Lymphocystic disease affects over 150 species of marine and freshwater fish worldwide. In this study, the lymphocystis pathogen was found in 2 (Amphiprion ocellaris and Amphiprion clarkii) of the 9 species of clownfish. Detection of lymphocystis disease virus (LCDV) was based on histopathological study, electron microscope observation of virus particles and gene sequence analysis from the MCP region. Infected A. ocellaris hosts showed sparse, multifocal, white, stiff, papilloma-like nodules on the body, skin, gills and fins; while, on A. clarkia, nodules were found on the operculum skin. Histopathologic study showed lymphocystic cells with an irregular nucleus, enlarged cytoplasm and intracytoplasmic inclusion bodies surrounded by the cell membrane. The viral particle presents virions 180–230 nm in diameter, hexagonal in shape with an inner dense nucleoid under transmission electron micrographs (TEM). From the ML polygenetic tree, the clownfish LCVD genotype was closely related to the LCDV strain from paradise fish, Macropodus opercularis (KJ408271) (pairwise distance: 92.5%) from China, then followed by the strain from Spain (GU320726 and GU320736) (pairwise distance: 90.8–90.5%), Korea (AB299163, AB212999, AB213004, and AB299164) (pairwise distance: 91.5–80.5%) and lastly Canada (GU939626) (pairwise distance: 83%). This is the first report of lymphocystis disease in A. clarkii in Taiwan.

Anisakid (Anisakis spp.) nematode is a fish-borne parasite that can cause zoonotic disease, Anisakiasis and IgE hypersensitivity in humans. Thus, the ecology and epidemiology of Anisakis nematode are important to control this zoonotic infection. Although Anisakis larvae have been reported in Malaysia, it has not been studied through morphological characteristics and molecular analyses. The objective of this study was to identify the Anisakis species and its infection status in Decapterus macrosoma from Terengganu waters, Malaysia. All Anisakis larvae found were morphologically similar to each other and identified as Anisakis typica. High infection level (P = 100%, M.I. = 23.31±17.26) of A. typica was found in D. macrosoma. There was a bioaccumulation of A. typica in D. macrosoma, showing significant correlation of body weight (p = 0.05) and total body length (p = 0.02) with the amount of A. typica present in D. macrosoma. Interestingly, the gonad was the specific site of infection of A. typica in D. macrosoma, where the intensity of A. typica was significantly (p < 0.003) higher than other visceral organs. Therefore, the migration of A. typica depended on the fatty tissue of the organ.

Background: The high mortality rate and stunted growth of marine shrimp in the farm have raised concerns about the outbreak of co-infection involving Enterocytozoon hepatopenaei (EHP) and white spot syndrome virus (WSSV), which could lead to significant economic loss. In a mixed-culture farm consisting of Scylla serrata and Peneaus vannamei located in Yunlin Country, Taiwan, were reported mortality cases on culture animals. Methods: Based on clinical signs, histology and molecular analyses, the disease was diagnosed in this study. In the histopathology examination, infected organs, such as the carapace and gills, were stained with hematoxylin and eosin (H and E), then observed under microscope. For the molecular analysis, SalI DNA fragment (WSSV) and spore wall protein (SWP) gene (EHP) were targeted to detected the pathogen in animal host. Result: The cumulative mortality data for this co-infection indicates that S. serrata (1.5% mortality) exhibits higher susceptibility compared to P. vannamei ( greater than 99% mortality). Phylogenetic tree analysis reveals that the spore wall protein (SWP) gene of EHP and the SalI DNA fragment of WSSV strain extracted from S. serrata are genetically similar to those extracted from Peneaus spp., indicating the potential for cross-species infection. Histopathological examination of lesion tissue observed the presence of WSSV basophilic intranuclear inclusion bodies in the carapace tissue and gill fragments of S. serrata. The source of the disease outbreak is highly suspected to be the feed used, which consisted of raw shrimp and fish. This study provides the first documented case of natural EHP infection with co-infection of WSSV in S. serrata.

Marine organisms are increasingly exposed to anthropogenic contaminants, yet the mechanisms linking environmental exposure to biological function remain poorly understood. In nesting green turtles (Chelonia mydas), elevated trace metal burdens were associated with coordinated changes across host metabolism and gut microbial composition. Average concentrations of magnesium, selenium, arsenic, and cadmium exceeded established health reference ranges, indicating elevated metal exposure. Multivariate integration revealed strong associations between metal exposure and metabolic pathways related to amino acid metabolism, gluconeogenesis, one-carbon metabolism, and the tricarboxylic acid cycle, indicating broad reorganization of energy and nitrogen-related metabolism. Metal burden profiles were also significantly concordant with gut microbiota composition associated with specific metal exposure gradients. These findings demonstrate coordinated interactions between environmental metal exposure, host metabolism, and gut microbial structure in nesting green turtles, highlighting the interconnected nature of contaminant-associated responses across multiple biological systems.