Distribution

Tropical to cool seas and oceans.

Fig. 4.3 Sea cucumber (Holothuria monocaria)

Biology

Sea urchins (Echinoidea) and sea cucumbers (Holothuroidea) are included in the phylum of echinoderms (Echinodermata), as are starfish. Sea urchins are also known to be venomous animals. The gonads (reproductive glands) of several species of sea urchins may be poisonous during the reproductive period.

As their name suggests, sea cucumbers have a cucumber- or sausage-like form. The surface of their body is generally covered with wart-like bumps. Some species have so-called cuvierian tubules in their visceral cavity which are enlargements of the respiratory tree. These fine and sticky tubules may contain toxins (e.g. holothurin) and are expelled in order to deter natural enemies. Holothurin is also secreted on the surface of their body.

Risk

In the Indo-Pacific region, sea cucumbers are eaten in dried form. There have been reports of poisoning due to Holothuria sp., Actinopyga sp. and Cucumaria sp., among others, but there are no clinical descriptions available. Skin contact with sea cucumbers or their cuvierian tubules can cause an inflammatory reaction. Paracentrotus lividus, Tripneustes ventricosus, Diadema antillarum and other species have been mentioned in connection with (oral) poisoning caused by sea urchins.

Signs and symptoms

Sea cucumbers: According to Halstead (2001b), skin contact causes burning pain, redness and a violent inflammatory reaction. Liquid ejected from the visceral cavity of some species may cause blindness if it enters the eye. Nothing is known about the signs and symptoms after ingestion, but fatalities have been reported.

Sea urchins (Halstead 2001b): general epigastric distress, nausea, diarrhoea, vomiting, severe migraine-like headaches and swelling of the lips and mouth.

Treatment

Symptomatic.

Literature (biological)

Halstead 1988, 2001b, Auerbach and Halstead 1989