length and weight of the total samples was determined using the following power function formula: W = 6.744 × 10−5 L2.653 (R2 = 0.962, n = 150) (Figure 5). The growth index (b) and the expected value 3 were compared using a t-test, indicating that the growth of E. davidi was negative allometric (t = 8.000, p < 0.05).
3.3. Age and Growth
Out of 150 specimens, age was successfully identified for 141. They were categorized into 10 age groups, i.e., 1–10 years. The dominant age groups were 1 and 2 years, accounting for 20.6% and 27.3% of the total specimens, respectively, followed by 3 and 6 years, accounting for 12% and 10.7%, respectively. The ages of 5 and 7 accounted for 8.5% and 9.2%, respectively. There were very few individuals with ages of 4, 8, 9, and 10 years (Figure 6). The number of samples, standard length, and weight of different age groups are depicted in Table 3.
The von Bertalanffy equation was used to describe the growth of E. davidi. The length growth equation was Lt = 260.8(1−e−0.104(t+1.942)), R2 = 0.897 (Figure 7) and the weight growth equation was Wt = 173.5(1−e−0.104(t+1.942))2.653 The growth inflection point was calculated to occur at 7.44 years, and the corresponding length and weight were 162.50 mm and 49.46 g, respectively. The growth performance index of E. davidi was 3.85.
3.4. Gonad Development and Secondary Sex Characteristics
The testis of mature males displayed branching and hanging on the dorsal wall of the abdominal cavity. The number of blood vessels on the testis surface decreased and the testes were hypertrophic, with milky white color. A small amount of white semen oozed out after squeezing the abdomen. The finger-like protrusions were plump, the sperm-storage vesicles and vas deferens were filled with spermatozoa, and the spermatozoa were evenly distributed with synchronous development (Figure 8a). The males of E. davidi possess a mating organ that is extremely rare in freshwater fishes of the class Osteichthyes. The genital papilla was usually located between the pelvic fins and anal fin, partially hidden in the abdomen; it protruded from the surface of the abdominal skin behind the anus. This organ was retractable, with a duct connected to the external cloaca, through which semen was released (Figure 8b). This male-specific organ allowed the easy distinction of the sexes directly by observing the genital papillae.
The ovary of females was single and cryptomere. During the mature stage, the ovaries were largely filled with yolk, had similarly sized oocytes, which were dark yellow, irregular, or oval shaped, and were sticky (Figure 8c). During the breeding season, the abdomen in the females was highly bulged and protruded (Figure 8d).
3.5. Oocyte Diameter and Sexual Maturity
Measurement of the oocyte diameter of randomly selected females displayed a single-peaked distribution (Figure 9). The oocyte diameters were distributed between 2.87 and 4.51 mm (with an average of 3.59 mm) and concentrated at 3.2–3.8 mm, accounting for 64.67%.
In the samples collected, the youngest sexually mature female was 4 years old, with a length of 132 mm and a weight of 28.34 g. The youngest sexually mature male was 3 years old, with a length of 99 mm and a weight of 22.76 g.
3.6. Fecundity
The standard length of the selected samples (35 individuals) ranged from 135 to 184 mm, whereas the weight ranged from 31.88 to 59.05 g. The absolute fecundity calculated was 105–352 eggs, with an average of 205.34 ± 45.38 eggs. The weight relative fecundity (FW) was 2.90–8.98 eggs/g, with an average of 5.65 ± 1.38 eggs/g. The length relative fecundity (FL) was 0.71–2.11 eggs/mm, with an average of 1.34 ± 0.29 eggs/mm. A significant relationship was observed between fecundity and standard length, weight, and ovary weight (p < 0.05); however, the correlation coefficient was low (Figure 10).
