Halimeda

Halimeda
Halimeda tuna
Scientific classification
Kingdom:	Plantae
Division:	Chlorophyta
Class:	Bryopsidophyceae
Order:	Bryopsidales
Family:	Halimedaceae
Genus:	Halimeda J.V.Lamouroux, 1812
Type species
Halimeda tuna (J. Ellis & Solander) J.V. Lamouroux, 1816
Species
see text.

see text.

Halimeda is a genus of green macroalgae. The algal body (thallus) is composed of calcified green segments. Calcium carbonate is deposited in its tissues, making it inedible to most herbivores.

As in other members of the order Bryopsidales, individual organisms are made up of single multi-nucleate cells. Whole meadows may consist of a single individual alga connected by fine threads running through the substrate.

Halimeda is responsible for distinctive circular deposits in various parts of the Great Barrier Reef on the north-east coast of Queensland, Australia. Halimeda beds form in the western or lee side of outer shield reefs where flow of nutrient-rich water from the open sea allows them to flourish, and are the most extensive, actively accumulating Halimeda beds in the world.

The genus is one of the best studied examples of cryptic species pairs due to morphological convergence within the marine macroalgae.

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