The melon jellyfish is an elongated sea gooseberry which propels itself with vibrating combs located along its rim. It is somewhat larger than a sea gooseberry and much less rigid in structure. Melon jellyfish have a large round opening below. This opening is the mouth, with which they swallow sea gooseberries and other species in one gulp. Because melon jellyfish are transparent, you can sometimes see sea gooseberries in the stomach.