Hydnophora exesa

*Hydnophora exesa*
Taxonomical systematics
	Scientific name	Hydnophora exesa (Pallas, 1766)
	Common names	Horn Coral, Branch, Knob, Green Velvet Horn
	Genus	Hydnophora Fischer de Waldheim, 1807
	Family	Merulinidae
	Order	Scleractinia
	Subclass	Zoantharia
	Class	Anthozoa
	Phylum	Cnidaria

Local ecology
	Distribution	Tropical Western Pacific, Great Barrier Reef, Northern and Western Indian Ocean, Red Sea.
	Habitat	Can be found in all reef habitats but is most common in lagoons and protected reef slopes (Veron, 2000).

Biological characteristics
		Zooxanthellate
		Hermatypic

	H. exesa in the aquarium.


	*Close up of H. exesa* in the aquarium showing hydnophores.**


	*Close up of H. exesa* in the aquarium with tentacles extended.**


	*Mesenterial filaments of a H. exesa* "attacking" an Acropora sp. fragment.**


	*Mesenterial filaments of a H. exesa* "attacking" an Acropora sp. fragment.**


	*Mesenterial filaments of a H. exesa* "attacking" a corallimorph.** The corallimorph is around 3 cm from the H. exesa.

Skeletal structure
	Corallum	Submassive, encrusting, laminar or subarborescent, even in the same colony (Veron, 2000).

Captive care
	Lighting	Medium to high light intensity (Borneman, 2001).
	Water flow	Moderate current (Borneman, 2001).
	Feeding	This species and others of the genus appear to be able to digest food externally by extending their mesenterial filaments. Food can be placed on the surface of the colony where it will be digested. Can be fed small to medium sized food items such as brine shrimp, mysid shrimp, fish eggs.

Reproduction
	Asexual methods	Fragmentation (Borneman, 2001).

References
	Borneman E.H. 2001. Aquarium Corals: Selection, Husbandry, and Natural History. Microcosm Ltd, Charlotte, VT. 464pp.
	Veron J.E.N. 2000. Corals of the World - Volumes 1, 2, 3. Australian Institute of Marine Science, Townsville, Australia. 1382pp.