Star Polyp Sinularia (Sinularia asterolobata) Care Guide
Sinularia asterolobata is a leather coral with prominent star-shaped polyps when extended, kept under medium light and flow in a stable reef.
Compiled by Aquairi from published sources · Published · Updated
Overview
Sinularia asterolobata is a leather coral with prominent star-shaped polyps when the colony is extended, giving it a distinctive texture. WoRMS lists it as accepted as Sclerophytum asterolobatum (Verseveldt, 1977); the knowledge-base name is retained here.
Taxonomy
- Class: Octocorallia
- Family: Alcyoniidae
- Genus: Sinularia
- Scientific name: Sinularia asterolobata
- WoRMS revision: accepted as Sclerophytum asterolobatum (Verseveldt, 1977)
Habitat
Sinularia is a genus of soft coral in the family Alcyoniidae, native to the tropical shallow waters of the Indo-Pacific. Like all soft corals it lacks a calcium carbonate exoskeleton, supported instead by an internal skeleton of sclerites. Colonies host symbiotic zooxanthellae that provide energy through photosynthesis, with colony colour depending on algal density. The World Register of Marine Species has reclassified many Sinularia species into the genus Sclerophytum (family Sinulariidae, order Malacalcyonacea); the knowledge-base name is retained in this guide.
Tank requirements
- Temperature: 24-26 °C (75-79 °F)
- pH: 8.1-8.4
- Salinity: 1.024-1.026 SG
- dKH (alkalinity): 8-11
- Calcium: 380-450 ppm
- Magnesium: 1280-1350 ppm
- Nitrate: below 15 ppm
- Phosphate: below 0.1 ppm
- Lighting: ~75-200 PAR (medium)
- Water flow: medium
- Minimum tank age: 3 months
Diet
The coral is photosynthetic, relying on its zooxanthellae for energy, and does not require direct feeding. Maintaining stable alkalinity, calcium, and magnesium supports tissue and sclerite health, while supplemental amino acids may aid growth.
Compatibility
The coral is passive and reef-safe with fish and shrimp. Leather corals periodically shed a surface film during self-cleaning, so steady water movement and good filtration help maintain water quality.
Sinularia asterolobata: Fragging and Propagation
Overview
Sinularia asterolobata is a leather coral of the family Alcyoniidae notable for prominent star-shaped polyps when extended, giving the colony a distinctive texture. As a Sinularia its small polyps sit on the surface without prominent dimorphism, the tissue is supported by sclerites, and it relies mainly on symbiotic zooxanthellae for energy.
Reproductive Mode
Home propagation is asexual by fragging lobes, which heal into new colonies; the base can also encrust and spread over rock. Sexual broadcast spawning occurs in the wild but is not a home method.
Fragging / Asexual Propagation
A clean, sharp blade is used to cut a lobe or part of one. Because the slick tissue resists glue, the frag is banded, held in mesh or an onion bag, or set on rubble in low flow until it attaches; once anchored it can be glued. An iodine dip followed by a seawater rinse after cutting helps disinfect the wound and clear slime.
Conditions for Propagation
- Lighting: 75-200 PAR (medium)
- Flow: moderate, increased after attachment
- Temperature: 24-26 C
- Mature tank: at least about 3 months old
- Net out shed mucus that can irritate neighbours
Sexual Reproduction
Gonochoric octocoral colonies release eggs or sperm during broadcast spawning; fertilised eggs become planula larvae that drift, settle on hard substrate and bud into colonies. This natural pathway is not used for home propagation.
Common Challenges
Leathers periodically close and form a shiny waxy film that is shed within a few days before the polyps reopen. Sinularia produces diverse terpene-based metabolites and toxic, allelopathic compounds that can inhibit competitors, so the slime released during fragging should be removed from the main system.