Astroides calycularis (Mediterranean Cup Coral) Care Guide

Astroides calycularis is a temperate Mediterranean non-photosynthetic cup coral, bright orange and requiring coolwater conditions, not a tropical reef.

Overview

Astroides calycularis is a colonial stony coral of the family Dendrophylliidae, endemic to the western Mediterranean Sea. It is bright orange and non-photosynthetic (azooxanthellate), lacking symbiotic dinoflagellates. Crucially for aquarists, it is a temperate, coolwater species rather than a tropical reef coral and should be kept in a coldwater marine system.

Taxonomy

Order: Scleractinia
Family: Dendrophylliidae
Genus: Astroides
Scientific name: Astroides calycularis
Common names: Mediterranean Cup Coral, Star Coral

Habitat

The species is endemic to the western Mediterranean and also occurs in the Atlantic near the Strait of Gibraltar, with records in the Adriatic. It grows on rocks and walls, under overhangs and in submarine caves, down to about 70 m. Colonies form orange-yellow patches around 25–30 cm in diameter and up to 10 cm high. Its absence from the northern part of its range is linked to lower sea temperatures during glaciation.

Tank requirements

Salinity: 1.024–1.026 SG
Temperature: 16–22 °C (61–72 °F) — temperate, not tropical
pH: 8.1–8.4
dKH (alkalinity): 8–11
Calcium: 400–450 ppm
Magnesium: 1280–1350 ppm
Nitrate: below 20 ppm; phosphate below 0.15 ppm
Lighting: low (0–50 PAR)
Flow: medium
Minimum tank age: about 6 months

Feeding

As a non-photosynthetic coral, it depends entirely on feeding. In the wild its nocturnal polyps capture zooplankton and small prey. In aquaria it requires regular spot-feeding with foods such as mysis and reef-roids, supported by good filtration to handle the resulting nutrients.

Compatibility

Astroides is passive but uses stinging tentacles to feed, so neighbours should be kept clear. It is regarded as reef-, shrimp- and fish-safe, but its temperate temperature needs make it incompatible with a standard tropical reef community.