Exhilarating was the only way to describe our walk along this shore this day, with the white-capped waves rolling in. The tide had turned, leaving smooth, glistening, expanses of sand as each wave receded, a tempting canvas for fresh footprints with the ever-present danger of wet feet from a treacherous wave crashing on to the shore.
And as one wave retreated, left behind on the sand was a shining blob, a ctenophore, or comb jelly. That triggered a memory from more than 40 years ago. Then I’d spent several days surveying plankton with a net towed behind a rowing boat and had caught scores of these little drifters.
This animal, of the genus pleurobrachia, is commonly referred to as the sea gooseberry because of its similarity in size and shape to the fruit. There the likeness ends, because they are as transparent as glass, looking like miniature bloated airships propelled by eight rows of rhythmically beating cilia. I had watched these predators in the net’s collecting bottle as they extended two long trailing tentacles, snaring arrow worms and crab and mollusc larvae.
I had tried to keep them in an aquarium but even with two changes of water daily they rarely survived for long; their place was out there in the ocean, in those few centimetres below the surface of the waves.
And now this one, which I rescued from the wet sand and held in a plastic tube of sea water, was fading fast. At first it seemed to revive. Its cilia, arranged like rows of combs – hence the colloquial name, comb jelly – beat frantically in the sunlight, creating electric flashes of green and blue iridescence along its flanks.
But in less than a minute they had slowed and then stopped; the spark of life was gone.
We looked for more comb jelly castaways on the beach but could find none. For a brief moment a capricious wave had delivered a glimpse of what lay beyond in countless numbers between the shore and horizon. As unexpected encounters with nature so often do, it revived an almost forgotten memory of another time and place.
