There was a sense of déjà vu at Little Sister’s Island. The turbulent landing at the jetty haunted by sleepless hunters. The soft stumbling over a lawn littered with copra and the rustling of land hermits. The tiny columns of termites that fan out in their lightless search for forage. About this time last year, the rubble in the little lagoon was draped with the fine green fronds of Bryopsis. This season, it was the turn of brown shrouds of Sargassum. The change of colours that swirled in the surge did little to reveal the swimmers that darted in between their cracks.
The steep fall of the reef slope and the rough waters between the sisters forces us into a narrow corridor between the clear depths and a fringing wall of boulders. Skipping the islands of rubble for fear of their stony mimics, we step onto miniature dunes populated by dancing shrimp. Scanning the perimeter of a plot of live rock, I spied the flash of an orange claw before it vanished down a hole. These bright pincers had eluded last year’s visit but this time round I braced my bum for a squat-out by one promising burrow whose occupant emerged with rapid wariness once every two minutes before scooting back into the deep end. A few record shots of a pair of closely-placed beady eyes and two pairs of long, laterally compressed chelae were all I could capture in fleeting moments between numb knees and legs pricked by pins and needles.
Named for the elusive nature and oft deathly-pale cuticles of many in their Infraorder, ghost shrimp are some of the weirder cousins of true crabs and prawns. Superficially resembling small, elongated lobsters, the animals lack hard carapaces for open foraging and instead dwell in burrows of mud, sand, rock or rubble. Some tiny species of Upogebia spend their entire lives in mazes bored out of coral skeletons and can be extricated only with the help of a sledgehammer. Down Under, one species is so abundant (hundreds can occupy each square metre of sand) that it inspired the invention of the misnamed yabbie-pump. Using the aforesaid tool, Art procured the above specimen from Thailand, which clearly shows the hinged abdomen of Thalassinids that facilitates movement in confined spaces. How they manage to drill their dens in formations of solid calcite is not clear, but they do it with finesse to match the smoothest of subways, lining their branched tunnels with fine-grained particles reinforced by chambers of coarser material.
Most sources suggest that ghost shrimps and their kin are detritus-sifters that rarely leave their abodes. Mud lobsters build man-high volcanoes as they dig into the mangrove substrate. Glypturus species are known to construct underwater mounds as they pass mud and water over their mouthparts while working their way through layers of sediment. One species is even thought to gather seagrass blades for storage in subsurface cellars for cultivating tasty colonies of microflora. The robust creatures on the shores of the little sister seem happy to try meatier meals though, as the shadow of passing fish would prompt the extension of a menacing claw by the marmalade phantom from the dark passage of its parlour.
Hi, I was wondering why the yabbie pump was misnamed. Here's something I have written recently for a seaside museum at Bribie Island, where I think the invention occurred.
The discovery of yabbies
Amazingly, until 1927, the anglers of Moreton Bay were entirely unaware of the saltwater yabbie Callianassa australiensis – the holy grail of baits for bream whiting and flathead. Ian Gall recounts the story in his book Fishing for the fun of it, when he was a ring-in for the QAFA in an early fishing competition. The rivals were the Tweed boys, who arrived at Bribie with some great big glass jars filled with wriggling pink and white things called yabbies. Naturally the Tweed boys wiped the floor with the locals.
That started the hunt in Moreton Bay for the wonder bait. Yabbie pumps were unknown. The method was to drop on all fours, dig a deep, wide hole in the sandy flats. Yabbie holes would appear as the sides caved in and if you were fast and strong enough you could wriggle your arm down to the armpit and grab a yabbie. Or it grabbed you, sinking its big nipper into your thumb. Then getting your arm out was quite a fight against the suction and the sand.
Necessity being the mother of invention, the yabbie pump swiftly evolved. First galvanised downpipe, then stainless steel, then the brass model still seen today.
Posted by: Robert Whyte | 24 February 2010 at 08:00 AM
oh i see! Thanks for the note. I think it was because here in Singapore, we tend to associate yabby with freshwater crayfish (which are often imported here under that name). I wasn't aware that it's used for ghost shrimp too.
Posted by: budak | 24 February 2010 at 08:43 AM