TankBud

Sun coral

Tubastraea

Also known as Sun Polyps, Orange Cup Coral

SaltwaterCoral

Sun coral (Tubastraea)
Franklin Samir Dattein · CC BY 2.0

Care at a glance

Temperature
75–81°F
24–27°C
pH
8.1–8.4
Adult size
7.9 in
20 cm
Minimum tank
20 gal
75 L
Temperament
Peaceful
Social behavior
Solitary
Swim level
Bottom
Diet
Carnivore
Difficulty
Difficult
Breeding
Hard
Rarity
Common
Reef safe
Reef safe
Family
Dendrophylliidae
Origin
Indo-Pacific reefs, typically on shaded overhangs, cave walls and deeper rock faces; several species have also become an invasive fouling organism on oil platforms and wrecks in the tropical Atlantic, including Brazil

Overview

The sun coral is a stony coral for a shaded spot, and it has to be fed by hand. That feeding is the whole challenge of keeping it, and it suits experienced keepers.

Did you know

A well-fed sun coral colony will reach out and grab food several times its own polyp size. Public aquariums sometimes favor it because a cave of glowing orange polyps needs no special lighting. It only needs a keeper willing to feed it by hand, night after night.

Caring for the sun coral

The sun coral does well under low light or no light at all. Place it in a shaded cave, an overhang or the dimmer lower part of the tank, not under strong lights. Plan the spot around easy access for feeding rather than around light. It needs a tank of at least 20 gal (75 L).

Give it low to moderate flow. Many keepers set it a few inches below a powerhead, so the current sweeps food past its polyps once the lights are down. Keep the water at 75 to 81°F (24 to 27°C) with a pH of 8.1 to 8.4.

Target feed every polyp, most nights if you can, with small meaty foods such as baby brine shrimp, mysis or chopped seafood. Puff the food onto each open polyp with a turkey baster or a similar tool. A handful of feedings a week is the bare minimum, and colonies fed close to daily tend to do best.

Skipped meals show up over weeks as shrinking, pale polyps and slow tissue loss. It is not a coral for the casual feeding schedule of a photosynthetic LPS. All that feeding also raises nutrients fast, so strong skimming and good water changes matter more than with almost any other coral.

The sun coral is not aggressive toward other corals and can sit close to peaceful neighbors. New heads bud slowly from the base of established polyps rather than through conventional fragging. Breeding it is hard.

Good to know

Tubastraea is a large polyp stony coral in the family Dendrophylliidae, the same family as Turbinaria. Unlike its photosynthetic relative, it is entirely non-photosynthetic, or azooxanthellate. Its bright orange or yellow color comes from pigments rather than symbiotic algae. The polyps stay closed through the day and open mainly after dark to catch food drifting past.

In the wild

Tubastraea grows on shaded overhangs, cave walls and deeper rock faces on Indo-Pacific reefs. It stays tucked out of direct sun, where its bright orange polyps stand out against the dark. Several Tubastraea species have become one of the most successful invasive corals on record. They spread along the Brazilian coast on oil platforms, ship hulls and wrecks after being introduced from their native range.

Common questions

What size tank does a sun coral need?

A sun coral needs at least 20 gal (75 L).

What temperature and pH does a sun coral need?

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

What does a sun coral eat?

A sun coral eats small meaty foods such as baby brine shrimp, mysis or chopped seafood. Target feed every polyp most nights, since a handful of feedings a week is the bare minimum.

How big does a sun coral get?

An adult sun coral reaches about 7.9 in (20 cm).

How does a sun coral breed?

A sun coral makes new heads slowly, budding them from the base of established polyps rather than through fragging. Breeding it is hard.

Related species