Linuche aquila
Linuche aquila is a species of cnidarian found in the tropical and subtropical Pacific Ocean. It is very small and is commonly known as a thimble jellyfish because of its size and shape. The larvae can cause bathers to develop an itchy red rash commonly known as seabather's eruption. Description. This is a very small jellyfish with a flat-topped bell separated from the vertical sides by a coronal groove. It can grow to a diameter of and a height of . There are sixteen bluntly oval marginal lappets (flaps) and eight rhopalia (sensory organs) between them. Underneath  the bell is a manubrium with a central mouth and four undivided lips. This leads to a four-chambered stomach which opens through four openings into a ring sinus which has sixteen branching pouches extending into the lappets. Eight gonads are present, arranged in four crescent-shaped pairs. This jellyfish has symbiotic zooxanthellae in its tissues which supply a major part of its energy requirements. Ecology. Some authorities consider "Linuche aquila" to be a synonym of "Linuche unguiculata", a species that occurs in the eastern Atlantic Ocean, the Caribbean Sea and the Gulf of Mexico. Both become very numerous at  some times of year, forming vast swarms, and in the case of "Linuche aquila" these can be found anywhere between Malaysia and the east coast of Africa. The larvae of both species are known as sea lice and are causative agents for a condition known as seabather's eruption. They cause itchy red rashes with raised pustules in areas where the larvae have got trapped under swimwear and discharged their stinging cells into the skin. Cases caused by "Linuche aquila" have been reported from Thailand and the Philippines. Most cases occur between the months of March and August, peaking in  May and June.