Nanotechnology can enhance nutrient delivery and bioavailability; hence, it has recently been considered the most practical alternative technology for nutritional supplements and disease control in fish farming. The present study was designed to evaluate the effects of mangosteen peel extract loaded in nanoemulsion (MSNE) on the inhibition of A. veronii (in vitro) and in vivo growth performance, serum biochemical parameters, the immune response, and the disease resistance of Nile tilapia (Oreochromis niloticus) against A. veronii challenge. The particle size, polydispersity index, and particle surface charge of MSNE were 151.9 ± 1.4 nm, >0.3, and −30 mV, respectively. Furthermore, MSNE, mangosteen peel extract (MPE), and nanoemulsion (NE) improved the antimicrobial activity against A. veronii. Fish fed MSNE, MPE, and NE-supplemented diets had a significantly lower (p < 0.05) feed conversion ratio (FCR) and higher specific growth rate (SGR) than fish fed the control diet. Furthermore, the MSNE had significantly higher serum glucose and protein levels than the control group in Nile tilapia. Total immunoglobulin, serum lysozyme, alternative complement activity, and survival of Nile tilapia fed with MSNE were significantly higher (p < 0.05) than the control diet. Therefore, MSNE has the potential to be employed as a supplement in sustainable Nile tilapia farming.

Polyparasitism is frequently documented in cetaceans; however, the pathological consequences of concurrent multispecies helminth infections and their associated tissue responses remain incompletely understood. This study characterized multispecies helminth infections in two live-stranded dolphins from the Andaman coast of Thailand, a spinner dolphin (Stenella longirostris) and a pantropical spotted dolphin (Stenella attenuata), using integrated postmortem, parasitological, molecular, histopathological, and immunohistochemical approaches. Both dolphins harbored helminths involving multiple organ systems. Pulmonary nematodes were identified as Halocercus delphini, while larval and intestinal cestodes were identified as Clistobothrium sp. and Tetrabothrius sp., respectively. The most prominent pathological alterations occurred in the respiratory tract and included chronic pyogranulomatous bronchopneumonia, airway epithelial injury, fibrosis, and pulmonary congestion associated with Halocercus infection. Additional parasite-associated lesions included chronic enteritis, cholangitis with biliary epithelial injury and ductular reaction, pancreatic inflammation, and localized inflammatory responses surrounding larval cestode cysts in the blubber and testis. Immunohistochemistry demonstrated extensive interleukin-4 (IL-4) immunoreactivity in affected pulmonary and intestinal tissues, whereas interleukin-10 (IL-10) was undetectable. Nitrotyrosine and heat shock protein 70 (HSP70) immunoreactivity were widely distributed across parasite-associated tissues, while caspase-3 immunoreactivity showed tissue-dependent patterns. Collectively, these findings demonstrate that multispecies helminth infections in stranded dolphins were associated with multisystem pathological alterations accompanied by inflammatory, oxidative/nitrosative stress, cellular stress, and apoptotic responses. These findings highlight the potential pathological significance of polyparasitism in stranded dolphins and support consideration of parasite burden and associated tissue responses during cetacean postmortem investigations.