What’s the summer holiday without a story about animals? We listen to tales about global reindeer and medieval animals by a manger. But here by the sea, what are the marine animal stories based on our own experiences? We’ve all known about the fish that got away and the dolphins among the surfers. But have you heard about the Ocean Shores photographer and a new species of jellyfish he found at high tide in the Brunswick River?
Denis Riek specialises in photographing very small marine animals (www.roboastra.com). Some of his work is used by the National Geographic. When he collected this golden creature, the size of a berry, he thought it was an unidentified juvenile. But in September, the Queensland Museum published a new paper by Lisa-ann Gershwin and Peter Davie. They named it a new species, Bazinga rieki. It’s a new suborder too. The first name is slang for ‘fooled you’ or ‘stung you’ and the second name is mock-Latin honouring Denis as the discoverer.
When I told my friend, she said she wanted to know more.
‘I saw a jellyfish this morning and can’t make head or tail of it!’
Jellyfish, together with sponges and segmented worms, are the earliest multicellular animals known. Fossil jellyfish imprints go back 600 million years. Today, jellies can be small like Bazinga or enormous, like the Nomura at 200cm and 200 kilograms.
When I first examined a jellyfish in a zoology class, I was shocked. Its body has a thin sheet of cells above and another below the wobbly middle. There is one opening below serving as mouth and anus. I learned the sheets include a nerve net complete with ganglions (small ‘brains’) and sensors so the animal can keep its balance.
True, no head or tail but clearly a sensitive creature, preferring to keep topside up. Many species can move at will up and down the water column. All species have ocelli (eye spots) which detect light. Some, like the box jellyfish, have better ones and can see in colour.
The cells below include dangling nematocysts (stinging cells) which kill smaller animals for food. Whether the jelly is alive or dead, the nematocysts trigger automatically. As invisible broken bits floating around in the sea, they cause some of those mysterious ‘sea lice stings’.
(Note: For jelly stings rinse with cold water for 10–20 minutes followed by an ice pack. Vinegar is useful but not on bluebottle stings. Different animal, different poison. Treat with a 10–20 minute hot shower: www.mydr.com.au/allergy/bluebottle-stings.)
The dark parts inside jellies are the gonads (sperm and eggs). Most well-fed adults have sex every day and each species prefers either dawn or dusk. The males release sperm and the females gather the whiskery threads, fertilise their eggs and then release them.
The hatchling floats for a day and then settles on some hard surface. It grows as a stalk and then buds a dozen miniature jellies. The entire cycle averages from two to six months. So each egg actually results in a dozen or more jellies,
By contrast, each fish egg develops a single fish each. They eat what small jellyfish do. The competition can seem stacked against baby fish. This is where jelly-munching turtles come in.
All that’s a story for another day. But first, how about telling your own story about marine animals? You and those clams, fish, sea eagles or whales. The internet makes it easy. Like shopping local markets for greens that grow here, local stories are good food for our community imagination.
Share your story with Echonetdaily readers using the comment section below.