7/21/2016 - Jellyfish - On the Lookout in Long Island Sound

BOLO: Small jellyfish with potential toxic sting


Annette F. Govindarajan, a research specialist with the Woods Hole Oceanographic Institution, would like your help in tracking a small jellyfish, Gonionemus vertens, in Long Island Sound.  It is about the size of a dime to a quarter, and is transparent with brown details. While this jelly has been in the Sound for about 100 years in a non-toxic form, a variant from the Western Pacific Ocean, known for its toxic sting symptoms, has apparently reached our shores and has been reported in Mumford Cove. Govindarajan is studying the DNA of this jelly and would appreciate knowing about any sightings. These jellyfish are usually found in quiet, back of bay, sheltered areas such as eelgrass habitat (not sandy beaches).

On a practical level, people should avoid sustained contact with dense aggregations, either by swimming or wading into them, or by allowing their hipboots to be flooded with water with jellyfish.  Sampling from small boats is the safest and more reliable way to minimize contact. If you are stung, seek medical attention.  Symptoms may include severe pain, respiratory distress, and paralysis. Sightings should be reported to Annette by email (

Margaret (Peg) Van Patten

Communications Director, Connecticut Sea Grant

University of Connecticut