Green brittle star
Ophiarachna incrassata
Also known as Green Serpent Star, Fancy Green Brittle Star, Stout Green Brittle Star, Green Brittle Starfish
SaltwaterInvertebrate
Care at a glance
- Temperature
- 75–81°F
- 24–27°C
- pH
- 8.1–8.4
- Adult size
- 15.7 in
- 40 cm
- Minimum tank
- 79 gal
- 300 L
- Temperament
- Mostly peaceful
- Social behavior
- Solitary
- Tankmates
- With caution
- Swim level
- Bottom
- Diet
- Carnivore
- Difficulty
- Easy
- Breeding
- No record
- Rarity
- Common
- Reef safe
- Reef safe with caution
- Family
- Ophiodermatidae
- Origin
- Indo-Pacific, hiding under rock and rubble on coral reefs by day.
Overview
The green brittle star is a large, predatory brittle star for a big saltwater tank with plenty of rockwork. It is easy to keep.
Did you know
The green brittle star hunts by curling its arms into a raised dome that lures and shelters sleeping fish underneath. Then it collapses onto them to feed.
Caring for the green brittle star
Give the green brittle star a large tank of at least 79 gal (300 L), with heavy rockwork to hide in. Hold the water at 75 to 81°F (24 to 27°C) and a pH of 8.1 to 8.4. It is hardy and easy to feed on chunks of shrimp, mussel or fish dropped near its arms.
It is rated mostly peaceful, and reef safe only with caution. A large one will hunt and eat small fish, shrimp and other brittle stars at night. Treat it as a predator, and keep it away from small gobies, cardinals and ornamental shrimp.
Good to know
Ophiarachna incrassata is a brittle star in the family Ophiodermatidae. It is unusual among brittle stars because it is an active predator, not just a scavenger. It has a disc a couple of centimeters across and five long, flexible arms. The green coloring often carries a faint banded pattern down the arms. It is also sold as the green serpent star, fancy green brittle star and stout green brittle star.
In the wild
The green brittle star lives on coral reefs across the Indo-Pacific. By day it hides under rock and rubble, with just an arm tip showing, and it comes out to feed after dark.
Common questions
What size tank does a green brittle star need?
A green brittle star needs at least 79 gal (300 L). It spends most of its time in the bottom.
What temperature and pH does a green brittle star need?
A green brittle star is comfortable at 75–81°F (24–27°C) with a pH of 8.1–8.4.
What does a green brittle star eat?
A green brittle star eats chunks of shrimp, mussel or fish dropped near its arms. A large one also hunts small fish, shrimp and other brittle stars at night.
How big does a green brittle star get?
An adult green brittle star reaches about 15.7 in (40 cm).
Related species
11.8 in (30 cm)26 gal (100 L)72–79°F (22–26°C)Serpent star
Ophioderma
11.8 in (30 cm) · 26 gal (100 L)
17.7 in (45 cm)50 gal (190 L)72–79°F (22–26°C)Tiger tail sea cucumber
Holothuria hilla
17.7 in (45 cm) · 50 gal (190 L)
11.8 in (30 cm)53 gal (200 L)75–81°F (24–27°C)Blue linckia star
Linckia laevigata
11.8 in (30 cm) · 53 gal (200 L)
11.8 in (30 cm)53 gal (200 L)75–81°F (24–27°C)Chocolate chip star
Protoreaster nodosus
11.8 in (30 cm) · 53 gal (200 L)
11.8 in (30 cm)53 gal (200 L)75–81°F (24–27°C)Red knob sea star
Protoreaster linckii
11.8 in (30 cm) · 53 gal (200 L)
11.8 in (30 cm)50 gal (190 L)75–81°F (24–27°C)Wedge sea hare
Dolabella auricularia
11.8 in (30 cm) · 50 gal (190 L)