Common name: Yellow Turnip

Scientific name: Rapa incurva (Dunker, 1852)
Yellow Turnip (Rapa incurva) shells

General Information

The Yellow Turnip (Rapa incurva) is a parasitic snail notorious among reefkeepers for its destructive behavior. This small, inconspicuous gastropod is a bane to leather coral enthusiasts, as it bores into soft corals such as Sarcophyton and Sinularia species, consuming them from the inside out. Its name, "Yellow Turnip," derives from its yellowish, bulbous shell, which often blends seamlessly with the coral it inhabits, making it difficult to detect.

While not a species aquarists intentionally keep, the Yellow Turnip is a fascinating example of parasitism in marine ecosystems. Its presence in a tank can serve as a warning sign of potential coral health issues, as it often targets weakened or stressed corals. However, its destructive nature makes it a pest rather than a welcomed addition to any aquarium.

Details

Estimated price
Unknown Not available in trade
Recommended minimum volume
20 liter (5.3 gallons)
Salinity
S.G. 1.023 to 1.026
Temperature
24 to 27 °C (75 to 81 °F)
Acidity
pH 8 to 8.5
Average size
2 cm (¾″)
Care level
Very difficult Specific diet requirements
Pest
Yes Parasitic to leather corals, causing tissue damage and death
Diet
Corallivore Feeds on leather coral tissue
Reefsafe
No
Aggression
Peaceful Non-aggressive but highly destructive to corals
Captive bred
No

Taxonomy

  1. Kingdom
    Animals
    Animalia
  2. Phylum
    Mollusks
    Mollusca
  3. Class
    Gastropods
    Gastropoda
  4. Order
    Neogastropods
    Neogastropoda
  5. Family
    Murex Snails
    Muricidae
  6. Genus
    Murex Snails
    Rapa Röding, 1798
  7. Species
    Yellow Turnip
    Rapa incurva (Dunker, 1852)
  8. Synonyms
    Bulbus incurvus Dunker, 1852
  9. Source: GBIF | Global Biodiversity Information Facility

Behavior and Compatibility

The Yellow Turnip is a solitary parasite that spends most of its life hidden within the tissues of its host coral. It is not aggressive towards other tank inhabitants but poses a significant threat to leather corals. Once it establishes itself within a coral, it begins feeding, often leading to the coral's decline and eventual death if not removed.

Due to its parasitic nature, the Yellow Turnip is incompatible with reef tanks aiming to maintain healthy coral populations. Its presence can quickly devastate a collection of leather corals, making early detection and removal critical.

Health and Common Issues

Detecting the Yellow Turnip can be challenging due to its ability to camouflage within its host coral. Signs of infestation include tissue recession, unusual bulges in the coral, and a general decline in the coral's health. If left unchecked, the snail can cause irreparable damage to the coral.

Manual removal is the most effective method of dealing with this pest. Carefully inspect corals for signs of infestation and remove the snail using tweezers or a similar tool. Quarantining new corals before introducing them to the main tank can help prevent the introduction of this parasitic snail.

Habitat

In the wild, Rapa incurva is found in tropical and subtropical reef environments, where it targets soft corals as its primary hosts. Its natural distribution includes regions of the Indo-Pacific, where leather corals are abundant. The snail's ability to blend with its surroundings and its parasitic lifestyle make it a challenging species to study in its natural habitat.