Ocular injury from saltwater coral palytoxin

We describe a case of a young male who presented to the emergency department with unilateral eye pain, blurred vision, conjunctival injection, and ocular pH of 9, one day after direct ocular exposure to palytoxin (PTX) from coral in a home saltwater fish tank. Although uncommon, ocular PTX toxicity is a potentially vision-threatening condition that requires prompt recognition. This case report documents the successful management of presumed ocular PTX exposure and suggests additional workup and treatment considerations for future patients.

Toxic Keratoconjunctivitis from Coral Reef

A 25-year-old woman presented with right eye pain, lid edema, conjunctival injection and chemosis, and mild corneal epitheliopathy after exposure to fluid content from an aquarium coral reef. Topical moxifloxacin and prednisolone were started 4 times daily, with full clinical resolution after 2 weeks. Toxin-mediated keratoconjunctivitis may occur after exposure to zoanthid coral reef, particularly in aquarium enthusiasts. Topical corticosteroids in tandem with topical antibiotics appear to be effective in mild disease. However, in severe cases that exhibit corneal infiltrates and stromal thinning, close observation is warranted in case of possible keratolysis.

Toxicity of crude organic extracts from the zoanthid Palythoa caribaeorum: A biogeography approach

Marine isolates such as palytoxin (PTX) are of concern within the Caribbean region due to their toxicity. PTX for example has been described as a one of the most known potent marine toxins, known to prevent predation from larger species (e.g. vertebrates) as well as the prevention of being overgrown from other coral species. PTX is a polyhydroxylated polyether toxin with a very large and complex chemical structure that possesses both hydrophilic and lipophilic properties. Previous acute toxicity tests using brine shrimp (Artemia salina) and PTX extract had shown it to be moderately toxic. In humans, PTX has been credited to be responsible for extreme symptoms such anaphylactic shock, rapid cardiac failure and eventual death occurring within minutes. Extrapolation for human dose ranges has therefore been suggested to be between 2.3 and 31.5 μg. This study isolates a potentially PTX-enriched extract from Palythoa caribaeorum and examines its organic extract toxicity from a biogeography perspective from a within-colony to a variety of reef sites around Trinidad and Tobago that are popular for marine visitors. This research represents an acute study with a high level of crude organic extract toxicity on A. salina whilst postulating potential factors which may contribute to its extreme toxicity and the risk posed to users of these environments.

Toxic corneal reaction due to exposure to palytoxin

A case is presented of corneal toxicity after exposure to palytoxin. A 42 year-old man came with symptoms of pain and blurred vision in his right eye. He reported that a zoanthid coral from a saltwater aquarium had squirted into his eye. Slit-lamp examination showed a prominent central ring infiltrate of 4×6mm without epithelial defect and satellite sub-epithelial micro-infiltrates. After 2 months of topical treatment with steroids, the stromal ring infiltrate was resolved, but a stromal thinning and residual fibrosis remained. Palytoxin is a potent vasoconstrictor that damages the ionic gradient of the cells, causing cell death. It is crucial to remove the toxin and start an aggressive topical therapy as soon as possible. In addition, considering the potential ocular and systemic adverse effects that this toxin can produce, it would be advisable to inform people of its existence and regulate the distribution of this type of corals.

Two new species of Neozoanthus (Cnidaria, Hexacorallia, Zoantharia) from the Pacific

The zoanthid genus Neozoanthus was originally described in 1972 from a single species in Madagascar. This monotypic genus was placed within its own family, Neozoanthidae, given its unusual characters of only partial sand encrustation, and an endodermal sphincter muscle combined with a brachycnemic mesenterial arrangement. Recently, undescribed specimens of Neozoanthus were discovered thousands of kilometers away in both Australia and Japan. While the phylogenetic and evolutionary aspects of Neozoanthus spp. are now somewhat well understood, the new specimens remained undescribed. Here we describe the specimens as two new species, Neozoanthus uchinasp. n. from the Middle Ryukyu Islands of southern Japan, and Neozoanthus caleyisp. n. from the waters around Heron Island, on the Great Barrier Reef in Australia. Both species can be distinguished from each other and the type species, Neozoanthus tulearensis, by their distributions, oral disk colors, and average numbers of tentacles. Additionally, each species appears to have subtle differences in their cnidae. The division of Japanese and Australian specimens into two species is strongly supported by recently reported phylogenetic data. The discovery and description of these two species highlights how little is known of zoanthid species diversity in the Indo-Pacific.