Aiptasia (Glass Anemone): Identification and Control
Aiptasia is a fast-spreading stinging anemone that stresses corals. Learn to identify it, why cutting backfires, and how injection plus natural predators control it.
Overview & Identification
Aiptasia is a genus of symbiotic sea anemones in the cnidarian subphylum Anthozoa. Each polyp has a pedal disc that attaches to the substrate, a smooth elongated body column, and an oral disc bearing the mouth and long stinging tentacles. They are widely distributed in temperate and tropical waters and naturally live on mangrove roots and hard substrates.
In the aquarium they appear as small, translucent brown anemones with thin tapering tentacles, often tucked into rock crevices where they are hard to reach.
Where They Come From
Aiptasia are often accidentally imported along with live rock, hitchhiking into the tank on rock, frags, or other introduced material.
Harmful or Beneficial?
Aiptasia are considered pests in the marine aquarium hobby because they are stressful to nearby corals and occasionally even sting fish and desirable invertebrates. They reproduce both sexually and asexually; asexually a small segment separates from the pedal disc and a new polyp usually forms within about 14 days, allowing populations to explode.
Control & Removal
Targeted injection is the common chemical approach: a paste such as Aiptasia-X is injected directly into the anemone's mouth so the polyp ingests it and dies. Turning off pumps during treatment keeps the paste from drifting. Biological control uses dedicated predators: the nudibranch Aeolidiella stephanieae (Berghia) is one of the best predators and feeds essentially only on Aiptasia, while peppermint shrimp and certain filefish and butterflyfish also consume them.
Prevention
- Quarantine and inspect all new live rock, corals, and frags before adding them
- Dip or treat incoming corals to remove hitchhikers
- Remove the first few individuals immediately, before they reproduce
- Keep a natural predator such as peppermint shrimp as ongoing insurance
Common Mistakes
- Scraping or cutting anemones, which multiplies them through fragmentation
- Treating only the tentacles instead of the mouth or base
- Leaving pumps running during injection so the paste spreads
- Relying on a Copperband butterflyfish, which may ignore Aiptasia and also pick at clams and other invertebrates