Gonadosomatic Index (GSI) of Stinging Catfish in Relation to Water Quality and Climatic Variables, and Its Trend Analysis Using SARIMA Model

ABSTRACT Stinging catfish ( Heteropneustes fossilis ) is a commercially important farmed freshwater species in Bangladesh; however, due to various challenges in natural reproduction, hatchery‐based seed supply is crucial. This longitudinal study (2022–2024) in an earthen pond assessed its reproductive performance through the gonadosomatic index (GSI), analysed its relationship with water quality and climatic variables and forecasted GSI trends using a seasonal autoregressive integrated moving average (SARIMA) model. Data from sampled female and male fish revealed clear sexual dimorphism, with female GSI peaking at 26.17 ± 0.11 during spawning in June compared to males at 1.54 ± 0.004 in July. Analysis of variance (ANOVA) revealed significant differences ( p < 0.05) in gonad weight and GSI across prespawning, spawning and postspawning periods. Female GSI exhibited strong positive correlations with water temperature, air temperature and rainfall, aligning reproductive peaks with monsoon conditions (April–September). SARIMA forecasts, based on 31 months of data, predicted a gradual decline in GSI for 2024–2025, with values in June 2025 projected at 22.89, reflecting a downward trend from 26.17 in 2022. The SARIMA model demonstrated robust accuracy, capturing seasonal patterns and residual stationarity. These findings reveal the vulnerability of H. fossilis to climate change and the need for adaptive seed production and farming strategies.