4. Discussion
4.1. Comparison of Calcified Structures
Age constitutes an important component of fish biology research. It is a basic parameter for studying growth, reproduction, and population structure, assessing fish resources, and providing basic data for formulating fishery conservation policies [25,26]. The most reliable aging method may vary among the species; thus, the evaluation of the precision and accuracy of calcified structures should be studied [26]. Because Siluriform fishes are scaleless, vertebrae, otoliths, and pectoral fins are used to determine their age. Certain studies have reported vertebrae as the best material for determining age in most Siluriformes [27,28,29,30]. Similarly, studies on Sisoridae fishes, including Euchiloglanis kishinouyei [31], Creteuchiloglanis macropterus [32], Pseudecheneis sulcatus [33], and Glyptosternon maculatum [10], report vertebrae as a highly reliable material to estimate age. In the present study, vertebrae were used to determine the age of E. davidi, with a success rate of 94%. However, inconspicuous opaque and translucent zones and blurred edges in a few individuals (6%) made it difficult to identify their ages. In addition, the age identification from otoliths is inaccurate in E. davidi because it is a small fish with thin, fragile, and small otoliths, which makes it difficult to read annuli after polishing. We found that the otoliths were irregularly shaped and difficult to process, whereas vertebrae were more convenient to handle and resulted in more accurate interpretation. A similar phenomenon was observed in G. maculatum [10] and P. sulcatus [33].
4.2. Growth Characteristics
The b value in the SL–W relationship reflects the growth situation of fish at different developmental stages and in different habitats. The b value is within the expected range of 2.5 to 3.5 [34]. The index b of E. davidi was 2.653, representing allometric growth, indicating that the length growth was faster than the weight growth at this stage. This is consistent with the results obtained for Pareuchiloglanis kamengensis [35] and C. macropterus [32]. In contrast, the b values of E. kishinouyei [31] and G. maculatum [36] were close to 3, reflecting isometric growth (Table 4). The variability in b values among different species of Sisoridae fishes indicates that species-specific values of b vary according to the fish shape and the diet condition of fish under different environments. Furthermore, the b values of the same species could vary between sexes or during different development periods [37].
Both the growth performance index (Ø) and growth coefficient (k) are key parameters for assessing the growth potential of fish populations; Ø was used to compare the growth performance of the congeneric fish [24]. The growth performance indices (Ø) of E. davidi were smaller than those of other Sisoridae fishes (except for G. fukiensis) (Table 4), revealing that the growth of E. davidi is relatively slower than others. In addition, k is the velocity curvature parameter that determines the velocity of fish reaching its asymptotic length, which reflects its life cycle and growth rate [23]. Furthermore, L∞ and k have an inverse relationship. A decreasing L∞ decreases the time to approach L∞ or increases the curvature k, and vice versa [38]. When compared to several other Sisoridae fishes, E. davidi had the smallest k value and the largest L∞ (except for E. kishinouyei) (Table 4). Slow-growing fish have k values of 0.05 to 0.10, medium-growing fish have k values of 0.10 to 0.20, and fast-growing fish have k values of 0.20 to 0.50 [37]. E. davidi (k = 0.104) is a slow-growing fish with a long life cycle, similar to the high-elevation fishes E. kishinouyei (k = 0.089) [31] and P. kamengensis (k = 0.073) [35]. P. sulcatus (k = 0.118) [33] is a medium-growing fish. The low-elevation Glyptothorax fukiensis (k = 0.254) [28] is a fast-growing fish (Table 4). Research has indicated that with an increase in altitude and a decrease in water temperature, the lifespan increases but the growth rate decreases in Sisoridae fishes [39]. The differences between the k values of E. davidi and other fishes in the Sisoridae family could be ascribed to several environmental factors, such as altitude, water temperature, and diet conditions, which are adaptations to the different living environments.
