Ornamental coral pests and parasites: a biosecurity alert for aquarium trade

Aquarium corals have emerged as a relevant sector not only from an economic perspective but also as a tool for ex situ conservation. However, coral pests and parasites, such as flatworms Prosthiostomum acroporae, nudibranchs Phestilla spp., parasitic copepods Tegastes acroporanus, epizoic acoelomorphs Waminoa spp., and histophagous ciliates Philaster spp., pose significant biological and economic risks in captive systems. This review synthesizes current knowledge on major pest groups affecting ornamental corals, emphasizing their life cycles, host specificity, and control strategies. Chemical treatments (e.g., levamisole, praziquantel, KCl, milbemycin, amoxicillin) show partial efficacy, yet many are limited to adult stages and risk disrupting coral microbiota. Biological control using compatible fish and invertebrates offers promise but remains underutilized. Emerging approaches, including probiotics and microbiome engineering, represent future directions for enhancing coral resilience. The aquarium environment acts as a sentinel model, often anticipating disease outbreaks later observed in wild reefs. Simple and low-cost measures, such as quarantining corals for 4 to 6 weeks, conducting visual inspections under adequate lighting, applying preventative baths, removing egg masses, and maintaining stable water quality parameters, are effective and affordable practices for reducing outbreaks in captive environments. In an era of climate change and increasing demand for captive-bred corals, integrating science-based management with aquarist practices is essential. Preventive measures, rapid diagnostics, and biotechnological innovation will be key to ensuring coral health and advancing the aquarium hobby as a tool for marine conservation.