River Jellyfish (Acromitus flagellatus)


Acromitus flagellatus also known as river jellyfish are found in brackish waters, like mangroves or estuaries, and even coasts. They’ve been seen in Bay of Bengal, Saptamukhi river channel and the coastal waters of Hainan Province. They are most seen throughout the Western Indian Ocean and Central Pacific Ocean. Acromitus flagellatus have an exumbrella that is 10-15 cm in diameter, with uneven red or brown spots. They have eight oral arms with long flagellum at the end of each of them. The medusa can be white, grey, pink, or transparent.


Species Information
  • Harmful to humans: No
  • Distribution: Western Pacific: Indonesia, Australia, Philippines, Japan and Palau.
  • Maximum Bell Size: 15 cm (5.9 inches)
  • Life Span: 1 year
  • Feeding: Freshly hatched baby brine shrimp
  • Temperature: 22-26C (72-79F)
  • Salinity: 18-26ppt
  • Photosynthetic: No
  • Care level: Difficult