4.3. Fecundity
Individual fecundity and oocyte size are often used as indicators to assess the potential reproductive capacity of fishes, which reflects their reproductive strategy. It is determined by a combination of genetics, environmental factors, and nutritional status. Fecundity varies among species and represents the adaptation of populations to environmental changes [40,41]. Studies on the reproductive strategy of fish contribute to the efficient management and utilization of fishery resources [42]. However, the literature on the reproductive biology of Sisoridae fishes is rare, with several reports only on E. kishinouyei [43], G. maculatum [17], P. sulcatus [44,45], and G. fukiensis [46]. Previous studies have reported differences in fecundity among different genera in Sisoridae fishes, which could be related to fish size, oocyte diameter, spawning type, and living conditions. Even the individual fecundity of the same fish in different environments is known to vary [47]. The absolute fecundity of Sisoridae fishes is low, ranging from a few hundred to a few thousand eggs, and the absolute and relative fecundity of E. davidi are both the lowest when compared with other Sisoridae fishes (Table 5). This could be attributed to the fact that the majority of Sisoridae fishes live in rapids and benthic environments with limited activity range and a lack of food sources.
Relative fecundity can be used to compare the fecundity of different species and understand the reproductive strategies of different populations. A low relative fecundity is usually accompanied by fewer eggs with a larger oocyte diameter and sufficient yolk. Large eggs are more likely to produce relatively larger and well-developed offspring. Fish tend to select the most suitable reproductive strategy as per the current environmental changes to improve the survival rate of their offspring [48]. For instance, E. davidi exhibited lower individual fecundity (2.90–8.98 eggs/g), with a diameter of 3.6 mm of the mature oocyte, suggesting higher survival rates. Lower relative fecundity and larger oocyte diameter are major characteristics of Sisoridae fishes, including E. kishinouyei [43], G. maculatum [17], and P. sulcatus [45]. These traits enhance the survival rate of offspring, maintain the stability of the population structure, and perpetuate the population size during the long-term evolutionary process.
5. Conclusions
We determined the age and studied the growth and reproduction of E. davidi in the middle and lower reaches of the Yalong River. Vertebrae were the most suitable material to estimate the age of E. davidi. Slow growth and low fecundity were found to be the primary biological characteristics of this species. Hence, the findings of this study complement the basic biological information of E. davidi and provide a reference for the subsequent research on the conservation and artificial breeding of this species.
Conceptualization, J.C. and B.M.; methodology, formal analysis, software, and writing—original draft preparation, J.C., X.Z. and X.H.; investigation, resources, and data curation, X.Y., B.X., K.W. and B.M.; writing—review and editing, visualization, supervision, and project administration, P.L. and B.M. All authors have read and agreed to the published version of the manuscript.
The experiments were approved by the Animal Experimental Ethical Inspection of Laboratory Animal Centre, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences (YFI2013MBS01).
The datasets that support the findings of this study are available from the corresponding author upon reasonable request.
We thank Yuanyuan Nie and Meng Liang for their assistance with the field work.
The authors declare no conflict of interest.
Footnotes
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Enlarge this image.Figure 1. Sampling locations of E. davidi from the middle and lower Yalong River in May 2013 and December 2015.
Enlarge this image.Figure 2. E. davidi (151 mm in SL and 38.09 g in W) collected from the middle and lower Yalong River.
Enlarge this image.Figure 3. Annulus character of vertebrae for E. davidi under transmitted light, where 1–10 represents the annulus of the fish.
Enlarge this image.Figure 4. Standard length distribution of E. davidi from the middle and lower Yalong River.
Enlarge this image.Figure 5. Length–weight relationships of E. davidi from the middle and lower Yalong River.
Enlarge this image.Figure 8. Gonad development (mature stage) and secondary sex character of E. davidi ((a): mature testis, (b): genital papilla, (c): mature ovary, (d): abdominal protrusion).
Enlarge this image.Figure 8. Gonad development (mature stage) and secondary sex character of E. davidi ((a): mature testis, (b): genital papilla, (c): mature ovary, (d): abdominal protrusion).
Enlarge this image.Figure 9. Oocyte diameter distribution in E. davidi from the middle and lower Yalong River.
