Needle coral, birdsnest coral

Morphology

The corallites form neat rows of oval cup-shaped depressions with raised rims from which the polyps protrude at night.

Evolution

Species age estimated to be 1.051 mya

Behaviour

S. hystrix is a zooxanthellate coral, housing symbiotic dinoflagellates within its tissues. It has been found that these symbionts are transferred during the brooding of the larvae and that different species of Symbiodinium are associated with the coral in different parts of its range, a likely example of coevolution and specialization. The bushy form of this coral provides a suitable habitat for other animals. A number of symbiotic decapod crustaceans find shelter and protection here and they also obtain food in the form of mucus secreted by the coral. Gall crabs are well known to live in association with Seriatopora hystrix. The female gall crabs manipulate the growth of the branch to form a breeding chamber where they can raise their young in relatively safety (see image).

Method of reproduction

Hermaphroditic brooder

Habitat

Marine

All habitats, protected and exposed from intertidal to 30+ meters.

Distribution

Indo-Pacific

Life Cycle

The sperm are released and get drawn into other polyps of the same or other colonies where eggs are fertilized and the developing larvae are brooded maternally. Self-fertilisation may be an important strategy for this species. When the larvae are released they settle close to the parent colony.