MARINE PLANTS - UAE Interact

T H E E M I R A T E S – A N A T U R A L H I S T O R YCharacteristically bright green, since the chlorophyll pigments arenot masked by other secondary pigments. Morphology rangesfrom single cells, simple or branched filaments of cells aligned ina single series to compact spongy forms through to flattenedfronds or tubes. A few are lime-impregnated.Acetabularia calyculus Quoy & GaimardUmbrella-like, often whitish and calcified, usually about 2–4centimetres high. Commonly on small stones, worm tubes andshell fragment embedded on the floor of shallow sand-lined tidepools on the lower shore and in the shallow subtidal zone.Avrainvillea amadelpha (Montagne) A. & E.S. GeppFan-shaped spongy erect fronds on long stipes, sometimes denselypacked, often several arising from a long bulbose rhizomatous base.Occurs on sediment in lower shore tide pools and the shallowsubtidal zone in seagrass beds.Caulerpa serularioides (S.G. Gmelin) HoweErect fronds flattened, pinnate, with the pinnules cylindrical anddisposed in a single plane or radially arranged (var. farlowii), arisefrom creeping stolon-like base attached by rhizoids. Commonlygrowing over sediments amongst seagrass and amongst othershallow-water seaweeds, including just below the water surfaceon pontoons in Abu Dhabi.Chaetomorpha linum (O.F. Müller) KützingLoose-lying and entangled, intertwined and unbranched filamentsof cylindrical cells. Often in wave-sheltered embayments andharbours where loose-lying over mud, entangled with seagrassesand commonly forming shrouds over the breathing roots of themangrove Avicennia marina.Cladophora nitellopsis BørgesenSoft woolly tufts of light green branched filaments of a single seriesof cells, with branchlets arising singly along main branches,alternately or oppositely except the final divisions lateral in position,apical cell cylindrical and rounded apically. Occurs as extensivemats on beds of mussels in sheltered shallow tide pools andextending into the shallows subtidal zone, often associated withthe breathing roots of mangroves in lagoons and muddy creeks.MARINE PLANTSSEAWEEDS GROW IN THE SEA AND brackish water on intertidal and subtidal rocks, seagrasses, the breathing roots ofmangroves, other seaweeds and animals, including dead coral skeletons. They belong to the ‘algae’ which is a termused for an unnatural assemblage of photosynthetic, oxygen-producing organisms that do not possess true roots,stems and leaves. These ‘macroalgae’ sometimes have root-like rhizoids, stem-like stipes and leaf-like structures.Seaweeds are divided into a number of groups or phyla, depending on pigmentation linked to a suite of othercharacters. Some of the more common seaweeds from the UAE are described below, all being listed separately.Microscopic algae are only listed.GREEN ALGAE (PHYLUM CHLOROPHYTA)Cladophoropsis sundanensis ReinboldCompact, spongy cushions (about 5 centimetres across), composedof light green and laterally branched filaments lacking a cross wallat base. Occurs commonly during the summer on lower eulittoralsubzone rocks, often forming very extensive, loose-lying mats invery shallow water in sheltered embayments and over tidal flats.Dictyosphaeria cavernosa (Forsskål) BørgesenGlobular and irregularly lobed, hollow, stiff and brittle, formed oflarge and conspicuous macroscopic cells (1–3 millimetres across),often older plants eroded at the top. Occurs on rocks in the lowereulittoral (subzone), often fringing rocky tidepools, occasionally inthe sublittoral fringe with Chondrophycus papillosus and Digeniasimplex.Enteromorpha (now Ulva) flexuosa (Wulfen ex Roth) J. AgardhBranches tubular, often divided near base, inflated and flattenedabove, single-layered. Occurs most commonly on partially sandburiedbeach rocks in the lower eulittoral subzone.BACKGROUND PHOTO: MacroalgaeBELOW: Cladophoropsis sundanensisM A R I N E P L A N T S160161