Enlarge this image.Figure 10. Relationships between the standard length (a), weight (b), ovary weight (c), age (d), and fecundity of E. davidi.
The annulus clearness grades of age materials.
| Rank | Readability Level | Annuli Characteristics |
|---|---|---|
| 1 | Excellent | The annulus is clear and obvious, which can accurately identify the age |
| 2 | Good | The annulus is basically clear, and can identify the age accurately |
| 3 | Average | Some annuli are not clear or cannot be accurately identified |
| 4 | Poor | Most annuli cannot be accurately identified and may count as possible |
| 5 | Unreadable | Annulus cannot be identified |
Distribution of scores for calcified structure of E. davidi.
| Calcified Structure | Proportion of Readability Scores (%) | ||||
|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | |
| Vertebrae | 47 | 27.35 | 8.55 | 9.40 | 7.69 |
Number, standard length, and weight in different age groups of E. davidi.
| Age | Number | Standard Length (mm) | Weight (g) | ||
|---|---|---|---|---|---|
| Mean ± S.D. | Range | Mean ± S.D. | Range | ||
| 1 | 31 | 76.6 ± 15.8 | 67–85 | 7.0 ± 7.2 | 3.42–11.16 |
| 2 | 41 | 80.0 ± 16.0 | 67–97 | 7.5 ± 7.2 | 4.30–11.68 |
| 3 | 18 | 101.7 ± 18.4 | 89–126 | 15.8 ± 8.1 | 8.57–36.02 |
| 4 | 3 | 126.3 ± 30.0 | 117–132 | 28.0 ± 15.2 | 17.20–38.36 |
| 5 | 12 | 145.3 ± 31.5 | 121–162 | 36.4 ± 14.7 | 28.09–44.40 |
| 6 | 16 | 149.9 ± 36.6 | 134–170 | 39.7 ± 17.6 | 28.98–53.54 |
| 7 | 13 | 160.9 ± 34.6 | 145–190 | 49.1 ± 17.0 | 36.07–75.06 |
| 8 | 5 | 160.2 ± 35.7 | 144–184 | 45.4 ± 17.5 | 36.60–59.05 |
| 9 | 1 | 159 | 159 | 46.86 | 46.86 |
| 10 | 1 | 179 | 179 | 71.38 | 71.38 |
| Total | 141 | 107.3 ± 35.6 | 67–190 | 20.8 ± 17.7 | 3.42–75.06 |
Comparison the growth characteristics of several Sisoridae fishes.
| Species | River Drainage | n | Length Range (mm) | Age Range | Growth Parameters | Reference | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| L∞ (mm) | k | t0 | b | Ø | ||||||
| Glyptosternum maculatum | Yarlung Zangbo River | 128 | 115–270 | 3–13 | 342.66 (♀) | 0.114 (♀) | 0.7488 (♀) | 3.1420 (♀) | 5.07 (♀) | [ |
| 77 | 147–320 | 3–13 | 460.24 (♂) | 0.082 (♂) | 0.2312 (♂) | 3.1474 (♂) | 5.32 (♂) | |||
| Glyptothorax fukiensis | Jialing River | 238 | 42.9–102.9 | 1–5 | 140.20 | 0.254 | 0.0696 | 3.2130 | 3.70 | [ |
| Euchiloglanis kishinouyei | Dadu River | 383 | 92–190 | 3–13 | 208.42 | 0.089 | 1.2000 | 2.9279 | 4.63 | [ |
| Pseudecheneis sulcatus | Yarlung Zangbo River | 203 | 50–144 | 1–9 | 189.56 | 0.118 | 1.9810 | 2.9292 | 4.55 | [ |
| Euchiloglanis davidi | Yalong River | 150 | 67–190 | 1–10 | 260.80 | 0.104 | 1.9420 | 2.6530 | 3.85 | This study |
♀, Female; ♂, Male.
