The annotated budak

Mantlepieces

It's hard to make head or tail of a bivalve, not least because these molluscs have long lost their cephalic portions, encasing their gills, guts and gonads in shells linked by a flexible ligament and closed by strong adductor muscles. Though surprisingly motile even in the early stages of settlement, the typical pelecypod is no adventurer in adulthood; clams, cockles and arc shells live on or in aquatic sediments, digging by means of a muscular foot, while mussels, oysters and many pectinids leash themslves to rock or rubble using sticky byssal threads.

Most bivalves maintain intercourse with the world at large via two extensible siphons, which protrude from the rear of the animal. The inhalant tube takes in fresh water for respiration, along with planktonic cells or organic deposits which are sorted in the mantle cavity, filtered by rows of ciliated lamellae and channeled to a ridged stomach. Shit and wastewater, as well as eggs and sperm, emerge from the exhalant siphon, completing a loop of vital functions regulated by a brain that is barely more than a few threads of nerve clusters. A few groups, such as solemyids and deep sea mytilids, harbour symbiotes that convert sulphides or methane into nutrients, while heart cockles and giant clams get by with a little help from single-celled friends, having borrowed a trick from zooxanthellate anthozoans.

Members of two groups of pteriomorphs, however, have learned to live with lower degrees of attachment; some scallops and file shells eschew permanent confinement, living on sandy bottoms or in crevices, from which they sieve for food and surprise predators such as echinoderms and carnivorous gastropods by vigorously flapping their valves, producing jets that propel the bivalve through the water and away from danger. Both pectinids and limids have pallial eyes lining the mantle edge, though those of the former are rather more well developed, with a cornea, two retinal layers and a lens little smaller than that of some mobile phone cameras. These optics clearly serve to detect approaching threats, but their resolving power, which has been compared to Newtonian telescopes in their ability to correct for spherical aberration, appears to have outpaced the ability of the scallop to process the pixels, much less picture the scene beyond its shells. Some correlation between visual acuity and swimming prowess has been observed, so it is possible that active clades derive an advantage from being able to somehow see where they are going or suss out suitable habitats. (Tridacnines also possess eyes, which despite being mere pinholes, are sharp enough to tell the animal where to squirt and probably help juveniles determine if they should move to a sunnier spot.)

Like scallops, limoideans have just one adductor muscle and may sport two small ears by the dorsal margin, but the shells of these unique bivalves, which bear ruts that feel rough to the touch, are usually deep rather than round. The foot, as in most non-burrowing molluscs, is short, functioning primarily to place byssal threads on hard substrates.

Limids are seldom seen during intertidal surveys, though this may be less a measure of scarcity than a result of their fondness for hidden cracks. But once spotted, file shells are unmistakable, save perhaps for some strange sea anemone should the creature behind the gape remain out of sight. For the mantle edge, which is richly pigmented and envelops the entire shell margin, is fringed by numerous long tentacles. Individual strands may be shed to ward off predators but the tentacles also play a row in locomotion, contracting en masse to help lift the animal from the seabed. Unlike scallops, Lima swims with its valves perpendicular to the substratum, sacrificing speed for staying power with the aid of lightly built shells and the voluminous pallial appendages. Elusive, disgustingly enduring and at times quite electrifying, these little clams defy the conventions of their class to float like fleshy butterflies and stick their necks out in a reef where life resists attempts to make heads or tails of its magic and majesty.

A few wires less

We found three large fish traps at Terumbu Pempang Tengah last Saturday. One held a few blue-spotted fantail rays and copperbanded butterflyfish. More chaetodontids, Chelmon rostratus as well as Chaetodon octofasciatus, shared a nearby cage with two yellowtail angelfish. The trap, fixed in place near the reef slope by several chunks of live rock and coral, is a modern reinterpretation of a traditional basket; thin wire envelops a steel frame that tapers at one end. Across the other side, the edges converge to form a funnel that surrounds a long cone, which facilitates entry but restricts, with its narrow gape, escape by stricken captives. A third prison housed several rays, groupers, tuskfish and a red egg crab, the last of which is a meal unfit for human consumption.

The proximal ends of a few playschool clippers, driven with rusty force and sore digits, were happily sharp enough to slice through the thin mesh, allowing the fish to make a break for the chasms between these patch reefs west of Pulau Hantu. There is no guarantee of freedom, though, should they succumb a second time to the appetites of boatmen who know, far better than most of their compatriots, the abundance of a straits under siege yet prefer to keep this to themselves and add to its depletion. Horseshoe crabs and other inhabitants of northern mudflats also fall prey to immortal filaments that refuse to let go of their victims, even when those who set them up lose their bearings and allow the nets to drift, phantoms with a fatal touch to every fin and foot. Here, in the shadow of islands trapped between smoke and ash, these snares of plastic and metal threaten an underwater world of colours and creatures with no peers in walls of glass, where life struggles to stay afloat and survive the depredations of an age in which wisdom stops short at the water's edge and sinks out of sight.

