The flat of mud, seagrass and rubble that abuts the western fringe of Pulau Semakau reveals itself even in a middling tide, surprising visitors who emerge from a tramp through coastal woods and burst onto a scene from lost times – a beach of baked sand, porcelain shards and broken piles, guarded by a loose wall of mangroves whose roots reach down, stretch up and infect the lower layers of the shore with pores that breathe life into the silt. In the branches above, spiders hunt on waxy leaves or weave sneaky platforms with silken retreats, while oriental white-eyes and sunda pygmy woodpeckers probe the axils, bark and flowerbuds for caterpillars and grubs.
From these low canopies, collared kingfishers, in between cackles of shrill content, launch themselves at crabs in blind spots or shrimp and fish in un-holesome puddles. Smaller arthropods: moths on the trail of distant mates, sparasitoid wasps seeking hosts for their young, warming flies, midges and gnats, and alates on the wing – the aerial plankton that spill out from the forest and form clouds around the heads of warm-blooded bodies sate the appetites of birds without feet and dull-red dragonflies that glide over the space between the trees and the tide. Brown seaweed drape the archs of exposed props, forming unruly sleeves that hide the tricks of limpets, periwinkles, creeper snails and potamids, the last consisting of an assembly of high-spired leaf and litter feeders of culinary interest to both mud crabs and men. Permanent residents of these intertidal boughs include barnacles, sea anemones and leaf oysters, flat-shelled clams that have lost the means to move and anchor their valves to wood or rock using sticky threads.
Around the base of the trunks, colonies of fiddler crabs make the most of low water to stuff damp sediment, freshly enriched with meiofauna, into their buccal cavities, which extract organic particles and extrude a pellet of clean grains. The crabs scatter back into their holes when the adwentoursomme approach, blindly obeying signals of urgency issued by stalked facets. But hunger, or less wholesome drives, soon compel them to brave the open and resume their routines if nothing else triggers their evasive instincts. Crabs of varying size occur in close proximity, a sign perhaps of communal strategies in which a dominant male defends his neighbours, including younger males, on his turf from wandering strangers, prefering the stability of known quantities to the risk of territorial upheavals.
Seagrasses grow in a trough between the rubble and a field of mostly firm, brown sponges that coalesce as mounds, lumps, cones and puffballs on stalks. Pools in this poriferan zone stir with tiny portunids and shadow gobies. The latter, unlike some of their fellow travailers, appear loathe to dive into holes, having lost the desire to hide to a corruption of the flesh, which confers to Acentrogobius nebulosus a measure of immunity from most, though not all, benthic predators. Flatheads and scorpionfish must patrol these soft margins of the Enhalus meadow when the waves rolls back, but the only spines visible when a walk is afoot are usually those of common sea stars, which seem to favour substrates into which they can plunge their arms with fluid ease.
The culprits behind a chorus of clicks that puncture the ostinato of a shallow sea are usually secluded in burrows. But the odd alpheid can at times be spotted traversing flooded pans, a mini lobster look alike with hooded eyes and unequal claws, one of which nips with traditional force, while the other emits soundwaves of violence that can stun small prey or convey missives of affection. Countless others snap from passages under rocks, coral and sponges, which they share with mates or cryptocentric gobies and cleanse from detritus that might impede their progress or choke their beds.
Creatures without domicile, or lacking hard coils or stiff segments, roam the flat with the freedom of soft toys, entering cracks that keep out tougher hides and pursuing morsels embedded in a tunic of lace or leathery tissue. Polyclad flatworms, which range from moveable stains on the lips of a swaying polyp to a slice of the universe at large on a rug of black velvet, glide over outcrops of sessile victims, parsing barriers without comment and greeting the swash of broken crests with ripples of composure. Some unveil a fancier side when prying fingers compel them to propel themselves through the water by undulating their body margins, a feat few nudibranchs can match.
Abrasive spicules, in clusters that stamp the surface of Jorunna funebris with bovine patterns, defend this slug from prurient jaws, but some individuals bear the marks of excessive samplings, with torn mantles and chewed-off flanks, the souvenirs of encounters with fish or crabs who bit off more than they could sample. Platyhelminths can restore frayed edges, but it is unclear if the nudibranchs have the means, or mind, to recoup their losses when more could be gained by the pursuit of happiness in feasts of liquid blue and a taste of life everlasting in random encounters that end in naked proximity and sidelong exchanges of ripe packets none, in such moments of public exposure, would otherwise emit.