Results for “coral”

coral

Any marine animal of the class Anthozoa, these being characterised by possessing a horny or calcareous skeleton, aggregations of which form coral reefs and islands.

Used in 13 profiles

coralline algae

Any red algae of the order Corallinales, characterised by possession of a hard thallus containing calcareous deposits. Often pink, purple or red in colour.

coral reef

Erosion-resistant aquatic structure formed from living corals, their rock-like skeletal secretions and calcium carbonate deposits from other organisms such as calcareous algae, molluscs, and protozoans.

coral sand

Sand originating from marine environments via bioerosion of the calcareous skeletal structures possessed by some organisms. Coral is not the chief constituent, however, with the majority of material deriving from foraminifera, calcareous algae, molluscs, and crustaceans.

Used in 6 profiles

allelopathy

A biological phenomenon by which an organism produces one or more biochemicals that affect the growth, survival, and reproduction of others. Typical in certain plants, algae, bacteria, coral, and fungi.

aragonite

Naturally-occurring, crsytalline form of calcium carbonate with a notable buffering capacity. Popular as a substrate or substrate additive in marine and freshwater aquaria where pH and hardness must be maintained at high levels, and has a more rapid, effective effect than coral sand, for example.

Cnidaria

Phylum of aquatic organisms that includes the corals, jellyfishes, sea anemones, hydrae, etc., and characterised by possession of specialised venomous cells known as cnidocytes. Formerly included in the now-defunct phylum Coelenterata.

zooxanthella

Any member of the yellow-green algae genus Symbiodinium, comprising unicellular, flagellate protozoa that exist within the cells of other protozoa and some invertebrates, especially corals. They thus form an endosymbiosis in which they can provide up to 90% of the host's energy requirements.