Chlorophyll

There is an item in the menu of a local fine restaurant, an interlude of soft and saline portions in an evening of choice cuts, called Chlorophyll. The confection, a blend of soybean paste, Japanese kelp and roasted buckwheat, is garnished by spinach leaves and what appear to be clusters of miniature grapes. The latter, reminiscent of plump, green peppercorns, would be familiar, though, to those who frequent domestic flats, who would have seen blooms of composite fronds draped over outcrops of rubble. But few, if any, go as far as to sample the alga, whose stolons creep over sand and stone, sending out minute filaments that anchor the multi-nucleate cell to its shallow refuge.

At least two species of Caulerpa show up on tables in the far east, particularly in the Philippines and Vietnam, where lentillifera is cultivated for animal feed and salty salads. Racemosa is somewhat less favoured, though this variable seaweed, with fronds that terminate in stalked spheres, flared discs, bells, cones or clubs, still has a significant fanbase in the region. Sea grapes, sensu stricto, produce densely packed bunches of globose branchlets, which veer little from the phenotypic norm and offer handy portions that fit into most mouths and slide down the gullet with slippery ease. Each bite of this berry, every nibble between fleshy lips, releases a drop of flavour that is nothing less than a burst of light and little more than a drop of the ocean in a ray of cytoplasm, the sliver of a cell with few nods to sophistication and sporadic accounting for taste.

Cow in a box

Longhorn cowfish are sometimes seen at Cyrene Reef, in pens of clean silt below a sheet of liquid glass. They hang in shallow water, hoping perhaps to be mistaken for a drifting frond, with their fins still, the 'horns' just piercing the surface and their tails furled in repose. Encased in a bony carapace with ventral processes and preorbital spines that make it just a bit harder to swallow, the fish is a little floating fortress with limited horsepower and high manœuvrability.

As in many tetraodontiforms, the dorsal and anal fins fan the animal forward, while twirling pectorals perform slow pirouettes that allow the ostracid to pan its surroundings for treats or threats. The tail, supported by a slim, flexible peduncle, is probably reserved for sudden bursts that quickly drag, angular boxes being inimical to long streaks. Corralled between a rim of rubble and a ridge of sand, the cowfish are content to cast headstrong shadows and keep trouble at bay, lest they find themselves in a corner where ties turn toxic and end in a slaughter of sacred things.

Cohabitation

It's easy to wander the shore, torch in hand and stained towel over shoulder, and count its inhabitants, overturning shells, teasing limbs and caressing lumps of pale gelatinousity, forgetting in this descent into mudness that few of these creatures exist in isolation and none live alone. The intertidal zone is a community with rare privileges, a country with no barriers to entry and the scene of endless competition for personal space, private lives and a chance to pursue the final tasks of a post-larval existence. Some have no choice but to bud off, a process that reduces solitary recruits to pawns in a larger body of parts. Others tolerate the arrival of neighbours, trading solitude for the safety of numbers and the prospect of partners in reproductive crime.

There are also local centres of gravity, magnets of living tissue that draw to their exposed arms and buried feet a company of smaller beasts with no place to go but a couch on the move. Hermit crabs share their coils with flattened snails that survive on gender fluidity. Shells, alive or inhabited by anomurans, are burdened by sea anemones that pay for the ride. Slender gobies and busy alpheids cohabit long burrows, the former serving as watchdog and its companion a slave to home improvement. Branching corals, already hosts to single-celled collaborators, house within their forks a crew of pugnacious crabs, pug-faced gobies and gun-toting shrimp – handy partners in a colonial protectorate. Sponges and soft corals allow brittle stars and pale couples to run through their inner chambers, while gorgonians harbour in their fans of horn a veritable hive of invisible fish, striped sea anemones, gaudy ophiuroids, camouflaged snails, arboreal bivalves, see-through crustaceans and strange worms – some are neutral guests, but others are nastier tenants who see no difference between board and breakfast. Sometimes the tables are turned, and sessile animals find themselves attached to wandering carapaces, providing a shield of stinging sacs or a cloak of invisible tunics.

