en aquaculture aquaculture پژوهشي Orginal research papers <p style="text-align:justify"><span lang="TR" style="font-size:11.0pt"><span style="font-family:&quot;Calibri&quot;,sans-serif"><span style="color:black">The aquaculture industry faces increasing challenges in developing sustainable and cost-effective feeding strategies. Plant-based protein sources, such as soybean meal and corn gluten, present promising alternatives to traditional fishmeal in shrimp diets. This study aimed to investigate the effects of varying levels of plant protein substitution on the growth performance, survival rate, and economic feasibility of Pacific white shrimp (<i>Litopenaeus vannamei</i>), while also determining the optimal level of plant protein replacement in shrimp feed. Six experimental diets were formulated with plant protein replacement levels of 0% (T0), 20% (T20), 40% (T40), 60% (T60), 80% (T80), and 100% (T100) relative to fishmeal. A 60-day culture period was implemented to evaluate the impact of these dietary treatments on growth indices, survival rates, and nutritional parameters. Additionally, cost analyses were conducted for each treatment group. The results indicated that growth indices, including weight gain and specific growth rate, did not significantly differ from the control group at replacement levels up to 60% (<i>p</i>&le;0.05). However, substituting plant protein at levels of 80% and 100% resulted in significant negative effects on growth performance (<i>p</i>&le;0.05). Survival rates remained stable across all dietary treatments throughout the culture period (p>0.05). The nutritional indices, such as feed conversion ratio and protein efficiency ratio, were significantly higher in the T0 and T60 groups compared to those with greater plant protein inclusion (<i>p</i>&le;0.05). This study concludes that partial substitution of fishmeal with plant proteins (up to 60%) is both nutritionally effective and economically advantageous. However, complete replacement at 80% and 100% levels significantly impairs growth performance in <i>L. vannamei</i>. The consistent survival rates across all dietary treatments suggest that the substitution of the plant-based proteins does not compromise shrimp health.</span></span></span></p> Fishmeal, Plant protein, Pacific white shrimp, Corn, Soy 607 616 http://jifro.ir/browse.php?a_code=A-10-31-3&slc_lang=en&sid=1 A. Dashtiannasab adashtiannasab@gmail.com 100319475328460059172 100319475328460059172 Yes Shrimp Research Center, Iranian Fisheries Sciences Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Bushehr 75169-89177, Iran. M. Sharifinia moslem.sharifinia@gmail.com 100319475328460059173 100319475328460059173 No Shrimp Research Center, Iranian Fisheries Sciences Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Bushehr 75169-89177, Iran. M. Hafezieh jhafezieh 100319475328460059174 100319475328460059174 No Iranian Fisheries Science Research Institute (IFSRI), Agricultural Research Education and Extension Organization (AREEO), IRAN