Tetrodotoxin and the Geographic Distribution of the Blue-Lined Octopus Hapalochlaena fasciata on the Korean Coast

Abstract

The genus Hapalochlaena, including the blue-lined octopus Hapalochlaena fasciata (H. fasciata), is highly toxic. Venomous, blue-lined octopuses were recently found in Korea, but their toxicity, toxin composition, and distribution remain largely unknown. Here we estimated the geographic distribution of the organisms along the Korean coast and clarified their toxicity. Tetrodotoxin (TTX) was present in all three specimens of H. fasciata examined, although the toxicity varied largely between individuals. The mean TTX concentration in the whole body of the three specimens was 6.5 ± 2.2 μg/g (range 3.3–8.5 μg/g). Among the body parts examined, the salivary glands exhibited the highest concentration (22.4 ± 9.7 μg/g). From 2012 to 2021, 26 individuals were obtained nearly every month from different regions of the Korean coast. A non-fatal case of a blue-lined octopus bite was reported along the Korean coast in June 2015. This is the first report on the widespread distribution of blue-lined octopuses on the Korean coast and TTX detection. The widespread distribution of the TTX-bearing H. fasciata along the Korean coast within the temperate zone indicates that the species may soon become a serious health issue in Korea. The toxicity of this species is also a potentially significant human health risk.

Verification of Tetrodotoxin Utilization Against Predators in Japanese Blue-lined Octopus Hapalochlaena Cf. Fasciata

“…Wild juveniles of tiger puffer sh (T. rubripes; toxic) were reported to have a higher survival rate compared with hatchery juveniles (nontoxic) in the same environment (Shimizu et al 2007(Shimizu et al , 2008. Gustatory cells of rainbow trout (Oncorhynchus mykiss) and Arctic char (Salvelinus alpinus) can detect low levels of TTX, which may result in the avoidance of toxic prey that secretes TTX (Yamamori et al 1988 Kim et al 2023). In the blue-lined octopus (Hapalochlaena fasciata, including H. cf.…”