<p>Schistosomiasis is a severe illness carried by snails of the genus <i>Biomphalaria</i>, which have a large distribution in Egypt. Control of the intermediate host snail is critical in limiting schistosomiasis spread. On the topic of snails’ management, bioactive products extracted from aquatic invertebrates have gained more interest. Here, for the first time, the current research intended to identify the bioactive compounds present in hemolymph collected from the freshwater crayfish <i>Procambarus clarkii</i> and to assess its molluscidal activity against <i>Biomphalaria alexandrina</i> snails. Results showed that following exposure to the sub-lethal concentrations (LC₁₀ 34.9 and LC₂₅ 42.8 mg/l) of hemolymph, a reduction in survival and reproductive rates of <i>B. alexandrina</i> was detected, as well as a substantial increase in transaminases (AST and ALT) activities, while a reduction in total protein and albumin levels. Also, levels of testosterone and 17β-estradiol hormones decreased compared to the control group. Histopathological examination of the digestive gland of treated <i>B. alexandrina</i> displayed a shrinkage of the tubules and an increase in the inter-tubular spaces, and also, degeneration in the oocytes and spermatocytes of the hermaphrodite glands with a loss of connective tissues between the acini was observed. Thus, based on these results, a new strategy should be developed for a better use of these agents in schistosomiasis control.</p>