Comparison of the fecundity of several Sisoridae fishes.
| Species | River |
n | Standard Length |
Absolute Fecundity |
Relative Fecundity |
Reference |
|---|---|---|---|---|---|---|
| Glyptosternum maculatum | Yarlung Zangbo River | 128 | 133–243 | 525–2058 | 3.24–27.01 | [ |
| Euchiloglanis kishinouyei | Zumuzu River | 69 | 120–165 | 123–489 | 2.80–13.95 | [ |
| Pseudecheneis sulcatus | Yarlung Zangbo River | 52 | 114–200 | 247–2886 | 16.80–77.10 | [ |
| Pseudecheneis sulcatus | Yarlung Zangbo River | 78 | 92.99–144.49 | 346–799 | 20.69–92.80 | [ |
| Glyptothorax fukiensis | Western Guangdong waters | 49 | 31.9–63.7 | 45–420 | 31.70–130.40 | [ |
| Euchiloglanis davidi | Yalong River | 35 | 135–184 | 105–352 | 2.90–8.98 | This study |
References
1. Feng, J.; Yang, D.; Qin, Z.; Jiang, B.; Pan, Y. Plasmic biochemistry indicators, classification of blood cells and haecytogenesis of wild Euchiloglanis davidi. J. Fish. China; 2009; 33, pp. 581-589. [DOI: https://dx.doi.org/10.1046/j.1365-313x.2000.00883.x]
2. Ding, R.H. The Fishes of Sichuan, China; Sichuan Publishing House of Science and Technology: Chengdu, China, 1994.
3. Geng, G.B.; Yan, S.G. Lists of wild animals under special state protection in China. Chin. J. Wildlife; 2021; 42, pp. 605-640.
4. Chu, X.L. Taxonomic revision of the genera Pareuchiloglanis and Euchiloglanis. Zool Res.; 1981; 2, pp. 25-31.
5. Zhou, W.; Li, X.; Thomson, A.W. Two new species of the Glyptosternine catfish genus Euchiloglanis (Teleostei: Sisoridae) from southwest China with redescriptions of E. davidi and E. kishinouyei. Zootaxa; 2011; 2871, pp. 1-18. [DOI: https://dx.doi.org/10.11646/zootaxa.2871.1.1]
6. Guo, X.G.; Zhang, Y.G.; He, S.P. Morphological variations and species validity of genus Euchiloglanis (Siluriformes: Sisoridae) in China. Acta Hydrobiol. Sin.; 2004; 28, pp. 260-268.
7. Zou, Y.C.; Hu, H.J.; Zhang, P.Y.; Wen, Z.Y.; Wei, Q.W. The complete mitochondrial genome of Euchiloglanis davidi and its phylogenetic implications. Mitochondrial DNA Part B; 2019; 4, pp. 1249-1250. [DOI: https://dx.doi.org/10.1080/23802359.2019.1566789]
8. Luo, Q.S.; Zhong, M.C. Morphological observations on the skull of Euchiloglanis davidi (Sisoridae). J. Southwest China Norm. Univ.; 1990; 15, pp. 233-238.
9. Pan, Y.Y.; Feng, J.; Du, W.P.; Jiang, B.G.; Luo, B.; Pang, W. The study about rate of flesh in body and nutritional composition of muscle in Euchiloglanic spp. Acta Hydrobiol. Sin.; 2009; 33, pp. 980-985. [DOI: https://dx.doi.org/10.3724/SP.J.1035.2009.50980]
10. Li, H.J.; Xie, C.X. Age and growth of the Tibetan catfish Glyptosternum maculatum in the Brahmaputra River, China. Zool. Stud.; 2008; 47, pp. 555-563.
