TankBud

Smooth skin acropora

Acropora tenuis

Also known as Tenuis Acro, Smooth Skin Acro, Corymbose Acropora, Acro

SaltwaterCoral

Smooth skin acropora (Acropora tenuis)
MDC Seamarc Maldives · CC BY-SA 4.0

Care at a glance

Temperature
75–81°F
24–27°C
pH
8.1–8.4
Adult size
9.8 in
25 cm
Minimum tank
40 gal
150 L
Temperament
Peaceful
Social behavior
Solitary
Swim level
Bottom
Diet
Photosynthetic
Difficulty
Difficult
Breeding
Hard
Rarity
Common
Reef safe
Reef safe
Family
Acroporidae
Origin
Widespread on shallow Indo-Pacific reef flats and slopes, from the Indian Ocean through the western Pacific.

Overview

The smooth skin acropora is a branching small polyp stony coral for a mature, stable reef tank. It is a coral for experienced keepers.

Did you know

Smooth skin acros like this one have tips that fluoresce a different color from the branches, in blues, pinks, greens and yellows. Aquacultured strains carry collector names and trade for a premium.

Caring for the smooth skin acropora

Keep the smooth skin acropora in a mature, stable reef of at least 40 gal (150 L) that has run for at least a year. Give it strong light around 300 to 400 PAR and strong, turbulent flow. Place it with clear space up in the light and flow.

Hold tight parameters, with alkalinity steady at around 8 to 9 dKH and calcium near 420 to 450 ppm. Keep magnesium around 1300 ppm, the temperature at 75 to 81°F (24 to 27°C) and the pH at 8.1 to 8.4. It hosts dense zooxanthellae and grows fast in good conditions.

Start with a captive-grown piece, because aquacultured frags adapt better than wild colonies. The smooth skin acropora is peaceful toward tank mates, but more aggressive corals sting it easily.

Good to know

The smooth skin acropora belongs to Acropora, the largest genus of reef-building corals, in the family Acroporidae. Its skin is smooth between the corallites, which sets it apart from the fuzzy or hairy branch textures of other Acropora. It is one of the most recognizable and sought-after Acropora forms, and a common subject in coral restoration and captive breeding work.

In the wild

The smooth skin acropora is widespread on shallow reef flats and slopes, from the Indian Ocean through the western Pacific. Wild colonies grow in a low, bushy corymbose shape, with many short upright branches rising from a spreading base. They stay compact compared with the tall staghorn types.

Symbiotic relationships

Clown gobies and their Acropora

Clown gobies spend their lives wedged in the branches of Acropora corals, eating the coral's mucus and the small animals that live on it. Their skin carries a toxin that puts off predators, so the coral becomes a safe house. The coral is paid back in a way nobody expected: when a toxic seaweed touches an Acropora, the coral releases a chemical signal within minutes, and the gobies swim out and trim the seaweed back. Corals with gobies lose far less tissue to seaweed than corals without them.

A clown goby wants a branching coral to sit in, and Acropora is the natural choice, though it will settle for other branching stony corals. It is tiny, peaceful and needs small food several times a day. The one caution is the coral itself: a pair may nip a patch of Acropora or Montipora bare to lay eggs on the skeleton, and a small colony can lose a branch that way. Keep one, or a pair, per tank; two males fight.

Every symbiotic relationship in the catalog

Common questions

What size tank does a smooth skin acropora need?

A smooth skin acropora needs at least 40 gal (150 L).

What temperature and pH does a smooth skin acropora need?

A smooth skin acropora is comfortable at 75–81°F (24–27°C) with a pH of 8.1–8.4.

What does a smooth skin acropora eat?

A smooth skin acropora hosts dense zooxanthellae and needs strong light, around 300 to 400 PAR.

How big does a smooth skin acropora get?

An adult smooth skin acropora reaches about 9.8 in (25 cm).

Related species