There are also relationships that beg questions and bewilder visitors to soft flats, where plumes on a primary stalk hide tender polyps as well as delicate 'crabs'. One pair of walking legs short of all true brachyurans and much tinier than most, porcellanids distinguish themselves with long feelers and feathery jaws, which resemble the feeding appendages of barnacles when expanded and similarly help to net suspended matter and sweep food into the mouth. These little decapods have traded active foraging for floating currencies, a small step, as it were, towards a life of settlement, on which some filter-feeding pagurids have already embarked. But there is still value in mobility for Porcellanella picta, in the ability to play hide-and-peek in the spiny folds of sea pens, steal glimpses from half-buried fronds and live under the roar of a coastal road. What the cnidarians gain, or get in return, for the favour is unclear – some colonies have no hanger-ons; others endure the mockery of tenants who borrow their patterns and bristle with affection for none but each other, living together between layers of pinnules and defying attempts to tear down their defenses and tease them apart.

Echinoderms, too, have their own entourage, associates of dubious merit from other branches of life as well as fellow stars that worm their arms around the knobs and spines of larger discs. Several genera of carideans and tiny crabs hitch a ride on feather stars as well as sea urchins, though the latter, despite their appeal as floating fortresses, have not the market share of upwardly mobile sea lilies. Clinging to spikes or clutching their eggs under slim forms that match the patterns of their host, most of these commensals probably offer little for their carriage and pose nary a burden to their armoured vehicles, but some pretty pairs make out in dangerous terrain, having nipped and tucked to bed a private boudoir guarded by fire and vice. There are also polychaetes that attach themselves to echinoids as well as sea cucumbers and asteroids; one of these, a species of Perinereis, Oxydromus cf. angustifrons, favours the oral surface of vain orbs, curling through the barrage and wrapping its segments around the ventral gap, where its coils present a contrast of bands to the brittle pikes. The hesionids, whose hollow quarters may hold other lodgers, infect many of the temnopleurids that plague Changi's beach, dealing a fair hand to those willing to stoop low and turn over the spheres until one relents and surrenders to the throes of a room where the thrill is all but gone and no words are safe.

Two butterflies

A thick reef lies beyond the long bund of Tanah Merah, mirroring in spirit the cliffs that once set the coast aflame before they were levelled for industrial parkland and empty courses. At times, the sea rises high enough to engulf the barrier or at least drive its minions through the porous wall into an inward fringe, where a calm shoal abuts an artificial beach. Purple crabs and plodding snails patrol the damp upper layers of these boulders, alert for edible filaments but doing little to prevent an invasion of the lower strata by recruits from the outer flat. Thus, stinging polyps, sticky tubes with swaying locks, and swelling colonies of soft bodies in hard cups have established themselves on coarse rocks and foreign sand, turning the grim layers into a land of glowing things.

Many fishes, including several species associated with coral reefs, are also drawn to the seawall for its provision of safe chambers and silty refuges. Groupers, tripletails, stonefish, scorpionfish, snappers, flatheads, morays, cardinalfish, rabbitfish, filefish, emperors, sergeants, damsels, halfbeaks, squirrelfish, gobies, silversides, tuskfish, eeltail catfish, wrasses, mojaras, dragonets, whitings, cowfish, remoras and even an eagle ray have found their way to the sheltered side of this eastern shore. Here, in pools that slither up stony terraces and under shelves of slime, predators slip into the shadows to join their prey in a truce that endures scrutiny but probably not a moment longer. Here, too, are butterflies in ill-advised forays to the littoral zone, compressed hunters born to suck the life out of crevices and which may at times turn on the very polyps that build their home. Prisoners of stripes that cross their eyes and confound their foes, young chaetodonids add a welcome dash of colour to the dull shades of grey that cloak the scene and which conceal, in a long, shallow grave by a lonely road, the memory of hills at once bright and burning. 

A quite different flash lit up the dim expanse beneath the canopy off Chestnut Avenue, where a craggy trail winds through a scrubland of albizia before plunging into denser woods. The shaded track is fought over by big blue dragonflies with dark wing tips and a fierce devotion to sweeping routines. Metalmarks also favour this habitat, hopping from leaf to leaf with half-opened wings to capture the sun in small doses. One of the few members of this family to survive in Singapore, the Malay tailed judy is a beast of reserved temperament, ill at ease in exposed parks and present in rare numbers even in the lowlands of the peninsula. Unique among local riodinids, Abisara savitri savitri bears on its hindwing a white-tipped tail and ocelli that recall the false heads of hairstreaks. But this little brown butterfly, suffused with scales of delicate confection, still prefers active flight to casual deception and so lingers just long enough to catch its breath and reveal, in the briefest of glimpses, a blink of its powdered beauty.