🐠 Merten's Butterflyfish (Chaetodon mertensii)
🐠 Merten's Butterflyfish (Chaetodon mertensii)
Marine Not-Reef-Safe Butterflyfish • Silvery-White Body With Grey Chevron Bars & an Orange-Yellow Posterior • Genuine Regional Naming Considerations • Intermediate Marine Fish
📋 The Merten's Butterflyfish, also known as the Atoll Butterflyfish, Yellowback Butterflyfish, or Orangetail Butterflyfish, has a genuinely elegant pearlescent silver-white body marked with five to seven blurred, criss-crossing grey chevron bars, a black band through the eye, and a striking yellow-to-orange posterior and tail.
Native to a genuinely wide range across the Indo-Pacific and central Pacific, this species inhabits coral-rich lagoon and outer reef environments to depths of around 30 metres. We want to be genuinely upfront that some regional populations are sometimes referred to under the closely related name Chaetodon madagascariensis, so please ask our team to confirm identification if you have any questions.
This is a genuinely peaceful, moderately hardy species once well established, though it's naturally somewhat nocturnal, and we want to be honest that it can sometimes be difficult to feed during the first days in a new aquarium, occasionally requiring live foods to start eating. It's genuinely uncommon in the trade, and does best kept alone or as a genuine pair introduced together, since it can become territorial toward its own kind and similarly patterned butterflyfish otherwise. We want to be upfront: this species is not reef safe, and will genuinely nip at coral polyps and small invertebrates.
⚪🟠 Highlights
🎨 Silvery Body With Grey Chevrons & Orange Posterior: A genuinely striking, elegant butterflyfish
💎 Genuinely Uncommon in the Trade: A distinctive find for serious butterflyfish keepers
🔍 Genuine Regional Naming Considerations: Please ask us to confirm identification if unsure
⚠️ Not Reef Safe: Will nip at coral polyps and small invertebrates
🌙 Genuinely Somewhat Nocturnal: May initially be a slow, hesitant feeder
🧾 A Quick Look at Merten's Butterflyfish
📛 Common Name: Merten's Butterflyfish (Atoll, Yellowback, Orangetail Butterflyfish)
🔬 Scientific Name: Chaetodon mertensii
👨👩👧 Family: Chaetodontidae
🌍 Origin: Indo-Pacific & Central Pacific
📏 Max Size: Up to 15 cm (≈ 6")
🧂 Specific Gravity: 1.020–1.025
🌡️ Temperature Range: 22–26°C (72–78°F)
🧠 Care Level: Moderate
💖 Temperament: Peaceful; genuinely territorial toward its own kind
🌿 Reef Safe: ❌ No — will nip at coral polyps and small invertebrates
🏠 Min Tank Size: 280 L (≈ 75 gallons)
📌 Tank Level: Mid Level
🧬 Stock Type: Wild-collected as standard stock; genuinely uncommon in the trade
⏳ Lifespan: 5–7 years, genuinely possibly longer
🍽️ Diet: Omnivore (coral polyps, invertebrates, meaty and algae-based foods)
🐣 Reproduction: Egg Layer; genuinely not bred in home aquariums

















