Lychnorhiza lucerna

When small, Lychnorhiza lucerna has a hemispherical bell, but this becomes flattened into a saucer shape as the jellyfish grows. Very large specimens have been known to reach 45 centimetres (18 in) in diameter and are dish-shaped. The upper surface is flexible and thin and is covered in low conical projections. Round the periphery are many small, triangular lappets. Hanging under the bell there are four pairs of oral tentacles, about two thirds as long as the diameter of the bell. The upper halves of these are somewhat flattened and the lower halves divide into three vanes which have multiple, inrolled edges. Among these are suctorial mouthlets leading to the interior of the bell and various thick dangling filaments. There is no central mouth. The stomach occupies most of the interior of the bell and there are a ring of small cream or white gonads round its edge. The colouration of this jellyfish varies, but in general, the bell is translucent and colourless or a pale shade of buff, sometimes with irregular streaks of light brown. The dangling lappets round the edge of the bell are darker brown and the lower parts of the oral tentacles may be brown as well, the upper parts being colourless.^[2]

Lychnorhiza lucerna is found in tropical waters in the western Atlantic Ocean. Its range extends from French Guiana to Buenos Aires Province in Argentina. It occurs in shallow coastal habitats and estuaries and is the most abundant jellyfish in its order (Rhizostomeae) in these waters. It often becomes stranded on beaches.^[3]