Hormosira

Hormosira is native to southeastern Australia (including Tasmania, Lord Howe Island and Norfolk Island) and New Zealand. Despite substantial morphological variation across its range, the species represents a single species and the genus Hormosira is monotypic. Genetic analyses of mitochondrial COI and microsatellite DNA sequence data have indicated that there is low genetic variation across the range of the species in Australia. ==Description==

Hormosira is a perennial Due to the buoyant thallus, Hormosira plants can drift out to sea over considerable distances, and floating plants can remain fertile for several weeks. ==Reproduction==

Hormosira reproduces sexually and is monoecious. The sex organs (conceptacles) are on the surface of the beads, and are visible to the naked eye as rough-looking dimples. Hormosira produces eggs throughout the year, but its peak reproduction is often confined to July–October (at least in northern New Zealand) when the sea temperature is around 14 °C, as the viability of the eggs can be low in high sea temperatures such as 17–22 °C. At high tide, the eggs are released directly into the surrounding water. The eggs are negatively buoyant they sink to the substrate to develop for several days before becoming attached. All individuals release at the same time, maximising fertilisation. The species can also reproduce asexually from broken and dislodged fragments. ==Ecology==

epiphyte, Notheia anomala. Hormosira is regarded as an ecosystem engineer or habitat former that occurs in large patches and outcompetes other algal species due to its high tolerance to desiccation. Hormosira is a food source for sea urchins, many small crustaceans, and some juvenile fish. Young crustaceans and molluscs often rely on the dense canopies of Hormosira for niche space, protection from predators, and avoid desiccation at low tide. Hormosira provides a substrate for sessile organisms to attach onto, including sea urchins and a wide range of facultative and obligate algal epiphytes such as Notheia anomala. This is beneficial to many organisms as competition for habitat space is a primary limiting factor in the intertidal environment. ==Uses==

Due to the species' high iodine content, Tasmanian schoolchildren were once urged to eat a bead a day to keep the goitres away. ==References==