Field Guide to Venomous and Medically Important Invertebrates ...

fishermen, especially those in Denmark, England and France where it occurs in about 10% of the
fishermen who contact the bryozoan. The allergic response typically follows repeated exposures
to these animals and not one time encounters. Topical antihistamine treatments are
recommended for treatment.
Figure 247. A marine Bryozoan (Alcyonidium gelatinosum). Photo: Ulster Museum.
Figure 248. Dogger’s Bank itch rash on the arm of a fisherman. Photo: John Chappell.
Echinoderms
Various members of the marine Phylum Echinodermata (sea stars, brittle stars, and sea urchins)
have been shown to have toxic properties that can harm people who contact them.
Sea Stars and Brittle Stars
Most species of sea stars (Class Asteroidea) are harmless, but a common tropical Indo-Pacific
species, Acanthaster planci (crown of thorns starfish) has venomous spines capable of causing
extremely painful wounds. This species can grow to more than 1 foot (300 mm) in diameter, and
is distint from most starfish in having more than a dozen spiny arms. Contact with the venomous
spines of this creature causes severe pain, swelling, profuse and frequent vomiting, numbness
and occasionally paralysis. In some victims, pain has been known to last for several days. The
sharp spines are capable of penetrating gloves, boots and wetsuits. Immersing the afflicted body
part in hot water can reduce the pain, but this may not be practical in some situations. Medical
attention is usually required for severe envenomations.
Figure 249. Crown of thorns starfish (Acanthaster planci). Photo: Linda Pitkin.