Leopard Flatworm

1. Name & Classification

• Common Names: Reticulated Flatworm, Leopard Flatworm
• Scientific Names: Pericelis tectivorum, Pericelis byerleyana
• Type: Invertebrate Pest (Polyclad Flatworm)

2. Appearance (Description, Color, Shape, Size)

• Description These flatworms exhibit a flattened, oval body with a distinctive reticulated or leopard-like pattern.
• Color Typically brown with lighter spots or marbling; coloration may vary based on diet and environment.
• Shape Broad, flat, and oval-shaped with undulating edge.
• Size Range Up to 7 cm (approximately 2.76 inches) in length.
• Distinctive Features Their unique patterning and relatively large size make them stand out among other flatworm species.

3. Where It’s Found (In the Tank & How It’s Introduced)

• *Typical Location in Aquarium: Often found on or under rocks, within the substrate, or hidden in crevices. They are nocturnal and may be observed during night hours.
• *Usual Entry/Trigger: Commonly introduced via live rock, coral frags, or other marine livestock without proper quarantine procedures.

4. Impact / Damage

• What Damage or Negative Effects It Causes:
  • *Fish/Inverts: Predatory behavior primarily targets mollusks, including Tridacna clams, but especially snails.

     

    *Severity: Moderate to High, depending on the size of the infestation and the value of the snail population in the aquarium.

5. Reproduction / Spread

• Method: Sexual reproduction; they are hermaphroditic but require a mate to reproduce.
• Rate/Speed of Growth: Slow to moderate. However, due to their elusive nature, populations can grow unnoticed.
• Specific Life Stage: Eggs are laid in concealed areas; larvae are free-swimming before setting.

6. Control / Treatment

• Manual Removal: Carefully extract using tweezers or siphoning during nocturnal hours when they are active. Ensure complete removal to prevent regeneration.
• Chemical Treatments: Currently, no reef-safe chemical treatments are proven effective against these flatworms.
• Environmental Adjustments: Maintaining optimal water quality and reducing excess nutrients can help deter their proliferation.
• Difficulty to Eliminate: Medium. Due to their size and hiding behavior, consistent monitoring and removal are required.

7. Biological Controls / Predators

• Known Predators: No specific predators are known to target these flatworms exclusively in reef aquaria.
• Effectiveness & Considerations: Introducing potential predators is not recommended due to the lack of specificity and potential risks to other tank inhabitants.

8. Prevention / Quarantine Measures

• *Outside the Tank:
  • Thoroughly inspect and quarantine all new live rock, corals, and invertebrates
  • Implement a quarantine period of at least 2–4 weeks for new additions.
• *In the Tank:
  • Regularly monitor for signs of flatworms, especially during nighttime
  • Maintain a balanced ecosystem to prevent opportunistic infestations.

9. Additional Notes / Tips

• Prevention: Quarantine new additions and maintain optimal tank conditions to reduce the risk of infestation.
• Learned Lessons: Early detection is crucial. Regular nighttime inspections can help identify and address issues promptly.

Special Warnings: While not harmful to humans, always handle with care to prevent potential skin irritation.