Abstract
Background:
The pumpkin (Cucurbita pepo) is a promising medicinal plant that has garnered considerable scientific attention. It is a widely cultivated plant with high nutritional value and has potential as an alternative feed additive.

Aim:
This study aims to examine the effects of a pumpkin flesh flour (PFF) diet on common carp (Cyprinus carpio) infected with Vibrio parahaemolyticus. The research focuses on growth performance, biochemical and immunological parameters, antioxidant capacity, and the functions of the liver and kidneys.

Methods:
V. parahaemolyticus was identified in infected common carp through molecular and biochemical analysis. PFF was added to the diet of infected fish at various percentages (0, 0.5, 1.0, 1.5, and 2.0%) over 70 days. Growth, haematological, and biochemical parameters, feed efficiency, immune responses, and antioxidant indices were measured.

Results:
After 70 days, the growth performance indicators (final body weight, weight gain, and specific growth rate) showed significant differences (P<0.05) in fish fed the PFF diet. The results indicate that PFF groups is an effective and efficient dietary supplement for promoting the growth of common carp. The highest concentrations yielded the best results, with improvements also seen in blood profiles, biochemical analysis, immune responses, and antioxidant indices. Based on these findings, 1.0, 1.5% and 2.0% PFF are promising therapeutic plants that could be used in medical research and to protect carp aquaculture from bacterial diseases.

Conclusion:
This study highlights the significant potential of PFF as a sustainable and effective feed ingredient in aquaculture. It demonstrates positive effects on fish growth, feed efficiency, immune health, and disease resistance. These findings support the idea that pumpkin can play a vital role in reducing reliance on costly and unsustainable traditional protein sources, thereby contributing to the development of a more efficient and environmentally friendly aquaculture industry.

Key words: Cucurbita pepo; Cyprinus carpio; Pumpkin flesh flour; V. parahaemolyticus.