11. Chen, Z.; Lu, H.; Liu, W.; Liu, K.; Chen, X. Beak microstructure estimates of the age, growth, and population structure of purpleback flying squid (Sthenoteuthis oualaniensis) in the Xisha Islands Waters of the South China Sea. Fishes; 2022; 7, 187. [DOI: https://dx.doi.org/10.3390/fishes7040187]
12. Bostancı, D.; Yedier, S.; Kontaş, S.; Kurucu, G.; Polat, N. Length-weight, length-length relationships and condition factors of some fish species in Yalıköy Stream (Ordu-Turkey). Yunus Res. Bull.; 2017; 17, pp. 375-383.
13. Yedier, S. Estimation of some population parameters of Squalius cephalus (Linnaeus 1758) in Tabakane Stream (Ordu-Turkey). Sak. Univ. J. Sci.; 2022; 26, pp. 14-23. [DOI: https://dx.doi.org/10.16984/saufenbilder.998273]
14. Wang, Y.F.; Lei, X.H.; Wen, X.; Fang, G.H.; Tan, Q.F.; Tian, Y.; Wang, C.; Wang, H. Effects of damming and climatic change on the eco-hydrological system: A case study in the Yalong River, southwest China. Ecol. Indic.; 2019; 105, pp. 663-674. [DOI: https://dx.doi.org/10.1016/j.ecolind.2018.07.039]
15. Jin, G.; Wang, Y.S.; Wu, W.B.; Guo, T.; Xu, J.L. Distribution features of landslides in the Yalong River Basin, Southwest China. Environ. Earth Sci.; 2021; 80, 285. [DOI: https://dx.doi.org/10.1007/s12665-021-09572-z]
16. Wang, Y.R.; Li, J.; Li, K.F.; Rui, J.L. Hydraulic parameters of habitat requirement for fish in water reduced river reach due to diversion of hydropower station. J. Hydraul. Eng.; 2007; 38, pp. 107-111. [DOI: https://dx.doi.org/10.3321/j.issn:0559-9350.2007.01.016]
17. Ding, C.Z. Reproductive biology of Glyptosternon maculatum in Yarlung Tsangpo River in Tibet, China. Acta Hydrobiol. Sin.; 2010; 34, pp. 762-768. [DOI: https://dx.doi.org/10.3724/SP.J.1035.2010.00762]
18. Esmaeili, H.R.; Sayyadzadeh, G.; Chermahini, M.A. Sexual dimorphism in two catfish species, Mystus pelusius (Solander, 1794) and Glyptothorax silviae Coad, 1981 (Teleostei: Siluriformes). Turk. J. Zool.; 2017; 41, pp. 144-149. [DOI: https://dx.doi.org/10.3906/zoo-1509-22]
19. Ding, C.Z.; Chen, Y.F.; He, D.K. Assessing the accuracy of using whole and sectioned vertebrae to determine the age of an endemic sisorid catfish, Glyptosternon maculatum, in Tibet, China. Ichthyol. Res.; 2011; 58, pp. 72-76. [DOI: https://dx.doi.org/10.1007/s10228-010-0184-0]
20. Ma, B.S.; Xie, C.X.; Huo, B.; Yang, X.F.; Li, P. Age validation, and comparison of otolith, vertebra and opercular bone for estimating age of Schizothorax o’connori in the Yarlung Tsangpo River, Tibet. Environ. Biol. Fishes; 2011; 90, pp. 159-169. [DOI: https://dx.doi.org/10.1007/s10641-010-9727-5]
21. Paul, L.J.; Horn, P.L. Age and growth of sea perch (Helicolenus percoides) from two adjacent areas off the east coast of South Island, New Zealand. Fish. Res.; 2009; 95, pp. 169-180. [DOI: https://dx.doi.org/10.1016/j.fishres.2008.08.011]
22. Pauly, D. Fish Population Dynamics in Tropical Waters: A Manual for Use with Programmable Calculators; ICLARM: Manila, Philippines, 1984; Volume 8, 325.
23. Von Bertalanffy, L. A quantitative theory of organic growth (inquiries on growth laws. II). Hum. Biol.; 1938; 10, pp. 181-213.
