TankBud

Button coral

Cynarina lacrymalis

Also known as Meat Coral, Cat's Eye Coral, Doughnut Coral

SaltwaterCoral

Button coral (Cynarina lacrymalis)
Alexander Vasenin · CC BY-SA 3.0

Care at a glance

Temperature
75–81°F
24–27°C
pH
8.1–8.4
Adult size
4.7 in
12 cm
Minimum tank
11 gal
40 L
Temperament
Peaceful
Social behavior
Solitary
Swim level
Bottom
Diet
Photosynthetic
Difficulty
Medium
Breeding
No record
Rarity
Common
Reef safe
Reef safe
Family
Lobophylliidae
Origin
Western Indo-Pacific, from the Red Sea and East Africa to Japan, Indonesia and Australia

Overview

The button coral is a peaceful, single-polyp stony coral for the sandbed of a reef tank. It takes a little more care than a beginner coral.

Did you know

A healthy button coral can inflate its translucent flesh to roughly twice the width of its own skeleton.

Caring for the button coral

Keep the button coral under low to moderate light, roughly 50 to 120 PAR, with low to moderate flow. Strong or direct current can keep its balloon-like tissue from inflating fully. Set it on a stable sandbed or smooth rubble rather than sharp rock, since its fleshy mantle tears easily on rough edges.

It needs at least 11 gal (40 L), at 75 to 81°F (24 to 27°C) and a pH of 8.1 to 8.4. It relies mainly on zooxanthellae for energy, and it engulfs food directly with its central mouth. Feed it minced meaty foods such as mysis or brine shrimp roughly every week or two, not more often. Overfeeding can trigger odd, uneven inflation.

The button coral is one of the more peaceful corals, with no strong stinging tentacles. Keep it apart from aggressive neighbors, mainly to protect its own delicate flesh.

It is a single free-living polyp, and it is not fragged in practice. Cutting through its one mouth has a very low success rate, so treat it as a display piece rather than a propagation project. In dim light, it sometimes splits part of its disc away, an unusual backup method of reproduction. That piece slowly grows into a second colony.

Good to know

Cynarina lacrymalis belongs to the family Lobophylliidae and is the only member of its genus. It is identified by twelve pairs of broad white septa, radiating out to a total of 96 inside a single translucent polyp. The species name lacrymalis is Latin for tearful, describing its watery, glassy-looking flesh. It is listed as Near Threatened by the IUCN, one of relatively few corals with an individual conservation assessment.

In the wild

The button coral lives across the western Indo-Pacific, from the Red Sea and East Africa to Japan, Indonesia and Australia. It usually sits on soft substrate or sheltered reef slopes.

Common questions

What size tank does a button coral need?

A button coral needs at least 11 gal (40 L).

What temperature and pH does a button coral need?

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

What does a button coral eat?

A button coral gets most of its energy from zooxanthellae. Feed it minced meaty foods such as mysis or brine shrimp every week or two, since overfeeding can cause uneven inflation.

How big does a button coral get?

An adult button coral reaches about 4.7 in (12 cm).

How does a button coral breed?

A button coral sometimes splits part of its disc away in dim light, and that piece slowly grows into a second colony. It is an unusual backup method of reproduction for a coral with only one mouth.

Related species