The Comprehensive Marine Biodiversity Survey was not the only oufit with designs on Changi Beach yesterday, when the sea briefly abandoned a productive and wholly unprotected stretch of seagrasses and sandy flats late in the evening. The way to the beach, through a wasteland of campsites and casuarinas, was manned by a swarthy fellow who toyed with the resident kittens and rained down curses on dog owners and cat lovers alike. In the water, a whale's length from the litter mark, a trio of women dug for edible clams while their heads bobbed in conversation and buckets waited on the sand. Students unaffiliated with the survey worked on a transect along the shoreline as curious families plodded by, seeing but not always believing.
The hand seine snagged a pail load of demersal creatures: a small stingray, slimy dragonets, a half-grown sweetlips, waspfish, pipefish, tongue-soles, large-tooth flounders, a kite butterflyfish, cardinalfish, filefish, tripodfish and several reticulated moon crabs. Legions of hermit crabs, some no larger than a nail clipping and inhabiting the shells of button snails and even tinier molluscs, tackled a course of loose weed and limp polypropylene in pools that shuddered and shrank with each swell of the tide. In one puddle, an old plastic bag defied convention, serving as a nursery for mitrids that had gathered to deposit a dense mat of egg sacs. Typical members of this family of predatory gastropods have long spires, but this species, possibly Pterygia undulosa, resembles olive snails, though its shell, which bears gridlines that are prone to fading, lacks the lustre of olivids and is rather less streamlined in profile.
The shoal also yielded a lone olive snail, but these gastropod analogues of moles (in both habit and appetite) were far harder to spot than buried sea cucumbers, which often betrayed themselves by exposing their hind ends. Dislodged perhaps by a rogue wave, a small Paracaudina floated by and performed a dance of feeble writhes. We unearthed squat Phyllophorus, plucked Cercodemas and Colochirus from raised beds and compelled a large Holothuria notabilis to expel a little of its guts. Plain and patterned Astropecten, arms aflail or half in amend, raced past small sea urchins, many of which attach sundry shells, seaweed and other marine refuse to their tests and harbour amid their white-and-lilac spines a squirming nereidid worm. A cake star, bristling with pedicellariae, maroon bumps and still in possession of youthful proportions, stretched its marginal plates while cerianthids with pale orange or sickly green tentacles loomed over the sediment.
The catch of the dying day this round was a small crab of sizeable interest to carcinologists and scant appeal to fans of meatier crustaceans. Gomeza bicornis shares its ecological niche with anomuran look-alikes, but is an aberrant brachyuran with convergent adaptations for digging into sandy bottoms. The specific epithet, meaning 'two-horned', refers to a pair of conical spines that project from between the eyes and flank long, ciliated antennae that probably help to maintain a respiratory channel for the buried crab. Fine hairs also coat the ambulatory legs, which are short and compressed for fossorial duties. Perhaps the largest specimen found in local waters to date, the animal was a berried female, a state that inhibited her usually rapid retreat into the silt and facilitated the capture of a creature few have seen in life and whose loss will scarcely be mourned by those who love the fruit of sea but sow in their folly their doom and deprivation.
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