As A few of us have been starting to get more interested in Distichopora I figure I would post up some infor from Arkive.org
Description
Lace corals form ornate tree-like structures, with all the flattened, blunt-ended branches growing in one plane. These fan-like corals are remarkable for their bright colours (2), including violet, red, orange, and yellow, and grow up to 25 cm tall (3). The colour is deposited within the limestone skeleton and remains even after the animal tissue is gone, unlike reef-building corals which have white skeletons and the only colour is found in the living tissue (4)
Habitat
Distichopora corals occur in temperate as well as tropical waters, and also occur at abyssal depths. Commonly found in caves and under overhangs in shallow reef environments, and in crevices, under ledges and in caverns (2).
Biology
Unlike many coral species, lace corals do not have the symbiotic algae zooxanthellae living within the coral tissue; they are azooxanthellate (2). They are therefore not dependent on light and thus can live where the reef-building corals, dependent on photosynthetic algae, can not.
Lace corals are hydrozoans, and thus have different type of polyps with different functions than anthozoan corals. The polyps of hydrozoans are near microscopic size and are mostly imbedded in the skeleton, connected by a network of minute canals. All that is visible on the smooth surface are pores of two sizes; gastropores and dactylopores. The rows of gastropores flanked by one of two rows of dactylopores are diagnostic of the genus (3). Dactylopores house long fine hairs that protrude from the skeleton. The hairs possess clusters of stinging cells (nematocysts) that can inflict stings on human skin. These hairs capture prey, which is engulfed by gastrozooids, or feeding polyps, situated within the gastropores (2).
Reproduction in lace corals is more complex than in reef-building corals. The polyps reproduce asexually, producing jellyfish-like medusae, which are released into the water from special cup-like structures known as ampullae. The medusae contain the reproductive organs, which release eggs and sperm into the water. Fertilised eggs develop into free-swimming larvae that will eventually settle on the substrate and form new colonies. Lace corals can also reproduce asexually by fragmentation (5) (6).
Glossary
Asexually: relating to asexual reproduction: reproduction that does not involve the formation of sex cells, such as sperm and eggs. Asexual reproduction only involves one parent, and all the offspring produced by asexual reproduction are identical to one another.
Colonies: relating to corals: corals composed of numerous genetically identical individuals (also referred to as zooids or polyps), which are produced by budding and remain physiologically connected.
Fragmentation: fragmentation is a form of asexual reproduction where a new organism grows from a fragment of the parent. Each fragment develops into a mature, fully grown individual.
Larvae: relating to corals: the stages of development before settlement on the reef. Larvae are typically very different in appearance to adults; they are able to feed and move around but usually are unable to reproduce.
Photosynthetic: plants that carry out a metabolic process in which carbon dioxide is broken down, using energy from sunlight absorbed by the green pigment chlorophyll. Organic compounds are produced and oxygen is given off as a by-product.
Polyps: typically sedentary soft-bodied component of Cnidaria (corals, sea pens etc), which comprise of a trunk that is fixed at the base; the mouth is placed at the opposite end of the trunk, and is surrounded by tentacles.
Symbiotic: describing a close relationship between two organisms. This term usually refers to a relationship that benefits both organisms.
References
1.CITES (October, 2009)
http://www.cites.org
2.Veron, J.E.N. (2000) Corals of the World. Vol. 3. Australian Marine Science Institute, Townsville, Australia.
3.Lindner, A., Cairns, S.D. and Guzman, H.M. (2004) Distichopora robusta sp. nov., the first shallow-water stylasterid (Cnidaria: Hydrozoa: Stylasteridae) from the tropical eastern Pacific. Journal of the Marine Biological Association of the UK, 84: 943 - 947.
4.Waikïkï Aquarium Education Department (July, 2007)
http://www.waquarium.org/MLP/search/sp_lace_coral.html
5.Borneman, E.H. (2001) Aquarium corals; Selection, Husbandry and Natural History. T.F.H. Publications, New Jersey, USA.
6.Wood, E.M. (1983) Reef corals of the world: biology and field guide. T.F.H. Publications, New Jersey, USA.
7.Wilkinson, C. (2004) Status of Coral Reefs of the World. Australian Institute of Marine Science, Townsville, Australia.
8.Green, E. and Shirley, F. (1999) The Global Trade in Corals. World Conservation Press, Cambridge, UK.