Pulsing xenia

Xenia elongata

Also known as Xenia, Pom Pom Xenia, Pulse Coral

SaltwaterCoral

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
11 gal
40 L
Temperament
Peaceful
Social behavior
Solitary
Swim level
Bottom
Difficulty
Easy
Breeding
Easy
Rarity
Very common
Reef safe
Reef safe
Family
Xeniidae
Origin
Indo-Pacific reefs

Overview

A sessile pulsing octocoral that spreads rapidly by budding and by dropping small pieces that reattach. It is passive and low-sting toward neighbors, competing only by fast overgrowth, so it is usually confined to an island rock and prized for its constant hypnotic motion.

In the wild

Xenia elongata is famous for the rhythmic opening and closing of its feathery polyps, which pulse like tiny grasping hands. It does well under moderate light around 100 to 200 PAR and prefers calmer, indirect flow, since strong direct current stops the pulsing. Place it low to mid on the rock, ideally on an isolated island surrounded by sand, because it spreads across rock extremely fast and is hard to remove once established.

Good to know

Xenia is an octocoral whose polyps pulse by actively contracting, and the exact purpose is still debated, with leading ideas being gas exchange, boosting photosynthesis, and shedding waste at the tissue surface. It relies heavily on zooxanthellae and dissolved nutrients rather than captured prey and can even do well in higher-nutrient water. It is notoriously sensitive to swings in alkalinity, which is the most common cause of a xenia colony suddenly melting.

Did you know

Xenia is one of the few animals that visibly moves on its own without external current, opening and closing its polyps dozens of times a minute, and no one has fully settled why it bothers to pulse at all.

Common questions

What size tank does a Pulsing xenia need?

A Pulsing xenia needs at least 11 gal (40 L). It spends most of its time in the bottom.

What temperature and pH does a Pulsing xenia need?

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

How big does a Pulsing xenia get?

An adult Pulsing xenia reaches about 7.9 in (20 cm).

Related species