Astroides calycularis (Mediterranean Cup Coral): Propagation Guide

Propagation overview of the Mediterranean cup coral Astroides calycularis, a temperate azooxanthellate species that grows by polyp budding and broods larvae.

Overview

Astroides calycularis is a colonial coral in the family Dendrophylliidae, first described by Peter Simon Pallas in 1766; the genus Astroides is monotypic, containing only this species. Polyps are yellow or orange, each with a fringe of about thirty very short tentacles around a slit-shaped mouth, and colonies reach 25 to 30 cm in diameter and about 10 cm high. The species is endemic to the western Mediterranean Sea and expanded into the Adriatic in 1989.

Unlike many tropical reef corals, A. calycularis does not contain symbiotic dinoflagellates in its tissues. It feeds nocturnally on zooplankton, small fish and perhaps bacteria, with polyps remaining retracted into their calices during the day. It is also a temperate, not tropical, animal, which shapes any attempt to keep or grow it.

Reproductive Mode

The species uses dual reproductive strategies. It is gonochoristic, with all the polyps in a colony being of the same sex, for sexual reproduction. It also grows by asexual reproduction, with new polyps budding off existing polyps, which is how a colony enlarges over time.

Fragging / Asexual Propagation

Because the colony naturally enlarges through polyp budding, a colony fragment that carries living polyps and skeleton can in principle continue to bud and grow, much as the colony does in nature. The whitelisted source documents the budding mechanism but not a specific home protocol, so any division should keep intact polyps on each piece and rely on the coral's own budding to expand. Survival still depends on feeding and temperate conditions.

Feeding & Conditions for Propagation

Sustained growth and budding depend on supplying the zooplankton-scale foods the coral eats at night, together with the cooler, temperate water of its native western Mediterranean range. Bright lighting is not a substitute for food in this azooxanthellate species, and feeding is the practical driver of any propagation.