Dykning med Svampkoraller

Lanta Marina Liv | Fungiidae

Svampkoraller av familjen Fungiidae är platta eller kupolformade, med runda eller ovala skelett och en möjlig central båge. Dessa koraller är oftast solitära och fritt levande (de är inte fästa vid underlaget), och ses ofta vid alla korallrev på Koh Lanta-dykresor.

De flesta svampkoraller är i själva verket en enda, gigantisk polyp, vissa med flera munnar. Några få arter bildar faktiskt små 'kolonier' där flera polyper lever i samma, delade skelett.

Alla arter har breda, slitsliknande munnar med korta tentakler som vanligtvis sträcker ut sig för att äta på natten, utom solros-korallen (Heliofungia actiniformis) som har mycket långa tentakler som sträcker ut sig under dagen och ofta misstas för en havsanemon.

Fritt levande individer kan röra sig, om än mycket långsamt. Det gör de genom att blåsa upp och tömma sina vävnader på luft. Medan mindre individer kan rätta till sig själva om de skulle välta av misstag, kommer större individer att dö om detta händer dem.

Unga svampkoraller börjar sitt liv fästade på en hård yta och ser faktiskt ut som en liten svamp med stjälk. När korallerna mognar bryter de sig så småningom loss från sin stjälk och lever som vuxna, utan att vara fästa vid botten. Hos några få arter sitter den vuxna korallen kvar och stjälken döljs av den växande skivan.

3 arter finns på denna sida:

Elongate Mushroom Coral (Ctenactis echinata)
Common Mushroom Coral (Fungia fungites)
Tongue Mushroom Coral (Herpolitha limax)

Elongate Mushroom Coral

(Ctenactis echinata)

Ctenactis echinata @ Koh Haa

The Elongate Mushroom Coral has an oblong-oval shape and is usually brownish, but may also be greenish.

This species is not colonial (it only has a single polyp/mouth) and is free living, with a dominant axial furrow.

The upper side has large, toothed costate septa (a septa is one of the radiating vertical plates within the corallite wall. When it extends beyond the coralite wall, it is called the costate). The underside has numerous pointed tips.

The Elongate Mushroom Coral can grow up to 25 cm long, and is common to all dive sites around Koh Lanta.

Common Mushroom Coral

(Fungia fungites)

Fungia fungites @ Koh Haa

The Common Mushroom Coral has a circular coral plate, occasionally with an arched center. The septal teeth are triangular and pointed.

The tentacles are short and bubble-shaped. The colour may vary from greyish-green to yellowish-brown to pink.

The Common Mushroom Coral is often seen solitary, or in small groups, usually in shallower areas. This single coral polyp can grow to 28 cm, but is usually observed 5 cm to 15 cm.

Tongue Mushroom Coral

(Herpolitha limax)

Herpolitha limax @ Koh Haa

The Tongue Mushroom Coral, also known as the Slipper Coral or Boomerang Coral, is a colonial, free-living mushroom coral, with many polyps living within a single colony.

Colonies may be flat or domed, and are usually elongate, with rounded ends. Colonies may also be Y, T or X shaped.

Tongue Mushroom Coral axial furrow with slit-like mouths

The Tongue Mushroom Coral has an indistinct axial furrow which runs most of the length of the colony, and contains multiple irregularly spaced slit-like mouths.

There are many smaller secondary mouths occurring outside the axial furrow. Septa costae are arranged in rows perpendicular to the colony edge and have regular, densely packed teeth which are interrupted by the numerous secondary mouths.

Tongue Mushroom Coral many secondary mouths

The white-tipped 'tentacles' along the costate septa rows are short and partially transparent. These are not true tentacles but inflated portions of the costate septa tissues. The true colony feeding tentacles are extended at night.

The Tongue Mushroom Coral grows to 50 cm, but more commonly observed around 20 - 30 cm at the dive sites around Koh Lanta.

This species may be pale or dark brown, or greenish-brown and is found on reef slopes.