For the record, Cassiopea stings. But its bite is mild, shallow and fleeting, a drop in an ocean of longer pains and eminently forgettable, a mere reminder of its links to the medusae that drift in midwater and haunt the littoral zones with seasonal regularity, shielding within their rings of tentacles young jacks and the parasitic larvae of burrowing sea anemones. This bell – broad, flat and non too concave – provides little lift, however; muscles in the rim contract with just enough force to steer the animal downwards or correct periodic deviations from the normal bearing of these placid jellyfish, which have assumed the poise, though not the pulse, of benthic polyps.
More basker than trapper, these scyphozoans appear restricted to sundrenched flats and patch reefs in the southern straits, where the sea lies beyond the range of polluted arteries, though not nearly far enough from mental waste. On shores such as Pulau Semakau's, Cassiopea shares the silt with seagrasses, giant clams, heart cockles and colonies entombed in calcite, all of which have learnt to survive on a diet of light but struggle to secure a footing in waters that risk losing ground to urban space. From the hub of the animal, eight primary arms stretch out, doubling as orifices for solar energy and obscured by a multiplicity of forks, lappets and lacy branches, which may serve to enhance the flow of vital gases and nutrients, and recall the furcated crowns of Phymanthus, a fellow cnidarian that peeks from rocky cracks. More bather than burrower, Cassiopea is content to float on a saucer, ride the tides and invite gentle swipes at a disc that has lost its killer instincts and can do little more than stroke to thrill.