Unravelling reproductive biology of the striped gourami, Trichogaster fasciata (Bloch and Schneider, 1801) with reference to climate change and implications on breeding phenology in Ganges basin, India

The present study explores the reproductive characteristics and breeding phenology of striped gourami, Trichogaster fasciata from river Gomti, a tributary of river Ganges, India in relation to eco-climatic variables. The calculated size at sexual maturity (Lm) is approximately 5.2 cm. The hydrological parameters such as temperature, pH and DO were found to be falling between 27-32 ºC, 6.30–6.87 and 2.22–3.81 mg/L, respectively. We found that striped gouramis can reproduce after even less precipitation (< 126 mm) throughout a broad range of temperatures. The reproductive period was initiated when the temperature exceeded 29 ºC and is considered to be favorable as it triggered the spawning which was peaked in July. The climatic data spanning 40 years (1983–2023) showed a gradual increase in average air temperature-maximum of 0.11 °C per year and an annual drop in rainfall by 2.49 mm. However, the results implies that there is a considerably low risk of climate change impact on the breeding phenology of T. fasciata in the near future. The baseline data could be used as a future point of reference for evaluating the effects of climate change on the reproductive ecology from a regional perspective. Further this knowledge is vital for protecting wild fish genetic resources through implementing sustainable management plans within the Ganga basin, which will help mitigate the possible effects of climate change.