24. Munro, J.L.; Pauly, D. A simple method for comparing the growth of fishes and invertebrates. Fishbyte; 1983; 1, pp. 5-6.
25. Casselman, J.M. Determination of age and growth. Biol. Fish Growth; 1987; pp. 209-242.
26. Campana, S.E. Accuracy, precision and quality control in age determination, including a review of the use and abuse of age validation methods. J. Fish Biol.; 2001; 59, pp. 197-242. [DOI: https://dx.doi.org/10.1111/j.1095-8649.2001.tb00127.x]
27. Khan, M.A.; Khan, S. Age and growth assessment of the near-threatened fish Rita rita (Siluriformes: Bagridae) in the Ganges basin. Rev. Biol. Trop.; 2023; 71, [DOI: https://dx.doi.org/10.15517/rev.biol.trop.v71i1.51734]
28. Shen, Y.J.; Pu, D.Y.; Gao, M.; Wang, H.L.; Wang, Z.J. Studies on the relationship between the age and growth of Glyptothorax fukiensis in the Jialing River. J. Southwest Agric. Univ.; 2005; 27, pp. 106-110.
29. Andrian Feitoza, L.; Kiyoshi Okada, E.; Maria Ambrósio, A. Age and growth of Pterodoras granulosus (Valenciennes, 1833),(Siluriformes, Doradidae) in Itaipu reservoir, state of Paraná, Brazil. Acta Sci. Biol. Sci.; 2004; 26, pp. 47-53.
30. Balboni, L.; Vargas, F.; Colautti, D. Age and growth of Pseudoplatystoma corruscans (Siluriformes: Pimelodidae) at the confluence of the Paraná and Paraguay rivers. Neotrop. Ichthyol.; 2021; 19, [DOI: https://dx.doi.org/10.1590/1982-0224-2020-0101]
31. Wang, Y.M.; Cao, M.; Xie, B.W. Age and growth of Euchiloglanis kishinouyei in the Dadu River Basin. Chin. J. Zool.; 2016; 51, pp. 228-240.
32. Huang, J.; Huang, Z.H.; Wei, Q.W. Age and growth of Creteuchiloglianis macropterus. Acta Hydrobiol. Sin.; 2018; 42, 10.
33. Jin, H.Y.; Li, L.; Jin, X.; Wang, N.M.; Ma, Q.Z.; Yin, J.S.; Ma, B. Age and growth of Pseudecheneis sulcatus in lower reach of Yarlung Zangbo River of Medog county reach. Freshw. Fish; 2020; 50, pp. 10-17.
34. Froese, R. Cube law, condition factor and weight–length relationships: History, meta-analysis and recommendations. J. Appl. Ichthyol.; 2006; 22, pp. 241-253. [DOI: https://dx.doi.org/10.1111/j.1439-0426.2006.00805.x]
35. Chen, F.; Ma, B.S.; Xie, C.X.; Zhang, H.J. Age and growth characteristics of Pareuchiloglanis kamengensis in Tibet. Freshw. Fish; 2018; 48, pp. 45-51.
36. Zhang, C.; Zhu, T.B.; Zhou, C.W.; Pan, Y.Z.; Liu, F.; Mou, Z.B. Length–weight relationships of three small fish species caught in the Yarlung Zangbo River basin, China. J. Appl. Ichthyol.; 2018; 34, pp. 1009-1010. [DOI: https://dx.doi.org/10.1111/jai.13638]
37. Branstetter, S. Age and growth estimates for blacktip, Carcharhinus limbatus, and spinner, C. brevipinna, sharks from the northwestern Gulf of Mexico. Copeia; 1987; 1987, pp. 964-974. [DOI: https://dx.doi.org/10.2307/1445560]
38. Gallucci, V.F.; Quinn, T.J. Reparameterizing, fitting, and testing a simple growth model. T. Aa. Fish. Soc.; 1979; 108, pp. 14-25. [DOI: https://dx.doi.org/10.1577/1548-8659(1979)108<14:RFATAS>2.0.CO;2]
39. Copp, G.H.; Fox, M.G.; Przybylski, M.; Godinho, F.N.; Gispert, A. Life-time growth patterns of pumpkinseed Lepomis gibbosus introduced to Europe, relative to North American populations. Folia Zool.; 2004; 53, pp. 237-254.
