Hydnophora exesa (Pallas 1766)

Hydnophora exesa, also called horn coral or spine coral, is a coral in the genus Hydnophora. It was described by Peter Simon Pallas in 1766.

Hydnophora aurorae est une espèce de coraux appartenant à la famille des Merulinidae.

Hydnophora exesa là một loài san hô trong họ Merulinidae. Loài này được Pallas mô tả khoa học năm 1766.

大碓珊瑚（学名：Hydnophora exesa）为繩紋珊瑚科碓珊瑚屬下的一个种。

zooxanthellate

The surface is covered with small monticules, small conical projections or pyramids. This species has large monticules, 3 to 5 mm tall and either 4 - 5 mm in diameter, or elongated, reaching 10 to 20 mm long. The colony is irregular in shape and form, being part massive but often with a foliaceous skirt. Many colonies also support irregular, nearly ramose projections. The species is widespread, being found in sheltered and moderately exposed habitats in particular, but also occurring from 10 to 25 m deep on exposed reef slopes. It is the less abundant of the two Hydnophora species, and is never common. Its living tissue is fairly fleshy, with visible tentacles in daytime (Sheppard, 1998). Colonies are submassive, encrusting or sub-arborescent with much of this variation occurring in the one colony. Hydnophores are 5-8 mm in diameter. Colour: cream or dull green. Abundance: common, especially in lagoons and on protected reef slopes (Veron, 1986). Characterised by a surface decorated with attractive conical, upright cones (hydnophores) and short ridges, 4-20 mm long and 3-5 mm tall. Grows as an encrustation with a tangle of short lumpy branches. Colour: pale creamy brown with light green valleys. Habitat: sheltered reefs and lagoons (Richmond, 1997). Tropical Indo-Pacific in Kalk (1958).