By CBSBoston.com Staff

CHATHAM (CBS) — Chatham beaches are back open after they had to be closed for swimming Monday due to Portuguese Man O’ War in the waters.

The town said seven of the jellyfish-like creatures were spotted on southside beaches between Harding’s Beach and Cockle Cove.

Staff walked Harding’s Tuesday morning and saw no sign of the Man O’ War. They will continue to monitor the situation.

The Portuguese man o’ war (Photo credit: Elizabeth Condon, National Science Foundation)

Man O’ War tentacles can extend as long as 100 feet and can sting people even weeks after washing ashore, according to NOAA. The stings are rarely deadly but can cause painful welts on exposed skin.

CBSBoston.com Staff