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Turbinaria ornata (Turner) J.Agardh |
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Description: Plants erect and stiff, 2-20(-30) cm long when reproductive. Plants isolated or in small groups, but occasionally forming low mats, especially in rocky intertidal habitats. Mostly light yellowish brown to dark brown in color when living, but occasionally light grayish or even yellowish white. Holdfast conical or irregular, usually with several unbranched or dichotomously branched stolons growing from basal area of the erect axes. Small juvenile plants with flattened leaves. These leaves and the stolons of larger plants can attach to the substratum and initiate new plants. One cylindrical main axis growing from the holdfast. Larger plants often with secondary branching; rarely with higher orders of branching. Leaves with a petiole and a double row of stiff spines around the margin of the leaves in apical view. Petiole cylindrical near base, becoming triangularly compressed in distal portions. Many buy not all plants have some leaves with hollow centers functioning as floats. Receptacles in tight branched clusters, mostly cylindrical, to 1.5 cm long, with rounded blunt apecies; developing in the leaf petiole near the base. Introduction and Origin: Native to Hawaii. Hawaiian Distribution: Molokai, Hawaii, Lanai, Maui, Laysan, Nihoa, Oahu, Kure, Necker, Lisianski, French Frigate Schoals, Pearl and Hermes Reef, Kauai. Habitat: Very common, found in a wide variety of habitats including exposed rocky intertidal areas, tide pools, intertidal benches, reef flats and in deeper water. Mid intertidal to at least 30 m. Sometimes the most abundant large alga on reef flats in waters from Environmental Effects: Not studied. May affect recruitment of other species by successfully competing for substrate. World Distribution: Widely distributed in tropical and subtropical areas of the central and western Pacific and Indian Oceans. Commercial Interests: None. Rate of Spread / Method: Growth rate unknown. In a Tahitian coral reef, settlement patterns of germlings observed in situ was limited to within 90 cm of the parental thalli, and the greatest number of settled germlings was observed during the cold season. Dispersal of germlings appears to be influenced by the dominant current during their release. This short-distance dispersal allows rapid establishment and maintenance of local populations. Not all oogonia present were released. The number of oogonia produced varied seasonally, being lower during the hot season (Stiger & Payri, 1999). Factors likely to influence Spread and Distribution: Temperature, nutrients availability. Reasons for Success: The particular morphology of the thallus withstands exposure and high wave action. The tendency for fertile thalli to float over long distances, combined with the keeping of part of their oogonia, and high settlement efficiencies, could account for its capacity to colonize new areas (Stiger & Payri, 1999). Control Methods: None used. References: Stiger, V. and Payri, C. E. (1999) Spatial and temporal patterns of settlement of the brown macroalgae Turbinaria ornata and Sargassum mangarevense in a coral reef on Tahiti. Marine Ecol. Progress Series 191:91-100 |
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