GROWTH CHARACTERISTICS AND ENVIRONMENTAL INFLUENCING FACTORS OF DIFFERENT GEOGRAPHICAL POPULATIONS OF CARASSIUS AURATUS

To explore the relationship between the growth characteristics and environmental factors of <italic>Carassius auratus</italic>, this study selected seven lakes with significant geographical differences (Songhua Lake, Wuliangsu Lake, Hengshui Lake, Hongze Lake, Gaoyou Lake, Taihu Lake, and Erhai). Based on growth parameters including the length-weight relationship, growth coefficient (<italic>k</italic>), asymptotic length (<italic>L</italic>_{<italic>∞</italic>}), and inflection age (<italic>t</italic>₁), it quantitatively assessed the growth and development of <italic>C. auratus</italic> in different waters. Furthermore, methods such as Mantel test, Spearman correlation, and redundancy analysis were employed to analyze the impact of environmental factors on their growth. The results showed that: (1) There were significant differences in the average body length and weight among different populations (<italic>P</italic>&lt;0.05). The growth index <italic>b</italic> ranged from 2.96 to 3.15, with <italic>C. auratus</italic> in lakes at lower latitudes exhibited isometric growth, while those in lakes at higher latitudes showing positive allometric growth. (2) All populations demonstrated a fast-growth pattern (<italic>k</italic>&gt;0.2), with asymptotic length <italic>L</italic>_{<italic>∞</italic>} ranging from 243.50 to 278.25 mm. The inflection age <italic>t</italic>₁ exceeded 2 years in Songhua Lake and Wuliangsuhai Lake populations, while that in the other lakes was around 1 year old. The growth performance index <italic>φ</italic>′ ranged from 4.36 to 4.76. (3) The analysis revealed that geographical spatial factors (altitude, latitude, and shoreline development coefficient) and physicochemical parameters (pH, turbidity, and water depth) jointly regulated the growth characteristics. Moreover, geographical spatial factors (altitude and shoreline development coefficient) accounted for 76.4% of the variation (<italic>P</italic>&lt;0.05) and played a dominant role. This study elucidated the growth strategies of <italic>C. auratus</italic> populations across different geographical regions and their relationship with the environment, providing a theoretical basis for further exploring the growth ecological characteristics of <italic>C. auratus</italic> and its response to environmental changes.