40. Wootton, R.J. The effect of size of food ration on egg production in the female three-spined stickleback, Gasterosteus aculeatus L. J. Fish Biol.; 1973; 5, pp. 89-96. [DOI: https://dx.doi.org/10.1111/j.1095-8649.1973.tb04433.x]
41. Healey, M.C. The dynamics of exploited lake trout populations and implications for management. J. Wildlife Manag.; 1978; 42, pp. 307-328. [DOI: https://dx.doi.org/10.2307/3800268]
42. Suzuki, H.I.; Agostinho, A.A.; Winemiller, K.O. Relationship between oocyte morphology and reproductive strategy in loricariid catfishes of the Paraná River, Brazil. J. Fish Biol.; 2000; 57, pp. 791-807. [DOI: https://dx.doi.org/10.1111/j.1095-8649.2000.tb00275.x]
43. Shi, J.R.; Luo, D.M.; Liang, L.Y.; Wang, Y.M.; Peng, P.L.; Xie, B.W. Individual fecundity of Euchiloglanis kishinouyei in the Zumuzu River. Sichuan J. Zool.; 2019; 38, pp. 305-310. [DOI: https://dx.doi.org/10.11984/j.issn.1000-7083.20180334]
44. Lin, P.C.; Hu, H.M.; Gong, Z.; Wang, J.; Gao, X. Reproductive Characteristics of Pseudecheneis sulcatus (Siluriforms: Sisoridae) in the Lower Yarlung Zangbo River, Tibet. Fishes; 2023; 8, 106. [DOI: https://dx.doi.org/10.3390/fishes8020106]
45. Jin, H.Y.; Li, L.; Jin, X.; Wang, N.M.; Ma, Q.Z.; Yin, J.S.; Ma, B. Fecundity of Pseudecheneis sulcatus in downstream of Yarlung Zangbo River in Xizang. Fish Sci.; 2020; 39, pp. 744-751. [DOI: https://dx.doi.org/10.16378/j.cnki.1003-1111.2020.05.013]
46. Chu, Q.Z.; Chen, G.; Zhang, J.D.; Pan, C.H.; Zhou, H. Feeding habits and productivity of Glyptothorax fukiensis in Waters of Western Guangdong. J. Guangdong Ocean Univ.; 2009; 29, pp. 10-13. [DOI: https://dx.doi.org/10.3969/j.issn.1673-9159.2009.04.003]
47. Al-Husaini, M.; Al-Baz, A.; Dashti, T.; Rajab, S.; Husain, H. Age, growth, and reproductive parameters of four species of sea catfish (Siluriformes: Ariidae) from Kuwaiti waters. Reg. Stud. Mar. Sci.; 2021; 46, 101885. [DOI: https://dx.doi.org/10.1016/j.rsma.2021.101885]
48. Roff, D.A. The evolution of life histories: Theory and analysis. Theory and Analysis; Chapman and Hall: London, UK, 1992; Volume 6, pp. 760-762.
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; Lin, Pengcheng 5 ; Xu, Bin 2 ; Kaijin Wei 2 ; Ma, Baoshan 2 1 National Agricultural Science Observing and Experimental Station of Chongqing, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China;
2 National Agricultural Science Observing and Experimental Station of Chongqing, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China;
3 Hunan Fisheries Science Institute, Changsha 410153, China;
4 School of Animal Science and Nutritional Engineering, Wuhan Polytechnic University, Wuhan 430023, China;
5 Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China;