Monday morning update:
As of Monday morning, purple flags remain at Gulf Shores and Orange Beach due to the presence of jellyfish. Both beaches are also flying yellow flags, indicating moderate surf and current conditions.
Portuguese Man O' War have been reported at Alabama beaches in recent days.
Yellow flags are also flying at Panama City, Destin, Pensacola and Fort Walton.
For more on tracking beach conditions, go here.
Earlier:
Purple flags are flying at Gulf Shores and Orange Beach to warn swimmers of particularly dangerous marine creatures.
Portuguese Man O' War have been reported at Alabama beaches, prompting the warning flags. Yellow flags indicating moderate surf and tide conditions are also flying. At least one person has reported being stung by the sea creatures while swimming in Gulf Shores.
Yellow flags are also flying at Panama City, Destin, Fort Walton and Pensacola. For updated beach conditions for those locations, go here.
Portuguese Man o' War, named for their resemblance to an 18th-century Portuguese warship at full sail, aren't actually jellyfish. They are a species known as siphonophores and often float in large groups. They have balloon-like floats on the top, which may be blue, violet or pink, with long strands of tentacles under the water.
The tentacles contain stinging nematocysts that can deliver venom capable of paralyzing and killing small fish and crustaceans. The stings are rarely deadly to people but can cause extreme pain and welts on exposed skin. Even Man o' War on the shore can be dangerous - they are capable of stinging even weeks after being washed on land, according to the National Oceanic and Atmospheric Administration.